The Relationship Between Body Weight and the Prevalence of Isolated Systolic Hypertension in Older Subjects.

The rise in systolic blood pressure and the increasing risk of isolated systolic hypertension with advancing age have been attributed, in part, to increased peripheral vascular resistance. Available evidence also suggests that at any given level of arterial pressure, overweight patients with hypertension have a higher cardiac output and a lower total peripheral vascular resistance than lean patients. The lower peripheral resistance associated with overweight patients may attenuate the rise in systolic blood pressure and modify the prevalence of isolated systolic hypertension with age. Using data from the third National Health and Nutrition Examination Survey we examined the relationship between body weight and the age-related rise in systolic blood pressure, and determined the implication of this relationship for the prevalence of isolated systolic hypertension in the older adult population. The age-related rise in systolic blood pressure and the prevalence of isolated systolic hypertension were higher among the lean than in the overweight (odds ratio 1.29 and p value 0.039). The prevalence of isolated systolic hypertension increased by 56% from 6.2% in the fourth to 9.7% in the first body mass index quartile. Among the overweight subjects the prevalence of isolated systolic hypertension continued to decrease until the body mass index exceeded 31.6. OBJECTIVE: To examine the relationship between body weight and the age-related rise in systolic blood pressure, and determine the implication of this relationship for the prevalence of isolated systolic hypertension in the older adult population. DESIGN: A cross-sectional study. SETTING: The study began with a 1-hour home visit for a household interview and ended a few weeks later with a 4-hour physical examination at a mobile examination center. PARTICIPANTS: A sample of the civilian, non-institutionalized population of the U.S. MAIN OUTCOME MEASURES: Age-related rise in systolic blood pressure and the prevalence of isolated systolic hypertension. RESULTS: The age-related rise in systolic blood pressure and the prevalence of isolated systolic hypertension were higher among the lean than in the overweight. The prevalence of isolated systolic hypertension decreased with increased body mass index of 31.6. Systolic blood pressures increased in obese than nonobese subjects. CONCLUSIONS: Body mass index less than 25 is associated with an increase in the age-related rise in systolic blood pressure and the prevalence of isolated systolic hypertension in the older population. (c)2000 by Le Jacq Communications, Inc.