Before and After StudyUsing the hyperinsulinemic euglycemic clamp to assess insulin sensitivity at 3Â months following Roux-en-Y gastric bypass surgery in type 2 diabetes patients with BMI <35Â kg/m2 in China

- The hyperinsulinemic euglycemic clamp is recognised as the gold standard for evaluation of peripheral insulin sensitivity.
- The hyperinsulinemic euglycemic clamp is limited in clinical application.
- It is the first report about the hyperinsulinemic euglycemic clamp in metabolic surgery in Chinese patients.
- We found that insulin sensitivity in mildly obese patients with T2DM can improve after RYGB.

BackgroundThe aim of this study was to describe short-time effect of Roux-en-Y gastric bypass (RYGB) on insulin sensitivity (IS) of Chinese diabetes patients with body mass index (BMI) <35 kg/m2 by hyperinsulinemic euglycemic clamp.Materials and methodsWe studied 15 type 2 diabete mellitus (T2DM) patients with BMI <35 kg/m2, who underwent laparoscopical Roux-en-Y gastric bypass (LRYGB). Hyperinsulinemic-euglycemic clamp were performed at baseline and at 3 months after LRYGB.ResultsThe glucose disposal rate (M value) increased significantly at 3 months after RYGB (from 3.36 ± 1.26 mg kg−1 min−1 to 6.30 ± 1.3 mg kg−1 min−1, p < 0.001). The time to reach euglycemia at the hyperinsulinemic euglycemic clamp reduced remarkably from baseline to 3 months after RYGB (from 114.40 ± 6.11 min to 97.93 ± 8.57 min, p < 0.001). There was a marked reduction in value of HOMA-IR (from 4.47 ± 2.20 mg kg−1 min−1 to 2.10 ± 0.75 mg kg−1 min−1, p < 0.001). The parameters of body fat distribution (body weight, BMI, waist circumference, waist to hip radio) changed obviously after surgery. RYGB caused a significant improvement in fasting and postprandial plasma glucose and insulin, HbAc1. Preoperative M value and the time to reach steady-state correlated with changes of M and the time to reach steady-state at 3 months after RYGB.ConclusionPeripheral and hepatic IS improved remarkably at 3 months following RYGB, as an important mechanism for early improvement in T2DM patients with low BMI. And the time to reach euglycemia at the hyperinsulinemic euglycemic clamp may be an useful index of assessing insulin sensitivity. It is more reasonal to combine the time to reach euglycemia with M value for assessing IS.