APOE and Alzheimer disease: Therefore, because of the strong link between lipid metabolism in the brain and AD and since no studies have been done to investigate the effect of exercise, the purpose of this study was to investigate the effects of aerobic training before and after the induction of AD on ABCA1 and the APOE mRNA expression and the level of soluble Aβ1-42 in the hippocampus of male Wistar rats.