New research reveals that erratic sleep patterns – late nights, irregular schedules, and disrupted circadian rhythms – may significantly raise disease risk, challenging the focus on sleep duration alone.
If you thought getting enough hours of sleep was all that mattered, new research says otherwise. A large-scale study has found that irregular sleep patterns, such as inconsistent bedtimes and disrupted circadian rhythms, may significantly raise the risk of developing a wide range of diseases.
The study published in Health Data Science, analysed objective sleep data from 88,461 adults in the UK Biobank over almost 7 years. Researchers from Peking University and Army Medical University uncovered compelling evidence that sleep irregularity play a much larger role in long-term health than previously thought.
Sleep Consistency vs Disease Risk
Researchers tracked participants using actigraphy over an average of 6.8 years. The findings revealed that poor sleep habits contributed to more than 20 percent of the risk for 92 diseases.
In total, the study estimated that 23% of disease burden across the identified conditions could be attributed to poor sleep traits. Notably:
- Late or irregular bedtimes: Going to bed after 12:30am was tied to 2.57x greater risk of liver cirrhosis
- Lower interdaily stability: Linked to 2.61x higher risk of gangrene
The Long Sleep Myth
The research also challenged earlier claims that sleeping for nine hours or more (“long sleep”) is harmful. While self-reported data had associated “long sleep” with heart disease and stroke, objective measurements revealed this link in only one condition.
Furthermore, over one-fifth of people who identified as “long sleepers” were actually sleeping less than six hours. This suggests that time spent lying in bed, rather than actual sleep, may have skewed past results.
“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.
Takeaway
Future studies may focus on whether improving sleep regularity can reduce the risk of these diseases and explore how sleep interventions might affect long-term health outcomes.
For one looking to make an actionable change to their lifestyle, don’t forget to keep an eye out on your bedtimes and sleep-wake cycles – they may be just as improtant as the number of hours you sleep!
External References
- Wang, Y., Wen, Q., Luo, S., Tang, L., Zhan, S., Cao, J., Wang, S., & Chen, Q. (2025). Phenome-wide Analysis of Diseases in Relation to Objectively Measured Sleep Traits and Comparison with Subjective Sleep Traits in 88,461 Adults. Health data science, 5, 0161. https://doi.org/10.34133/hds.0161
