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 7 patients (3 men, 4 women) with type 1 diabetes: mean age 44±7 yr, body mass index (BMI) 23.5±0.9 kg/m² and HbA1c 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 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, non-esterified fatty acids (NEFA) or endogenous glucose production. Sleep restriction did not alter endogenous glucose production during the hyperinsulinemic clamp compared to the unrestricted night (6.2±0.8 vs. 6.9±0.6 μmol.kgLBM⁻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.kgLBM⁻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 7 patients with type 1 diabetes. Therefore, sleep duration is a determinant of insulin sensitivity in patients with type 1 diabetes.