Study links sleep duration and quality to disease risk

Sleep quantity and quality are priorities of China’s National Health Commission and a broader public health focus in China. According to the latest 2026 China Sleep Health White Paper, surveyed Chinese adults slept an average of 6.97 hours per night, while 23% slept fewer than six hours. Only 26% of respondents reported having a consistent sleep schedule, and the report said sleep problems are increasing over time.

Understanding how sleep patterns are associated with disease risk is therefore important for the Chinese public. However, researchers still have limited insight into how specific sleep stages and real-world sleep habits affect health outcomes. One challenge is that self-reported sleep measurements often correlate poorly with objective assessments.

How the sleep study was conducted

Researchers analyzed data from 95,559 UK Biobank participants who wore wrist accelerometers for seven consecutive days and nights. Using deep learning algorithms, they calculated participants’ REM, deep and light sleep, total sleep time, wakefulness after sleep onset, and nighttime sleep irregularity.

Participants were followed for a median of 8.9 years. Researchers used available health records to examine associations between sleep patterns and more than 1,000 disease outcomes.

More REM sleep was associated with lower risk of 83 diseases

More REM sleep—measured as an increase of 47.6 minutes per interquartile range—was associated with a lower risk of 83 diseases. These included heart failure, with a hazard ratio of 0.74; dementia, with a hazard ratio of 0.54; and Parkinson’s disease, with a hazard ratio of 0.20.

More deep sleep was associated with a lower risk of seven diseases, including type 2 diabetes and major depressive disorder.

By contrast, irregular sleep patterns and more wakefulness after falling asleep were associated with an increased risk of several diseases, including anxiety and substance use disorders.

Sleeping less than five hours was linked to higher disease risk

Total sleep time showed a non-linear relationship with disease risk for many conditions. The lowest risk was generally concentrated in the six- to eight-hour range.

People who slept fewer than five hours per night had the greatest clinical vulnerability, with an increased risk of 37 diseases. The researchers also found that sleep duration had significant non-linear associations with 86 disease phenotypes. For 69 of those phenotypes, the duration associated with the lowest risk was centered within the six- to eight-hour window.

Study identified 156 significant sleep-disease associations

The authors reported that a phenome-wide association analysis identified 156 significant associations between sleep patterns and incident diseases after Bonferroni correction.

“The results of this study provide additional evidence supporting the role of 6 to 8 hours of sleep as a protective measure for the health of middle-aged and older adults, likely due to a more favorable distribution of sleep stages,” the authors said. “Maintaining 6-8 hours of sleep can effectively reduce the risk of multiple diseases, providing new insights into health promotion and prevention practices.”

Observational study cannot prove cause and effect

Because the research was observational, it cannot prove that sleep duration or sleep patterns directly cause changes in disease risk. The findings show associations between objectively measured sleep characteristics and later health outcomes.

Study funding

The research was supported by the National Science Fund for Outstanding Young Scholars (82025031 to RC), the Key Program of the National Natural Science Foundation of China (82230109 to RC), the Beijing Outstanding Young Scientists Program (JWZQ20240101024 to RC), and the Beijing Young Scholars Project of the Chinese Institute of Medical Research in Beijing (CX23YZ01 to RC).

The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.