Effect Of Gastric Bypass On Goto-kakizaki Rat With Type2Diabetes Mellitus With Different Preoperative Glycosylated Haemoglobin Level

【Objective】To investigate the effect of gastric bypass on the non-obese Goto-Kakizaki(GK)rat with type II diabetes mellitus with preoperative different glycosylatedhaemoglobin level， and to find out the relationship between the level of thepreoperative glycosylated haemoglobin and glycemic control, and to explore thefeasibility of the surgery for the type II diabetes mellitus and the potentialmechanisms for the glycemic control, with a purpose to provide a theoreticalfundation and a basical material for the surgery treatment to the non-obese patientswith type2diabetes mellitus, clinical prognosis and eligibility criteria of the surgerytreatment.【Methods】Goto-Kakizaki rat is the spontaneous type2diabetic rat. We chosen the male,8～10weeks old,220～240g weight GK rats as our research object. The GK ratswere divided into three groups according to preoperative glycosylated haemoglobinlevel: Group A,(HbA1c6.5%～7.9%，n=8); Group B,(HbA1c8.0%～9.9%，n=8);Group C,(HbA1c>10%，n=8). After24hours’ fasting, no limit of drinking andanesthesia adopted pentobarbital (0.5%) by40mg/kg, taken the abdominal medianincision, then applied the whole stomach remaining, duodenum and8cm proximaljejunum bypass (Roux-en-Y gastric bypass, RYGBP). The food-intake, weight,fasting plasma glucose (FPG), and glycosylated hemoglobin (HbA1c) were analyzedbefore surgery (0week) and1,4,12,24weeks after surgery, and the efficiency of thesurgery was analyzed by comparison of all indexes at all time point. Finally, wewould find whether there was a relationship between the efficiency of the RYGBPsurgery and the level of pre-operation glycosylated hemoglobin. 【Results】1. Food-intakeThere was no significant differences can be found among the three groups rats’food-intake before the operation (P>0.05). And, no significant differences can befound among the three groups during postoperative measurement period at the sametime (P>0.05). Compared with pre-operation, the food-intake was significantlydecreased at one week after surgery during the entire postoperative measurementperiod in the three groups (P<0.01). As the age and growth increasing, food intakegradually regained and exceeded preoperative levels (P<0.01).2. WeightThere was no significant differences can be found among the three groups rats’weight before the operation (P>0.05). And, no significant differences can be foundamong the three groups rats’ weight during postoperative measurement period at thesame time (P>0.05). Compared with pre-operation, the food-intake was significantlydecreased at one week after surgery during the entire postoperative measurementperiod in the three groups (P<0.01). As the age and growth increasing, weightgradually regained and exceeded preoperative levels (P<0.01).3. Fasting blood glucose (FPG)The fasting blood glucose (FPG) in the three groups have significant differencesbefore operation (P<0.01). After operation, fasting glucose levels has no statisticallysignificant difference between Group A (pre-operation HbA1c6.5%～7.9%) andGroup B (pre-operation HbA1c8.0%～9.9%)(P>0.05). But there was statisticallysignificant difference when Group A or Group B compared to Group C (pre-operationHbA1c>10%)(P<0.05or P<0.01). Compared with pre-operation, the fasting plasmaglucose was significantly decreased at one week after surgery among three groups(P<0.01). No significant differences can be found in fasting plasma glucose betweenthe twelfth week and the twenty-fourth week of post-operation (P>0.05). The lattersingle measurement of the remaining three measurements (the first week, the fourthweek, the twelfth week of post-operation) compared with the previous measurementof fasting blood glucose were significantly decreased(P<0.01). And they were significantly reduced compared with the pre-operation fasting blood glucose (P<0.01).4. Glycosylated hemoglobin (HbA1c)Glycosylated hemoglobin (HbA1c) in the three groups have significantdifferences before operation (P<0.01). At the first week and the fourth weekpost-operation, difference of glycosylated hemoglobin level among three groups wasconsistent with pre-operation (P<0.01). Glycosylated hemoglobin levels hasstatistically significant difference between Group A (pre-operation HbA1c6.5%～7.9%) and Group B (pre-operation HbA1c8.0%～9.9%) at the twelfth week and thetwenty-fourth week of post-operation (P=0.01). Also, there was statisticallysignificant difference when Group A or Group B compared to Group C (pre-operationHbA1c>10%)(P<0.01). Compared with pre-operation, the glycosylated hemoglobinhas no significantly changes at the first week and the fourth week of post-operationamong three groups (P>0.05), but it was significantly decreased on the three groups atthe twelfth week and the twenty-fourth week of post-operation (P<0.01). The lattersingle measurement of the remaining three measurements (the fourth week, thetwelfth week and the twenty-fourth week of post-operation) compared with theprevious measurement of glycosylated hemoglobin were significantly decreased(P<0.05).5. Percentage of HbAlc up to the standardAt the postoperative twenty-fourth week, all of8rats’ glycosylated hemoglobinlevel were up to the standard in Group A; only7rats’ glycosylated hemoglobin levelwere up to the standard,1case was substandard in Group B;5rats’ glycosylatedhemoglobin level were up to the standard,3case was substandard in Group C; byFisher’s Exact Test statistical analysis, no statistically significant difference can befound among the three groups (Group A, Group B and Group C)(X2=3.545，ν=2，P=0.273). There was no statistically significant difference in percentage of HbAlc upto the standard among Group A (pre-operation HbA1c6.5%～7.9%), Group B(pre-operation HbA1c8.0%～9.9%) and Group C (pre-operation HbA1c>10%)(P>0.05). However, due to the Group A compliance rate (100.0%)> the B groupcompliance rate (87.5%)> overall compliance rate (83.3%)> the group C compliance rate (62.5%), so the order of efficacy from superior to inferior is Group A, group B,overall and Group C.6. Curative effect observation of the twenty-fourth week post-operationAt the postoperative twenty-fourth week,7rats were cured,1rats were improved,no case was invalid in Group A;5rats were cured,2rats were improved,1case wasineffective in Group B;2rats were cured,3rats were improved,3cases wereineffective in Group C; by Ridit statistical analysis, RA=1.1250, RB=1.5000, RC=2.1250，Rtotal=1.5833，so the surgical curative effect of Group A (pre-operationHbA1c6.5%～7.9%) and Group B (pre-operation HbA1c8.0%～9.9%) was moresuperior than overall surgical curative effect, while the surgical curative effect ofGroup C (pre-operation HbA1c>10%) was inferior to the overall surgical curativeeffect. Statistically significant difference can be found among the surgical curativeeffect of three groups (F=4.397, P=0.025). There was statistically significantdifference in surgical curative effect when Group A (pre-operation HbA1c6.5%～7.9%) versus Group C (pre-operation HbA1c>10%)(P<0.05). While, there was nostatistically significant difference in surgical curative effect when Group A(pre-operation HbA1c6.5%～7.9%) versus Group B (pre-operation HbA1c8.0%～9.9%) and Group B (pre-operation HbA1c8.0%～9.9%) versus Group C(pre-operation HbA1c>10%)(P>0.05).7. Complications after the operationNear after the operation,2rats occurred diarrhoea in both Group A and Group C,3rats occurred in Group B;1rat occurred delayed gastric emptying in both Group Aand Group B,2rats occurred in Group C;1rat occurred epilation in both Group Band Group C,2rats occurred in Group A; and mortality of the there groups was0%.By Fisher’s Exact Test statistical analysis, no statistically significant difference can befound among the three groups (Group A, Group B and Group C)(X2=1.659，ν=4，P=1.000). There was no statistically significant difference in complications after theoperation when Group A (pre-operation HbA1c6.5%～7.9%) versus Group C(pre-operation HbA1c>10%) or Group B (pre-operation HbA1c8.0%～9.9%) versus Group C (pre-operation HbA1c>10%) or Group A (pre-operation HbA1c6.5%～7.9%) versus Group B (pre-operation HbA1c8.0%～9.9%)(P>0.05).【Conclusions】1. Roux-en-Y gastric bypass surgery can improve diabetes-related metabolicparameters, and was not depend on change of food-intake and body weight decreased;2. There was significant improvement on the diabetes-related metabolicparameters in all of the groups, and most of the individuals could keep theimprovement for a long time;3. With the preoperative glycosylated haemoglobin level increased, curativeeffect of the Roux-en-Y gastric bypass surgery decreased;4. When the preoperative HbA1c <10%, Roux-en-Y gastric bypass surgery caneffectively improve glucose metabolism;...