Your sleep schedule could be making you sick, says massive new study

Using actigraphy data over an average of 6.8 years, researchers identified that 92 diseases had over 20% 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% of “long sleepers” actually slept less than 6 hours, suggesting that time spent in bed is often confused with actual sleep time.

“Our findings underscore the overlooked importance of sleep regularity,” said Prof. 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.