MRI markers of accelerated brain aging and misappraisal of sleep depth. (31st December 2021)

• Record Type: Journal Article
• Authors: Baril, Andree‐Ann; Mysliwiec, Vincent; Beiser, Alexa S.; Redline, Susan; DeCarli, Charles S.; Seshadri, Sudha; Pase, Matthew P.; Himali, Jayandra J.
• Is Part Of: Alzheimer's & dementia. Volume 17(2021)Supplement 5
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-31
• Subjects: Alzheimer's disease -- Periodicals; Alzheimer Disease -- Periodicals; Dementia -- Periodicals; Démence; Maladie d'Alzheimer; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.83
• DOI: 10.1002/alz.056257
• Languages: English
• ISSNs: 1552-5260

Abstract

Abstract: Background: Slow‐wave sleep (SWS) is the deepest sleep stage, and has been linked to many important physiological functions, including the cerebral metabolic clearance of toxins associated with Alzheimer's disease. SWS loss might correlate with accelerated brain aging. However, older individuals and people with cognitive impairment have an impaired ability to appraise their sleep, suggesting that accelerated brain aging might affect how sleep depth is perceived. The purpose of this study was to evaluate whether misappraisal of sleep depth was associated with MRI markers of accelerated brain aging. Method: We studied 242 participants (mean: 62.0±8.7 years) participants in the Framingham Heart Study Offspring Cohort that were evaluated with an overnight in‐home polysomnography and an MRI 3.4 years later on average. Self‐reported sleep depth (whether sleep was light or deep) on the night of the polysomnography was compared to objective SWS (percent of total sleep spent in SWS, separated by the median). Four groups were created: 36% of the sample had consistent appraisal of deep sleep; 12% of the sample had consistent appraisal of light sleep; 36% misappraised their light sleep as deep; and 16% misappraised their deep sleep as light. We evaluated total brain volume, cortical gray matter volume, and subcortical gray matter volume on MRI. A first set of models were adjusted for age, sex, time between MRI and neuropsychology; a second set of models were additionally adjusted for APOE4 allele status, body mass index, sleeping pills, depression, and stroke risk. Result: Participants who misappraised light sleep, i.e., reported deep sleep but had lower SWS, had lower cortical gray matter volume (model 1: β±SE=‐0.62±0.26, p=0.018; model 2: ‐0.56±0.27, p=0.036) compared to those that reported deep sleep with higher SWS. We also observed a trend for lower subcortical gray matter volume in the same group (model 1:β±SE=‐0.09±0.05, p=0.084). No other between‐group differences were observed. Conclusion: Participants with lower SWS that reported their sleep as deep displayed lower cortical volume. Accelerated brain aging might affect the ability to appropriately perceived sleep depth, which could be occurring in preclinical stages of dementia. Relying on self‐report sleep depth may introduce systematic misclassification.