Sleep Duration and Subsequent Cortical Thinning in Cognitively Normal Older Adults

STUDY OBJECTIVES:To determine the association between self-reported sleep duration and cortical thinning among older adults. METHODS:We studied 122 cognitively normal participants in the Baltimore Longitudinal Study of Aging with a mean age = 66.6 y (range, 51-84) at baseline sleep assessment and 69.5 y (range, 56-86) at initial magnetic resonance imaging (MRI) scan. Participants reported average sleep duration and completed a mean of 7.6 1.5-T MRI scans (range, 3-11), with mean follow-up from initial scan of 8.0 y (range, 2.0-11.8). RESULTS:In analyses adjusted for age, sex, education, race, and interval between sleep assessment and initial MRI scan, participants reporting > 7 h sleep at baseline had thinner cortex in the inferior occipital gyrus and sulcus of the left hemisphere at initial MRI scan than those reporting 7 h (cluster P 7 h of sleep had higher rates of thinning in the superior frontal and middle frontal gyrus of the left hemisphere (cluster P 7 h may increase the rate of subsequent frontotemporal gray matter atrophy. Additional studies, including those that use objective sleep measures and investigate mechanisms linking sleep duration to gray matter loss, are needed.