Partial Sleep Restriction Decreases Insulin Sensitivity in Type 1 Diabetes

Abstract

OBJECTIVE Sleep restriction results in decreased insulin sensitivity and glucose tolerance in healthy subjects. We hypothesized that sleep duration is also a determinant of insulin sensitivity in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS We studied seven patients (three men, four women) with type 1 diabetes: mean age 44 ± 7 years, BMI 23.5 ± 0.9 kg/m², and A1C 7.6 ± 0.3%. They were studied once after a night of normal sleep duration and once after a night of only 4 h of sleep. Sleep characteristics were assessed by polysomnography. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp studies with an infusion of [6,6-²H₂]glucose. RESULTS Sleep duration was shorter in the night with sleep restriction than in the unrestricted night (469 ± 8.5 vs. 222 ± 7.1 min, P = 0.02). Sleep restriction did not affect basal levels of glucose, nonesterified fatty acids (NEFAs), or endogenous glucose production. Endogenous glucose production during the hyperinsulinemic clamp was not altered during the night of sleep restriction compared with the night of unrestricted sleep (6.2 ± 0.8 vs. 6.9 ± 0.6 μmol · kg lean body mass⁻¹ · min⁻¹, NS). In contrast, sleep restriction decreased the glucose disposal rate during the clamp (25.5 ± 2.6 vs. 22.0 ± 2.1 μmol · kg lean body mass⁻¹ · min⁻¹, P = 0.04), reflecting decreased peripheral insulin sensitivity. Accordingly, sleep restriction decreased the rate of glucose infusion by ∼21% (P = 0.04). Sleep restriction did not alter plasma NEFA levels during the clamp (143 ± 29 vs. 133 ± 29 μmol/l, NS). CONCLUSIONS Partial sleep deprivation during a single night induces peripheral insulin resistance in these seven patients with type 1 diabetes. Therefore, sleep duration is a determinant of insulin sensitivity in patients with type 1 diabetes.