Clinical Briefs

By Louis Kuritzky, MD

Stroke Reduction in Older Hypertensives with Abnormal Nocturnal Blood Pressure Dipping

The relationship between adverse cardiovascular events and blood pressure (BP) is direct and linear. Numerous prospective randomized trials indicate that reduction of BP produces a substantial reduction in stroke, with less impressive benefits demonstrated for coronary heart disease (CHD) end points. Since most clinical trials have been based upon clinic or casual’ BP measurements, rather than 24-hour monitoring (ABPM), we have much less information about whether specific attributes of BP during the circadian pattern variations are important indicators of cardiovascular risk. Some data have indicated that not only is ABPM a much more potent prognosticator for cardiovascular risk, but that specifically, persons whose blood pressure does not evidence the normal 10% or greater decline in the evening (so-called "non-dippers") are at substantially greater risk for target organ damage.

In this prospective study of elderly hypertensives (n = 811) who underwent ABPM, the cardiovascular end point effect of treatment upon nondipper hypertensives was much more dramatic than on dippers (ie, normal pattern’). Additionally, individuals who were determined to be white-coat’ hypertensives by ABPM did not show the beneficial reduction of CV end points as seen in nondippers. Increasing application of ABPM may help discern high-risk HTN groups most likely to benefit from intervention.

Hishide Y, et al. Am J Hypertens. 2002;15:844-850.

Primary Prevention of Hypertension

According to JNC VI reporting, as many as 43 million adults in America have hypertension (HTN), defined as blood pressure > 140/90. Although treatment with a variety of agents has been shown to reduce cardiovascular morbidity and mortality, effective primary prevention would be a more desirable goal. The National High Blood Pressure Education Program Coordinating Committee has provided evidence-based recommendations for primary prevention of hypertension in this communication.

The interventions documented to be efficacious in prevention of HTN include weight loss, reduction in dietary sodium, moderation in alcohol, increased physical activity, increased dietary potassium, and adherence to a DASH type diet.

Specifically, the interventions recommended include maintaining BMI < 25, keeping dietary sodium to < 2.4 g daily, engaging in at least 30 minutes of vigorous activity (such as brisk walking) most days of the week, limiting daily alcohol to 30 mL of ethanol (or the equivalent) including at least 3500 mg/d of dietary potassium, and following a diet that is rich in fruits, vegetables, and low-fat diary products, but modest in saturated and total fat.

Blood pressure reductions from these interventions may be as large as those seen with pharmacotherapy for HTN, and have been demonstrated to be sustainable.

Whelton PK, et al. JAMA. 2002;288: 1882-1888.

Effect of Aggressive Screening and Treatment on Prostate Cancer Mortality

There remains a great deal of heated debate about the appropriate use of PSA screening amongst asymptomatic men. Although mortality for prostate cancer has declined since the mid-1990s, it remains uncertain whether this favorable outcome is indeed attributable to enhanced screening. Insight about the relationship between prostate cancer mortality and screening may be gained by comparing two different populations of men who underwent different patterns of PSA screening. During the 1987-1990 time period, men in the Seattle-Puget Sound region (n = 94,000) were more than 5 times more likely to undergo PSA testing than men in Connecticut (n = 120,000). Correspondingly, biopsy rates in the West Coast population were more than twice that of the East Coast population.

Over an 11-year follow-up, there was no discernible difference in prostate cancer mortality between the 2 populations. In ensuing years, the prostate cancer screening rates became much more similar. The men in these analyses were all 65 years or older, hence applicability for younger men is uncertain. Nonetheless, the mortality of prostate cancer effects mostly men older than age 70, so the age of this group matches the demographic consequences of the disease. This study suggests that more avid PSA screening may not reduce prostate cancer mortality.

Lu-Yao G, et al. BMJ. 2002;325:740-743.