Effects of Sleeve Gastrectomy and Treadmill Exercise on Skeletal Muscle and Ectopic Fat in High-Fat Diet-Induced Obese Rats

A high-fat diet (HFD) can lead to obesity and skeletal muscle atrophy. Sleeve gastrectomy (SG) improves obesity and increases skeletal muscle mass. This study examined whether SG prevented skeletal muscle atrophy in a diet-induced rat obesity rat model. First, 8-week-old male Sprague-Dawley rats underwent surgical (sham-operated or SG) and dietary (standard, high-fat diet, or same pair feeding as SG [PF]) interventions without exercise. In the second experiment, treadmill exercise was added for 4 weeks post-SG (SG + Ex). In the third experiment, rats received an adiponectin receptor agonist (AdipoRon) injection. The HFD induced weight gain and decreased muscle fiber area. SG + Ex reversed these levels, followed by increases in adiponectin in the blood and skeletal muscle and myoblast determination protein 1 (MyoD) and decreased peri-muscular adipose tissue (PMAT) mass, but SG alone did not. No similar changes were observed in the PF group, with or without exercise. Injection of AdipoRon had a similar effect on skeletal muscle and PMAT as SG + Ex. The combination of SG and exercise, but not calorie restriction alone, had better impacts on skeletal muscle and PMAT than SG or exercise alone.