A Preliminary Research On The Effectiveness And Mechanism Of Gastric Bypass Surgery As A Treatment For Type-2Diabetes

Objective: This research on non obese type2diabetes mellitus(T2DM) rats underwent gastric bypass surgery (GBP), test blood glucose、serum insulin、gastric inhibitory polypeptide (GIP)、glucagon like peptide-1(GLP-1) levels, to observe the efficacy and investigate the mechanism ofGBP as a treatment for Type-2diabetes.Methods:60GK rats were randomly divided into3groups,20rats ineach group. Divided into GBP operation group (group A), sham operationgroup (group B) and control group (group C), rats in group A underwentGBP, B group rats end to end anastomosis in situ and in the same part of GBP,before and after the operation, test rats of each group in the postoperativefirst、second、fourth and eighth week，including fasting and after meal bloodglucose、serum insulin、GIP、GLP-1levels.Results: The fasting blood glucose levels of the rats in the A groupbegin to decline in postoperative first week; With same group compared inpreoperative and postoperative first、second week，The fasting and postprandialblood glucose levels of the rats in the A group were significant decline inpostoperative fourth and eighth week (P<0.01); In the postoperative first、second、fourth and eighth week, the fasting and postprandial blood glucoselevels of the rats in the A group were significant lower than the levels of thesame time points in the other two groups (P<0.01); The postprandial insulinlevels of the rats in the A group begin to increase in postoperative first week.With same group compared in preoperative and postoperative first、secondweek，The fasting and postprandial insulin levels of the rats in the A group were significant increase in postoperative fourth and eighth week (P<0.01); In thepostoperative first、second、fourth and eighth week,the fasting and postprandialinsulin levels of the rats in the A group were significant higher than the levelsof the same time points in the other two groups (P<0.01); The postprandial GIPlevels of the rats in the A group begin to decline in postoperative first week;With same group compared in preoperative and postoperative first、secondweek，The fasting and postprandial GIP levels of the rats in the A group weresignificant decline in postoperative fourth and eighth week (P<0.01); In thepostoperative first、second、fourth and eighth week,the fasting and postprandialGIP levels of the rats in the A group were significant lower than the levels ofthe same time points in the other two groups (P<0.01); The postprandial GLP-1levels of the rats in the A group begin to increase in postoperative first week.With same group compared in preoperative and postoperative first、secondweek，The fasting and postprandial GLP-1levels of the rats in the A group weresignificant increase in postoperative fourth and eighth week (P<0.01); In thepostoperative first、second、fourth and eighth week,the fasting and postprandialGLP-1levels of the rats in the A group were significant higher than the levelsof the same time points in the other two groups (P<0.01); The fasting andpostprandial blood glucose、serum insulin、GIP、GLP-1levels of the rats inthe B group and C group are no significant change in the process of experiment(P>0.05).Conclusion:1. Fasting and postprandial blood glucose levels significant decrease in thepostoperation of GBP, fasting and postprandial serum insulin levels significantincrease, so the GBP has good therapeutic effect for T2DM.2. GBP has good therapeutic effect for T2DM is exact, and the therapeuticeffect of surgery for diabetes is direct and independent, does not depend on the weight loss after the surgery.3. GBP can reduce the the stimulation of food to proximal duodenum andjejunum, thereby reducing secretion of GIP, may make the insulin resistance ofthe surrounding tissue to release, so the blood glucose level declines, T2DM tobe relieved significantly.4. Food into the terminal ileum and colon in advance in the postoperationof GBP, it causes the secretion of GLP-1increasing, the decreasing of bloodglucose level may be related to the increased secretion and the correspondingphysiological function of GLP-1.