Alzheimer’s Disease Patients, Especially ApoE4 Carriers, Have Significantly Reduced High‐density Lipoprotein Particle Size Revealed by Negative‐stained Transmission Electron Microscopy

High density lipoproteins (HDL) are protective against a wide array of diseases and have recently also been found to be associated with reduced risk of Alzheimer’s Disease (AD). However, the amount of circulating HDL‐cholesterol does not correlate closely with function, explaining only about 40% of the variance in HDL’s ability to perform its primary role of cholesterol efflux. HDL particle composition, size and structure are important determinants of functional capacity, however little is known about HDL particle physical characteristics in AD patients, in particular whether there are apolipoprotein E (APOE) genotype‐dependent effects.