Napping may help with blood pressure management

ScienceDaily (Feb. 28, 2011) — A daytime sleep could have cardiovascular benefits according to new research by Ryan Brindle and Sarah Conklin, PhD, from Allegheny College in Pennsylvania in the US. Their study, looking at the effect of a daytime nap on cardiovascular recovery following a stress test, found that those participants who slept for at least 45 minutes during the day had lower average blood pressure after psychological stress than those who did not sleep.

Long work schedules, shift work, increased anxiety and a greater use of the internet and television late at night -- all characteristics of our modern society -- have had an impact on nocturnal sleep. We no longer sleep as long as we used to: The average sleep duration is now almost 2 hours shorter per night than it was 50 years ago. And this could be impacting our long-term health. For example, sleeping less has been linked to an increased risk of hypertension and cardiovascular problems generally.

Brindle and Conklin's experiment examined how daytime sleep might influence cardiovascular recovery after a mental stress test in the laboratory. They split 85 healthy university students into two groups: One group was allotted a 60-minute interval during the day when they had the opportunity to sleep; the other group did not sleep during the day. The researchers also asked the students to complete questionnaires assessing sleep quality and complete a cardiovascular reactivity task, involving a complex mental subtracting exercise. Brindle and Conklin measured the students' blood pressure and pulse rates at regular intervals throughout the experiment.

They found that daytime sleep seemed to have a restorative effect with students in the sleep condition reporting lower scores of sleepiness than those who did not sleep. Although blood pressure and pulse rates rose in both groups between baseline and the stress phase, during the recovery phase, those who had napped had significantly lower average blood pressure readings than those who had not slept. These results show that sleeping between 45 and 60 minutes during the day appears to facilitate blood pressure recovery after a mental stress task in the laboratory.

Brindle and Conklin conclude: "Our findings suggest that daytime sleep may offer cardiovascular benefit by accelerating cardiovascular recovery following mental stressors. Further research is needed to explore the mechanism by which daytime sleep is linked with cardiovascular health and to evaluate daytime sleep as a recuperative and protective practice, especially for individuals with known cardiovascular disease risk and those with suboptimal sleep quality."

The work is published in Springer's journal International Journal of Behavioral Medicine.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Springer Science+Business Media, via AlphaGalileo.

Journal Reference:

Brindle RC and Conklin S. Daytime sleep accelerates cardiovascular recovery after psychological stress. International Journal of Behavioral Medicine, 2011

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Proteins regulating water retention in salt-sensitive hypertension identified

ScienceDaily (Oct. 25, 2010) — Research conducted by scientists at LSU Health Sciences Center New Orleans has found that two proteins in the brain act as valves to turn the hormone that regulates water retention in the body on and off. Their findings may lead to advances in treatment for diseases like high blood pressure, congestive heart failure, and cirrhosis of the liver.

The research is published in the Nov. 1, 2010 issue of Endocrinology.

Daniel Kapusta, PhD, Professor of Pharmacology at LSU Health Sciences Center New Orleans, and Richard Wainford, PhD, LSUHSC Instructor of Pharmacology, report the role of these brain proteins, called Gaq and Gaz, in producing elevated secretion of the hormone, vasopressin, and water retention in salt-sensitive hypertension, a condition in which blood pressure becomes elevated when salt is consumed. It is estimated that salt-sensitive hypertension occurs in about 26% of Americans with normal blood pressure and in 58% of those whose blood pressure is already high.

"Throughout the day, vasopressin, a peptide hormone produced by the hypothalamus, is released into the circulation from the pituitary gland and plays a vital role as the flood-gate keeper to prevent excessive loss of water from the kidneys," notes Dr. Kapusta. "Under most conditions, the water-retaining action of vasopressin is vital for survival. However, it has remained essentially a black box as to why, in susceptible individuals, the regulatory mechanisms that control vasopressin secretion cannot turn off when the body already has elevated water content."

For 21-days, the research team fed groups of male salt-resistant and salt-sensitive rats a diet containing either normal or high salt. Then they measured how the treatments influenced the animal's ability to excrete water and how the salt stress altered levels of vasopressin, Gaq and Gaz.

The consumption of high salt triggered a decrease in Gaq proteins in the brain of salt-resistant, but not salt-sensitive, rats. In salt-sensitive rats, the team demonstrated that reducing brain Gaq proteins returned plasma vasopressin to normal levels, decreased salt-induced water retention, and restored the animal's ability to excrete water.

"Our findings are novel and provide evidence that the Gaq sub-unit proteins in the hypothalamus act as a molecular/cellular switch to control the level of vasopressin secretion," says Dr. Wainford.

The researchers concluded that reducing brain Gaq proteins plays a critical counter-regulatory role in preventing the secretion of too much vasopressin in those with salt-resistance and may represent a new therapeutic target in diseases associated with fluid retention.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Louisiana State University Health Sciences Center, via EurekAlert!, a service of AAAS.

Journal Reference:

R. D. Wainford, D. R. Kapusta. Hypothalamic Paraventricular Nucleus Gaq Subunit Protein Pathways Mediate Vasopressin Dysregulation and Fluid Retention in Salt-Sensitive Rats. Endocrinology, 2010; 151 (11): 5403 DOI: 10.1210/en.2010-0345

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Deep brain stimulation may help hard-to-control high blood pressure

ScienceDaily (Jan. 24, 2011) — Researchers were surprised to discover what may be a potential new treatment for difficult-to-control high blood pressure, according to a case report published in the January 25, 2011, print issue of Neurology®, the medical journal of the American Academy of Neurology.

The report involved one man who received a deep brain stimulator to treat his pain from central pain syndrome that developed after a stroke. Deep brain stimulation uses a surgical implant similar to a cardiac pacemaker to send electrical pulses to the brain.

The 55-year-old man was diagnosed with high blood pressure at the time of the stroke, and his blood pressure remained high even though he was taking four drugs to control it.

While the electrical stimulation did not permanently alleviate his pain, researchers were surprised to see that stimulation decreased his blood pressure enough that he could stop taking all of the blood pressure drugs.

"This is an exciting finding as high blood pressure affects millions of people and can lead to heart attack and stroke, but for about one in 10 people, high blood pressure can't be controlled with medication or they cannot tolerate the medication," said Nikunj K. Patel, BSc MBBS, MD, FRCS, of Frenchay Hospital in Bristol, UK, who wrote the case study.

Patel noted that the decrease in blood pressure was a response to the deep brain stimulation, and not a result of changes to his other conditions.

The man's blood pressure gradually decreased after the deep brain stimulator was implanted in the periaqueductal-periventricular grey region of the brain, which is involved in regulating pain. His blood pressure was controlled for the nearly three years of follow-up; at one point he went back on an anti-hypertension drug for a slight increase in blood pressure, but that drug was withdrawn when the blood pressure went down again.

At one point researchers tested turning off the stimulator. This led to an increase of an average of 18/5 mmHg in blood pressure. When the stimulator was turned back on, blood pressure dropped by an average of 32/12 mmHg. Repeating the tests produced the same results.

"More research is needed to confirm these results in larger numbers of people, but this suggests that stimulation can produce a large, sustained lowering of blood pressure," Patel said. "With so many people not responding to blood pressure medications, we are in need of alternative strategies such as this one."

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Academy of Neurology.

Journal Reference:

N.K. Patel, S. Javed, S. Khan, M. Papouchado, A.L. Malizia, A.E. Pickering, J.F.R. Paton. Deep brain stimulation relieves refractory hypertension. Neurology, 2011; 76: 405-407 DOI: 10.1212/WNL.0b013e3182088108

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Population-wide reduction in salt consumption recommended

ScienceDaily (Jan. 14, 2011) — The American Heart Association January 13 issued a call to action for the public, health professionals, the food industry and the government to intensify efforts to reduce the amount of sodium (salt) Americans consume daily.

In an advisory, published in Circulation: Journal of the American Heart Association, the association sets out the science behind the American Heart Association's recommendation for the general population, which is to consume no more than 1500 milligrams (mg) of sodium a day because of the harmful effects of sodium -- elevated blood pressure and increased risk of stroke, heart attacks and kidney disease. Elevated blood pressure (hypertension) is a major public health problem -- approximately 90 percent of all Americans will develop hypertension over their lifetime.

Sodium consumption is currentlymore than two times higher than the recommended upper limit of 1,500 mg daily, with 77 percent of that consumption coming from packaged, processed and restaurant foods. "Even a modest decline in intake -- say 400 mg per day -would produce benefits that are substantial and warrant implementation," say the advisory authors. The 2005 United States Dietary Guidelines for Americans recommended a sodium intake limit of 2,300 mg per day, which many health experts say is too much for most Americans. Earlier this year, the Dietary Guidelines Advisory Committee recommended to the secretaries of the United States Departments of Agriculture (USDA) and U.S. Department of Health and Human Services (HHS) that the goal should be modified to 1,500 mg per day for the general population. The advisory committee consists of leading scientists who reviewed the most recent scientific studies and created a set of recommendations that are being reviewed by the secretaries.

Recently, the American Heart Association lowered their recommendation to no more than 1500 mg of sodium daily for the general public, after a report from the Centers for Disease Control found that a majority of the American population either have high blood pressure or are at high risk for developing it.

According to the advisory:

As sodium intake rises, so does blood pressure and the risk of negative health outcomes.Independent of its effects on blood pressure, excess sodium intake adversely affects the heart, kidneys, and blood vessels.The potential public health benefits of sodium reduction are enormous and extend to all Americans.Scientific evidence on the adverse effects of excess sodium is strong and compellingThe American Heart Association's 2020 impact goals -- to improve the cardiovascular health of all Americans by 20 percent while reducing deaths from cardiovascular diseases and stroke by 20 percent -- include a population-wide reduction of sodium consumption to less than 1,500 mg/daily as one of the ways the association will measure the nation's cardiovascular health. Furthermore, a normal range blood pressure is another key factor the association will use to measure the nation's cardiovascular health status.The American Heart Association is part of the National Salt Reduction Initiative, which is working with the food industry to reduce sodium content in packaged and restaurant food.

Inherent to the negative health effects are rising healthcare costs, the authors add. They point to one recent study that suggests a national effort that reduces sodium intake by 1,200 mg per day should reduce the health burdens related to heart disease in addition to reducing costs by up to $24 billion per year.

"Americans deserve the opportunity to choose how much sodium is in the food they eat. By supporting measures that will reduce sodium in the overall food supply, we are giving consumers freedom to select foods that could allow them to meet sodium recommendations and improve their ideal cardiovascular health," said Ralph Sacco, M.D., president of the American Heart Association.

The American Heart Association advocates for more robust sodium criteria within school nutrition standards, foods advertised and marketed to children and foods purchased by employers or government feeding programs, and for the Secretaries of HHS and USDA to adopt the Dietary Guidelines Advisory Committee recommendations.

The association also supports improved food labeling that helps consumers understand how much sodium is in their diet and consumer education in restaurants to help consumers choose lower-sodium options.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Heart Association.

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Gene therapy can reverse pulmonary hypertension, study suggests

ScienceDaily (Oct. 25, 2010) — A Heart and Stroke Foundation researcher has discovered what could be the first truly effective breakthrough in the diagnosis and treatment of pulmonary hypertension, a devastating, life-threatening condition which results in an enlargement of the heart.

"We have discovered an early warning system in a protein called PIM-1," Dr. Sébastien Bonnet told the Canadian Cardiovascular Congress 2010, co-hosted by the Heart and Stroke Foundation and the Canadian Cardiovascular Society.

Dr. Bonnet has established that the PIM-1 cells can be used as markers of pulmonary hypertension.

"Blood samples were taken from patients to measure PIM-1 expression in the blood," says Dr. Bonnet, who is a professor at Laval University and a researcher at Centre hospitalier universitaire de Québec. "We were surprised to find that the greater the PIM-1 levels, the more severe the pulmonary hypertension in the patient."

He says this opens the doors to using regular blood tests to look at PIM-1 levels. "If there is a slight increase in PIM-1, we will know that something is going on." This is important since the condition is under-diagnosed and often not discovered until it is in a late stage. Without earlier treatment it has a very poor prognosis. The condition has traditionally been diagnosed by a six minute walking test.

PIM-1 also offers the opportunity to move beyond the diagnosis of pulmonary hypertension to treatment. By blocking the PIM-1 protein, researchers were able to reverse the condition.

"This is a remarkable finding," says Dr. Bonnet. "We have found that using gene therapy to inhibit the inappropriate activation of this protein is a novel and effective therapy that can reverse the disease altogether."

Before this discovery there has been no agent to reverse the disease. Current drug treatments can improve quality of life but to this date there has been nothing that can cure the disease.

"Pulmonary hypertension is a rare but life-threatening condition," says Heart and Stroke Foundation spokesperson Dr. Beth Abramson. "These are often very sick individuals. By the time a patient gets to a doctor, the disease is usually well established." Individuals at increased risk of developing pulmonary hypertension include those with a family history and people with a history of blood clots in the lungs (pulmonary embolism).

She recommends that patients pay particular attention to any symptoms like shortness of breath or extreme tiredness. "There are treatments that can help patients live longer, healthier lives."

Pulmonary hypertension is abnormally high blood pressure in the pulmonary arteries, the arteries which carry blood from the heart to the lungs. The condition makes it more difficult for blood to flow to the lungs, causing shortness of breath, fatigue, and swelling of the feet and ankles. It can make everyday tasks almost impossible.

The number of Canadians with pulmonary hypertension is difficult to estimate, because it is under-diagnosed and the early symptoms are common to other conditions such as asthma and general fatigue. In addition, few studies have been conducted.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Heart and Stroke Foundation of Canada, via EurekAlert!, a service of AAAS.

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Storytelling may help control blood pressure in African-Americans

ScienceDaily (Jan. 18, 2011) — Controlling blood pressure is not only a medical challenge, but a social one as well. Because patients are required to strictly adhere to a treatment plan that may include medication, dietary restrictions and regular doctor visits, the ideas of wellness and health are also powerful parts of the social reinforcement needed for behavioral change.

This is especially true in the African American population, which is particularly susceptible to hypertension. Social and cultural barriers have been found to contribute to African American patients being far more likely than white patients to suffer from uncontrolled high blood pressure and resulting complications.

A new study suggests that a storytelling approach -- in which recognizable members of a community provide positive messages aimed at controlling hypertension through diet and medication adherence -- may offer a unique opportunity to communicate positive disease management choices in a culturally appropriate context.

Researchers at UMass Medical School, working with colleagues at Cooper Green Mercy Hospital and the University of Alabama at Birmingham have identified one promising approach. They identified "exceptionally eloquent and persuasive" patients with hypertension from focus groups where blood pressure control and the benefits of intervention were discussed; these volunteers were then videotaped, and edited DVDs, distilled from 80 hours of taping, were created.

The study appears in the Jan. 18 issue of the Annals of Internal Medicine. Researchers randomly assigned 299 African American patients with hypertension to receive either usual care or to view three videos that presented stories of real patients with hypertension. Among patients who had uncontrolled hypertension, those assigned to view the stories had better blood pressure control than those assigned to usual care -- the first such study that based a health intervention for hypertensive African Americans on positive, culturally sensitive storytelling.

"Overall," the authors wrote, "Among the 300 patients randomized, we found a difference in blood pressure favoring the intervention group, and the significance of this difference was driven by the positive effect among those with uncontrolled blood pressure. Patients with uncontrolled hypertension who were randomized to the intervention group experienced a 10 mmHg advantage in systolic blood pressure reduction relative to control Meaningful advantages were also found for diastolic pressure among the uncontrolled substrata. Blood pressures for both groups subsequently increased over time, but the relative advantage for the intervention group was maintained until the end of follow up."

What accounts for the result? Although there is no direct evidence about the mechanism by which the intervention worked, the researchers believe that the DVDs provided a "parasocial" interaction, one that rendered the viewer of the messages more susceptible to behavior change. "In prior hypertension work, we…translated patient stories into re-enactments using trained actors using high production quality in studio. To maximize [the] para-social interaction [in this study], we enhanced the realism of the current intervention by purposefully avoiding the studio, taping patients in the actual hypertension clinic."

Authors included Thomas K. Houston, MD, MPH, professor of quantitative health sciences and division chief, health informatics and implementation science; Jeroan J. Allison, MD, MSc, vice chair and professor of quantitative health sciences; John Trobaugh, MFA; Yendelela L. Cuffee, MPH; Bruce Barton PhD, research professor of quantitative health sciences; and Catarina I. Kiefe, PhD, MD, professor and chair of quantitative health sciences.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Massachusetts Medical School, via EurekAlert!, a service of AAAS.

Journal Reference:

Houston et al. Culturally Appropriate Storytelling to Improve Blood Pressure: A Randomized Trial. Annals of Internal Medicine, 2011;

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One in four U.S. adults had high blood pressure in 2008

ScienceDaily (Mar. 5, 2011) — More than 59 million Americans age 18 and older were diagnosed with high blood pressure in 2008, according to the latest News and Numbers from the Agency for Healthcare Research and Quality.

AHRQ also found that in 2008:

Three-quarters of people diagnosed with high blood pressure were overweight, obese, or morbidly obese. Roughly 15 percent of healthy weight adults were diagnosed with high blood pressure.Adults who exercised vigorously for 30 minutes or more at least three times a week were one-third less likely than those who didn't to have reported having high blood pressure (21 percent versus 32 percent, respectively).Nearly 32 percent of black adults reported having high blood pressure, compared to 27 percent of white and 18 percent of Hispanic adults.Roughly 29 percent of adults less than 65 years old with public health insurance reported having high blood pressure, versus 19 percent with private insurance and 14 percent of the uninsured.Almost 59 percent of seniors age 65 and older reported having been told they had high blood pressure, compared to nearly 34 percent of people ages 45 to 64, 10 percent of those ages 25 to 44, and almost 3 percent of younger adults.

Statistical Brief: Hypertension in America: Estimates for the U.S. Civilian Noninstitutionalized Population Age 18 and Older, 2008

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E. coli infection linked to long-term health problems

ScienceDaily (Nov. 19, 2010) — People who contract gastroenteritis from drinking water contaminated with E. coli are at an increased risk of developing high blood pressure, kidney problems and heart disease in later life, finds a study published on the British Medical Journal website.

The findings underline the importance of ensuring a safe food and water supply and the need for regular monitoring for those affected.

It is estimated that E. coli O157:H7 infections cause up to 120,000 gastro-enteric illnesses annually in the US alone, resulting in over 2,000 hospitalisations and 60 deaths. However, the long term health effects of E. coli infection in adults are largely unknown.

So a team of researchers in Canada assessed the risk for hypertension, renal impairment and cardiovascular disease within eight years of gastroenteritis from drinking contaminated water.

They used data from the Walkerton Health Study -- the first study to evaluate long term health after an outbreak of gastroenteritis in May 2000 when a municipal water system became contaminated with E. coli O157:H7 and Campylobacter bacteria.

Study participants were surveyed annually and underwent a physical examination and laboratory assessment to track their long term health.

Of 1,977 adult participants, 1,067 (54%) experienced acute gastroenteritis of whom 378 sought medical attention.

Compared with participants who were not ill or only mildly ill during the outbreak, participants who experienced acute gastroenteritis were 1.3 times more likely to develop hypertension, 3.4 times more likely to develop renal impairment, and 2.1 times more likely to have a cardiovascular event, such as a heart attack or stroke.

The authors conclude: "Our findings underline the need for following up individual cases of food or water poisoning by E. coli O157:H7 to prevent or reduce silent progressive vascular injury."

They add: "These long term consequences emphasise the importance of ensuring safe food and water supply as a cornerstone of public health."

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by BMJ-British Medical Journal, via EurekAlert!, a service of AAAS.

Journal Reference:

W. F. Clark, J. M. Sontrop, J. J. Macnab, M. Salvadori, L. Moist, R. Suri, A. X. Garg. Long term risk for hypertension, renal impairment, and cardiovascular disease after gastroenteritis from drinking water contaminated with Escherichia coli O157:H7: a prospective cohort study. BMJ, 2010; 341 (nov17 2): c6020 DOI: 10.1136/bmj.c6020

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Short and long sleep in early pregnancy linked to high blood pressure in the third trimester

ScienceDaily (Oct. 2, 2010) — A study in the Oct. 1 issue of the journal Sleep found that getting too little or too much sleep in early pregnancy is associated with elevated blood pressure in the third trimester. The study suggests that improving prenatal sleep hygiene may provide important health benefits.

Results show that the mean systolic blood pressure in the third trimester was 114 mm Hg in women with a normal self-reported nightly sleep duration of nine hours in early pregnancy, 118.05 mm Hg in women who reported sleeping six hours or less per night, and 118.90 mm Hg in women with a nightly sleep duration of 10 hours or more in early pregnancy. After adjustments for potential confounders such as age, race and pre-pregnancy body mass index, mean systolic blood pressure was 3.72 mm Hg higher in short sleepers and 4.21 mm Hg higher in long sleepers. Similar results also were found for diastolic blood pressure.

"Both short and long sleep duration in early pregnancy were associated with increased mean third trimester systolic and diastolic blood pressure values," said principal investigator and lead author Dr. Michelle A. Williams, professor of epidemiology in the School of Public Health at the University of Washington and co-director of the Center for Perinatal Studies at Swedish Medical Center in Seattle, Wash.

The study also found an association between sleep duration and preeclampsia, a condition that involves pregnancy-induced hypertension along with excess protein in the urine. The risk of developing preeclampsia was almost 10 times higher (adjusted odds ratio = 9.52) in very short sleepers who had a nightly sleep duration of less than five hours during early pregnancy. Overall, about 6.3 percent of participants were diagnosed with either preeclampsia or pregnancy-induced hypertension without proteinuria.

"If our results are confirmed by other studies, the findings may motivate increased efforts aimed at exploring lifestyle approaches, particularly improved sleep habits, to lower preeclampsia risk," said Williams.

According to the National Heart, Lung, and Blood Institute, systolic blood pressure -- the top number in a blood pressure reading -- is the force of blood in the arteries as the heart beats. A systolic blood pressure reading is considered to be "high" if it is 140 or more millimeters of mercury.

The Eunice Kennedy Shriver National Institute of Child Health and Human Development reports that preeclampsia is a syndrome that occurs after the 20th week of pregnancy. It should be monitored closely by a medical professional because it can have a severe impact on the health of the mother and her baby.

The study involved 1,272 healthy, pregnant women who completed a structured interview at 14 weeks gestation, on average. Sleep duration in early pregnancy was evaluated by the question, "Since becoming pregnant, how many hours per night do you sleep?" Only about 20.5 percent of women reported a sleep duration of nine hours per night, which was used as the "normal" reference category because prior research indicates that pregnant women tend to have longer sleep duration patterns. About 55.2 percent of women reported sleeping seven to eight hours per night, 13.7 percent slept six hours or less and about 10.6 percent slept 10 hours or more.

After delivery, data on maternal blood pressures at routine prenatal care visits were abstracted from participants' medical records, providing an average of 12 blood pressure values for each participant. Women with pre-gestational chronic hypertension were excluded from the study. Mean systolic blood pressures were 111.8 mm Hg and 111.4 mm Hg in the first and second trimesters, and 114.1 mm Hg in the third trimester.

According to the authors, a number of mechanisms by which habitual short sleep duration may lead to increased blood pressure have been proposed. Because blood pressure is known to dip by an average of 10 to 20 percent during sleep, short sleep durations may raise the average 24-hour blood pressure and heart rate. This may lead to structural changes that gradually raise the pressure equilibrium of the entire cardiovascular system. Sleep restriction also may produce abnormalities in the levels of hormones such as endothelin and vasopressin, which play an important role in the cardiovascular system. The authors suspect that the association between long sleep duration and elevated blood pressures may be related to unmeasured confounders such as obstructive sleep apnea, depression or insulin resistance.

Williams noted that this study is the first step at filling an important gap in the scientific literature. Because most sleep studies exclude pregnant women, little is known about how insufficient sleep during gestation contributes to increased risks of medical complications of pregnancy.

"Moving forward, large-scale sleep studies should include pregnancy cohorts so that health care providers and mothers-to-be can more fully appreciate the health risks of insufficient sleep," she said.

Williams advises pregnant women and women who are planning to become pregnant to develop healthy habits that promote sufficient sleep. The tips she suggested include:

Establishing a consistent sleep scheduleFollowing a relaxing bedtime routineCreating a comfortable sleep environmentKeeping technological distractions such as the TV and computer out of the bedroomEating at least two to three hours before bedtimeExercising regularly during the dayAvoiding caffeine and alcohol before bedtime and giving up smoking

The study was supported by grants from the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Academy of Sleep Medicine, via EurekAlert!, a service of AAAS.

Journal Reference:

Michelle A. Williams et al. Associations of early pregnancy sleep duration with trimester-specific blood pressures and hypertensive disorders in pregnancy. Sleep, (in press)

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New study singles out factors linked to cognitive deficits in type 2 diabetes

ScienceDaily (Sep. 11, 2010) — Older adults with diabetes who have high blood pressure, walk slowly or lose their balance, or believe they're in bad health, are significantly more likely to have weaker memory and slower, more rigid cognitive processing than those without these problems, according to a new study published by the American Psychological Association.

These three health factors stood out from more than a dozen suspected to shape how Type 2 diabetes is frequently shadowed by cognitive impairment, including dementia. An analysis in September's Neuropsychology stresses that although these factors might not actually cause cognitive problems, their presence can warn doctors that such problems may exist or soon develop.

"Awareness of the link between diabetes and cognition could help people realize how important it is to manage this disease--and to motivate them to do so," said co-author Roger Dixon, PhD, of the University of Alberta.

Type 2 diabetes has been found by other researchers to nearly double the risk of dementia and Alzheimer's disease, said Dixon, who studies how health affects cognition in aging. As diabetes becomes more common, this heightened risk could dramatically hike the number of older people with dementia -- a double whammy of serious chronic disease. Among people older than 60, the U.S. prevalence of Type 2 diabetes is more than 23 percent, according to the National Institute of Diabetes and Digestive & Kidney Diseases. The Canadian prevalence is nearly 19 percent, according to the Public Health Agency of Canada.

An analysis of older Canadians living in British Columbia -- 41 with Type 2 diabetes (ages 55-81) and 458 matched healthy controls (ages 53-90) -- found that systolic blood pressure (the top number, or maximum pressure on artery walls during a single heartbeat), a low combination score for gait and balance, and a patient's own reports of poor health all played a statistically significant role in the relationship between diabetes and cognitive impairment relationship.

In other words, higher but still normal blood pressure, slower gait and shakier balance, and/or reporting one's self to be in bad health regardless of actual problems boosted the likelihood that someone with Type 2 diabetes had impaired cognition. The relationships were linear: For example, the worse the balance, the higher the likelihood of cognitive problems, as measured by mental speed (reaction time, switching time and perceptual speed), mental control and flexibility (executive functioning), and recall of recent learning (episodic memory).

The results highlight factors that may work indirectly, gradually and cumulatively to make older diabetics more likely to develop dementia. Researchers tested 13 different variables in all, in the areas of general fitness, emotional health, subjective and functional health, and lifestyle activities.

Mediating Factors

Because diabetes and hypertension often go together, Dixon said he was not surprised that high systolic blood pressure accounted for one-third to one-half of significantly worse scores on four tests. That finding, said the authors, suggests that diabetes and cognition may be connected via diabetics' vascular problems. For example, diabetes and hypertension may both play a role in a larger metabolic syndrome that includes high blood sugar and insulin resistance.

However, the other two factors raised new questions. Combined gait and balance had the greatest influence, accounting for between 32 percent and 62 percent of performance on seven cognitive tests. Diabetes might affect the specific nerves that control gait and balance, the authors wrote, or more broadly affect the overlapping brain areas that support both gait-balance and cognition.

Like blood pressure, what people said about their health accounted for about one-third to one-half of performance on five different cognitive tests. Negativity about one's health could reflect related factors such as stress or depression, which did not, in this study, directly mediate between diabetes and cognition. Self-reported health is "an important indicator of ways in which a cluster of health-related beliefs and behaviors can modulate the effect of this disease on cognitive adaptation," Dixon said.

"It's important to pay attention to the health beliefs of older adults, not because they are necessarily accurate or valid indicators of specific health status, but because they might track overall health," Dixon said.

Type 2 diabetes in adults accounts for 90 percent to 95 percent of all diagnosed cases of diabetes, according to the National Institute of Diabetes and Digestive & Kidney Diseases.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Psychological Association, via EurekAlert!, a service of AAAS.

Journal Reference:

McFall et al. Testing covariates of Type 2 diabetes-cognition associations in older adults: Moderating or mediating effects? Neuropsychology, 2010; 24 (5): 547 DOI: 10.1037/a0019246

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Using gene therapy to prevent heart failure

ScienceDaily (Nov. 15, 2010) — A Nova Southeastern University (NSU) researcher has discovered how to use gene therapy to block a protein that can contribute to heart failure. The finding will appear in an upcoming issue of the Journal of the American College of Cardiology.

Anastasios Lymperopoulos, Ph.D., an NSU College of Pharmacy assistant professor of pharmacology, has discovered a novel method, using gene therapy, to block the actions of a gene-encoded protein known as beta-arrestin 1, which causes an increase of aldosterone production from the body's adrenal glands into the blood. Aldosterone is a hormone. It increases the reabsorption of sodium and water into the kidneys, causing high blood volume and blood pressure. It also has several direct damaging effects on the heart, such as fibrosis, hypertrophy, and inflammation.

An increase in blood volume causes high blood pressure. This in turn decreases the pumping action of the heart, and is one of the causes of heart failure.

By finding a way to block beta-arrestin 1 through this gene therapy approach, Prof. Lymperopoulos hopes it will lead to the reduction of the severity of heart failure. He is now testing new and existing heart failure medications such as Cozaar, Diovan and Atacand, to see how effective they are at blocking this damaging effect of beta-arrestin on the heart.

Lymperopoulos receives funding from the American Heart Association through a Scientist Development Grant for his research at NSU.

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Bioactive compounds in berries can reduce high blood pressure

ScienceDaily (Jan. 15, 2011) — Eating blueberries can guard against high blood pressure, according to new research by the University of East Anglia (UEA) and Harvard University.

High blood pressure -- or hypertension -- is one of the major cardiovascular diseases worldwide. It leads to stroke and heart disease and costs more than $300 billion each year. Around a quarter of the adult population is affected globally -- including 10 million people in the UK and one in three US adults.

Published next month in the American Journal of Clinical Nutrition, the new findings show that bioactive compounds in blueberries called anthocyanins offer protection against hypertension. Compared with those who do not eat blueberries, those eating at least one serving a week reduce their risk of developing the condition by 10 per cent.

Anthocyanins belong to the bioactive family of compounds called flavonoids and are found in high amounts in blackcurrants, raspberries, aubergines, blood orange juice and blueberries. Other flavonoids are found in many fruits, vegetables, grains and herbs. The flavonoids present in tea, fruit juice, red wine and dark chocolate are already known to reduce the risk of cardiovascular disease.

This is the first large study to investigate the effect of different flavonoids on hypertension.

The team of UEA and Harvard scientists studied 134,000 women and 47,000 men from the Harvard established cohorts, the Nurses' Health Study and the Health Professionals Follow-up Study over a period of 14 years. None of the participants had hypertension at the start of the study. Subjects were asked to complete health questionnaires every two years and their dietary intake was assessed every four years. Incidence of newly diagnosed hypertension during the 14-year period was then related to consumption of various different flavonoids.

During the study, 35,000 participants developed hypertension. Dietary information identified tea as the main contributor of flavonoids, with apples, orange juice, blueberries, red wine, and strawberries also providing important amounts. When the researchers looked at the relation between individual subclasses of flavonoids and hypertension, they found that participants consuming the highest amounts of anthocyanins (found mainly in blueberries and strawberries in this US-based population) were eight per cent less likely to be diagnosed with hypertension than those consuming the lowest amounts. The effect was even stronger in participants under 60.

The effect was stronger for blueberry rather than strawberry consumption. Compared to people who ate no blueberries, those eating at least one serving of blueberries per week were 10 per cent less likely to become hypertensive.

"Our findings are exciting and suggest that an achievable dietary intake of anthocyanins may contribute to the prevention of hypertension," said lead author Prof Aedin Cassidy of the Department of Nutrition at UEA's Medical School.

"Anthocyanins are readily incorporated into the diet as they are present in many commonly consumed foods. Blueberries were the richest source in this particular study as they are frequently consumed in the US. Other rich sources of anthocyanins in the UK include blackcurrants, blood oranges, aubergines and raspberries."

The next stage of the research will be to conduct randomised controlled trials with different dietary sources of anthocyanins to define the optimal dose and sources for hypertension prevention. This will enable the development of targeted public health recommendations on how to reduce blood pressure.

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Benefit of exercise in patients with hypertension has been insufficiently investigated, experts say

ScienceDaily (Oct. 26, 2010) — There are many good reasons to ensure sufficient exercise in everyday life. However, advising patients with increased blood pressure (hypertension) to exercise regularly is often regarded as a specific medical measure aiming to reduce the increased risk of late complications. But whether more exercise actually helps to avoid illnesses related to hypertension or at least delay their onset has been insufficiently investigated. In order to provide better advice to patients with hypertension, informative clinical studies are therefore needed.

This is the result of a report published by the German Institute for Quality and Efficiency and Health Care (IQWiG) on Sept. 22, 2010.

Comprehensive commission package on hypertension

This report is part of a comprehensive commission package awarded by the Federal Joint Committee (G-BA) in which the benefit of various non-drug treatment strategies for essential hypertension was to be assessed. This is the most common type of hypertension, for which no clear cause can be found.

People with increased blood pressure receive much well-meant advice, for example, to adopt stress-management strategies, smoke less and drink less alcohol. These measures are also recommended in clinical practice guidelines. IQWiG has already completed reports on the questions as to how a reduction in weight and salt intake affect blood pressure.

What should "more exercise" achieve?

Patients with hypertension have an increased risk of certain diseases of the heart and circulatory system. Strokes, heart attacks and also kidney failure are more common in people with hypertension than in those without this disorder.

The researchers at IQWiG were therefore particularly interested firstly, to know whether people with hypertension, by exercising more, can actually reduce the risk of heart attacks or stroke, for example, and secondly, to determine how more exercise affects their health-related quality of life.

Studies included only a few participants

The researchers searched for studies in which volunteers with hypertension had been randomly assigned to two groups. Patients in the intervention group had been advised to exercise more over a longer period of time (e.g. cycling, running, hiking, swimming), while those in the control group had not been given this advice. In addition, only studies lasting 24 weeks or more were considered.

Overall, IQWiG and its external experts included 8 randomized controlled trials lasting 6 to 12 months in the assessment. The studies were relatively small; most included a maximum of 20 people per study group. In addition, most studies were prone to bias, which greatly limited their informative value.

Side effects not investigated

As the assessment showed, the studies considered in the report allow no conclusions on patient-relevant aspects of the benefit of increased physical activity in hypertension. The studies did not provide sufficient results, neither on mortality, disease of the heart and circulatory system (cardiovascular morbidity), and kidney failure (end-stage renal disease), nor on health-related quality of life. Sufficient data were also lacking on side effects (adverse events): as many elderly patients suffer from hypertension they could potentially have a higher risk of falling or injuring themselves.

Systolic blood pressure lowered

In contrast, in all studies the effects of exercise on blood pressure were analysed. The data show that increased physical activity could lower the systolic (higher) value by 5 to 8 mmHg. In contrast, no differences between treatment groups were shown for the diastolic (lower) value. However, the researchers cannot safely predict whether the reduction in the systolic value is long term and what the effects on health are. A reduction in blood pressure is an indication that the risk of late complications may be diminished. However, it is well-known with regard to drugs that even if medications are similarly effective in reducing blood pressure, they may still fail to prevent late complications such as heart damage equally well, and also produce different side effects.

In addition, it could not be concluded from the studies whether participants could reduce the intake of blood-pressure lowering medications through exercising more often.

Advice on lifestyle changes also investigated in studies

"To avoid misunderstandings: our conclusion is not that more exercise is useless or even harmful," says Professor Dr. med. Jürgen Windeler, IQWiG's Director. "However, it is a sobering fact that medications to lower blood pressure have been tested in dozens of large studies but we still know little about the advantages and disadvantages of physical activity, even though national and international professional associations have recommended this measure for a long time." This imbalance should be corrected. "Advising patients with hypertension to exercise more will often mean a substantial change in their life style; patients should know whether they benefit from this."

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Lead exposure may affect blood pressure during pregnancy

ScienceDaily (Feb. 6, 2011) — Even minute amounts of lead may take a toll on pregnant women, according to a study published by Lynn Goldman, M.D., M.S., M.P.H., Dean of George Washington University's School of Public Health and Health Services in D.C., and colleagues, in the journal Environmental Health Perspectives. Although the levels of lead in the women's blood remained far below thresholds set by the Centers for Disease Control and Prevention (CDC) and standards set by the Occupational Safety and Health Administration, women carrying more lead had significantly higher blood pressure.

"We didn't expect to see effects at such low levels of lead exposure," says Goldman, "but in fact we found a strong effect." If confirmed, this would indicate that pregnant women may be as sensitive to lead toxicity as young children.

Blood pressure is slightly higher during pregnancy, child labor, and delivery as the heart pumps harder. But prolonged high blood pressure during pregnancy (pregnancy-induced hypertension) can lead to complications called preeclampsia and then eclampsia. This potentially lethal condition also can predispose women to a heart attack in their future. While any increase in blood pressure during pregnancy is worrisome, the study did not find an association between lead and pregnancy-induced hypertension or preeclampsia.

The CDC advises to take action to reduce exposures when pregnant women or children have a blood lead level of 5 micrograms (ug) per deciliter (dL) or higher. However, very few studies have assessed the effect of lower levels of lead in pregnant women. Goldman feels that the recent study suggests that there are cardiovascular effects of lead in pregnant women at levels well below 5 ug/dL.

Of the 285 pregnant women monitored by the team at Johns Hopkins Hospital in Baltimore, Maryland, about 25% had a lead level higher than about 1 ug/dL of umbilical cord blood; it was these women who on average had a 6.9 mmHg increase in systolic pressure and a 4.4 mmHg increase in diastolic pressure. To arrive at these results, the team statistically controlled for other factors related to raised blood pressure, including ethnicity, obesity, anemia, household income and smoking.

"Hopefully our study will contribute to efforts to determine what a safe level of lead is for adults," said Ellen Wells, PhD, first author of the study and postdoctoral scholar at Case Western Reserve University School of Medicine in the Department of Environmental Health Sciences. The best way to reduce lead in women's blood is to prevent exposure, not only during but also prior to pregnancy. "Because lead is stored in bones for many years," Wells says, "even childhood exposure could impact lead levels in pregnancy."

Limiting levels of lead permitted in adults at the workplace might be a good place to start. "The occupational standard right now is a level of 40 um/dL," says Goldman, "and we see blood pressure changes at a level of 2."

Her words come at a pivotal time. On December 17, President Obama was asked to sign a bill into law that would reduce exposure to lead by tightening restrictions on lead in drinking water plumbing. The bill follows a series of investigations finding significant levels of lead in water in schools and in households in New York City and Washington, D.C. Although lead exposure has steadily declined in the U.S. since the nineties, primarily because of bans on lead in gasoline and drinking water regulations, this study suggests lead restrictions should remain a public health priority.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by George Washington University.

Journal Reference:

Ellen M. Wells, Ana Navas-Acien, Julie B. Herbstman, Benjamin J. Apelberg, Ellen K. Silbergeld, Kathleen L. Caldwell, Robert L. Jones, Rolf U. Halden, Frank R. Witter, Lynn R. Goldman. Low Level Lead Exposure and Elevations in Blood Pressure During Pregnancy. Environmental Health Perspectives, 2011; DOI: 10.1289/ehp.1002666

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Adherence course reduces hypertension

ScienceDaily (Feb. 16, 2011) — A high proportion of patients with high blood pressure are failing to take their medication properly and would benefit clinically from a course of 'adherence therapy', according to new research from the University of East Anglia (UEA).

High blood pressure -- or hypertension -- is one of the major cardiovascular diseases worldwide. It leads to stroke and heart disease and costs more than $300 billion each year. Around a quarter of the adult population is affected -- including 10 million people in the UK.

Around half of patients with hypertension fail to reduce their blood pressure because they are not taking their prescribed medication correctly. Some cease taking their medication altogether, others only take some of it, and others do not follow the instructions to take their medicine after food, for example.

The reasons for this non-adherence are complex and include ambivalence about taking drugs, concerns over side effects, and complexity of treatment regimes. Previous attempts to improve adherence with information leaflets, monthly outpatient visits, reminders and self-monitoring have been shown to be mostly ineffective.

The UEA resesarchers studied 136 patients with high blood pressure in three outpatient clinics in Jordan. Half were given a course of seven weekly 'adherence therapy' sessions and half continued with their usual treatment. The 20-minute face-to-face sessions allowed a trained clinician to provide tailored information about the illness and treatment, and explore the patient's individual beliefs, fears and lifestyle.

Published February 16 in the Journal of Human Hypertension, the results show that the patients given adherence therapy took 97 per cent of their medications (compared with only 71 per cent for those given treatment as usual) and, on average, reduced their blood pressure by around 14 per cent -- taking it to just above the healthy range.

Lead author Prof Richard Gray of UEA's School of Nursing and Midwifery said: "Our findings suggest a clear clinical benefit in these patient-centred sessions.

"High blood pressure affects millions of people in both the developed and developing world and the problem is likely to increase dramatically over the next 15 years. Tackling the widespread failure to take medication correctly would lead to a major reduction in stroke and heart disease.

"If adherence therapy were a new drug it would be hailed as a potentially major advance in hypertension treatment."

Adherence therapy was originally developed by Prof Gray for patients with mental health problems who failed to take their medication correctly. The total cost of delivering a course of seven weekly sessions is calculated to be approximately £80 per person. Although the UEA study was not designed to formally evaluate cost effectiveness, other studies predict that a long-term reduction of blood pressure would lead to a reduction in stroke of 56 per cent and a reduction in chronic heart disease of 37 per cent -- suggesting that adherence therapy would likely be a cost-effective intervention.

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Journal Reference:

Fadwa Allalaiqa, Katherine Deane, Ahmed Nawafleh, Allan Clark and Richard Gray. Adherence therapy for medication non-compliant patients with hypertension: a randomised controlled trial. Journal of Human Hypertension, February 17 2011

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Consumption of 'good salt' can reduce population blood pressure levels, research finds

ScienceDaily (Sep. 15, 2010) — An increased intake of 'good' potassium salts could contribute significantly to improving blood pressure at the population level, according to new research. The favourable effect brought about by potassium is even estimated to be comparable with the blood pressure reduction achievable by halving the intake of 'bad' sodium salts (mostly from table salt).

Those are the conclusions drawn by Linda van Mierlo and her colleagues at Wageningen University, part of Wageningen UR, and Unilever in their investigation of the consumption of potassium in 21 countries. An article describing their findings appears in the journal Archives of Internal Medicine.

The risk of developing cardiovascular diseases rises as blood pressure increases. In Western countries only 20-30% of the population has 'optimal' blood pressure, with the systolic (maximum) pressure being lower than 120 mm Hg and the diastolic (minimum) pressure lower than 80 mm Hg. Blood pressure increases with age in most people. Men more often have a higher blood pressure than women.

Diet and lifestyle plays an important role in managing blood pressure. High intakes of sodium and low intakes of potassium have unfavorable effects on blood pressure. Therefore, reducing the consumption of sodium and increasing the consumption of potassium are both good ways to improve blood pressure.

The study carried out by food researchers from the Human Nutrition department at Wageningen University and from the Nutrition & Health department at Unilever demonstrates that the average potassium intake in 21 countries including the US, China, New Zealand, Germany and the Netherlands varies between 1.7 and 3.7 g a day. This is considerably lower than the 4.7 g a day, which has been recommended based on the positive health effects observed at this level of intake.

A hypothetical increase in the potassium intake to the recommended level would reduce the systolic blood pressure in the populations of these countries by between 1.7 and 3.2 mm Hg. This corresponds with the reduction that would occur if Western consumers were to take in 4 g of salt less per day. The intakes of both potassium and sodium are therefore of importance in preventing high blood pressure.

Earlier studies have shown that salt reduction of 3 g per day in food could reduce blood pressure and prevent 2500 deaths per year due to cardiovascular diseases in the Netherlands. In Western countries, salt consumption can be as high as 9-12 g a day whereas 5 g is the recommended amount according to WHO standards. Most household salt is to be found in processed foods such as bread, ready-made meals, soups, sauces and savoury snacks and pizzas. An effective way of increasing potassium intake is to follow the guidelines for healthy nutrition more closely, including a higher consumption of vegetables and fruit. In addition, the use of mineral salts in processed foods -- by which sodium is partly replaced by potassium -- would contribute to an improved intake of both sodium and potassium.

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Journal Reference:

Linda A. J. van Mierlo; Arno Greyling; Peter L. Zock; Frans J. Kok; Johanna M. Geleijnse. Suboptimal Potassium Intake and Potential Impact on Population Blood Pressure. Archives of Internal Medicine, 2010; 170 (16): 1501-1502 DOI: 10.1001/archinternmed.2010.284

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Small BMI change in overweight children could have big blood pressure impact

ScienceDaily (Oct. 15, 2010) — Small changes in weight can make bigger differences in the blood pressure for overweight children, compared to those at normal weight, according to a new study.

Researchers tracked blood pressure, height and weight of 1,113 children over time, with the longest follow-up exceeding 10 years. They then compared the children's body mass index (BMI, a measure of body weight) to national charts adjusted for age, sex and height. Kids with BMIs in the 85th percentile or higher are considered overweight.

"Below the 85th percentile, BMI effects on blood pressure appear to be fairly linear," said Wanzhu Tu, co-author of the study. "After the 85th, particularly after the 90th percentile, the BMI effect became noticeably stronger."

Analysis indicated the effect on systolic blood pressure of overweight boys' BMI percentile was 4.6 times that in normal-weight boys. Systolic blood pressure is a measure of the force of the blood pumped by the heart against the arteries when the heart is contracted. Findings were similar for diastolic pressure in boys, and both readings in girls. Diastolic blood pressure is a measure of the force of the blood against the arteries when the heart is relaxed and is the top number in a blood pressure reading.

In normal-weight children, BMI percentile and blood pressure remained related but the associations were weaker.

BMI and blood pressure studies typically don't separate normal-weight and overweight children, so findings tend to overestimate BMI's effect on blood pressure in normal-weight children but underestimate it in overweight kids, Tu said.

"Because our estimate of the BMI effect was much greater in overweight kids, the results suggest that even a modest reduction in BMI may produce a much greater benefit in blood pressure in overweight kids," Tu said. "Conversely, a small increase in BMI could put them at much greater risk of blood pressure elevation."

The paper was presented October 15 at the American Heart Association's High Blood Pressure Research 2010 Scientific Sessions (HBPR 2010) held in Washington, DC, USA.

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Blood pressure control system found in kidney's structural units

ScienceDaily (Jan. 14, 2011) — A new finding shows how the million working units in the kidney regulate salt handling. This identifies a new possible therapeutic target for treating high blood pressure. The kidney is made up of roughly 1 million working units called nephrons. These basic structural units remove waste products from the blood, recycle some substances to be reused and eliminate what is left as urine. The end segment of nephrons, called the distal nephron, helps set blood pressure by controlling the amount of sodium in our blood.

Scientists at The University of Texas Health Science Center San Antonio have reported how this essential function of the distal nephron is regulated. They demonstrated that sodium handling by the distal nephron is under the control of a local regulatory system.

Loss or dysfunction of this system leads to hypertension resulting from improper salt retention by the kidneys, the scientists found in mouse studies.

"These studies provide the first unequivocal evidence of a blood pressure control system in the distal nephron of the kidney," said senior author James Stockand, Ph.D., professor of physiology at the Health Science Center. "It turns out control of sodium re-absorption by this system is as important to normal blood pressure regulation as is a better-understood system, called the renin-angiotensin-aldosterone system, which works outside the kidney."

Many medications that treat high blood pressure target salt handling in the kidney. "Our work identifies a possible new therapeutic target," Dr. Stockand said.

The research was funded by the U.S. National Institutes of Health and American Heart Association and included colleagues at the University of Southern California. The findings are in the Jan. 14 issue of the Journal of Biological Chemistry.

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Blood pressure: 100 million Americans may be unnecessarily labeled abnormal

ScienceDaily (Mar. 9, 2011) — As many as 100 million Americans may currently be misclassified as having abnormal blood pressure, according to Dr. Brent Taylor from the Veterans Affairs Health Care System in Minneapolis and the University of Minnesota and his colleagues. Their findings show that these people are not actually more likely to die prematurely than those with 'normal' blood pressure, i.e. below 120/80. Taylor and colleagues' article in the Journal of General Internal Medicine, published by Springer, also shows that in those under 50, diastolic blood pressure* is the more important predictor of mortality, whereas in those over 50, systolic blood pressure* is the stronger predictor. The authors argue it is time to consider a new definition of 'normal' blood pressure.

Taylor and colleagues examined the independent contribution of diastolic blood pressure (DBP) and systolic blood pressure (SBP) on mortality, as well as how these relationships might affect the number of Americans currently labeled as having abnormal blood pressure.

The authors looked at data for 13,792 people from the National Health and Nutrition Examination Survey, which enrolled participants in 1971-76 and followed them up for two decades -- they studied DBP, SBP and long-term survival data specifically. In order to assess the underlying distribution of untreated blood pressure in American adults by age, Taylor and team also looked at data for 6,672 adults from the first National Health Examination Survey carried out between 1959 and 1962.

They found that in people aged over 50, those with SBPs above 140, independent of DBP, were significantly more likely to die prematurely. In those aged 50 or less, DBPs above 100 were linked to significant increases in premature death. The authors' analysis offers alternative cut-off points for the definition of 'normal'.

Dr. Taylor concludes: "Our findings highlight that the choice of approach used to define normal blood pressure will impact literally millions of Americans. If we cannot reliably see an effect on mortality in a large group of individuals followed for nearly 20 years, should we define the condition as abnormal? We believe considering this kind of approach represents a critical step in ensuring that diagnoses are given only to those with a meaningful elevation in risk, and targeted towards individuals most likely to benefit."

* Diastolic blood pressure is the lowest pressure within the bloodstream, occurring between heart beats i.e. when the heart relaxes. Systolic blood pressure is the highest pressure within the bloodstream, occurring during each heart beat i.e. when the heart contracts.

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Sugar-sweetened drinks associated with higher blood pressure

ScienceDaily (Mar. 1, 2011) — Soda and other sugar-sweetened beverages such as fruit drinks are associated with higher blood pressure levels in adults, researchers report in Hypertension: Journal of the American Heart Association.

In the International Study of Macro/Micronutrients and Blood Pressure (INTERMAP), for every extra sugar-sweetened beverage drunk per day participants on average had significantly higher systolic blood pressure by 1.6 millimeters of mercury (mm Hg) and diastolic blood pressure higher by 0.8 mm Hg. This remained statistically significant even after adjusting for differences in body mass, researchers said.

Researchers found higher blood pressure levels in individuals who consumed more glucose and fructose, both sweeteners that are found in high-fructose corn syrup, the most common sugar sweetener used by the beverage industry.

Higher blood pressure was more pronounced in people who consumed high levels of both sugar and sodium. They found no consistent association between diet soda intake and blood pressure levels. Those who drank diet soda had higher mean BMI than those who did not and lower levels of physical activity.

"This points to another possible intervention to lower blood pressure," said Paul Elliott, Ph.D., senior author and professor in the Department of Epidemiology and Biostatistics in the School of Public Health at Imperial College London. "These findings lend support for recommendations to reduce the intake of sugar-sweetened beverages, as well as added sugars and sodium in an effort to reduce blood pressure and improve cardiovascular health."

In INTERMAP, researchers analyzed consumption of sugar-sweetened drinks, sugars and diet beverages in 2,696 participants, 40- to 59-years-old, in eight areas of the United States and two areas of the United Kingdom. Participants reported what they ate and drank for four days via in depth interviews administered by trained observers, underwent two 24-hour urine collections, eight blood pressure readings and responded a detailed questionnaire on lifestyle, medical and social factors.

The researchers found that sugar intake in the form of glucose, fructose and sucrose was highest in those consuming more than one sugar-sweetened beverage daily. They also found that individuals consuming more than one serving per day of sugar-sweetened beverages consumed more calories than those who didn't, with average energy intake of more than 397 calories per day.

Those who did not consume sugar-sweetened beverages had lower average body mass index (BMI) than those who consumed more than one of these drinks daily.

"People who drink a lot of sugar-sweetened beverages appear to have less healthy diets," said Ian Brown, Ph.D., research associate at Imperial College London. "They are consuming empty calories without the nutritional benefits of real food. They consume less potassium, magnesium and calcium.

"One possible mechanism for sugar-sweetened beverages and fructose increasing blood pressure levels is a resultant increase in the level of uric acid in the blood that may in turn lower the nitric oxide required to keep the blood vessels dilated. Sugar consumption also has been linked to enhanced sympathetic nervous system activity and sodium retention."

The study's limitations include that it was cross-sectional and diet was self-reported.

"This is a population study. It's one piece of the evidence in a jigsaw puzzle that needs to be completed," Brown said. "In the meantime, people who want to drink sugar-sweetened beverages should do so only in moderation."

The American Heart Association recommends no more than half of the discretionary calorie allowance from added sugars, which for most American women is no more than 100 calories per day and for most American men no more than 150 calories per day. Discretionary calories are the remaining calories in a person's "energy allowance" after consuming the recommended types and amounts of foods to meet all daily nutrient requirements.

Co-authors are: Jeremiah Stamler, M.D.; Linda Van Horn, Ph.D., R.D.; Claire E. Robertson, Ph.D., R.Nutr.; Queenie Chan, M.Sc.; Alan R. Dyer, Ph.D.; Chiang-Ching Huang, Ph.D.; Beatriz L. Rodriguez, M.D., Ph.D.; Liancheng Zhao, M.D.; Martha L. Daviglus, M.D., Ph.D.; Hirotsugu Ueshima M.D., Ph.D.; and Paul Elliott, Ph.D. Author disclosures are on the manuscript.

The National Heart, Lung, and Blood Institute, National Institutes of Health, Chicago Health Research Foundation and national agencies in China, Japan and the United Kingdom funded the study.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Heart Association.

Journal Reference:

Ian J. Brown, Jeremiah Stamler, Linda Van Horn, Claire E. Robertson, Queenie Chan, Alan R. Dyer, Chiang-Ching Huang, Beatriz L. Rodriguez, Liancheng Zhao, Martha L. Daviglus, Hirotsugu Ueshima, Paul Elliott, and for the International Study of Macro/Micronutrients and Blood Pressure Research Group. Sugar-Sweetened Beverage, Sugar Intake of Individuals, and Their Blood Pressure: International Study of Macro/Micronutrients and Blood Pressure. Hypertension, February 28, 2011 DOI: 10.1161/HYPERTENSIONAHA.110.165456

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Whey supplements lower blood pressure: Low-cost protein gets big results in people with elevated blood pressure

ScienceDaily (Dec. 13, 2010) — Beverages supplemented by whey-based protein can significantly reduce elevated blood pressure, reducing the risk of stroke and heart disease, a Washington State University study has found.

Research led by nutritional biochemist Susan Fluegel and published in International Dairy Journal found that daily doses of commonly available whey brought a more than six-point reduction in the average blood pressure of men and women with elevated systolic and diastolic blood pressures. While the study was confined to 71 student subjects between the ages of 18 and 26, Fluegel says older people with blood pressure issues would likely get similar results.

"One of the things I like about this is it is low-cost," says Fluegel, a nutritional biochemistry instructor interested in treating disease through changes in nutrition and exercise. "Not only that, whey protein has not been shown to be harmful in any way."

Terry Shultz, co-author and an emeritus professor in the former Department of Food Science and Human Nutrition, said the findings have practical implications for personal health as well as the dairy industry.

"These are very intriguing findings, very interesting," he said. "To my knowledge, this hasn't been shown before."

The study, which Fluegel did for her doctorate in nutritional biochemistry, notes that researchers in a 2007 study found no blood-pressure changes in people who took a whey-supplemented drink. At first, she saw no consistent improvement either. But then she thought to break out her subjects into different groups and found significant improvements in those with different types of elevated blood pressure. Improvements began in the first week of the study and lasted through its six-week course.

The supplements, delivered in fruit-flavored drinks developed at the WSU Creamery, did not lower the blood pressure of subjects who did not have elevated pressure to begin with. That's good, said Fluegel, as low blood pressure can also be a problem.

Other studies have found that blood-pressure reductions like those seen by Fluegel can reduce cardiovascular disease and bring a 35 to 40 percent reduction in fatal strokes.

Health benefits aside, researchers are excited about the prospect of improving the market for whey, a cheese byproduct that often has to be disposed of at some expense. Its potential economic impact is unclear, says Shannon Neibergs, a WSU extension economist, "but any positive use of that product is going to be beneficial."

Several supplement makers contributed product to the study, which was funded in part by the Washington Dairy Products Commission. None of the contributors had a role in analyzing the data or writing the report.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Washington State University.

Journal Reference:

Susan M. Fluegel, Terry D. Shultz, Joseph R. Powers, Stephanie Clark, Celestina Barbosa-Leiker, Bruce R. Wright, Timothy S. Freson, Heidi A. Fluegel, Jonathan D. Minch, Lance K. Schwarzkopf. Whey beverages decrease blood pressure in prehypertensive and hypertensive young men and women. International Dairy Journal, 2010; 20 (11): 753 DOI: 10.1016/j.idairyj.2010.06.005

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Blood pressure breakthrough holds real hope for treatment of pre-eclampsia

ScienceDaily (Oct. 7, 2010) — Scientists have discovered a mechanism which raises blood pressure in pre-eclampsia, a potentially deadly condition which occurs during pregnancy.

After 20 years of research, scientists from the University of Cambridge have now cracked the first step in the main process that controls blood pressure. Their findings, published in the journal Nature, are likely to have significant implications for the treatment of pre-eclampsia as well as high blood pressure (also known as hypertension).

Blood pressure is controlled by hormones called angiotensins, which cause the blood vessels to constrict. These hormones are released by the protein angiotensinogen. Until now, it was not understood how this occurred.

Dr Aiwu Zhou, a British Heart Foundation (BHF) Fellow at the University of Cambridge, who made the breakthrough, said: "Although we primarily focused on pre-eclampsia, the research also opens new leads for future research into the causes of hypertension in general."

To make the discovery, the researchers solved the structure of angiotensinogen with the help of an extremely intense X-ray beam produced by Diamond Light Source, the UK synchrotron. Their results revealed that the protein is oxidised and changes shape to permit ready access to angiotensinogen by an enzyme, renin. Renin cuts off the tail of the protein to release the hormone angiotensin, which then raises blood pressure.

Taking their lab results into the clinic at the University of Nottingham, the research team showed that the amount of oxidised, and hence more active, angiotensinogen was increased in women with pre-eclampsia.

Professor Robin Carrell at the University of Cambridge, who led the 20-year research project, explained: "During pregnancy oxidative changes can occur in the placenta. These changes, the very ones we have found stimulates the release of the hormone angiotensin and lead to increased blood pressure, can arise as the circulation in the placenta readjusts the oxygen requirements of the growing foetus with the delivery of oxygen to the placenta from the mother."

Drugs currently used to treat high blood pressure -- such as ACE inhibitors -- focus on the later stages of the mechanism that controls blood pressure. The latest findings, which give insight into the previously mysterious early stages of the regulation process, provide scientists with new opportunities to research novel treatments for hypertension.

Professor Peter Weissberg, Medical Director of the BHF, which largely funded the study, said: "Every year in the UK pre-eclampsia is responsible for the deaths of around six women and several hundred babies. This research is of the highest quality and offers real hope for developing strategies to prevent or treat this dangerous condition by targeting the process that these scientists have identified. And of course, although the researchers only looked at pre-eclampsia in this study, similar strategies may be useful for those people with high blood pressure that is not effectively controlled by current medicines."

High blood pressure frequently affects pregnancy. However, in 2-7 per cent of pregnancies this develops into pre-eclampsia, which threatens the health and survival of both the mother and child. In Britain, it affects about one in 20 women during pregnancy, and every year 50,000 women and 500,000 infants die globally as a result of pre-eclampsia. There is no treatment for pre-eclampsia and often the mother is either induced early or undergoes a Caesarean.

The research was largely funded by the British Heart Foundation, with additional funding provided by the Medical Research Council, the Wellcome Trust and the Isaac Newton Trust.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Cambridge, via EurekAlert!, a service of AAAS.

Journal Reference:

Aiwu Zhou, Robin W. Carrell, Michael P. Murphy, Zhenquan Wei, Yahui Yan, Peter L. D. Stanley, Penelope E. Stein, Fiona Broughton Pipkin, Randy J. Read. A redox switch in angiotensinogen modulates angiotensin release. Nature, 2010; DOI: 10.1038/nature09505

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Lower blood pressure may preserve kidney function in some patients

ScienceDaily (Sep. 2, 2010) — Intensively treating hypertension in some African Americans with kidney disease by pushing blood pressure well below the current recommended goal may significantly decrease the number who lose kidney function and require dialysis, suggests a Johns Hopkins-led study publishing in the New England Journal of Medicine.

"This is not a panacea. We have a lot more to figure out. But our evidence suggests that we have a way to at least delay or possibly even prevent end-stage kidney disease in some patients," says Lawrence J. Appel, M.D., M.P.H., a professor of medicine at the Johns Hopkins University School of Medicine and the study's leader.

End-stage kidney disease is the point at which patients need to be on dialysis or receive a kidney transplant in order to survive.

Still, not everyone in the study was helped by the aggressive blood pressure treatment. Those patients who had little or no protein in their urine -- that is, patients who were not as sick -- saw their kidney disease progress at roughly the same rate regardless of how low they tried to get their blood pressure. It was the sicker patients, that is, those with protein in their urine, who benefited most from the more intensive blood pressure therapy, with roughly a 25 percent reduction in end-stage kidney disease as compared with those who met the standard blood pressure goal. Roughly one-third of the participants had higher amounts of protein in their urine.

"This has always been a hot topic: Is a lower blood pressure goal better at preserving kidney function than the standard goal? The answer is a qualified yes, notably in people who have some protein in their urine," Appel says.

In the National Institutes of Health-sponsored African-American Study of Kidney Disease and Hypertension (AASK), 1,094 hypertensive African Americans with chronic kidney disease were randomized to one of two groups: standard blood pressure goal versus intensive (or lower) blood pressure goal. Both groups needed to get their blood pressure in check -- the first group's goal was a blood pressure of roughly 140/90 (the standard target of doctors when treating hypertensive patients), while the second group's goal was approximately 130/80. Researchers lowered blood pressure through a combination of commonly used drugs. The patients were followed between 8.8 and 12.2 years.

Chronic kidney disease is a major public health problem and one that is only growing, Appel says. In the United States, roughly one-third of cases of end-stage kidney disease -- in which the kidneys no longer function and patients require dialysis or a transplant -- are attributed to hypertension. The burden of kidney disease is especially high in African Americans. Though they constitute only 12 percent of the population, African Americans make up 32 percent of those with end-stage kidney disease. Appel says African Americans are four to 20 times more likely to reach end-stage kidney disease, though researchers remain unsure of the reasons why.

Physicians consider patients with blood pressure over 140/90 to be hypertensive, and they will often put those patients on blood pressure-lowering medication with the goal of getting them back below that hazardous threshold. In recent years, some doctors have suggested that their patients with kidney disease try to get their blood pressure lower than that to stave off the progression of kidney disease, though without much scientific evidence, Appel says.

Appel says his study suggests that physicians should check for protein in the urine before determining the blood pressure goal for African Americans with kidney disease. If the patient has protein in the urine, a lower blood pressure goal has the potential to slow the progression of kidney disease. But if the patient has little or no protein in the urine, Appel says, the study suggests that reaching the lower blood pressure goal is not worth the extra effort, and the standard goal is just as good. Getting hypertensive patients down to 130/80 takes more doctor visits and requires more medication -- on average, one more blood pressure prescription. However, once the lower blood pressure level is achieved, keeping the blood pressure there is not particularly difficult.

Even though the study found a benefit of aggressive blood pressure treatment in one group of hypertensive African Americans with kidney disease, a significant number of those patients still ended up with end-stage kidney disease or worse. While roughly 90 percent of those who were in the standard blood pressure group saw their disease progress, about 75 percent of those in the aggressive therapy arm of the trial still progressed to a poor outcome.

"That's still pretty high," Appel says. "The key is preventing early kidney damage in the first place."

More research is necessary, he says, to identify more factors that prevent early kidney damage, as well as factors that delay kidney disease progression among those who already have chronic kidney disease.

The study was conducted at 20 medical centers in the United States. Along with Appel, other Johns Hopkins faculty and staff involved in the research include Edgar Miller, M.D., Ph.D., Brad Astor, Ph.D., M.P.H., M.S.; Charalett Diggs, R.N.; Jeanne Charleston, R.N.; and Charles Harris.

The National Institutes of Health was the primary sponsor of the study. In addition, King Pharmaceuticals provided financial support and donated antihypertensive medications. Pfizer Inc., AstraZeneca Pharmaceuticals, Glaxo Smith Kline, Forest Laboratories, Pharmacia and Upjohn also donated medication.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Johns Hopkins Medical Institutions, via EurekAlert!, a service of AAAS.

Journal Reference:

Appel et al. Intensive Blood-Pressure Control in Hypertensive Chronic Kidney Disease. New England Journal of Medicine, 2010; 363 (10): 918 DOI: 10.1056/NEJMoa0910975

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Common antibiotics and blood pressure medication may result in hospitalization

ScienceDaily (Jan. 18, 2011) — Mixing commonly used antibiotics with common blood pressure medications may cause hypotension (abnormally low blood pressure) and induce shock in older patients, requiring hospitalization, according to a study published in CMAJ (Canadian Medical Association Journal).

"Macrolide antibiotics (erythromycin, clarithromycin and azithromycin) are among the most widely prescribed antibiotics, with millions of prescriptions dispensed in Canada each year." writes Dr. David Juurlink, Scientist at the Sunnybrook Research Institute and the Institute for Clinical Evaluative Sciences with coauthors. "The drugs are generally well-tolerated, but they can cause several important drug interactions."

This study was conducted among Ontarians 66 years and older who were treated with a calcium-channel blocker (drugs often used to treat high blood pressure) between 1994 and 2009. The researchers then identified those who were hospitalized for low blood pressure and, in that group, whether or not a macrolide antibiotic had been prescribed shortly beforehand.

The researchers identified 7100 patients hospitalized for low blood pressure or shock while taking a calcium channel blocker. Treatment with erythromycin was found to increase the risk of low blood pressure almost 6-fold, while clarithromycin increased the risk almost 4-fold. In contrast, azithromycin did not increase the risk of hypotension.

"In older patients receiving calcium channel blockers, the two macrolide antibiotics erythromycin and clarithromycin are associated with a major increase in the risk of hospitalization for hypotension," conclude the authors. "However, the related drug azithromycin appears safe. When clinically appropriate, it should be used preferentially in patients receiving a calcium channel blocker."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Canadian Medical Association Journal, via EurekAlert!, a service of AAAS.

Journal Reference:

Alissa J. Wright, Tara Gomes, Muhammad M. Mamdani, John R. Horn and David N. Juurlink. The risk of hypotension following co-prescription of macrolide antibiotics and calcium-channel blockers. CMAJ, 2011; DOI: 10.1503/cmaj.100702

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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