APOE-ε4 carrier status,33 a heritable component also associated with OSA, has been found to be associated with an increased number of microbleeds.37 In our study, the increased risk of CMBs in association with moderate to severe OSA remained significant even after adjustment for APOE-ε4 genotype, indicating an independent association between OSA and occurrence of CMBs. Here, APOE is linked to obstructive sleep apnea syndrome.