Background: This study aims to assess the effect of laparoscopic Roux-en-Y gastric bypass (LRYGB) on body composition, fat distribution, and insulin resistance (IR) in Chinese type 2 diabetes mellitus (T2DM) patients.
Methods: Eighteen patients with T2DM were studied before and 3 months post LRYGB. Fasting plasma glucose (FPG), fasting insulin (FINS), and triglyceride (TG) were measured. IR index was determined using the homeostasis model assessment of insulin resistance (HOMA-IR). Body composition and fat distribution were measured by dual-energy X-ray absorptiometry (DXA). Fat mass (FM), muscle mass (MM), bone mineral content (BMC), and percent fat mass (%FM) at the whole body and five body regions including the arms, legs, trunk, android, and gynoid were obtained from DXA scans.
Results: HOMA-IR decreased from 5.02 at baseline to 1.43 3 months post LRYGB (p < 0.05). There was significant decrease in total and regional body mass and body fat (all p < 0.05). A significant reduction was observed in %FM at every tested body region (all p < 0.05). There was more fat mass loss (31.03 %) in android region than any other tested body region. Preoperative android %FM was significantly correlated with IR (r = 0.49, p < 0.05). Changes in android FM showed significant correlations with changes in IR, FPG, FINS, and TG (r = 0.54, 0.64, 0.54, and 0.67, respectively; all p < 0.05).
Conclusions: Body composition in Chinese T2DM patients is rebalanced after LRYGB. Reduction of central obesity can result in improvement of IR, and android fat distribution may be a good indicator of postoperative benefits for LRYGB.