Sleep disturbances and dementia risk: A multicenter study

Introduction: Few longitudinal studies assessed whether sleep disturbances are associated with dementia risk. Methods: Sleep disturbances were assessed in three population-based studies (H70 study and Kungsholmen Project [Sweden]; Cardiovascular Risk Factors, Aging and Dementia study [Finland]). Late-life baseline analyses (3-10 years follow-up) used all three studies (N = 1446). Baseline ages 70 years (Cardiovascular Risk Factors, Aging and Dementia, H70), and approximate to 84 years (Kungsholmen Project). Midlife baseline (age approximate to 50 years) analyses used Cardiovascular Risk Factors, Aging and Dementia (21 and 32 years follow-up) (N = 1407). Results: Midlife insomnia (fully adjusted hazard ratio = 1.24, 95% confidence interval = 1.02-1.50) and late-life terminal insomnia (fully adjusted odds ratio = 1.94, 95% confidence interval = 1.08-3.49) were associated with a higher dementia risk. Late-life long sleep duration (>9 hours) was also associated with an increased dementia risk (adjusted odds ratio = 3.98, 95% confidence interval = 1.87-8.48). Discussion: Midlife insomnia and late-life terminal insomnia or long sleep duration were associated with a higher late-life dementia risk. (C) 2018 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.