Abstract
INTRODUCTION: Little is known about change in sleep duration over time and Alzheimer's Disease and Related Dementias (ADRD) risk. METHODS: ADRD cases were identified among Southern Community Cohort Study participants enrolled in Medicare. Sleep duration was reported at enrollment and first study follow-up and categorized (short (< 7 hours), recommended (7-9) and long (> 9)), change was calculated between timepoints. Adjusted Cox proportional hazards regression was used to estimate hazard ratios (HRs, 95% CIs) for incident ADRD. RESULTS: We identified 2,093 ADRD cases among 17,945 participants. Compared to maintaining optimal sleep duration (7-9 hours) over 5 years, suboptimal changes were associated with 20-69% greater ADRD risk: adjusted HR (95% CI) was 1.50 (1.23-1.82) for long-recommended, 1.56 (1.21-2.01) for long-long, 1.69 (1.25-2.27) for long-short, 1.49 (1.16-1.91) for short-long, and 1.20 (1.06-1.36) for short-short. DISCUSSION: Suboptimal 5-year change in sleep durations were associated with ADRD risk among lower-income adults underrepresented in ADRD research. HIGHLIGHTS: The study calculated 5-year change in sleep duration in a large community-based cohort of predominately lower-income adults. Cases of Alzheimer's Disease and Related Dementias (ADRD) were ascertained from Medicare claims data among 17,945 participants with up to 12 years of follow-up. Compared to maintaining 7-9 hours of sleep, older adults with suboptimal sleep categories were consistently at a greater risk of ADRD.