APOE and sleep apnea syndrome: Analysis via two-way ANOVA also revealed that, Black/African American but not White participants continued to demonstrate a significant association between WMH volume and both sleep apnea (F1,39 = 229.248, p < 0.001) and APOE-e4 (F2,38 = 246.115, p < 0.001) independently, and their interaction (F2,38 = 274.095, p < 0.001).