I13 - Aging and essential hypertension: Effect of left ventricular hypertrophy on cardiac function

Abstract

OBJECTIVE: To examine and compare the relationships between the level of plasma renin activity (PRA) and ambulatory blood pressure variability for hypertensive women aged under 45 years (n = 72, aged 36 +/- 6 years) and for women aged over 50 years (n = 175, aged 61 +/- 8 years). METHODS: The 247 white women studied were a nonrandom subset of a larger cohort of patients being assessed to determine the prognostic significance of ambulatory blood pressure measurements. The average awake ambulatory blood pressures (a minimum of 30 readings during at least 8 h), their SD and the coefficient of variation of the awake ambulatory blood pressures (awake SD/average awake blood pressure) of the women were examined by age group and three levels of PRA (less than 1.0, 1.0-4.0, and greater than 4.0 ng/ml per h) using two-way analysis of variance. The PRA was determined at the time of ambulatory monitoring. RESULTS: For the women aged 50 years and older, the average awake diastolic blood pressure was higher among women who had PRA greater than 4.0 ng/ml per h than it was among women who had PRA less than 1.0 ng/ml per h (P < 0.05). The average awake systolic blood pressure and systolic blood pressure variability were greater among women aged over 50 years than they were among women aged 45 years (P < 0.05). There were no significant relationships between the ambulatory blood pressure variability and the PRA, although the systolic blood pressure variability tended to be associated with the PRA among women aged under 45 years. These results contrasted sharply to previously reported findings among men, for whom there was an inverse relationship between the blood pressure and the PRA, particularly among those aged over 45 years, and a powerful positive association between measures of the awake ambulatory diastolic pressure variability and the PRA, again among older men. CONCLUSION: There seems to be a sex difference between hypertensive men and women in the relationship between the PRA and the ambulatory blood pressure variability. This difference might be related to factors associated with the menstrual cycle of women, although other biologic and behavioral influences may also play a role.