APOE and Insulin resistance: We have previously demonstrated similar associations between insulin resistance and BMI and TSPO binding mainly in the parietal cortex utilizing [11C]PBR28, a second-generation TSPO ligand, in a sample of elderly (mean age 70.1 years) individuals without dementia.27 The present study was performed on a different and slightly younger study population (mean age 67.6 years), that was enriched for APOE4 homo- and heterozygotes, and the study protocol included screening for cognitive decline.