Sleep-disordered breathing and white matter disease in the brainstem in older adults

Study Objectives: To examine whether sleep-disordered breathing is associated with white matter disease in the brainstem. Design: A population-based longitudinal study. Setting: Allegheny County, PA; Sacramento County, CA; and Washington County, MD. Patients or Participants: A total of 789 individuals, aged 68 years or older, drawn from the Sleep Heart Health Study. Interventions: N/A. Measurements and Results: The participants underwent home polysomnography in 1995-1998 and cerebral magnetic resonance imaging in both 1992-1993 and 1997-1998. The apnea-hypopnea index was not associated with white matter disease in the brainstem, with or without adjusting for age, sex, race, community, body mass index, smoking status, alcohol use, systolic blood pressure, and the use of antihypertensive medication. In contrast, the arousal index (number of arousals per hour of sleep) was inversely associated with brainstem white matter disease (odds ratio = 0.75 for a SD increase in the arousal index, 95% confidence interval: 0.62, 0.92). Conclusions: The frequency of apneas and hypopneas was not associated with brainstem white matter disease in these older adults. A unique relationship with arousal frequency suggests that ischemic changes in the brainstem may be associated with arousals during sleep.