Additionally, in Black/African American but not White participants there was an association between WMH volume and both sleep apnea and APOE-e4 independently, and their interaction, while a previously unseen association emerged between Hippocampal volume and sleep apnea independently and the interaction between sleep apnea and APOE-e4, though not APOE-e4 independently. This evidence concerns the gene APOE and Sleep apnea.