Bariatric surgery is considered as an effective therapeutic strategy for weight loss in severe obesity. Remission of type 2 diabetes is often achieved following the surgery. We investigated whether increase in self-reported habitual physical activity associates with improved skeletal muscle insulin sensitivity and reduction of fat depots after bariatric surgery.

We assessed self-reported habitual physical activity using Baecke questionnaire in 18 diabetic and 28 non-diabetic patients with morbid obesity (median age 46 years and BMI 42.0 kg·m-2) before and six months after bariatric surgery operation. Insulin-stimulated femoral muscle glucose uptake was measured using FDG PET -method during hyperinsulinaemia. In addition, abdominal subcutaneous and visceral fat masses were quantified using magnetic resonance imaging and liver fat content using magnetic resonance spectroscopy. Also, serum pro-inflammatory cytokines were measured.

Patients lost on average 22.9% of weight during the follow-up period of six months (p<0.001). Self-reported habitual physical activity level increased (p=0.017). Improvement in skeletal muscle insulin sensitivity was observed only in those patients who reported increase in their physical activity postoperatively (p=0.018). The increase in self-reported physical activity associated with the loss of visceral fat mass (p=0.029). Postoperative self-reported physical activity correlated also positively with postoperative hepatic insulin clearance (p=0.02) and tended to correlate negatively with liver fat content (p=0.076). Postoperative self-reported physical activity also correlated negatively with serum TNFα, MCP and interleukin 6 levels.

Self-reported physical activity is associated with reversal of skeletal muscle insulin resistance following bariatric surgery as well as with the loss of visceral fat content and improved postoperative metabolism in bariatric surgery patients.