Persistent Rather Than Variable Short Sleep Associates With Cardiovascular Events in Middle-Aged and Older Chinese Adults: A CHARLS Cohort Study

Q: What are the key findings of this study?

Persistent short sleep was associated with a 22% higher risk of incident cardiovascular events compared with persistent optimal sleep (HR 1.22, 95% CI 1.05–1.42; p=0.009).

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: Incident cardiovascular events (heart disease or stroke) (n=11050). Intervention: Persistent short sleep (<6 hours per night) vs. Persistent optimal sleep (6–8 hours per night). Primary outcome: Incident cardiovascular events (self-reported physician-diagnosed heart disease or stroke, per 1,000 person-years) (HR 1.22, 95% CI 1.05-1.42, p=0.009).

Q: What does this research mean for the field?

Persistent short sleep, but not variable short sleep, is associated with a significantly increased risk of incident cardiovascular events in middle-aged and older adults. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Zehua Wang; Xianxian Fan; Long Chen; Yiping Shi; Qin Shao

doi:10.21203/rs.3.rs-11058097/v1

October 11, 2026Open Access

Persistent Rather Than Variable Short Sleep Associates With Cardiovascular Events in Middle-Aged and Older Chinese Adults: A CHARLS Cohort Study

View Full Paper

Ask AI

Bookmark

Share

Key result

Persistent short sleep linked to ~22% higher risk of incident cardiovascular events.

HR 1.22
95% CI 1.05-1.42
P=0.009
n=11,050

Why the study?

Single-time sleep assessments cannot distinguish persistent from variable short sleep, and it remained uncertain whether these sleep-trajectory phenotypes and the CHG index predict incident cardiovascular events in middle-aged and older adults.

Does persistent short sleep or variable short sleep increase the risk of incident cardiovascular events compared with persistent optimal sleep in middle-aged and older Chinese adults?

Key Points

To determine whether longitudinal sleep-duration trajectories predict incident cardiovascular events in middle-aged and older adults, and to evaluate the risk-stratifying utility of the CHG index.
Analyzed 11,050 CHARLS cohort participants aged 45 years or older without heart disease or stroke through 2015, with sleep duration measured across at least two surveys from 2011 to 2015 and follow-up through 2018 or 2020 (mean follow-up: 4.65 years).
Categorized sleep trajectories into persistent optimal, variable short, persistent short, optimal-to-short, and other patterns.
Used multivariable Cox proportional hazards models adjusting for demographic, socioeconomic, lifestyle, clinical, depressive symptoms, and physical activity variables.
Across 51,330 person-years of follow-up, 1,923 incident cardiovascular events occurred (17.4% event rate; 1,294 heart disease, 790 stroke).
Compared with persistent optimal sleep, persistent short sleep was associated with higher cardiovascular risk (HR 1.22, 95% 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).
High CHG combined with persistent short sleep conferred the highest joint risk (HR 1.35, 95% CI 1.08–1.69; p = 0.008), with sex-stratified analysis showing elevated risk in women (HR 1.30, 95% CI 1.04–1.64) but not men (sex-by-CHG interaction p = 0.027).

Study Design

Type

Cohort (n=11,050)

Multicenter

Yes

Structured PICO

Does persistent short sleep or variable short sleep increase the risk of incident cardiovascular events compared with persistent optimal sleep in middle-aged and older Chinese adults?

P

Population

11,050 middle-aged and older Chinese adults aged ≥45 years (median age 57 years, 51.7% female), free of baseline heart disease and stroke through 2015, followed for a mean of 4.65 years.

E

Exposure

Sleep-duration trajectory phenotypes assessed across the 2011, 2013, and 2015 survey waves: persistent short sleep (all available measurements <6 hours, n=1,345), variable short sleep (at least two short-sleep measurements <6 hours and coefficient of variation ≥15%, n=1,208), optimal-to-short sleep (first category 6–8 hours and last category <6 hours, n=1,114), and other sleep patterns (n=3,556), as well as evaluation of the cholesterol, high-density lipoprotein, and glucose (CHG) index (n=9,672).

C

Comparator

Persistent optimal sleep trajectory (all available exposure-window measurements within 6–8 hours and a coefficient of variation <15%, n=3,827); for joint exposure analyses, low CHG (below median) plus persistent optimal sleep.

O

Outcome

Incident cardiovascular events, defined as a composite of self-reported physician-diagnosed heart disease or stroke occurring after the 2015 exposure window, assessed at the 2018 (3-year) and 2020 (5-year) follow-up waves (mean follow-up 4.65 years; 51,330 person-years).composite

Main Result

Hazard Ratio: 1.22 (95% CI 1.05–1.42)

Absolute Event Rate: 46.95% vs 31.94%

p-value: p=0.009

Repeated sleep assessments demonstrate that persistent short sleep, rather than fluctuating variable short sleep, independently predicts incident cardiovascular events in middle-aged and older Chinese adults, particularly when combined with an elevated CHG metabolic index.

Limitations

Cardiovascular events were self-reported physician diagnoses and were not centrally adjudicated.
Event occurrence was observed only at follow-up waves (2018 and 2020) rather than by exact diagnosis date.
Death during follow-up was not incorporated as a competing event because mortality data were unavailable in the analytic dataset.
Missing covariates were handled with a missing-indicator approach rather than multiple imputation.
Event occurrence was observed only at follow-up waves rather than by exact diagnosis date, limiting conventional Schoenfeld residual diagnostics.
Death during follow-up was not incorporated as a competing event because death information was not available in the analytic dataset.
Missing covariates were handled with a pragmatic missing-indicator approach rather than multiple imputation.
Subgroup, sensitivity, and interaction analyses were exploratory and were not adjusted for multiplicity.

Implication

Persistent short sleep was associated with higher cardiovascular risk; hypothesis-generating for sleep interventions and requires randomized confirmation before practice change.

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.

Discussion

No takes yet. Share an insight, caveat, or question.

Cite This Study

Wang et al. (2026) conducted a cohort in Incident cardiovascular events (heart disease or stroke) (n=11,050). Persistent short sleep (<6 hours per night) vs. Persistent optimal sleep (6–8 hours per night) was evaluated on Incident cardiovascular events (self-reported physician-diagnosed heart disease or stroke, per 1,000 person-years) (HR 1.22, 95% CI 1.05-1.42, p=0.009). Persistent short sleep was associated with a 22% higher risk of incident cardiovascular events compared with persistent optimal sleep (HR 1.22, 95% CI 1.05–1.42; p=0.009).

synapsesocial.com/papers/6ae682a3e432e7a5c4ef35db https://doi.org/10.21203/rs.3.rs-11058097/v1

View Full Paper

Ask AI

Bookmark

Share

Persistent Rather Than Variable Short Sleep Associates With Cardiovascular Events in Middle-Aged and Older Chinese Adults: A CHARLS Cohort Study

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Cite This Study

Persistent Rather Than Variable Short Sleep Associates With Cardiovascular Events in Middle-Aged and Older Chinese Adults: A CHARLS Cohort Study

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Cite This Study

Keep reading

Keep reading