Pulse pressure and mortality in older people

Background: In older people, observational data are unclear concerning the relationships of systolic and diastolic blood pressure with cardiovascular and total mortality. We examined which combinations of systolic, diastolic, pulse, and mean arterial pressure best predict total and cardiovascular mo rtality in older adults. Methods: In 1981, the National Institute on Aging initiated its population- based Established Populations for Epidemiologic Studies of the Elderly in 3 communities. At baseline, 9431 participants, aged 65 to 102 years, had blo od pressure measurements, along with measures of medical history, use of me dications, disability, and physical function. During an average follow-up o f 10.6 years among survivors, 4528 participants died, 2304 of cardiovascula r causes. Results: In age- and sex-adjusted survival analyses, the lowest overall dea th rate occurred among those with systolic pressure less than 130 mm Hg and diastolic pressure 80 to 89 mm Hg; relative to this group, the highest dea th rate occurred in those with systolic pressure of 160 mm Hg or more and d iastolic pressure less than 70 mm Hg (relative risk, 1.90; 95% confidence i nterval, 1.47-2.46). Both low diastolic pressure and elevated systolic pres sure independently predicted increases in cardiovascular (P<.001) and total (P<.001) mortality. Pulse pressure correlated strongly with systolic pressu re (R=0.82) but was a slightly stronger predictor of both cardiovascular an d total mortality. ln a model containing pulse pressure and other potential ly confounding variables, diastolic pressure (P=.88) and mean arterial pres sure (P=.11) had no significant association with mortality. Conclusions: Pulse pressure appears to be the best single measure of blood pressure in predicting mortality in older people and helps explain apparent ly discrepant results for low diastolic blood pressure.