Dual trajectories of nighttime sleep duration and frailty in relation to cardiovascular disease risk in middle-aged and older Chinese adults: a longitudinal study.
Wu Q, Zhang J, et al. • Archives of gerontology and geriatrics • 2026
Sleep duration and frailty trajectories are interrelated over time and jointly influence CVD risk, with the highest CVD risk observed among individuals with both stable pre-frail/frail and stable-5-hours sleep trajectories.
Key Findings
Results
Four distinct nighttime sleep duration trajectories were identified among middle-aged and older Chinese adults over three biennial waves.
Trajectories were modeled using three biennial waves (2011-2015) of the China Health and Retirement Longitudinal Study (CHARLS)
Total sample included 6972 participants
Group-based trajectory modeling was used to identify distinct sleep patterns
One identified trajectory was a stable-8-hours group and another was a stable-5-hours group, among four total trajectories
Results
Three distinct frailty index trajectories were identified, including stable pre-frail and stable frail trajectories.
Frailty index (FI) trajectories were modeled across the same three biennial waves (2011-2015)
Three frailty trajectories were identified using group-based trajectory modeling
Stable pre-frail and frail trajectories were among the identified patterns
Dual trajectory modeling was used to capture co-development patterns of sleep and frailty
Results
Stable short sleep duration (approximately 5 hours) was associated with significantly higher risks of CVD and heart disease compared to stable 8-hour sleep.
Compared with stable-8-hours sleep trajectory, stable-5-hours group had HR: 1.33 (95% CI: 1.05-1.68) for CVD
Stable-5-hours group had HR: 1.42 (95% CI: 1.07-1.88) for heart disease
These associations were significant only for women in sex-stratified analyses
CVD events were assessed during the 2015-2018 follow-up period using Cox proportional hazards models
Results
Stable pre-frail and stable frail trajectories were each independently associated with substantially elevated risks of CVD and heart disease in both sexes.
Stable pre-frail trajectory: HR 1.92 (95% CI: 1.45-2.55) for CVD and HR 2.28 (95% CI: 1.60-3.24) for heart disease
Stable frail trajectory: HR 3.70 (95% CI: 2.63-5.21) for CVD and HR 4.61 (95% CI: 3.03-7.00) for heart disease
Associations were significant in both sexes, unlike the sleep-only findings which were significant only in women
CVD events were followed from 2015 to 2018
Results
The combination of stable pre-frail/frail and stable short sleep trajectories was associated with the highest CVD risk in dual-trajectory analyses.
HR for CVD among individuals with both stable pre-frail/frail and stable-5-hours trajectories: 3.04 (95% CI: 1.88-4.91)
Dual-trajectory analyses revealed co-development patterns of sleep and frailty
This joint risk exceeded the risk associated with either trajectory alone
Dual trajectory modeling was used to identify these combined patterns
Methods
Baseline characteristics across trajectory groups were examined and compared using multinomial logistic regression.
Multinomial logistic regression was used to compare baseline characteristics across trajectory groups
Data came from the China Health and Retirement Longitudinal Study (CHARLS), a longitudinal study of middle-aged and older Chinese adults
Trajectories were based on 2011-2015 data with CVD follow-up from 2015-2018
The study included 6972 participants in total
What This Means
This research suggests that both how long people sleep at night and how frail they are over time are important predictors of heart and cardiovascular disease risk. Using data from nearly 7,000 middle-aged and older adults in China tracked over several years, researchers identified distinct long-term patterns (trajectories) of sleep duration and frailty. They found that people who consistently slept around 5 hours per night faced about a 33% higher risk of cardiovascular disease and a 42% higher risk of heart disease compared to those who consistently slept around 8 hours — and this relationship was particularly pronounced in women. People who were consistently pre-frail or frail faced even greater risks, with frail individuals having more than three and a half times the cardiovascular disease risk compared to those with healthier frailty levels.
The most striking finding came from looking at sleep and frailty together. People who were both consistently frail or pre-frail and consistently short sleepers had the highest cardiovascular disease risk of all — about three times higher than those with healthier patterns in both areas. This suggests that short sleep and frailty do not act independently; rather, they appear to interact and compound each other's effects on heart health over time.
This research suggests that tracking both sleep patterns and frailty levels over time — rather than just measuring them at a single point — could help identify people at especially high risk for cardiovascular disease. Monitoring these long-term patterns in middle-aged and older adults may improve the ability to target prevention efforts more precisely, particularly for women and for those showing signs of both poor sleep and physical frailty.
Wu Q, Zhang J, Liu J, Huang H, Zhang Z, Yue S, et al.. (2026). Dual trajectories of nighttime sleep duration and frailty in relation to cardiovascular disease risk in middle-aged and older Chinese adults: a longitudinal study.. Archives of gerontology and geriatrics. https://doi.org/10.1016/j.archger.2026.106149