Association between apolipoprotein E epsilon4 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 >/=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.