Plasma lipid levels in the elderly are not associated with the risk of mild cognitive impairment

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 6 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, APOE epsilon 4 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. Copyright (c) 2008 S. Karger AG, Basel.