Clinical Research Of Modified Roux-en-Y Gastric Bypass To Treat Type2Diabetes Mellitus Patients With Low BMI: A Prospective And Propensity-matched Study

BackgroundDiabetes, particularly type2diabetes mellitus (T2DM), has reached epidemicproportions in China and globally, placing a severe burden on health care systems.Because of both the scale of the problem and the current epidemic growth of diabetes, itis a priority to find new approaches to better understand and treat this disease.Gastrointestinal surgery, especially Roux-en-Y gastric bypass (RYGB), has shown itsgood effect on obese T2DM patients, but for non-obese T2DM patients with BMI below30kg/m~2the outcomes are still unidentified. This study is mainly aimed to evaluate theshort-term effect of modified RYGP in the treatment of non-obese T2DM patients withlow BMI, in order to optimize the standard on surgical selection of such patients. Methods:1. Using the data of84diagnosed T2DM patients treating by modified RYGP in XijingHospital from June2009to June2010, collecting the follow-up data including fastingplasma glucose (FPG),2h plasma glucose after oral glucose challenge (2hPG),hemoglobin A1c (HbA1c), fasting C-peptide (C-P), fasting serum insulin (Fins),Homeostasis Model Assessment of Insulin Resistance index (HOMA-IR),weight, BMI(Body Mass Index) and medication usage in1month,3months,6months and1yearpostoperative, the statistical analysis was then performed by SPSS17.0software,respectively.2. In contrast, choosing the290counterparts treating only by medical therapy in thesame year, collecting their data including age, gender, history, FPG,2h-PG, BMI, HbA1cand complications, then matching them with the RYGP group by propensity score (PS),finally we got42matches. After one year of follow-up, we compare the data statisticallyto see the differences.3. To investigate the effect of gastric bypass (GBP) on SD rats (T2DM model),32SDmale rats were into4groups:(8cases each group) DO, DS, DC and NO group.Streptozotocin (STZ) intraperitoneal injection induced diabetic group. The plasma glucoseconcentration, Fins, HOMA-IR and the Paw withdrawal threshold were detected beforeand after the operation at1st,4th and8th week.Results1. Compared with the preoperative, FPG, HbA1c, C-P and HOMA-IR,2hPG, weightand BMI in one year after surgery were significantly improved (P<0.05) and there wasno obvious difference in Fins (P>0.05). The complete remission rates in one month, threemonths, six months and one year after surgery were gradually improved (P<0.05),22.2%,27.8%,36.1%and60.6%, respectively, and the effective ratio of operation was93%. TheC-P level of complete remission group was higher than partly remission group (P<0.05).2. Among all42matched patients selected by PS, weight, BMI, FPG,2hPG, C-P,HbA1c, and the complete remission rate of RYGB group was better than the medicaltherapy group after6month of follow-up. And BMI, HbA1c, the incidence of complications and the complete remission rates showed significant difference in statistics(P<0.05). After one year of follow-up, in addition to weight, the rest of the factors ofsurgical treatment group mentioned above were markedly better than that of the medicaltherapy group respectively.(P<0.05) Complete remission rate of surgical treatment groupwas57.1%, while there is only2.4%in medical therapy group.3. Compared with the three groups, the level of FPG, Fins and HOMA-IR werestatistically improved in DO group post-operation at1st,4th, and8th week. Comparedwith the DS group (5.51±2.68) g, the Paw withdrawal threshold (12.99±3.03) g in DOgroup was increased after GBP (P<0.05). But the Paw withdrawal threshold were stillhigher in DO、DS、DC group than NO group pre and post operation..Conclusions1. Modified RYGB acted safely and effectively in the treatment of non-obese type2diabetes patients, the function of islet cells was significantly improved, especially for thepatients whose islet cells function was normal. The patients with higher C-P level, lowerHOMA-IR and less use of insulin before surgery, have the best rate of completeremission after one year.2. Compared with the medical therapy, treating with RYGB surgery, patients show betterimprovement of their indexes of blood glucose, BMI, the incidence of complications andthe complete remission rate.3. GBP can improve the symptom and FPG、Fins, HOMA-IR of diabetes rats induced bySTZ. Also, GBP can increase the Paw withdrawal threshold and attenuate diabetic pain instreptozotocin induced rats.