Hypercholesteremia, diabetes mellitus (DM), hypertension, apolipoprotein E (APOE) genotype, and atherosclerosis are vascular risk factors involved in chronic inflammation, neurotoxicity and neurodegeneration, which lead to the subsequent cerebral vascular disease, vascular dementia (VaD), and Alzheimer's disease (AD) previously [4], [5], [6], [7]. The gene discussed is APOE; the disease is diabetes mellitus.