Multidimensional self-reported sleep health, cognitive decline, and risk of all-cause dementia: A population-based multi-cohort study

Background Considering the multidimensional nature of self-report sleep health may improve identification of those at risk of accelerated cognitive decline and dementia. Objective We compared how composite measures of multidimensional sleep health relate to cognitive performance and the risk of dementia over time in older adults. Methods Self-reported indicators of sleep health domains (satisfaction, alertness, timing, efficiency, and duration) were measured in 7892 Rotterdam Study (RS) participants (mean +/- SD age: 69.5 +/- 8.9 years, 58.2% female) and 1601 Rush Memory and Aging Project and Minority Aging Research Project (MAP/MARS) participants (79.5 +/- 7.9 years, 77.3% female). Sleep items were harmonized and used to derive a sleep health score (number of adverse sleep health items) and sleep health clusters (with latent class analysis). During follow-up, multiple cognitive tests were performed repeatedly and participants were followed for incident all-cause dementia. Relationships of sleep health with cognitive decline (linear mixed models) and risk of dementia (Cox proportional hazards models) were assessed in both samples, adjusting for covariates. Results Three sleep health clusters were identified: average sleep, inefficient sleep, and poor sleep. During follow-up of 10.6 +/- 4.5 years in RS and 5.3 +/- 2.9 years in MAP/MARS, 1148 (14.5%) and 286 (19.8%) participants developed dementia, respectively. Multidimensional sleep health scores and clusters were not significantly associated with accelerated cognitive decline or the risk of dementia in either sample (Hazard Ratios [HRs] between 0.72-1.15). Conclusions Findings suggest composite measures of self-reported multidimensional sleep health need refinement to be useful in identifying older adults at risk of accelerated cognitive decline and dementia.