High Blood Pressure

Hypertension stands out as the major risk factor for cardiovascular disease and mortality in elderly persons (Forette et al., 1982). Both systolic and diastolic blood pressure are involved, but with advancing age, systolic blood pressure has been identified as a better predictor of cardiovascular risk than diastolic blood pressure, in both men and women (Kannel and Gordon, 1978). Since at any given level of systolic blood pressure, mortality was found to increase as diastolic pressure decreased, pulse pressure must also be considered a risk factor (Staessen et al., 2000).

Systolic, diastolic, and combined hypertension increase the risk of stroke. Data from the Framingham Study have shown that apart from this risk, elevated systolic blood pressure is a major risk factor for all cardiovascular diseases, including left ventricular hypertrophy, congestive heart failure, ischemic cardiopathy, and peripheral artery diseases. High midlife blood pressure has been shown to be a strong independent predictor of later cognitive impairment. However, some authors who studied very old patients reported a J curve profile with higher cognitive impairment in subjects with low blood pressure. The decrease in blood pressure may be due to pathological processes that also affect cognitive functioning or, alternatively, it may be a consequence of dementia. In addition, hypertension appears to be the strongest risk factor for vascular dementia and possibly for Alzheimer's disease.

A correlation between mortality and high blood pressure has been widely shown. This excess mortality is mainly correlated with systolic blood pressure (Kannel et al., 1976). However, in people over eighty years old, some authors have reported either no association between blood pressure and mortality or an inverse association, which disappears after adjustment for indicators of poor health.