APOE and Sleep apnea: Analysis via two-way ANOVA revealed that both sleep apnea (F1,199 = 6.058, p = 0.015) and APOE-e4 (F2,198 = 5.459, p = 0.005) independently, and their interaction (F2,198 = 3.827, p = 0.23), were significantly associated with WMH volume.