Impaired insulin signaling in human adipocytes after experimental sleep restriction: a randomized, crossover study

Ann Intern Med. 2012 Oct 16;157(8):549-57. doi: 10.7326/0003-4819-157-8-201210160-00005.


Background: Insufficient sleep increases the risk for insulin resistance, type 2 diabetes, and obesity, suggesting that sleep restriction may impair peripheral metabolic pathways. Yet, a direct link between sleep restriction and alterations in molecular metabolic pathways in any peripheral human tissue has not been shown.

Objective: To determine whether sleep restriction results in reduced insulin sensitivity in subcutaneous fat, a peripheral tissue that plays a pivotal role in energy metabolism and balance.

Design: Randomized, 2-period, 2-condition, crossover clinical study.

Setting: University of Chicago Clinical Resource Center.

Participants: Seven healthy adults (1 woman, 6 men) with a mean age of 23.7 years (SD, 3.8) and mean body mass index of 22.8 kg/m(2) (SD, 1.6).

Intervention: Four days of 4.5 hours in bed or 8.5 hours in bed under controlled conditions of caloric intake and physical activity.

Measurements: Adipocytes collected from subcutaneous fat biopsy samples after normal and restricted sleep conditions were exposed to incremental insulin concentrations. The ability of insulin to increase levels of phosphorylated Akt (pAkt), a crucial step in the insulin-signaling pathway, was assessed. Total Akt (tAkt) served as a loading control. The insulin concentration for the half-maximal stimulation of the pAkt-tAkt ratio was used as a measure of cellular insulin sensitivity. Total body insulin sensitivity was assessed using a frequently sampled intravenous glucose tolerance test.

Results: The insulin concentration for the half-maximal pAkt-tAkt response was nearly 3-fold higher (mean, 0.71 nM [SD, 0.27] vs. 0.24 nM [SD, 0.24]; P = 0.01; mean difference, 0.47 nM [SD, 0.33]; P = 0.01), and the total area under the receiver-operating characteristic curve of the pAkt-tAkt response was 30% lower (P = 0.01) during sleep restriction than during normal sleep. A reduction in total body insulin sensitivity (P = 0.02) paralleled this impaired cellular insulin sensitivity.

Limitation: This was a single-center study with a small sample size.

Conclusion: Sleep restriction results in an insulin-resistant state in human adipocytes. Sleep may be an important regulator of energy metabolism in peripheral tissues.

Primary funding source: National Institutes of Health.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / metabolism*
  • Adolescent
  • Adult
  • Cross-Over Studies
  • Dose-Response Relationship, Drug
  • Female
  • Glucose Tolerance Test
  • Humans
  • Insulin / administration & dosage
  • Insulin Resistance*
  • Male
  • Polysomnography
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction
  • Sleep Deprivation / metabolism*
  • Young Adult


  • Insulin
  • Proto-Oncogene Proteins c-akt