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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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Institute for Quality and Efficiency in Health Care, via EurekAlert!, a service of AAAS.

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

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African-Americans with high blood pressure need treatment sooner, more aggressively, experts urge

ScienceDaily (Oct. 4, 2010) — According to a consensus statement by the International Society on Hypertension in Blacks (ISHIB), high blood pressure in African-Americans is such a serious health problem that treatment should start sooner and be more aggressive. The ISHIB statement is published in Hypertension: Journal of the American Heart Association.

Complications related to high blood pressure such as stroke, heart failure and kidney damage occur much more frequently in African-Americans compared with whites.

"Evidence from several recently completed studies converged to convince our committee that we were waiting a little bit too long to start treating hypertension in African-Americans," said John M. Flack, M.D., M.P.H., lead author and chairman of the Department of Internal Medicine at Wayne State University in Detroit.

The update to the ISHIB's 2003 consensus statement makes two major recommendations: First, the thresholds at which African-American patients begin treatment should be lowered. Second, doctors should move quickly from single-drug therapy to multi-drug therapy to keep a patient's blood pressure comfortably below the thresholds.

"We believe that these recommendations will lead to better blood pressure control, and a better outlook for African-Americans with high blood pressure," Flack said.

Blood pressure is reported as two numbers, measured in millimeters of mercury (mm Hg). The top number represents the pressure in the arteries when the heart beats and the lower number reflects the pressure when the heart relaxes between beats.

Blood pressure below 120/80 is considered normal for healthy U.S. adults. However, the ISHIB proposes that doctors recommend lifestyle changes to lower blood pressure in otherwise healthy African-Americans with blood pressure at or above 115/75. Those changes include reduced dietary sodium (salt) and increased potassium from eating more fruits and vegetables, as well as losing weight if necessary, getting regular aerobic exercise and drinking in moderation, Flack said.

"Epidemiological data shows that 115/75 is the critical blood pressure number for adults, and every time that figure goes up by 20/10 the risk of cardiovascular disease essentially doubles. We think it makes perfect sense to start lifestyle changes at that lower threshold," he said. "The natural history of blood pressure is that it continues to go up as a person ages. In fact, from the age of 50 and onward, Americans have a 90 percent chance of developing hypertension."

Doctors currently begin drug therapy to reduce blood pressure in patients without a history of cardiovascular disease, diabetes or high blood pressure-related organ-damage when blood pressure is at or above 140/90. This is referred to as primary prevention. The ISHIB recommends tightening the primary prevention threshold to 135/85 for African-Americans.

In addition, the ISHIB recommends starting treatment earlier for African-Americans who have cardiovascular disease, diabetes, kidney disease or damage to target organs (the heart, brain, kidneys). This treatment, known as secondary prevention, should start when blood pressure is at or above 130/80, according to the ISHIB statement.

The ISHIB also recommends that doctors move swiftly from single-drug therapy to multi-drug therapy if one agent doesn't lower the pressure.

"The majority of patients of any race, and certainly African-Americans, are going to need more than one drug to be consistently controlled below their goal," Flack said. "The debate in the medical community over which single drug is best overwhelms the most pressing question: Which drugs work best together?"

Based on a review of recently completed studies, the ISHIB document provides doctors with step-by-step guidance on the best second, third and fourth drugs to add based on individual patient characteristics. The ISHIB statement provides charts with alternate multi-drug combinations so physicians have several options for keeping patients' blood pressure under targets, Flack said.

Flack stressed that the ISHIB tried whenever possible to suggest cheaper generic drugs to keep cost from becoming a treatment barrier.

"These guidelines raise the question for addressing issues surrounding treatment strategies and goals for African-Americans with hypertension," said Sidney C. Smith Jr., M.D., an American Heart Association spokesman and professor of medicine at the University of North Carolina School of Medicine in Chapel Hill, N.C. "Studies continue to accumulate that address ethnic, age and gender differences, as well as optimal therapies."

A major comprehensive statement regarding hypertension is expected to be published by the National Institutes of Health (NIH) by late 2011, Smith said.

The American Heart Association participates as a member organization in the NIH Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC) guidelines.

Co-authors of the ISHIB statement are: Domenic A. Sica, M.D.; George Bakris, M.D.; Angela L. Brown, M.D.; Keith C. Ferdinand, M.D.; Richard H. Grimm, Jr., M.D., Ph.D.; W. Dallas Hall, M.D.; Wendell E. Jones, M.D.; David S. Kountz, M.D.; Janice P. Lea, M.D.; Samar Nasser, P.A.-C., M.P.H.; Shawna D. Nesbitt, M.D.; Elijah Saunders, M.D.; Margaret Scisney-Matlock, R.N., Ph.D. and Kenneth A. Jamerson, M.D. Individual author disclosures are on the manuscript.

Story Source:

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