PREDICTORS OF THE AGE-RELATED INCREASE IN BLOOD-PRESSURE IN MEN AND WOMEN

Background. The age-related increase in blood pressure frequently observed in men and women may be more related to deleterious alterations in physical fitness, body composition, and diet than to a true aging phenomenon. Our purposes were to: (a) characterize the relationship between age and blood pressure in normotensive men and women; (b) identify physiological predictors of the age-related increase in blood pressure; and (c) examine whether the relationship between age and blood pressure persists after controlling for differences in these predictor variables. Methods. Three hundred and sixty four Caucasian men (17-80 yr) and 215 Caucasian women (18-81 yr) were characterized for supine resting blood pressure, peak oxygen consumption, body composition, body fat distribution, plasma insulin and glucose concentrations, and nutritional intake. Results. In men, the relationship between age and mean arterial pressure (MAP) (r = .25, p < .01) was no longer significant (partial r = .07, p = .20; 0.03 mmHg increase per year) after four predictor variables of MAP (fat mass, sum of 9 skinfolds, alcohol intake, and supine heart rate) were statistically controlled. In women, the relationship between age and MAP (r = .44, p < .01) no longer existed in women younger than 62 years of age (partial r = .06, p = .46; .04 mmHg increase per year) after three predictor variables of MAP (waist-to-thigh ratio, supine heart rate, and alcohol intake) were held constant, whereas in women older than 62 the relationship persisted (partial r = .37, p < .01; 0.9 mmHg increase per year). Conclusion. In healthy Caucasian men and women between 17-81 years of age: (a) The relationship between MAP and age was stronger in women than in men, primarily due to an accelerated increase in MAP in women older than 62 years of age; (b) the age-related increase in MAP in men was primarily related to an increase in body fatness, whereas in women the distribution of fat was the primary factor; and (c) after the influence of the predictor variables of MAP were controlled, the relationship between MAP and age persisted in women beyond 62 years of age, but not in women younger than age 62 or in men of any age.