Unlock better sleep: even mild lack of sleep impairs insulin sensitivity | Prof Luigi Fontana
Unlock better sleep; even mild lack of sleep impairs insulin sensitivity | Prof Luigi Fontana A recent small randomized clinical trial involving 38 women, aged 20 to 75, revealed that restricting sleep to around 6 hours per night led to notable reductions in insulin sensitivity and increased plasma insulin after 6 weeks. Even when accounting for changes in body fat, these effects persisted. The trial, conducted in a crossover design with two 6-week phases, demonstrated elevated fasting insulin and HOMA-IR values in those with reduced sleep. Postmenopausal women exhibited a more pronounced impact on fasting insulin and HOMA-IR compared to premenopausal women. Despite changes in adiposity, the study suggests that curtailing sleep to 6.2 hours per night mildly but significantly impairs insulin sensitivity, emphasizing insufficient sleep as a potential contributor to aging and chronic diseases, given the established link between excess insulin and the PI3K AKT motor pathway associated with aging and chronic diseases. The Diabetes Care study involved 38 women, including 11 postmenopausal, free of cardiometabolic diseases, with actigraphy-confirmed habitual total sleep time of 7–9 hours per night. In this randomized crossover study with two 6-week phases, women were assigned to either maintain adequate sleep or experience a reduction of 1.5 hours per night. Assessments included plasma glucose and insulin levels, HOMA-IR values, total area under the curve for glucose and insulin, Matsuda index, and disposition index from an oral glucose tolerance test. Adjusted linear models showed increased fasting insulin (β = 6.8 ± 2.8 pmol/L; P = 0.016) and HOMA-IR (β = 0.30 ± 0.12; P = 0.016) values in women with sleep restriction by an average of 1.34 ± 0.04 hours per night compared to those with normal sleep. The impact on HOMA-IR was more prominent in postmenopausal women than premenopausal women (β = 0.45 ± 0.25 vs. β = 0.27 ± 0.13, respectively; P for interaction = 0.042). Adiposity changes did not mediate the effects of sleep restriction on glucose metabolism across the entire sample when included as a covariate. In conclusion, the trial indicates that reducing sleep to 6.2 hours per night, mirroring the median sleep duration of U.S. adults with short sleep, mildly yet significantly impairs insulin sensitivity over 6 weeks, irrespective of adiposity. These findings underscore insufficient sleep as a potential factor contributing to aging and cancer.
Unlock better sleep; even mild lack of sleep impairs insulin sensitivity | Prof Luigi Fontana A recent small randomized clinical trial involving 38 women, aged 20 to 75, revealed that restricting sleep to around 6 hours per night led to notable reductions in insulin sensitivity and increased plasma insulin after 6 weeks. Even when accounting for changes in body fat, these effects persisted. The trial, conducted in a crossover design with two 6-week phases, demonstrated elevated fasting insulin and HOMA-IR values in those with reduced sleep. Postmenopausal women exhibited a more pronounced impact on fasting insulin and HOMA-IR compared to premenopausal women. Despite changes in adiposity, the study suggests that curtailing sleep to 6.2 hours per night mildly but significantly impairs insulin sensitivity, emphasizing insufficient sleep as a potential contributor to aging and chronic diseases, given the established link between excess insulin and the PI3K AKT motor pathway associated with aging and chronic diseases. The Diabetes Care study involved 38 women, including 11 postmenopausal, free of cardiometabolic diseases, with actigraphy-confirmed habitual total sleep time of 7–9 hours per night. In this randomized crossover study with two 6-week phases, women were assigned to either maintain adequate sleep or experience a reduction of 1.5 hours per night. Assessments included plasma glucose and insulin levels, HOMA-IR values, total area under the curve for glucose and insulin, Matsuda index, and disposition index from an oral glucose tolerance test. Adjusted linear models showed increased fasting insulin (β = 6.8 ± 2.8 pmol/L; P = 0.016) and HOMA-IR (β = 0.30 ± 0.12; P = 0.016) values in women with sleep restriction by an average of 1.34 ± 0.04 hours per night compared to those with normal sleep. The impact on HOMA-IR was more prominent in postmenopausal women than premenopausal women (β = 0.45 ± 0.25 vs. β = 0.27 ± 0.13, respectively; P for interaction = 0.042). Adiposity changes did not mediate the effects of sleep restriction on glucose metabolism across the entire sample when included as a covariate. In conclusion, the trial indicates that reducing sleep to 6.2 hours per night, mirroring the median sleep duration of U.S. adults with short sleep, mildly yet significantly impairs insulin sensitivity over 6 weeks, irrespective of adiposity. These findings underscore insufficient sleep as a potential factor contributing to aging and cancer.