Bariatric surgery in obesity: Changes of glucose and lipid metabolism correlate with changes of fat mass

Abstract Background and Aim Bariatric surgery induces significant weight loss and improves glucose metabolism in obese patients (BMI > 35 kg/m 2 ). Our aim was to compare restrictive (LAGB, laparoscopic gastric banding) and malabsorptive approaches (BIBP, biliary-intestinal bypass) on the loss of fat-free mass (FFM), fat mass (FM), and on changes of glucose and lipid metabolism. Methods and Results Body composition (bio-impedance analysis, BIA), blood glucose (BG), insulin, triglycerides, total- and HDL-cholesterol, liver enzymes (AST and ALT) were measured at baseline and 1 year after surgery in patients undergoing LAGB, BIBP, and in diet-treated control patients. In the main study, with patients matched for initial BMI (43–55 kg/m 2 , LAGB = 24, BIBP = 12, controls = 6), decreases of BMI, FM, BG and cholesterol were greater in patients with BIBP than with LAGB ( p Conclusion BMI, FM, BG and cholesterol decrease more with malabsorptive than with restrictive surgery, while FFM, insulin, HOMA-IR and triglycerides decrease in a similar way. FFM loss is of low entity. Changes of glucose and lipid metabolism are proportional to a decrease of fat mass but not of fat-free mass.