What the study found
The study found a U-shaped relationship between self-reported sleep duration and biological age gaps across 23 biological ageing clocks drawn from imaging, plasma proteomics, and metabolomics. The lowest biological age gaps were seen at about 6.4 to 7.8 hours of sleep, with variation by organ and sex.
Why the authors say this matters
The authors conclude that this cross-organ, multi-omics pattern suggests sleep optimization may help promote healthy ageing, lower disease risk, and extend longevity. They also note links between short and long sleep duration and systemic disease risk beyond the brain, including all-cause mortality.
What the researchers tested
The researchers examined self-reported sleep duration in the UK Biobank, covering participants aged 37 to 84 years, and related it to 23 biological ageing clocks derived from in vivo imaging, plasma proteomics, and metabolomics. They also assessed associations with disease risk, genetic correlations, time-to-incident survival predictions, and pathways related to late-life depression.
What worked and what didn't
Sleep duration showed the lowest biological age gaps at roughly 6.4 to 7.8 hours, depending on organ and sex. Short sleep (<6 hours) and long sleep (>8 hours), compared with normal sleep (6–8 hours), were associated with increased risk of systemic diseases and all-cause mortality, with examples including depression and diabetes. For late-life depression, ageing clocks may partially mediate the association with long sleep, while short sleep showed a more direct link.
What to keep in mind
The abstract notes that Mendelian randomization did not provide strong evidence that disease causally affects sleep, but it could not fully rule out reverse causality. Other limitations are not described in the available summary.
Key points
- The study reports a U-shaped link between sleep duration and 23 biological ageing clocks.
- The lowest biological age gaps occurred at about 6.4 to 7.8 hours of sleep.
- Short sleep and long sleep were associated with higher risk of systemic disease and all-cause mortality.
- Examples of linked conditions included depression and diabetes.
- For late-life depression, ageing clocks may partly mediate the long-sleep association, while short sleep was more directly linked.
Disclosure
- Research title:
- Sleep duration shows a U-shaped link with biological ageing
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