Bariatric surgery improved insulin sensitivity within 1 week independent of caloric intake, with RYGB and LAGB leading to 5.5 kg and 5.2 kg weight loss vs 2.1 kg with very low caloric intake alone.
Cohort (n=20)
Does bariatric surgery (LAGB or RYGB) improve insulin sensitivity independently of caloric restriction in nondiabetic obese subjects?
Bariatric surgery, particularly Roux-en-Y gastric bypass, improves insulin sensitivity within 1 week independently of caloric restriction in nondiabetic obese subjects.
OBJECTIVE: Bariatric surgery has been shown to have important long-term metabolic effects resulting in enhanced insulin sensitivity and improved glucose tolerance in patients with type 2 diabetes. The contribution of reduced caloric intake to these beneficial effects of surgery remains unclear. The aim of this study was to compare the short-term effects (1 week) of bariatric surgical procedures with a very low caloric intake (VLCI) on insulin sensitivity (IS) and insulin secretion (ISR) in nondiabetic obese subjects. RESEARCH DESIGN AND METHODS: ) were admitted to the clinic for 1 week. At baseline and 1 week after VLCI (600 kcal/day), subjects received a hyperinsulinemic-euglycemic clamp with tracer infusion to quantify endogenous glucose production (EGP), lipolysis (rate of appearance of glycerol RaGlycerol), peripheral insulin sensitivity (insulin-stimulated glucose disposal M value divided by the steady-state plasma insulin concentration M/I), hepatic insulin sensitivity (Hep-IS = 1/(EGP ⋅ insulin)), and adipose insulin sensitivity (Adipo-IS = 1/(RaGlycerol ⋅ insulin)). An intravenous glucose bolus was administered at the end of the insulin clamp to measure ISR and β-cell function (disposition index DI). Approximately 3 months later, patients were admitted for laparoscopic adjustable gastric banding (LAGB) (n = 10) or Roux-en-Y gastric bypass (RYGB) (n = 10), and were restudied 1 week after surgery under the same caloric regimen (600 kcal/day). RESULTS: After 1 week of VLCI, patients lost 2.1 kg without significant changes in Hep-IS, Adipo-IS, M/I, or DI. RYGB and LAGB led to greater weight loss (5.5 and 5.2 kg, respectively) and to significant improvement in Hep-IS, EGP, and lipolysis. Only RYGB improved Adipo-IS and M/I. No change in ISR or DI was observed in either surgical group. CONCLUSIONS: Bariatric surgery improves IS within 1 week. These metabolic effects were independent of caloric intake and more pronounced after RYGB compared with LAGB.
Gastaldelli et al. (Mon,) conducted a cohort in Nondiabetic obesity (n=20). Laparoscopic adjustable gastric banding (LAGB) or Roux-en-Y gastric bypass (RYGB) vs. Very low caloric intake (VLCI) was evaluated on Insulin sensitivity (IS) and insulin secretion (ISR). Bariatric surgery improved insulin sensitivity within 1 week independent of caloric intake, with RYGB and LAGB leading to 5.5 kg and 5.2 kg weight loss vs 2.1 kg with very low caloric intake alone.
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