| |
Sleep Duration & Quality & Cognitive
Function (MCI, Alzheimers, Dementia)
|
| |
| |
Download the PDF here
Download the PDF here
Association of Sleep Duration and Change Over Time With Imaging Biomarkers of Cerebrovascular, Amyloid, Tau, and Neurodegenerative Pathology
In this longitudinal community-based cohort, we observed that an increase of self-reported sleep duration over time was associated with neuroimaging biomarkers of vascular brain injury, namely higher WMH burden and FW fraction. WMH are well-known markers of small vessel disease and have been identified as AD risk factors.21 FW fraction is a novel measure inferring on unrestricted extracellular water and is associated with ischemic vasogenic edema.20 FW fraction is elevated in patients with MCI and dementia22 and associated with poorer cognitive function and dementia progression.23
We concomitantly investigated ATV(N) neuroimaging biomarkers in association with self-reported changes in sleep duration. Vascular pathology in the brain as evidenced by higher WMH burden and FW fraction was associated with self-reported sleep duration that became longer over time in our large community-based cohort. Longer sleep duration over time may be an early change in the AD trajectory but whether it could subsequently provoke Aβ or tau pathology remains unclear, despite the previous association between AD risk and longer sleep duration over time.2-4 Future studies are necessary to understand the directionality of this association to inform whether preventing longer sleep duration over time could be beneficial or detrimental to brain health.
-------------------------
Association Between Sleep Quantity and Quality in Early Adulthood With Cognitive Function in Midlife
In conclusion, we found that actigraphy-measured sleep fragmentation in early midlife was associated with late midlife cognition among Black and White adults. Our findings indicate that the quality rather than the quantity of sleep matters most for cognitive health in midlife and that the measures of sleep should go beyond self-report. Although this study reported on sleep and cognition in a middle-aged diverse population, larger studies are required to determine if race or sex differences exist
Sleep dysregulation is a feature of dementia but it remains unclear whether sleep duration prior to old age is associated with dementia incidence. Using data from 7959 participants of the Whitehall II study, we examined the association between sleep duration and incidence of dementia (521 diagnosed cases) using a 25-year follow-up. Here we report higher dementia risk associated with a sleep duration of six hours or less at age 50 and 60, compared with a normal (7 h) sleep duration, although this was imprecisely estimated for sleep duration at age 70 (hazard ratios (HR) 1.22 (95% confidence interval 1.01–1.48), 1.37 (1.10–1.72), and 1.24 (0.98–1.57), respectively). Persistent short sleep duration at age 50, 60, and 70 compared to persistent normal sleep duration was also associated with a 30% increased dementia risk independently of sociodemographic, behavioural, cardiometabolic, and mental health factors. These findings suggest that short sleep duration in midlife is associated with an increased risk of late-onset dementia.
Those who had actigraphy-measured shorter sleep duration or higher sleep fragmentation were significantly more likely to be male, Black adults, had higher BMI, and were more likely to have a history of depression or hypertension. In total, 142 (64.3%) participants with shorter (<6 hours) sleep duration vs 17 (17.5%) of those with long (>7 hours) sleep were Black adults.
|
|
| |
| |
|
|
|
