Long-term follow-up after bariatric surgery shows greater rate of diabetes remission

Obesity and diabetes have reached epidemic proportions and constitute major health and economic burdens. Worldwide, 347 million adults are estimated to live with diabetes and half of them are undiagnosed. Studies show that type 2 diabetes is preventable. The incidence of diabetes can be reduced by as much as 50 percent by lifestyle and pharmacological interventions, according to background information in the article. Short-term studies show that bariatric surgery results in remission of diabetes. The long-term outcomes for bariatric surgery and diabetes remission and diabetes-related complications have not been known.

Lars Sjostrom, M.D., Ph.D., of the University of Gothenburg, Sweden, and colleagues performed a follow-up of the Swedish Obese Subjects (SOS) study, conducted at 25 surgical departments and 480 primary health care centers in Sweden. Of patients recruited between September 1987 and January 2001, 260 of 2,037 control patients and 343 of 2,010 bariatric surgery patients had type 2 diabetes at baseline. For the current analysis, the presence of diabetes was determined at SOS health examinations and information on diabetes complications was obtained from national health registers. For diabetes complications, the median follow-up time was 17.6 years in the control group, and 18.1 years in the surgery group.

The proportion of patients in remission (defined as blood glucose <110 mg/dL and no diabetes medication) after 2 years was 72.3 percent in the surgery group and 16.4 percent in the control group. At 15 years, the diabetes remission rates decreased to 30.4 percent for bariatric surgery patients and 6.5 percent for control patients. All types of bariatric surgery (adjustable or nonadjustable banding, vertical banded gastroplasty, or gastric bypass) were associated with higher remission rates compared with usual care.

In addition, bariatric surgery was associated with a decreased incidence of microvascular and macrovascular complications.

"In this very long-term follow-up observational study of obese patients with type 2 diabetes, bariatric surgery was associated with more frequent diabetes remission and fewer complications than usual care. These findings require confirmation in randomized trials," the authors conclude.