Specifically, levels of apoA-I, the major HDL-associated protein, positively correlate with Mini-Mental State Examination (MMSE) and Cognitive Ability Screening Instrument (CASI) scores (Merched et al., 2000) and high serum HDL-C levels (>55 mg/dl) in cognitively normal elderly individuals is associated with significantly reduced risk (HR 0.4) of AD even after adjusting for APOE genotype and vascular risk factors including obesity and T2DM (Reitz et al., 2010). This evidence concerns the gene APOE and Alzheimer disease.