Glycemic control in diabetic patients after bariatric surgery

Background: Morbid obesity is associated with a high prevalence of diabetes mellitus, and weight loss is fundamental to improve glycemic control. The aim of the present study was to evaluate the impact of weight reduction during the late postoperative period (greater than or equal to12 months) after gastric bypass on the glycemic control of diabetic patients. Methods: Fasting glycemia (glucose oxidase) and glycohemoglobin A1c (enzymatic fluorescence, reference value: 4-6%) were determined before and after surgery. Results were compared by the Student t-test for paired samples (P<0.05). Results: 23 women and 8 men with diabetes, with a mean follow-up of 27.2 months and a mean age of 42.5 years (30-68), were studied. Before surgery, mean SD weight, BMI, excess weight, glycemia and glycohemoglobin were 135.9+/-11.6 kg, 51.8+/-6.4 kg/m(2), 68.3+/-14.5kg, 173+/-71.2 mg/dl, and 7.4+/-1.9%, respectively. After surgery, mean weight, BMI, excess weight, percent weight loss, percent excess weight loss, glycemia and glycohemoglobin were 89.7+/-8.8 kg, 35+/-4.5 kg/m(2), 24.6+/-11.6 kg, 32.6%+/-1.8 (12.6-46.5%), 64.7+/-18.3%, 98+/-17.3 mg/dl (P<0.01), and 5.4+/-1.0% (P<0.05), respectively. Oral anti-diabetic drug and/or insulin treatment was discontinued in 89.2% of the patients. After surgery, 90.3% of the patients maintained glycohemoglobin A1c levels <7.0%. Conclusion: Weight loss led to a significant and sustained improvement of glycemic control in these patients submitted to bariatric surgery.