Association between apolipoprotein E epsilon 4 and sleep-disordered breathing in adults

Context Apolipoprotein E epsilon4 (ApoE epsilon4) is a well-known risk fact or for Alzheimer disease and cardiovascular disease. Sleep-disordered breat hing occurs in Alzheimer disease patients and increases risks for cardiovas cular disease. Complex interactions among sleep, brain pathology, and cardi ovascular disease may occur in ApoE epsilon4 carriers, Objective To study whether genetic variation at the level of ApoE is associ ated with sleep-disordered breathing or sleep abnormalities in the general population. Design, Setting, and Participants Ongoing longitudinal cohort study of slee p disorders at a US university beginning in 1989, providing a population-ba sed probability sample of 791 middle-aged adults (mean [SD] age, 49 [8] yea rs; range, 32-68 years). Main Outcome Measure Nocturnal polysomnography to evaluate apnea-hypopnea i ndex. Results The probability of moderate-to-severe sleep-disordered breathing (a pnea-hypopnea index greater than or equal to 15%) was significantly higher in participants with epsilon4, independent of age, sex, body mass index, an d ethnicity (12.0% vs 7.0%; P=.003). Mean (SEM) apnea-hypopnea index was al so 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 a lleles carried. Conclusions A significant portion of sleep-disordered breathing is associat ed with ApoE epsilon4 in the general population.