Hypertension Health Article

Prevention

The need for the prevention of HTN is widely recognized. An effective population-wide strategy to prevent blood pressure rise with age and to reduce overall blood pressure levels could affect overall cardiovascular morbidity and mortality as much as or more than that of treating only those with established disease.

Lifestyle modifications offer the potential for preventing HTN, have been shown to be effective for lowering blood pressure, and can reduce other cardiovascular risk factors at little cost and with minimal risk. Patients should be strongly encouraged to adopt these lifestyle modifications, particularly if they have additional risk factors for premature cardiovascular disease. Modifications that do not require the active participation of individuals but that can be provided to the entire population (eg, a reduction in the amount of sodium chloride added to processed foods) can also be effective.

Lifestyle modification includes the following.

• maintaining a healthy weight;
• being physically active;
• following a healthy eating plan that emphasizes fruits, vegetables, and low-fat dairy foods;
• choosing and preparing foods with less salt and sodium;
• limiting alcohol intake to no more than 1 oz ethanol per day for men or 0.5 oz ethanol per day for women and lighter-weight persons; and.
• smoking cessation.

Nearly three-fourths of men and women 80 years old and older have hypertension (HTN), but their conditions are frequently not kept under control, according to the results of a study published in the July 27, 2005, issue of The Journal of the American Medical Association. .

New data from the National Heart, Lung, and Blood Institute's (NHLBI) long-standing Framingham Heart Study show that, in this age group, only 38% of men and 23% of women had blood pressures that met targets set forth in The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure clinical guidelines, which were issued by the NHLBI's National High Blood Pressure Education Program (NHBPEP) in 2003.

Investigators from the Framingham Heart Study, a landmark epidemiologic study that began in 1948, analyzed data from its original cohort of participants, who were enrolled from 1948 to 1952, and their offspring, who were enrolled from 1971 to 1973. In all, the study included 5,296 participants contributing 14,458 total examinations over the period studied.

High blood pressure was defined as a systolic blood pressure (SBP) of ≥ 140 mm Hg, a diastolic blood pressure (DBP) of ≥ 90 mm Hg, or the use of medication to reduce blood pressure.

The study demonstrated that, although the rate of HTN increased with age, numbers of people receiving treatment for the condition did not. Seventy-four percent of persons 80 years old and older had HTN as compared with 63% of those between the ages of 60 and 79 years and 27% of those younger than 60 years. However, less than two thirds of patients with HTN in the two older age groups received treatment.

"Many more men and women are now living healthy and active lives into their 80s and 90s. As clinicians, we should not loosen our management of high blood pressure just because a patient has had the good fortune to reach an older age," said Dr Daniel Levy, director of the Framingham Heart Study and co-author of the study. "For these patients, managing high blood pressure may make the difference between living many more healthy years, or spending those years recovering from a debilitating stroke or heart attack.".

According to the study authors, the data suggest that the poor control rates may be due in part to poor selection of drug classes or from the use of a single drug for therapy. Among all ages studied, 60% of patients were treated with only one antihypertensive medication, and only 23% of men and 38% of women older than 80 years were being treated with a diuretic.

The guidelines issued by the NHBPEP state that most patients with HTN will require two or more medications to reduce blood pressure to target levels and that a diuretic should be one of the medications used. Diuretics have been shown to be more beneficial for lowering blood pressure and for protecting against adverse complications of HTN.

The authors conclude that greater efforts should be made for safe and effective risk reduction among the oldest patients with HTN.

In other news, prehypertension is associated with an increased risk of major cardiovascular events, according to a study published in the July/August 2005 issue of Annals of Family Medicine. .

Dr Heather A. Liska and colleagues from the Medical University of South Carolina in Charleston conducted analyses on participants in the National Health and Nutrition Examination Survey I (1971-1975) who were observed for 18 years for major cardiovascular disease events.

The relative risk of cardiovascular disease, including stroke, myocardial infarction, and heart failure, was calculated in participants with prehypertension (defined as a SBP of 120 to 139 mm Hg or a DBP of 80 to 89 mm Hg) and normal blood pressure (defined as a SBP less then 120 mm Hg and a DBP less then80 mm Hg).

The researchers found that prehypertension was associated with an increased risk for cardiovascular disease (1.79 [95% confidence interval (CI), 1.40-2.24]) in unadjusted analysis. After adjustment for cardiovascular risk factors, the relationship of prehypertension to cardiovascular disease was diminished but persisted (1.32 [95% CI 1.05-1.65]). Ninety-three percent of persons with prehypertension had at least 1 cardiovascular risk factor.

Lower levels of prehypertension (120-129/80-84 mm Hg) were associated with increased cardiovascular disease in unadjusted analyses (1.56 [95% CI, 1.23-1.98]) but they were not statistically significant in adjusted analyses (1.24 [95% CI, 0.96-1.59]). Blood pressure in the high-normal range (130-139/85-89 mm Hg) remained a predictor of cardiovascular disease in unadjusted (2.13 [95% CI, 1.64-2.76]) and adjusted (1.42 [95% CI, 1.09-1.84]) analyses.

Dr Liska and her colleagues conclude that these findings support recommendations that physicians actively target lifestyle modifications and multiple risk reduction in persons with prehypertension.

Finally, diuretic medications work better than newer therapies for treating high blood pressure and reducing the risk of heart disease in both black and non-black patients, according to the results of a racial analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), which was published in the April 6, 2005, issue of The Journal of the American Medical Association. .

ALLHAT is the first large-scale trial—with 33,357 participants—to compare diuretics, calcium-channel blockers, and angiotensin-converting enzyme (ACE) inhibitors as initial therapies in a population with a substantial number of black participants. This analysis by race confirms earlier findings about the effectiveness of diuretics, and it emphasizes that diuretics should be preferred as a first therapy for most patients with high blood pressure.

The study concludes that diuretics are either similar or superior to newer drugs for lowering blood pressure, for tolerability, and for preventing major complications from high blood pressure. Across both racial subgroups, a substantially higher risk of heart failure existed (37%) among participants taking calcium-channel blockers as compared with those taking diuretics. As compared with ACE inhibitors, diuretics were more effective for preventing cardiovascular disease, especially heart failure, for all participants, and they were significantly more effective for reducing high blood pressure and preventing stroke in blacks.

On the basis of this study finding, the authors conclude that, as the initial drug for treating high blood pressure, ACE inhibitors work less well than alternatives in black patients. "This analysis confirms and extends to all races ALLHAT's original conclusion that diuretics are the right first-line therapy for high blood pressure. While some other recent studies have evaluated newer therapies (including drug combinations), the weight of evidence, particularly in this multi-racial study, supports the diuretic recommendation," said Dr Jeffrey Cutler, NHLBI Senior Analyst and study co-author.