Chronic Insufficient Sleep in Women Impairs Insulin Sensitivity Independent of Adiposity Changes: Results of a Randomized Trial.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 37955852 · doi:10.2337/dc23-1156
What was done
Researchers conducted a randomized crossover trial in 38 women aged 20–75 years (11 postmenopausal) without cardiometabolic disease and with actigraphy-confirmed baseline habitual sleep of 7–9 hours per night. Participants completed two 6-week phases: adequate sleep maintenance and 1.5 hours per night sleep restriction. Investigators evaluated fasting glucose and insulin, HOMA-IR, and oral glucose tolerance test metrics (AUC for glucose and insulin, Matsuda index, disposition index), adjusting for baseline values and assessing whether changes in adiposity mediated the outcomes.
What was found
Actigraphy confirmed total sleep time was reduced by 1.34 ± 0.04 hours per night during sleep restriction compared to adequate sleep (P < 0.0001). Sleep restriction resulted in significant increases in fasting insulin (β = 6.8 ± 2.8 pmol/L; P = 0.016) and HOMA-IR (β = 0.30 ± 0.12; P = 0.016). The increase in HOMA-IR was more pronounced in postmenopausal women than in premenopausal women (β = 0.45 ± 0.25 vs. β = 0.27 ± 0.13; P for interaction = 0.042). Changes in adiposity did not mediate these effects.
Why it matters
This trial demonstrates that prolonged, real-world levels of mild sleep restriction directly worsen insulin resistance in women, an effect that is not driven by changes in body fat and is more pronounced after menopause.
Limits
The study had a small sample size (n = 38 total, with only 11 postmenopausal women) and was restricted exclusively to women without baseline cardiometabolic disease. While fasting insulin and HOMA-IR changes are quantified, the abstract does not report specific numerical results for the dynamic oral glucose tolerance test outcomes.
Cited by
- supports Six weeks of mild sustained sleep restriction (reduced by 1.5 hours per night to roughly 6 hours) in free-living individuals increases insulin resistance, reduces insulin sensitivity, and increases blood pressure.