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."

Story Source:

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

Note: If no author is given, the source is cited instead.

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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Expensive new blood pressure meds no better than generics, according to long-term data

ScienceDaily (Aug. 14, 2010) — Expensive brand-name medications to lower blood pressure are no better at preventing cardiovascular disease than older, generic diuretics, according to new long-term data from a landmark study.

Paul Whelton, MB, MD, MSc, reported the results on Aug. 13 at the plenary session of the China Heart Congress and International Heart Forum in Beijing. Whelton is president and CEO of Loyola University Health System and chairman of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heat Attack Trial (ALLHAT), which has examined the comparative value of different blood pressure-lowering medications.

More than 33,000 patients with high blood pressure were randomly assigned to take either a diuretic (chlorthalidone) or one of two newer drugs, a calcium channel blocker (amlodipine) or an ACE inhibitor (lisinopril).

In 2002, ALLHAT researchers reported that among patients followed for four-to-eight years, the diuretic was better than the calcium channel blocker in preventing heart failure and better than the ACE inhibitor in preventing stroke, heart failure and overall cardiovascular disease.

In the new study, researchers followed ALLHAT participants for an additional four to five years after completion of the trial, bringing the total follow-up period to between eight and 13 years. During this longer follow-up period, the differences between the three drugs narrowed -- by most measures they were a statistical dead heat.

But the diuretic still was superior in two measures: Compared with the diuretic group, the ACE inhibitor group had a 20 percent higher death rate from stroke, and the calcium channel blocker group had a 12 percent higher rate of hospitalizations and deaths due to heart failure.

Diuretics, sometimes called "water pills," are the traditional medications for high blood pressure. They cause kidneys to remove sodium and water from the body, thereby relaxing blood vessel walls. ACE inhibitors such as lisinopril (brand names, Prinivil® and Zestril®) decrease chemicals that tighten blood vessels. Calcium channel blockers such as amlodipine (brand name, Norvasc®) relax blood vessels.

Diuretics cost $25 to $40 per year, while newer brand-name hypertension drugs can cost $300 to $600 per year.

The National Heart, Lung and Blood Institute recommends patients control their blood pressure by first controlling their weight, exercising, reducing sodium, increasing potassium and drinking alcohol in moderation. The institute says that if lifestyle changes are not sufficient, diuretics then normally should be the drug of first choice.

However, newer, higher-priced drugs are heavily marketed, and diuretics account for only about 30 percent of prescriptions written for high blood pressure medications, Whelton said.

Whelton is senior author of a study published in the May 24, 2010, Archives of Internal Medicine that found that using techniques similar to those employed by pharmaceutical sales reps can help persuade doctors to prescribe diuretics.

Like drug sales representatives, researchers in the study met with small groups of doctors, especially opinion leaders. They detailed guidelines for treating high blood pressure, and handed out studies, newsletters, exam room posters, etc. An examination of prescribing patterns found that this technique, known as "academic detailing," influenced what drugs doctors prescribed.

ALLHAT is sponsored by the National Heart, Lung and Blood Institute. "We are continuing to mine data that we collected during the trial," Whelton said.

Story Source:

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

Note: If no author is given, the source is cited instead.

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.

View the original article here