0275 Disturbed Sleep is associated with Faster Cognitive Decline in Mild Cognitive Impairment

Abstract Introduction Mild cognitive impairment (MCI) represents a pivotal stage in the trajectory toward dementia. Approximately 15% of individuals with MCI advance to dementia within two years, roughly one-third within five years, while half remain in the MCI stage after ten years. Little is known about the factors driving this high variation. The goal of this study was to investigate the impact of disturbed sleep (i.e., trouble falling asleep, waking up during the night, waking up too early, or not feeling rested) on the progression from MCI to dementia among older adults with MCI. Methods This was a longitudinal analysis using data from biannually national survey from U.S.: Health Retirement Survey (HRS) 2006-2022. Survival analysis including Kaplan Meier curves and Cox Proportional Models were used to examine the association of existence of disturbed sleep complains prior to MCI onset (pre-clinical phase) with the risk and speed of progression from MCI to dementia. GEE models were used to examine the dynamic association of disturbed sleep and cognitive decline (measured by scores) during the MCI phase. All analyses control for demographic characteristics and self-report health status at the wave of MCI onset. Results There were a total of 9,428 participants from HRS with newly onset MCI, 1,901 individuals progressed from MCI to dementia, with the average progression time 4 ± 2 years. There were 7,527 respondents who remained in MCI phase during the whole observation. Existence of disturbed sleep complaints during preclinical phase was associated with a faster progression from MCI to dementia: trouble falling asleep (HR=1.14, 95% CI: 1.026-1.267), waking up during the night (HR=1.11, 95% CI: 1.002-1.222), waking up too early (HR=1.117, 95% CI: 1.005-1.242). There was a significant, negative relationship between cognitive scores and sleep disturbances. Conclusion Disturbed sleep is associated with a faster cognitive decline. Sleep can be a promising early indicator to identify individuals with MCI at risk for a fast progression to dementia, and to inform effective strategies to delay cognitive decline at the primary care level. More investigations are needed to elaborate the relationship between sleep and cognitive decline prior to and during the MCI phase. Support (if any)