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Effects of Two-Week Sleep Extension on Glucose Metabolism in Chronically Sleep-Deprived Individuals
Randomized crossover sleep hygiene + extension versus continued habitual short sleep in chronically sleep-restricted adults: only participants who objectively extended sleep beyond 6 hours per night showed improved HOMA-IR, insulinogenic index, and disposition index in per-protocol analysis.
Design
- Randomized crossover in chronically short-sleeping adults (mean baseline ~5.6 h/night)
- Arms: sleep hygiene + extension vs control (maintain habitual sleep)
Metabolic outcomes (per-protocol subgroup sleeping >6 h during extension)
- HOMA-IR: adjusted mean difference −0.50 (95% CI −0.89 to −0.11; P = .013)
- Insulinogenic index: +0.39 (95% CI 0.15–0.63; P = .001)
- Disposition index (β-cell function): +1.07 (95% CI 0.17–1.97; P = .02)
Evidence hygiene
- Benefits concentrated in the subgroup that actually lengthened sleep—adherence is the active ingredient.
Publication
So-Ngern A, Chirakalwasan N, Saetung S, et al. J Clin Sleep Med. 2019 May 15;15(5):711-718. PMID 31053213; PMC6510689.
Outcomes
- Per-protocol participants who extended objective sleep to >6 h/night: HOMA-IR improved with adjusted mean difference −0.50 (95% CI −0.89 to −0.11; P=0.013) vs control period.
- Same per-protocol subgroup: insulinogenic index +0.39 (95% CI 0.15–0.63; P=0.001) and disposition index +1.07 (95% CI 0.17–1.97; P=0.02) versus control period.