Adding gastric bypass to traditional management may help control comorbidities of diabetes

Adding gastric bypass surgery to intensive lifestyle-medical management may increase the chances of controlling comorbid risk factors in mild to moderately obese patients with type 2 diabetes, a recent study suggested.

Researchers studied 120 patients at four teaching hospitals in the U.S. and Taiwan for 12 months, starting in April 2008. All patients had hemoglobin A1c (HbA1c) levels of 8.0% or higher, body mass index (BMI) between 30 and 39.9, and C peptide level of more than 1.0 ng/mL and had been in a physician's care for type 2 diabetes for at least six months. All patients also received lifestyle-medical management, which included medications to control glycemia and cardiovascular disease risk factors while helping with weight loss.

The lifestyle component included regular counseling on strategies for weight management and increasing physical activity, as well as self-recording of eating, exercise and weight. Sixty patients were randomized to receive laparoscopic Roux-en-Y gastric bypass in addition to the lifestyle-medical management. Orlistat and sibutramine were added if needed for the non-gastric bypass group (until the latter was withdrawn from the market). The main outcome at one year was a triple end point recommended by the American Diabetes Association: HbA1c less than 7.0%, low-density lipoprotein cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg. Results were published June 5 by the Journal of the American Medical Association.

At 12 months, 28 participants (49%) in the gastric bypass group and 11 (19%) in the lifestyle-medical management group had reached the composite end point (odds ratio, 4.8). Those in the bypass group needed three fewer medications and lost 26.1% of their initial body weight compared with 7.9% for the other group. Reaching the composite end point was mostly attributable to weight loss, according to regression analysis. The largest treatment effect was on diabetes; control of dyslipidemia and hypertension was similar between the two groups. The numbers of serious adverse events were higher in the bypass group at 22 compared to 15 in the other group. Events in the bypass group included four perioperative complications and six late postoperative complications; the bypass group also had more nutritional deficiencies.

The merit of gastric bypass surgery for moderately obese patients with type 2 diabetes “depends on whether potential benefits make risks acceptable,” the researchers concluded. An accompanying editorial agreed, adding that “the frequency and severity of complications [reported in the study] is problematic.” The editorialists praised the study for being well designed and more generalizable than past trials. The editorial called for additional research with greater numbers of patients to determine the perioperative safety of gastric bypass in diabetic patients with BMIs less than 35 and follow-up beyond one year to help determine long-term safety.