Blood pressure change and survival after age 75.

Abstract

Higher diastolic pressure predicted better survival in men 75 years or older in two prior analyses in the Rancho Bernardo population. Diastolic change was implicated as a possible explanation. We studied this by assessing survival according to blood pressure change in 795 men and women aged 75 years and older at the time of a second measurement taken an average of 11 years after the first, who were then followed for 5 years. Sex-specific analyses compared participants with a diastolic decrease of 5 mm Hg or greater and participants with a systolic decrease of 10 mm Hg or greater with those whose blood pressure levels did not change or increased. In men, after adjustment for baseline pressure, a decrease in diastolic pressure of 5 mm Hg or greater was associated with higher all-cause mortality (relative risk, 2.33; 95% confidence interval, 1.39 to 3.91) and cardiovascular mortality (3.13, 1.47 to 6.66). The mortality risk was strongest in men who took antihypertensive medication and had a fall in diastolic pressure (12.33, 2.73 to 55.72) compared with treated men whose pressures did not decrease. Among men with isolated systolic hypertension, those treated whose diastolic pressure remained stable had the best survival. A systolic fall in men and a decrease in either diastolic or systolic in women was not associated with poorer survival after adjustment for baseline pressure. We conclude that a fall in diastolic pressure of 5 mm Hg was associated with poor survival in men after age 75. This risk was strongest in men who took antihypertensive medication.