Mapping the 9-year sleep trajectory and its implications for chronic disease risks among middle-aged and older adults

Objective: To identify the 9-year trajectories of sleep duration and to assess the relationship between time- dependent sleep duration and sleep trajectories with 14 chronic diseases in adults. Methods: This study used five waves of data of the China Health and Retirement Longitudinal Survey. Participants with complete sleep duration data and at least one record of 14 chronic diseases were included. The group-based trajectory model was used to identify sleep trajectories from 2011 to 2020. Time-dependent survival analysis and logistic regression were used to examine the relationship between time-dependent sleep duration and sleep trajectories with chronic diseases. Results: A total of 9063 participants were included, with a mean (standard deviation, SD) sleep duration of 6.37 (1.83) h/d. Sleeping <7 h/d predicted higher risks of 11 chronic diseases at follow-up, with hazard ratios (HR) and 95 % confidence intervals (CI) ranging from 1.71 (1.26-2.33) for psychiatric disease to 1.15 (1.04-1.27) for dyslipidemia. Five sleep trajectories were identified and labeled as group 1-5 based on ascending order of sleep duration. Consistently sleeping <4 h/d (group 1) and 4-6 h/d predicted higher risks of most chronic diseases, with the highest HR (95 %CI) of 3.50 (1.73-6.92) and 2.94 (1.82-4.49) for psychiatric diseases, respectively. Consistently sleeping 6-7 h/d (group 3) predicted higher risks of digestive diseases and arthritis. Decreasing sleep (group 4) predicted higher risks of psychiatric diseases and memory-related diseases. Conclusions: Consistently sleeping <6 h/d predicted higher risks of most chronic diseases, especially psychiatric diseases. Digestive disease and arthritis were more sensitive to consistently inadequate sleep.