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Something to Think About With Aging
Along with declining memory performance, elevation of systolic blood pressure and an increased prevalence of hypertension are expected consequences of advancing age. It is not surprising, therefore, to expect that the two processes may be related. In 1987, Inzitari et al1 first identified brain injury and subtle cognitive impairment associated with elevated levels of systolic blood pressure (SBP). In 1995, Launer et al2found that elevations in middle-life blood pressure were associated with reduced cognitive function in later life. Many studies subsequently confirmed and extended research related to the relationships among middle-life blood pressure, brain injury, and cognitive function among community-living individuals, suggesting that the inverse relationship between middle-life blood pressure and reduced cognitive ability is nearly universal. Using a twin study design, Swan et al3 also confirmed the association between middle-life patterns of SBP and cognition and identified that the cognitive differences were likely mediated by brain injury related to the level of middle-life blood pressure.
This seemingly straightforward association between elevated SBP and reduced cognitive ability was challenged when a number of studies found that blood pressure appeared to decline years before the onset of dementia, that cross-sectional measures of blood pressure obtained later in life were not strongly associated with brain structure or cognition, and that treatment of elevated blood pressure in later life was not associated with reduced likelihood of incident dementia.4 The literature is further limited by the fact that hypertension prevalence is greater among nonwhite populations, and dementia is more prevalent in nonwhite populations, but much of the research on the relationship between hypertension and cognition is from white cohorts.