oh man I love sleeping and easily get over 8.

Limitations

Several limitations warrant consideration. First, although our findings revealed U-shaped associations between sleep duration and various phenotypes, these patterns require external validation in independent cohorts, potentially on the same scale as UKBB. Second, the reliance on self-reported, questionnaire-based sleep duration measurement may introduce recall bias or misclassification; future studies incorporating objective measures, such as polysomnography, are essential to better understand underlying mechanisms. Third, the cross-sectional design of this study limits our ability to determine causality or the direction of effect; although our current analysis positions sleep disturbance as a modifiable risk factor, longitudinal follow-up is needed to clarify whether sleep disturbance is a modifiable risk factor or a consequence of disease burden. Furthermore, proteomic and metabolomic signals fluctuate with time, illness, medication and diet, so single snapshots can misclassify biology. Longitudinal sampling may yield more reliable estimates and separate transient noise from persistent, risk-relevant biology. Fourth, our analyses were restricted to individuals of predominantly European ancestry, which limits generalizability. Studies in more ethnically diverse and under-represented populations are needed to ensure broader applicability. Fifth, despite adjusting for a wide array of covariates, residual confounding and the potential for reverse causality, particularly for long sleep as a marker of subclinical illness, cannot be fully excluded. Moreover, circadian misalignment and sleep fragmentation were not directly assessed, which may influence the observed associations between sleep duration and organ-specific biological ageing. Sixth, future research needs to extend the Sleep Chart across the lifespan to better capture dynamic patterns of sleep duration beyond adulthood.

Do naps count?

I sleep about 10-12 hours a day and very irregular. Probably bad but anyway there's so many things that are bad for us.

I can't really worry about this stuff anymore. Whatever you do in this day and age, there will be some expert ready to berate you for it. Meanwhile the actual huge issues like PFAS, fine particle pollution and global warming that cause lots of health issues are completely ignored.

Also, this kind of study tends to have unclear causation. For example people like me who sleep a lot and irregularly could be doing so because of other issues like mental health problems, irregular work hours, stress, respiratory issues (I have apnea myself so I never really sleep well) which themselves have negative health effects. Making it possible the correlation is not causal.