Plasma Lipid Levels in the Elderly Are Not Associated with the Risk of Mild Cognitive Impairment

Abstract

Background: There are conflicting data relating plasma lipids to the risk of Alzheimer‘s disease (AD). We explored the association of plasma lipids to mild cognitive impairment (MCI), a transitional stage between normal cognition and dementia, in a prospective community-based cohort study among randomly sampled Medicare recipients ≧65 years. Baseline data were collected from 1992 to 1994, follow-up data were collected at 18-month intervals. Methods: Multivariate proportional hazards regression was used to relate plasma lipid levels to incident total MCI, amnestic MCI and nonamnestic MCI in 854 persons without MCI or dementia at baseline. Results: There were 324 cases of incident MCI, 153 cases of amnestic MCI and 171 cases of nonamnestic MCI during 4,189 person-years of follow-up. Higher levels of total cholesterol and LDL were associated with a decreased risk of total MCI in models adjusting for age and sex. However, these associations were attenuated after adjusting for ethnicity, education, APOEΕ4 and vascular risk factors. There was no association between lipids and the risk of amnestic or nonamnestic MCI, and there was no effect of lipid-lowering treatment on MCI risk. Conclusions: Plasma lipid levels or lipid-lowering treatment in the elderly are not associated with the risk of MCI.