The association between midlife lipid levels and late-life brain amyloid deposition.

Elevated low-density lipoprotein cholesterol and total cholesterol in midlife and decline in total cholesterol from mid- to late-life are associated with incident dementia. Whether brain amyloid deposition mediates this relationship is unclear. We explored the association between midlife blood lipid levels and mid- to late-life change in lipid levels with brain amyloid deposition assessed using florbetapir PET scans in a biracial sample of 325 nondemented participants of the Atherosclerosis Risk in Communities-PET Amyloid Imaging study. Midlife total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides were not significantly associated with late-life amyloid burden after adjusting for covariates. Associations between changes in lipids and late-life amyloid deposition were similarly null. Lipids may contribute to dementia risk through alternate mechanisms.