Abstract / Summary
Abstract Background Short sleep has been linked to cardiometabolic disease, but single-time sleep assessments cannot separate persistent short sleep from recurrent variable short sleep. Whether these sleep-trajectory phenotypes predict incident cardiovascular events in middle-aged and older adults, and whether the cholesterol, high-density lipoprotein, and glucose (CHG) index identifies higher-risk sleep-metabolic profiles, remains uncertain. Methods We analysed 11,050 China Health and Retirement Longitudinal Study (CHARLS) participants aged 45 years or older who were free of heart disease and stroke through 2015, had sleep-duration data from at least two of the 2011–2015 survey waves, and had 2018 or 2020 follow-up. Sleep trajectories were classified as persistent optimal, variable short, persistent short, optimal-to-short, or other patterns. Incident cardiovascular events were self-reported physician-diagnosed heart disease or stroke. Multivariable Cox models adjusted for demographic, socioeconomic, lifestyle, clinical, depressive-symptom, and physical-activity covariates; sensitivity, CHG, joint-exposure, and exploratory sex-stratified analyses were performed. Results During 51,330 person-years, 1,923 incident cardiovascular events occurred. Compared with persistent optimal sleep, persistent short sleep was associated with higher cardiovascular risk (hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.05–1.42; p = 0.009), whereas variable short sleep was not (HR 1.03, 95% CI 0.88–1.21; p = 0.701); estimates were similar across sensitivity analyses. CHG was modestly associated with events after adjustment for sleep trajectory (HR per standard deviation 1.06, 95% CI 1.01–1.11; p = 0.024). High CHG combined with persistent short sleep identified the highest joint-risk group (HR 1.35, 95% CI 1.08–1.69; p = 0.008). In exploratory sex-stratified analyses, persistent versus variable short sleep carried higher risk among women (HR 1.30, 95% CI 1.04–1.64) but not men, with a significant sex-by-CHG interaction (p = 0.027). Conclusions Persistent short sleep, but not variable short sleep, was associated with incident cardiovascular events after multivariable adjustment in this national cohort of middle-aged and older Chinese adults. The CHG index may help characterise higher-risk sleep-metabolic subgroups, particularly among women in exploratory analyses. Repeated sleep assessment and routine metabolic markers may support prevention-oriented cardiovascular risk assessment in ageing populations. Clinical trial number: Not applicable.