Factors influencing the effect of gastric bypass surgery on type 2 diabetes mellitus

Objective To investigate the factors influencing the effect of gastric bypass surgery on type 2  diabetes mellitus.
 Methods The clinical data of 99 patients with type 2 diabetes mellitus who received gastric bypass surgery at the General Hospital of Chengdu Military Command from March 2009 to March 2010 were retrospectively analyzed. All the patients were followed up for 1 year. The results of oral glucose tolerance test (OGTT) and Cpeptid release test were obtained, the levels of insulin and glycosylated hemoglobin (HbA1c) were dynamically monitored, and the insulin resistance indexes (HOMA IR) and body mass indexes (BMI) were calculated. Complete clinical remission was defined as not requiring any hypoglycemic measures and capable of maintaining long term random blood glucose levels<11.1 mmol/L, fasting blood glucose levels<7.0 mmol/L, 2 hour-blood glucose levels<11.1 mmol/L and HbA1c<6.5%; improved condition was defined as having a significant reduction in necessary drug administration or dietary modifcation to control normal blood glucose levels after surgery; any patient who did not meet these criteria was considered unaffected. All data were analyzed using  the repeated measures design, one way analysis of variance or LSD t  test.
Results Of the 99 patients, 79 patients (80%) met the criteria of complete remission, the conditions of 9 patients (9%) were improved, and the surgery was ineffective in 11 patients (11%). The preoperative body weight, BMI, fasting, 30 minutes and 1 , 2 , 3 hour postprandial C peptide, 30 minutes and 1 hour postprandial glucose, 30 minutes and 1 hour postprandial insulin were (75±14)kg, (27±4)kg/m², (2.1±0.8)nmol/L, (2.8± 1.2)nmol/L,(3.8±1.7)nmol/L, (4.5±2.2)nmol/L, (3.5±1.2)nmol/L, (16±3)mmol/L, (19±4)mmol/L, (29±21)U/L, (37±27)U/L for patients with complete remission, (62±10)kg, (24±4)kg/m2, (1.3±0.5)nmol/L, (1.8±1.0)nmol/L, (1.9±0.8)nmol/L, (2.8±1.7)nmol/L, (2.7±1.5)nmol/L, (17±5)mmol/L, (20±6)mmol/L, (18±13)U/L and (17±12)U/L for patients with improved condition, and (71±12)kg, (24±3)kg/m2, (1.6±0.6)nmol/L,(2.2±0.9)nmol/L, (2.8±1.3)nmol/L, (2.8±1.0)nmol/L, (2.5±1.4)nmol/L, (17±5)mmol/L, (20±4)mmol/L, (17±10)U/L and (24±16)U/L for patients who were unaffected, with significant differences between the 3 groups ( F=3.989, 5.328, 5.860, 4.315, 7.504, 5.208, 4.512, 3.341, 8.154, 3.456, 3.514, P <0.05).
Conclusion The body weight, BMI, fasting, 30 minutes and 1, 2, 3 hour postprandial C-peptide, 30 minutes and 1-hour postprandial glucose, 30 minutes and 1-hour postprandial insulin are factors influencing the effect of gastric bypass surgery on type-2 diabetes mellitus.