Spotlight on bariatric surgery for diabetes

Recent studies assessed the impact of bariatric surgery on diabetes remission, mortality, and health care costs.

The effects of bariatric surgery on patients with type 2 diabetes were analyzed by several studies published in the last month.

Diabetes remission was significantly more common among 569 British patients who underwent bariatric surgery than 1,881 similar controls, according the first population-based study of this question, published by JAMA Surgery on Sept. 30. Overall, surgery patients had an 18 times greater rate of remission, with gastric bypass having the greatest effect, followed by sleeve gastrectomy, then gastric banding. Body mass index (BMI) and HbA1c decreased during the 2 years following surgery, the study also found.

Reductions in weight and HbA1c after bariatric surgery remained significant 5 years postsurgery, according to another retrospective cohort study, which included 52 surgery patients and 299 medically treated patients, all Taiwanese, with type 2 diabetes and a baseline BMI below 35 kg/m2. The surgical patients had a mean weight loss of 21% and their mean HbA1c dropped from 9.1% to 6.3%, compared to no significant change in BMI or HbA1c in medical patients. Three (1.2%) medical patients had complete remission, compared to 18 (36%) surgical patients, but no difference in survival was observed, according to results published in JAMA Surgery on Sept. 16.

Bariatric surgery was associated with improved cardiovascular and overall mortality, in a study published by The Lancet Diabetes & Endocrinology on Sept. 29. The Swedish study included more than 6,000 gastric bypass patients and a similar number of controls and found a 58% relative risk reduction in overall mortality, as well as 49% reduction in myocardial infarction and 59% reduction in cardiovascular death. The mortality benefit might stem from the weight reduction itself, changes in physiology and metabolism, improved care and treatment, changes in lifestyle, or a combination of these factors, the authors noted.

Another Swedish study, looking at about 2,000 obese adults who had bariatric surgery between 1987 and 2001, found that surgery was associated with higher total health care costs in patients with normal blood sugar or prediabetes but that those with diabetes had similar costs whether they received bariatric surgery or usual care. The finding supports the prioritization of diabetic patients for bariatric surgery, the authors wrote in The Lancet Diabetes & Endocrinology on Sept. 16.