A large observational study published in BMJ Open Diabetes Research & Care suggests that the ideal sleep duration to reduce the risk of insulin resistance—an early stage of type 2 diabetes—might be 7 hours and 18 minutes per night. The study also found that catching up on sleep over the weekend could increase the risk of impaired glucose metabolism for those who sleep more than this optimal amount.
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Prior research indicated a strong link between sleep duration and risks of insulin resistance and diabetes, but the influence of weekend catch-up sleep was less clear. The study utilized the estimated glucose disposal rate (eGDR) as a measure of insulin resistance, with lower rates indicating a higher risk.
The study analyzed data from 23,475 participants, aged 20 to 80, from the National Health and Nutrition Examination Survey (NHANES) collected between 2009 and 2023. Of these, 10,817 had reported their weekend sleep durations. Weekend catch-up sleep was categorized as none, up to 1 hour, 1 to 2 hours, and more than 2 hours. Researchers calculated eGDR using waist circumference, fasting blood glucose, and blood pressure.
On average, participants had an eGDR of 8.23 and reported sleeping 7 hours and 30 minutes on weekdays, with over 48% indicating they engaged in catch-up sleep on weekends, averaging 8 hours.
The analysis revealed an inverted U-shaped relationship between sleep duration and eGDR, pinpointing 7 hours and 18 minutes as the optimal sleep amount. Sleeping less than this resulted in a higher eGDR, while exceeding it led to lower eGDR, particularly for women and participants aged 40 to 59.
Further analysis indicated that individuals sleeping less than the optimal amount during the week benefitted from 1 to 2 hours of weekend catch-up sleep, as it was linked to a higher eGDR compared to no catch-up sleep. Conversely, those who slept more than the ideal duration during the week showed lower eGDR when catching up on sleep for over 2 hours on weekends, after controlling for factors such as lifestyle and education.
The researchers emphasized a bidirectional relationship between sleep and metabolism, noting that poor glycemic control could lead to both short and extended sleep durations, creating a cycle where metabolic issues disrupt normal sleep.
As an observational study, definitive conclusions about cause-and-effect relationships cannot be established. The researchers highlighted the reliance on self-reported sleep data and acknowledged the possibility that disrupted glucose metabolism might negatively impact sleep rather than the reverse.
The findings suggest that understanding sleep patterns, particularly during weekends, could be crucial for metabolic health management in diabetes care.
Research Reference: Association of weekday sleep duration and estimated glucose disposal rate: the role of weekend catch-up sleep. Doi:10.1136/bmjdrc-2025-005692
Funding: National Natural Science Foundation of China.