Reduced Slow-Wave Sleep and Severe Sleep Apnea are Associated with Neuroimaging Biomarkers of Cerebrovascular Disease
Diego Carvalho1, Stuart McCarter1, Erik St. Louis1, Scott Przybelski1, Timothy Morgenthaler1, Bradley Boeve1, Ronald Petersen1, Jack Clifford1, Jonathan Graff-Radford1, Prashanthi Vemuri1
1Mayo Clinic
Objective:
We aimed to investigate whether polysomnographic (PSG) sleep parameters are associated with neuroimaging biomarkers of cerebrovascular disease in older adults.
Background:
White matter abnormalities are reflective of vascular contributions to cognitive impairment and dementia (VCID) in the elderly, but their relationship with sleep remains unclear.
Design/Methods:
From the population-based Mayo Clinic Study of Aging, we identified 140 non-demented participants who underwent at least one brain MRI and a split-night PSG. We quantified two VCID biomarkers - white matter hyperintensities (WMH) from FLAIR-MRI (n=140) and fraction anisotropy of the genu of the corpus callosum (genu FA) from diffusion MRI (n=103). For this cross-sectional analysis, we fit linear models to assess associations between diagnostic PSG parameters (N1%, N3%, mean oxyhemoglobin saturation, and log of AHI) and VCID biomarkers (log of WMH and log of genu FA), respectively, while adjusting for age (at MRI), sex, APOΕ4 status, composite cardiovascular and metabolic conditions (CMC) score, REM%, supine%, sleep duration (from diagnostic portion), and interval between MRI and PSG.
Results:
The absolute median [IQR] interval between MRI imaging and PSG was 1.74 [0.9 – 3.2] years. For every 10-point decrease in N3%, there was a 0.058 (95% CI 0.006 to 0.111, p=0.030) increase in the log of WMH and 0.006 decrease ([95% CI -0.012 to -0.0002], p=0.042) in the log of genu FA. Participants with severe sleep apnea had higher WMH burden when compared to those with mild disease, after matching for age, sex, and N3% (median [IQR] of 0.0073 [0.0044 - 0.0149] vs 0.0067 [0.0034 to 0.01], p=0.039).
Conclusions:
We found that reduced slow-wave sleep and severe sleep apnea were associated with higher burden of white matter abnormalities in predominantly cognitively unimpaired older adults, which contribute to greater risk of cognitive impairment, dementia, and stroke. Our study provides support for the links between sleep depth/fragmentation and intermittent hypoxia and VCID.