Long sleep durations and sleep disorders were associated with increased all-cause mortality, especially among individuals with impaired glucose regulation, while short sleep duration was associated with increased mortality risk only in people with normoglycaemia.
Long sleep duration (more than 8 hours) was associated with increased all-cause mortality risk across all glycaemic groups, with progressively stronger associations from normoglycaemia to diabetes.
Short sleep duration (less than 6 hours) was associated with increased all-cause mortality only in individuals with normoglycaemia, not in those with prediabetes or diabetes.
Sleep disorders were associated with increased all-cause mortality among individuals with prediabetes and diabetes, but not reported as significant for normoglycaemia.
The study cohort included 534,238 participants from the Taiwan MJ cohort enrolled between 1996 and 2022, with 52,208 deaths recorded over a median follow-up of 19 years.
Cox proportional hazards regression models were used to evaluate associations between sleep patterns and all-cause mortality risk across glycaemic status groups.
This research suggests that the relationship between sleep patterns and risk of death is not the same for everyone — it differs depending on a person's blood sugar status. Using data from over 534,000 people in Taiwan followed for a median of 19 years, the study found that sleeping more than 8 hours per night was linked to higher risk of death in all groups (those with normal blood sugar, prediabetes, and diabetes), with the risk being highest among people with diabetes. Sleeping less than 6 hours was only linked to higher mortality in people with normal blood sugar, not in those with prediabetes or diabetes. Having a sleep disorder was associated with increased mortality risk specifically in people with prediabetes or diabetes. These findings suggest that the health consequences of poor sleep may be amplified when combined with blood sugar problems. The progressively stronger association between long sleep and mortality across normal blood sugar, prediabetes, and diabetes groups points to a possible interaction between glucose regulation and sleep health. Sleep disorders added additional risk on top of already elevated mortality risk in people with impaired glucose control. This research suggests that assessing sleep patterns could be a useful tool for identifying individuals at higher health risk, particularly those with prediabetes or diabetes. However, because this is an observational study, it cannot prove that poor sleep directly causes earlier death — other unmeasured factors could be involved. The findings highlight the importance of considering both sleep health and metabolic health together rather than in isolation.
Xu A, Zhi C, Wang S, Cai F, Zhang Z, Chu D, et al.. (2026). Association of sleep and glycaemic status with all-cause mortality: a prospective cohort study.. Journal of global health. https://doi.org/10.7189/jogh.16.04002