Hypertension and Cognitive Decline in Rural Elderly Chinese

Hypertension is a leading cause of cardiovascular disease, but results from longitudinal studies on hypertension and cognitive decline have been inconsistent. There is a consensus that midlife high blood pressure (BP) is associated with late-life low cognitive function.1,2 A comprehensive review of the relationship between BP, hypertension, and cognitive decline indicates that many large cohort studies report no association between late-life BP and cognitive decline or dementia.2 Among plausible explanations for this null effect is the possibly protective effects of antihypertensive medications taken by substantial number of individuals in the study samples. The relationship between late-life BP and cognitive decline deserves further examination because of the sharp increase of hypertension prevalence with increase in age. It has been reported that there is a 90% lifetime risk of developing hypertension for people who are not hypertensive at age 55.3 Because hypertension is a chronic disease that can be managed using medications, controlling hypertension may lead to potential prevention strategies for dementia and cognitive decline if the relationship between late-life BP and cognitive decline exists. Few of the published studies on hypertension and cognitive decline have included populations from developing countries, with the exception of one newly published clinical trial that included patients from China, Eastern Europe, and North Africa.4 The tripling of older persons living in developing countries from 249 million in 2000 to an estimated 690 million in 20305 and that many of these elderly persons do not have adequate access to medical diagnosis or treatment of chronic diseases underscores the projected significance of the relationship between late-life BP and cognitive decline. Given the increasing prevalence of hypertension with age and the paucity of research conducted in developing countries, it is of great public health interest to examine the relationship between hypertension and cognitive decline in these developing countries. This article reports findings from a prospective study in a rural elderly Chinese cohort.