Moderate chronic sleep perturbation impairs glucose and lipid homeostasis in rats.

STUDY OBJECTIVES:Sleep deprivation is a potential risk factor for metabolic diseases, including obesity and type 2 diabetes. We evaluated the impacts of moderate chronic sleep deprivation on glucose and lipid homeostasis in adult rats. METHODS:Wistar rats (both sexes) were sleep-perturbed daily for two hours at the early (06:00-08:00) and the late light cycle (16:00-18:00) five days a week (except weekends) for four weeks. RESULTS:Sleep perturbation (SP) resulted in reduced body weight gain in both sexes, associated with altered food intake and reduced adiposity. SP did not alter the short- or long-term memories or cause anxiogenic behavior. No major changes were observed in the plasma insulin, leptin, triacylglycerol, non-esterified fatty acids and blood glucose upon SP. After SP, females exhibited a transitory glucose intolerance, while males became glucose intolerant at the end of the experimental period. Male rats also developed higher insulin sensitivity at the end of the SP protocol. Morphometric analyses revealed no changes in hepatic glycogen deposition, pancreatic islet mass, islet-cell distribution, or adrenal cortex thickness in SP rats from both sexes, except for lower adipocyte size compared with controls. We did not find homogeneous changes in the relative expression of circadian and metabolic genes in muscle or hepatic tissues from the SP rats. CONCLUSIONS:Moderate chronic SP reduces visceral adiposity and causes glucose intolerance with a more pronounced impact on male rats, reinforcing the metabolic risks of exposure to sleep disturbances.