Association between apolipoprotein E ε4 and sleep-disordered breathing in adults

Context Apolipoprotein E epsilon4 (ApoE epsilon4) is a well-known risk factor for Alzheimer disease and cardiovascular disease. Sleep-disordered breathing occurs in Alzheimer disease patients and increases risks for cardiovascular disease. Complex interactions among sleep, brain pathology, and cardiovascular disease may occur in ApoE epsilon4 carriers, Objective To study whether genetic variation at the level of ApoE is associated with sleep-disordered breathing or sleep abnormalities in the general population. Design, Setting, and Participants Ongoing longitudinal cohort study of sleep disorders at a US university beginning in 1989, providing a population-based probability sample of 791 middle-aged adults (mean [SD] age, 49 [8] years; range, 32-68 years). Main Outcome Measure Nocturnal polysomnography to evaluate apnea-hypopnea index. Results The probability of moderate-to-severe sleep-disordered breathing (apnea-hypopnea index greater than or equal to 15%) was significantly higher in participants with epsilon4, independent of age, sex, body mass index, and ethnicity (12.0% vs 7.0%; P=.003). Mean (SEM) apnea-hypopnea index was also significantly higher in participants with ApoE epsilon4 (6.5 [0.6] vs 4.8 [0.3]; P=.01). These effects increased with the number of ApoE epsilon4 alleles carried. Conclusions A significant portion of sleep-disordered breathing is associated with ApoE epsilon4 in the general population.