Nightly sleep of about 7 hours 18 minutes may link to lower diabetes risk

A long-term observational study of about 25,000 people reported the lowest insulin resistance near seven hours and 18 minutes of weekday sleep, while both shorter and longer sleep were associated with worse insulin sensitivity. The study was published in BMJ Open Diabetes Research & Care and authors noted it shows associations rather than cause and effect, with sleep duration self-reported.

Chinese researchers report that weekday sleep duration was linked to insulin resistance in a long-term observational study. The study followed about 25,000 participants from 2009 to 2023 and was published in BMJ Open Diabetes Research & Care. Researchers identified a "sweet spot" of about seven hours and 18 minutes of sleep per night associated with lower insulin resistance. They reported that both shorter and longer sleep durations were associated with worse insulin sensitivity. Key findings: - The study was an observational analysis conducted from 2009 to 2023 with about 25,000 participants. - The lowest measured insulin resistance occurred near seven hours and 18 minutes of weekday sleep. - Larger deviations from that benchmark — both shorter and longer sleep — were associated with worse insulin sensitivity, and weekend "catch-up" sleep did not appear to offset weekday deficits in some participants. - Authors noted the study shows associations rather than causation, and sleep duration was self-reported; the study did not measure sleep quality and other factors (diet, stress, shift work) may have influenced results. - Independent experts cited in the report described the findings as consistent with known links between sleep and metabolic regulation but emphasized that the study cannot prove sleep causes changes in insulin resistance. Summary: The study offers observational evidence that weekday sleep duration is associated with insulin resistance, with the lowest levels reported near seven hours and 18 minutes. The findings do not establish causation and are limited by self-reported sleep measures and other unmeasured factors. Undetermined at this time.