APOE and Alzheimer disease: A further study indicated that insulin concentrations were lower in older APOE-ε4 carriers, including cognitively normal individuals and those with AD, than in APOE-ε4 non-carriers, despite comparable blood glucose concentrations between the groups [19], suggesting that the decreased body mass and FM in older adults with APOE-ε4 may be due to the lack of insulin anabolic reactions.