Relationship Between Changes Of Body Composition And Insulin Resistance After Laparoscopic Roux-en-Y Gastric Bypass In Obese Patients With Type 2 Diabetes Mellitus

Objective:To study the changes of body composition in obese patients with type 2diabetes mellitus after laparoscopic Roux-en-Y gastric bypass and to assess the relationship between body fat distribution and insulin resistance.Methods:This study retrospectively analyzed 13 patients who was admitted to our department and had laparoscopic Roux-en-Y gastric bypass from October 2015 to May2017.The obese patients with type 2 diabetes whose body mass index at least 27.5kg/m~2.To measure changes in body composition of different parts and regions of the patients in preoperative,3 and 6 months after surgery using DEXA.Insulin resistance index was calculated by steady-state model and to analyze the correlation between body fat distribution and insulin resistance.Results:The body mass index,total mass and total fat mass of all cases during follow-up were significantly decreased.Regional analysis showed that Fat mass and muscle mass in Android,Gynoid,upper and lower limbs were decreasing trend,and fat mass was dropped more significantly in the Android area(Δ6 months:52.24%±14.93%;t=12.855 p=0.000).The fasting blood glucose,fasting insulin,fasting C-peptide,HbA1c and HOMA-IR of patients were significantly lower than preoperative.Preoperative HOMA-IR were positively correlated with arms of FM%,legs of FM%,percent of fat mass in Android and total body FM%.The improvement of postoperative HOMA-IR was positively correlated with the change of fat content in the area of Android.Conclusion:The fat tissue decreased significantly in obese patients with T2DM who had LRYGB surgery.The insulin resistance improved as a result of the reduction of abdominal fat.The fat content of the Android zone may be a good indicator of glycemic control after LRYGB surgery.