Negative energy balance induced by paradoxical sleep deprivation causes multicompartmental changes in adipose tissue and skeletal muscle

Abstract

Objective. Describe multicompartmental changes in the fat and various muscle fiber types, as well as the hormonal profile and metabolic rate induced by SD in rats. Methods. Twenty adult male Wistar rats were equally distributed into two groups: experimental group (EG) and control group (CG). The EG was submitted to SD for 96 h. Blood levels of corticosterone (CORT), total testosterone (TESTO), insulin like growth factor-1 (IGF-1), and thyroid hormones (T3 and T4) were used to assess the catabolic environment. Muscle trophism was measured using a cross-sectional area of various muscles (glycolytic, mixed, and oxidative), and lipolysis was inferred by the weight of fat depots from various locations, such as subcutaneous, retroperitoneal, and epididymal. The metabolic rate was measured using oxygen consumption ([Formula: see text]O2) measurement. Results. SD increased CORT levels and decreased TESTO, IGF-1, and T4. All fat depots were reduced in weight after SD. Glycolytic and mixed muscles showed atrophy, whereas atrophy was not observed in oxidative muscle. Conclusion. Our data suggest that glycolytic muscle fibers are more sensitive to atrophy than oxidative fibers during SD and that fat depots are reduced regardless of their location.

Figure 1

Weight variation during each 24 h of SD. Control group (CG), experimental group (EG). The data are shown as the mean ± standard deviation. (^*) Difference between EG and CG and (^#) difference from those 24 h, within the same group. P < 0.05.

Figure 2

Oxygen consumption for 24 hours after the end of SD. (-■-) Experimental group (EG) and (-●-) control group (CG). The horizontal black line shows the dark period (7:00 pm–6:59 am). Data are shown as the mean ± standard deviation; statistical significance was accepted at P < 0.05; (^*) difference between the CG at EG at each time point, (^#) mean different between light and dark periods within each group.

Figure 3

(a) Weight of subcutaneous (SC), retroperitoneal (RT), and epididymal (EPI) fat pads and (b) cross-sectional area (CSA) of the Flexor Digitorum Longus (FDL), Tibialis Anterior (TA), Gastrocnemius (GASTRO), and Soleus (SOL) muscles. The data are shown as mean ± standard deviation; statistical significance was accepted at P < 0.05. (^*) Difference between the EG and CG.