The Effect Of Bariatric Surgery On Glucose Metabolism In Morbidly Obesity

BACKGROUNDObesity can contribute to many diseases that threaten human health even life, one of which is type 2 diabetes. Obese patients are typically at higher risk of progressing to type 2 diabetes. Bariatric surgery is a rapidly growing branch of surgical science, aiming at inducing significant weight loss in those obese patients at high risk of serious health problems. Different bariatric surgical procedures have different effects on obese patients. There has little clinical experiens and experimental research on bariatric surgery in our coutry.In this study, we proposed a new concept of bariatric surgery in China, which focuses on the treatment of obesity related diseases, and investigated the effects of bariatric surgery on improving glycemic control of morbidly obese patients and its mechanism based on extensive clinical observations and experimental study on glucose metabolism of morbidly obese patients before and after bariatric surgery.PartⅠThe effects of laparoscopic gastric bypass on glucose metabolism in morbid obesityObjectives: To investigate the effects of laparoscopic adjustable gastric banding (LAGB) on glucose metabolism of morbidly obese patients and its mechanism.Methods: Between July 2007 and March 2008, 79 morbidly obese patients underwent LAGB in our department and had at least 1 year of follow-up. We evaluated pre- and postoperative (after one year) glucose metabolism. All non-T2DM patients had oral glucose tolerance tests. Data collected included demographics, markers regarding weight loss (BMI and EWL%),diabetes control (FPG,PPG and HbA1C) and HOMA-IR, and metabolic diseases in all patients. Mean and standard deviation were calculated for all these variables. The change in each of these markers of each patient was analyzed by variance statistical analyses of repeated measurements, the ratios comparison by X2 testing, with the aid of SPSS 14.0 software.Results: 1. All laparoscopical operations were successfully performed and no severe complication or death occurred. 2. Of 79 patients, 15 were preoperatively diagnosed as T2DM, 42 impaired glucose regulation and 22 normal glucose tolerance. One year after surgery, 27 were impaired glucose regulation and 37 were normal glucose tolerance. 6 of 15 T2DM patients were cured. 3. After LAGB, weight decreases from 101.3±13.2 kg to 84.4±10.5kg (P<0.01), BMI from 35.3±4.8 kg/m2 to 29.8±3.9 kg/m2 (P<0.01), FPG from 5.8±2.0mmol/L to 5.2±0.9mmol/L (P<0.01), PPG from 9.3±3.1mmol/L to 7.8±2.3mmol/L (P<0.01), HbA1C from 5.8%±1.2% to 5.4%±0.9% and HOMA-IR from 3.22±1.84 to 2.13±1.04 (P<0.01), and EWL% was 34.5% . 4. 14 of 27 patients with metabolism syndrome, 5 of 14 patients with hypertension, 11 of 23 patients with dyslipidemia and 27 of 69 patients with non-alcoholic fatty liver had the result of amelioration postoperatively.Conclusion: 1. LAGB is an effective and relatively safe procedure for morbidly obese patients. 2. Significant weight loss and IR decrease after LAGB can improve and even cure glucose metabolism disorders which occur much more frequently in obese patients. 3. The course of T2DM would have an effect on the treatment and early intervention can be more effective. 4. LAGB can also improve the treatment of MS and other obesity-related co-morbidities.PartⅡThe efficacy of laparoscopic gastric bypass on morbid obesity with type 2 diabetes mellitusObjective: To investigate the effects of laparoscopic gastric bypass (LGB) on improving glycemic control of morbidly obese patients with diabetes mellitus and its mechanism.Methods: With the approved of the Hospital Ethics Committee and signed consent from all participants, seven laparoscopic gastric bypass were performed on obesity patients with T2DM between July of 2007 and August of 2008, one of which was laparoscopic Roux-en-y gastric bypass (LRYGB) and the other six, laparoscopic mini-gastric bypass (LMGB) that were performed for the first time in China. All patients had been followed up for at least 8 months.. Pre- and postoperative data, including demographics, weight, body mass index (BMI), waist circumference(WC), waist-to-hip ratio(WHR), excess weight loss percentage(EWL %), fasting plasma glucose(FPG), postprandial plasma glucose(PPG), fasting plasma insulin(FINS), glycosylated hemoglobin(HbA1C), HOMA-IR , HOMA-βand metabolic diseases in all patients, were elavated The process of the surgeries and postoperative complications were recorded., Mean and standard deviation were calculated for all these variables. The changes in these markers of each patient were analyzed by variance statistical analyses of repeated measurements with the aid of SPSS 14.0 software.Results: 1. All laparoscopical operations were successfully performed and no complication or death occurred. Mean operation time was 120 minutes and mean postoperative hospital stay was 5.0 days. LMGB needs less operation time because of its simpler procedure. 2. One year after operation, weight decreased from 98.6±16.6 kg to 75.3±7.7kg (P<0.01), BMI from 33.6±4.7 kg/m2 to 25.9±1.7 kg/m2 (P<0.01), FPG from 7.1±1.0mmol/L to 5.0±0.7mmol/L (P<0.01), HbA1C from 8.0%±1.0% to 5.7%±0.6%, HOMA-IR from 5.38±1.73 to 2.49±0.81 (P<0.01). EWL% was 72.1% and HOMA-βincreased from 100.3±47.5 to 224.2±127.8. 3. Five patients had the result of resolution and the other two patients had the result of amelioration on T2DM postoperatively. Four of the five patients with metabolism syndrome had the result of resolution. Three of the four patients with hypertension had the result of resolution. Four patients with dyslipidemia had the result of resolution. Four of the seven patients with non-alcoholic fatty liver had the result of amelioration. One patient with diabetic nephropathy cured and one had the result of amelioration on hypertensive nephropathy.Conclusion: 1. LGB is an effective procedure for morbidly obese patients with T2DM. It can significantly reduce weight and bring about resolution or improvement of T2DM, as well as other obesity-related comorbidities. 2. Laparoscopic mini-gastric bypass is a relatively safe and simple procedure. 3. LGB had improved insulin resistance and beta-cell function. The changes of gastroenteritic-insular axis may play a major role on the surgical treatment of diabetes mellitus.PartⅢThe research on serum adiponectin and visfatin in morbid obesity before and after laparoscopic adjustable gastric bandingObjective: To investigate the changes of serum adiponectin and visfatin levels before and after laparoscopic gastric banding (LAGB) and its association with obesity and type 2 diabetes (T2DM).Methods: In a prospective study, fasting serum visfatin and adiponectin concentrations were measured before and 1 year after LAGB in 20 morbidly obese patients and 15 morbidly obesity combined T2DM patients. Twenty healthy subjects with a BMI less than 25 kg/m2 served as controls. Pre- and postoperative data, including demographics, weight, body mass index (BMI), waist circumference(WC), waist-to-hip ratio(WHR), excess weight loss percentage(EWL %), fasting plasma glucose(FPG), fasting plasma insulin(FINS) and HOMA , were evaluated Serum adiponectin and visfatin levels were detected by enzyme linked immunosorbent assay (ELISA). Average preoperative and postoperative biochemical markers for the study groups were calculated and analyzed by Student's t-test and ANOVA, and the average change in these markers within each operation group compared by Repeated Measurement Data Analysis Of Variance. The relationships between different markers were analyzed by Pearson statistics method.Results: 1. Adiponectin serum concentrations were markedly decreased in obese subjects (13.9±4.3mg/L) and obese combined T2DM subjects (9.8±3.3mg /L) , compared with controls (18.8±5.4mg/L) (P < 0.01). The concentrations of adiponectin are inverse correlation with BMI,WC,WHR,FPG,FINS and HOMA. 2. Visfatin serum concentrations were markedly elevated in obese subjects (25.7±8.4ng/ml) and obese combined T2DM subjects (32.9±10.5ng/ml), compared with controls (12.8±6.7ng/ml) (P<0.05). The concentrations of adiponectin have direct correlation with BMI,WC and WHR. 3. One year after operation, weight decreased from 105.1±9.1kg and 103.8±8.65kg to 85.7±10.2kg and 88.6±7.1kg (P<0.01), BMI from 35.4±3.7kg/m2 and 34.8±3.5 to 30.1±3.2kg/m2 and 29.7±3.5 kg/m2 (P<0.01), WC from 111.5±11.1 and 109.7±7.08cm to 96.1±11.2 and 95.8±6.45cm (P<0.01), WHR from 0.97±0.14 and 0.96±0.12 to 0.91±0.09 and 0.91±0.07(P<0.01), FPG from 5.6±1.4 and 6.8±1.8 mmol/L to 5.2±0.7mmol/L and 5.6±1.2 mmol/L (P<0.01), FINS from 12.1±4.2 and 16.5±5.7mIU/L to 9.2±3.1mIU/L and 10.7±3.7 mIU/L (P<0.01), HOMA-IR from 3.21±1.41 and 4.99±1.75 to 2.13±0.74 and 2.66±1.04 (P<0.05),visfatin from 25.7±8.4ng/mland 30.9±10.5ng/ml to 19.3±5.9ng/ml and 24.9±8.5ng/ml (P < 0.05) in MO and MO+T2DM. Adiponectin serum concentrations increased from 13.9±4.3 mg/L and 10.8±5.3mg/L to 16.5±5.1mg/L and 12.4±5.1mg/L (P<0.05) in MO and MO+T2DM. EWL% was 35.1% in MO and 33.6% in MO+T2DM (P>0.05). 4. The changes of adiponectin were significantly associated with the changes of BMI, FINS, weight, WC,FPG and HOMA-IR. The changes of visfatin were significantly associated with the changes of BMI, FINS and HOMA-IR.Conclusions: 1. Adiponectin serum concentrations were significantly higher and visfatin serum concentrations significantly lower in morbidly obese and whatever combined T2DM. 2. LAGB was an effective bariatric surgery. After weight loss, decreased serum adiponectin concentrations were elevated and elevated serum visfatin concentrations were reduced in morbidly obese subjects. 3. Adiponectin and Visfatin are significantly correlated with centric obesity and insulin resistance.