Correlation between changes of body fat distribution and insulin resistance after Roux-en-Y gastric bypass

Abstract

Objective To investigate the effect of laparoscopic Roux-en-Y gastric bypass(LYGB) on body fat distribution, and relationship between the changes of body fat distribution and improvement of insulin resistance. Methods A total of 65 patients with type 2 diabetes who underwent LYGB were selected for a retrospective analysis.Metabolic parameters, anthropometric measurements, body composition and fat distribution measured by dual-energy X-ray absorptiometry(DEXA) were collected separately before and 6 months post LYGB. All data of pre- and postoperation were compared with pair t test, Pearson correlation analysis was used to evaluate correlation of two variables. Results Weight, body mass index, waist circumference, waist-to-hip ratio, triglyceride, fasting plasma glucose, fasting insulin and homeostatic model assessment for insulin resistance (HOMA-IR) were significantly decreased in 6 months after surgery (P<0.05). Total fat mass, body fat mass of trunk, upper and lower limbs decreased significantly (P<0.05). Percent fat mass at the whole body, Android region, upper and lower limbs decreased significantly (P<0.05). After 6 months postoperatively, abdominal obesity indices waist circumfernce decreased from (98.10±13.03) cm to (91.60±7.68) cm (P<0.01) and percent fat mass at the Android region decreased from (35.71±10.24)% to (29.44±12.11) % (P<0.05), HOMA-IR decreased from 3.62±5.18 to 1.79±1.52 (P<0.05). The improvement of postoperative insulin resistance is positively correlated with the changes in waist circumference (P<0.01) and percent fat mass of Android region (P<0.05). Conclusions The body fat distribution changes after LYGB, change of abdominal fat distribution is positively correlated to the improvement of insulin resistance. Key words: Gastric bypass; Diabetes mellitus, type 2; Body fat distribution; Insulin resistance