Mild sleep restriction acutely reduces plasma glucagon levels in healthy men

Background: Sleep loss has repeatedly been suggested to affect glucose metabolism adversely, raising the question as to the impact of subtle forms of sleep loss. Objective: The aim of the study was to assess the effects of a single night of sleep restriction to 4.5 h on endocrine parameters of glucose metabolism. Design: We conducted crossover, balanced experiments including two conditions, i.e. one night of 4.5 h and one night of 7 h of sleep. Subjects and Measurements: In 10 healthy men, circulating concentrations of insulin, C-peptide, epinephrine, norepinephrine, GH, ACTH, cortisol, and glucagon were measured after sleep and sleep restriction, respectively, during basal rest and a subsequent stepwise hypoglycemic clamp. Results: Mild sleep restriction induced a robust reduction in basal plasma glucagon levels that persisted throughout the hypoglycemic clamp (P < 0.03). Basal glucose, insulin, and C-peptide levels were unaffected by sleep restriction. Also, basal and hypoglycemia-stimulated concentrations of epinephrine, norepinephrine, and GH were unchanged after sleep restriction. Concentrations of ACTH (P < 0.05) and cortisol (P < 0.001) were reduced after sleep loss during baseline and at the start of hypoglycemia, but reached roughly comparable levels in both conditions at the end of the clamp (ACTH, P > 0.06; cortisol, P > 0.93). Conclusion: Our data show that mild restriction of nocturnal sleep to 4.5 h has a reducing effect on circulating glucagon levels. This finding provides further evidence for the notion that glucose homeostasis is sensitive to subtle changes in sleep duration.