Michael A. Weber, M.D., an editor of the journal, said that the American study helped to confirm that overweight people with hypertension, although at risk for cardiovascular events, often seem to have better outcomes than thin patients.

"Martins and colleagues point out the importance of treating high blood pressure and aggressively using cardiovascular risk reduction strategies in obese and lean elderly people with hypertension," Dr. Weber said. "Too often the treatment focus is on the obese and thin hypertensives are overlooked.

"In fact, high blood pressure in lean people is particularly dangerous and should be treated aggressively with appropriate medications to protect against fatal and non-fatal strokes and heart disease," he said. "The elderly are also vulnerable and treating their high blood pressure helps reduce the incidence of these serious events."

The researchers examined the relationship between body mass index and pulse pressure in 1,192 older adults with isolated systolic hypertension from data generated by the Third National Health and Nutrition Examination Survey (NHANES III). The survey was designed to estimate the prevalence of common chronic conditions and associated risk factors for disease control and prevention; it was conducted from 1988 to 1994.

"The [NHANES III] data derive from a representative sample of the United States population and provides some of the best available estimates of the prevalence and treatment of hypertension in the United States," the researchers said. "Multiple blood pressure measurements by trained and certified observers using a standardized protocol enhance accuracy of the blood pressure data [in NHANES III]."

The study included 624 women and 568 men who were 55 years or older, had isolated
systolic blood pressure and were not taking antihypertensive medications. The researchers noted that overweight participants were in the majority in most age categories, except for the 123 people 85 years or older.

More overweight than lean participants reported a history of diabetes mellitus, admitted to smoking at least 100 cigarettes in their lifetimes, or had cholesterol levels greater than 250 mg/dL.

"The higher pulse pressure observed among nonsmokers in this study may be attributed, in part, to a higher prevalence of smoking among the younger subset of participants, as well as the tendency for pulse pressure to increase with advancing age," the investigators said. "Our results lend additional support to the role of pulse pressure as a predictor of
cardiovascular outcomes in older persons with hypertension."

They said their results in lean male hypertensive men were consistent with the excess cardiovascular mortality reported in lean hypertensive men from the Hypertension Detection and Follow-up Program.

"The pulse pressure results from our study seem to suggest that the optimal weight for longevity may be higher in older persons with isolated systolic hypertension," the researchers said. "More prospective studies in older patients over a wider range of body mass index are needed to define better the level at which obesity assumes morbid and prognostic significance, particularly in the elderly.

"The relationship between blood pressure, body weight and age is complex and controversial," they concluded. "Despite these limitations, however, we believe that our findings provide further insight into the role of pulse pressure as a predictor of cardiovascular outcomes in the elderly with isolated systolic hypertension."