Vascular Risk and Cognitive Impairment in an Older, British, African‐Caribbean Population

Abstract

In an older, British, African-Caribbean population with high prevalence rates of hypertension and diabetes mellitus, we ascertained clinical vascular disease (stroke or ischemic heart disease) and vascular risk (including hypertension, diabetes, and lipid profile) and investigated their associations with cognitive impairment. Cross-sectional community-based study. The sample was drawn from registration lists for seven primary care services in south London, United Kingdom. 278 individuals, age 55 to 75, who were born in a Caribbean nation. Participants were interviewed and examined for cardiovascular risk factors, including a blood test for lipid profile and fibrinogen. A battery of 11 psychometric tests was administered blind to medical status. Cognitive impairment was defined on the basis of a composite measure derived from individual test scores. Seventy-nine (28%) subjects were classified as having relative cognitive impairment and were compared with the remainder of the sample. Marked differences were seen between low and normal/high educational levels in the strength of associations between measures of vascular risk and cognitive impairment. Hypertension, diabetes, and raised triglycerides were significant factors in those with lower levels of education. Low fibrinogen (negatively associated), high cholesterol, and manual occupation were significant factors in those with normal/high levels of education. Physical exercise was negatively associated with cognitive impairment: an association that persisted after adjustment for age, occupation, depression, and physical disability and after excluding subjects with the most severe imipairment. Measures of vascular risk were associated with relative cognitive impairment in this population. These associations were modified by previous educational attainment. Physical activity was negatively associated with cognitive impairment.