Hepatic and Peripheral Insulin Sensitivity and Diabetes Remission at 1 Month After Roux-en-Y Gastric Bypass Surgery in Patients Randomized to Omentectomy

Abstract

OBJECTIVEEarly after Roux-en-Y gastric bypass (RYGB), there is improvement in type 2 diabetes, which is characterized by insulin resistance. We determined the acute effects of RYGB, with and without omentectomy, on hepatic and peripheral insulin sensitivity. We also investigated whether preoperative diabetes or postoperative diabetes remission influenced tissue-specific insulin sensitivity after RYGB.RESEARCH DESIGN AND METHODSWe studied 40 obese (BMI 48 ± 8 kg/m2) participants, 17 with diabetes. Participants were randomized to RYGB alone or in conjunction with omentectomy. Hyperinsulinemic-euglycemic clamps with isotopic-tracer infusion were completed at baseline and at 1 month postoperatively to assess insulin sensitivity.RESULTSParticipants lost 11 ± 4% of body weight at 1 month after RYGB, without an improvement in peripheral insulin sensitivity; these outcomes were not affected by omentectomy, preoperative diabetes, or remission of diabetes. Hepatic glucose production (HGP) and the hepatic insulin sensitivity index improved in all subjects, irrespective of omentectomy (P ≤ 0.001). Participants with diabetes had higher baseline HGP values (P = 0.003) that improved to a greater extent after RYGB (P = 0.006). Of the 17 participants with diabetes, 10 (59%) had remission at 1 month. Diabetes remission had a group × time effect (P = 0.041) on HGP; those with diabetes remission had lower preoperative and postoperative HGP.CONCLUSIONSPeripheral insulin sensitivity did not improve 1 month after RYGB, irrespective of omentectomy, diabetes, or diabetes remission. Hepatic insulin sensitivity improved at 1 month after RYGB and was more pronounced in patients with diabetes. Improvement in HGP may influence diabetes remission early after RYGB.

Early Enhancements of Hepatic and Later of Peripheral Insulin Sensitivity Combined With Increased Postprandial Insulin Secretion Contribute to Improved Glycemic Control After Roux-en-Y Gastric Bypass

“…Also, at 1 week after surgery, glucose disposal could still be influenced by postoperative stress (40,41), possibly counteracting a beneficial effect of surgery. However, lack of improvement in glucose disposal is in line with other clamp studies performed 4 weeks after RYGB when surgical stress has abated (17,42). Elevated FA levels also act to reduce glucose disposal (43,44) and were seen in both groups 1 week after RYGB, in accordance with previous studies early after RYGB (12,22,42) and calorie restriction (22).…”

“…HOMA-IR primarily reflects hepatic insulin resistance, while the hyperinsulinemic clamp estimates peripheral insulin sensitivity (16); this could indicate a differential effect of RYGB on hepatic and peripheral insulin sensitivity (6). Endogenous glucose production has not been assessed immediately after RYGB, but one study showed reductions after 1 month (17), whereas another did not detect changes at 2 weeks (12).…”

Roux-en-Y gastric bypass increases hepatic and peripheral insulin sensitivity in rats with type 2 diabetes mellitus

“…The results obtained showed that, overall, skeletal muscle insulin sensitivity had improved slightly 2 weeks after RYGB, and a significant increase in M-value was detected until 4 weeks after RYGB. This is consistent with the report by Dunn et al, involving obese patients with or without type 2 diabetes, which showed that hepatic tissue may contribute to the early metabolic improvements after RYGB surgery [22]. The severe insulin resistance in skeletal muscle was not readily normalized in contrast to the hepatic insulin resistance soon after RYGB surgery.…”

Clinical trial demonstrates exercise following bariatric surgery improves insulin sensitivity

“…A 50% dextrose bolus (0.3 g/kg body mass) was administered after fasting samples were collected, and insulin (0.025 U/kg body mass) was then injected at minute 20. Blood samples were collected in EDTA tubes at minutes 2,3,4,5,6,8,10,12,14,16,19,22,23,24,25,27,30,40,50,60,70,80,90,100,120,140,160, and 180. Plasma samples were stored at −80°C until later analyses.…”