Trial: Surgery and therapy improve type 2 diabetes

Bariatric surgery plus medical therapy may be a useful strategy for managing uncontrolled diabetes, according to the results of a recent study published in the New England Journal of Medicine.

“Despite improvements in pharmacotherapy, fewer than 50% of patients with moderate-to-severe type 2 diabetes actually achieve and maintain therapeutic thresholds, particularly for glycemic control,” wrote lead author Philip R. Schauer, MD, from the Bariatric and Metabolic Institute at the Cleveland Clinic, and colleagues.

They designed the Surgical Treatment and Medications Potentially Eradicate Diabetes Efficiently (STAMPEDE) trial to compare intensive medical therapy with either gastric bypass or sleeve gastrectomy as a means of improving glycemic control in obese patients with type 2 diabetes. The primary end point was the proportion of patients with a glycated hemoglobin level of 6% or less (with or without diabetes medications) 12 months after randomization.

The trial was a randomized, controlled, single-center study conducted from March 2007 to January 2011. The investigators assigned 150 eligible patients to undergo intensive medical therapy alone or intensive medical therapy plus either Roux-en-Y gastric bypass or sleeve gastrectomy.

Patients with uncontrolled type 2 diabetes who underwent bariatric surgery plus 12 months of medical therapy saw a significant improvement in health status compared with similar patients who received medical therapy alone.

At 12 months, the investigators had complete data on 93% of patients and noted that nearly half (42%) of patients in the gastric-bypass group and 37% of patients in the sleeve-gastrectomy group achieved the primary end point compared with 12% of patients in the medical therapy group. The investigators also noted that the 21 patients who achieved the primary end point in the gastric-bypass group did so without medications, while 5 of the 18 patients who achieved the primary end point in the sleeve-gastrectomy group required 1 or more glucose-lowering drugs.

Study data also showed that glycemic control had improved in all 3 groups; however, it was significantly lower in the 2 surgical groups than in the medical therapy group. The investigators observed a large and rapid improvement by 3 months that was sustained over the course of the year in patients who underwent surgery, whereas they saw a smaller and more gradual improvement in patients who received only medical therapy. Patients who underwent surgery also achieved greater weight loss, and the average number of diabetes agents per patient per day to lower glucose, lipid, and blood-pressure decreased significantly in the 2 surgical groups compared with the medical therapy group.

“Reductions in the use of diabetes medications occurred before achievement of maximal weight loss, which supports the concept that the mechanisms of improvement in diabetes involve physiologic effects in addition to weight loss, probably related to alterations in gut hormones,” the authors wrote.

Although some patients had complications due to surgery, including 4 patients who required re-operation, no adverse events were life-threatening. The authors concluded that weight loss surgery may be a useful strategy for managing uncontrolled diabetes and subsequently improving cardiovascular risk factors, although benefits would have to be weighed against surgical risk and further research should be conducted through larger, multicenter trials.

The study was sponsored by Ethicon Endo-Surgery, with support from LifeScan, the Cleveland Clinic, and the National Institutes of Health.