Lipid Metabolism, Abdominal Adiposity, and Cerebral Health in the Amish.

Abstract

ObjectiveTo assess the association between peripheral lipid/fat profiles and cerebral grey matter (GM) and white matter (WM) in healthy, Old Order Amish (OOA).MethodsBlood lipids, abdominal adiposity, liver lipid contents and cerebral microstructure were assessed in OOA (N=64, 31 Males/33 Females, ages 18–77). Orthogonal factors were extracted from lipid and imaging adiposity measures. GM assessment used the Human Connectome Project protocol to measure whole-brain average cortical thickness. Diffusion weighted imaging derived WM fractional anisotropy and kurtosis anisotropy measurements.ResultsLipid/fat measures were captured by three orthogonal factors explaining 80% of the variance. Factor 1 loaded on cholesterol/LDL-C; Factor 2 on triglyceride/liver measurements; Factor 3 on abdominal fat measurements. A two-stage regression including age/sex (1st stage) and the three factors (2nd stage) examined the peripheral lipid/fat effects. Factors 2 and 3 significantly contributed to WM measures after Bonferroni corrections (p<0.007). No factor significantly contributed to GM. Blood pressure inclusion did not meaningfully alter the lipid/fat-WM relationship.ConclusionsPeripheral lipid/fat indicators significantly and negatively associated with cerebral WM rather than GM, independent of age and blood pressure. Dissecting the fat/lipid components contributing to different brain imaging parameters may open a new understanding of the body-brain connection through lipid metabolism.