A groundbreaking international study, recently published in Health Data Science, analyzed objective sleep data from 88,461 adults in the UK Biobank and found significant associations between sleep traits and 172 diseases. The research, led by teams from Peking University and Army Medical University, highlights sleep regularity—such as bedtime consistency and circadian rhythm stability—as an underrecognized but critical factor in disease risk.

Using actigraphy data over an average of 6.8 years, researchers identified that 92 diseases had more than 20 percent of their risk attributable to poor sleep behavior. Notably, irregular bedtime (after 00:30) was linked to a 2.57-fold higher risk of liver cirrhosis, while low interdaily stability increased the risk of gangrene by 2.61 times.

Importantly, the study challenges previous claims that “long sleep” (≥9 hours) is harmful. While subjective reports have linked long sleep to stroke and heart disease, objective data revealed this association in only one disease. Misclassification may be to blame: 21.67 percent of “long sleepers” actually slept less than six hours, suggesting that time spent in bed is often confused with actual sleep time.

“Our findings underscore the overlooked importance of sleep regularity,” said Professor Shengfeng Wang, senior author of the study. “It’s time we broaden our definition of good sleep beyond just duration.”

The team confirmed several associations in U.S. populations and identified inflammatory pathways as a possible biological link. Future research will explore causality and assess the impact of sleep interventions on chronic disease outcomes.

For more information, visit https://spj.science.org/journal/hds.