Karlsson IK, et al. - Whether DNA methylation of the apolipoprotein E (APOE) locus affects the risks of dementia, Alzheimer's disease (AD) or cardiovascular disease (CVD), was investigated in this study. Increased odds of dementia and AD, but not CVD, resulting from higher DNA methylation levels in the promoter region of APOE, was reported. This impact was independent of APOE genotype, suggesting that allelic variation and methylation variation in APOE may act independently to increase the risk of dementia.