Differences in Insulin Secretion and Sensitivity in Short-Sleep Insomnia

Abstract

Short-sleep insomnia is associated with increased risk of diabetes. The role of altered insulin secretion and action in this association is poorly understood. Observational study. Academic clinical research center. Nondiabetic individuals with insomnia (mean [standard deviation] age 48 [9] y, body mass index 25.6 [3.9] kg/m(2)) with ≤ 6 h (short sleep, n = 14) and > 6 h of sleep (n = 14) during overnight laboratory polysomnography. Standard oral glucose testing was used to assess glucose tolerance, beta-cell function (homeostasis model assessment [HOMA-B]; second-phase insulin secretion) and insulin resistance (HOMA-IR; insulin sensitivity index). There was no significant difference in hemoglobin A1C and fasting or 2-h blood glucose concentrations between sleep groups. Short-sleep insomnia sufferers had lower fasting and postchallenge serum insulin concentrations associated with lower estimates of fasting and glucose-stimulated insulin secretion, and increased insulin sensitivity. Individuals with short-sleep insomnia appear to have higher indices of systemic insulin sensitivity and secrete less insulin without changes in overall glucose tolerance.