Bariatric surgery puts type 2 diabetes into remission for many, but relapse rises after five years

Around 60% of patients remained in remission five years after bariatric surgery, but longer-standing diabetes and higher pre-surgery HbA1c were linked to relapse.

A new retrospective study published in Obesity Surgery suggests that bariatric surgery can put type 2 diabetes into remission for many patients with obesity, but that the benefit is not always permanent. About 60% of the 151 patients studied were still in remission five years after surgery, while roughly four in five had achieved remission at some point during follow-up. The findings add to a growing body of evidence that metabolic surgery can sharply improve glucose control, while also underscoring the need for longer-term monitoring.

The research, led by Juan Alberto Sanchez Forero of Hospital General Universitario de Ciudad Real in Spain, followed patients who underwent Roux-en-Y gastric bypass or sleeve gastrectomy between January 2006 and December 2020. Remission was defined using American Diabetes Association criteria, and patients were followed for an average of just under seven years. Most of the participants were women, and their mean age at surgery was 49.

The study found that patients with a shorter history of diabetes and better blood sugar control before surgery were more likely to remain in remission five years later. Each additional month living with type 2 diabetes before surgery was linked with lower odds of remission, while each one-point increase in HbA1c, a measure of average blood sugar, also reduced the likelihood of success. The authors said these results highlight the importance of careful patient selection and early postoperative weight loss.

Relapse was not uncommon. Of the 120 patients who at some point entered remission, 27 later saw their diabetes return, and most of those relapses happened in years four and five after the operation. Again, longer diabetes duration and higher pre-surgery HbA1c were associated with greater relapse risk, while stronger excess weight loss during the first year appeared to protect against later deterioration. The study was retrospective, single-centre and relatively small, so its findings should be read with caution.

Even so, the results fit with broader research showing that metabolic surgery can deliver durable diabetes benefits for many people. The National Institutes of Health has reported that patients undergoing bariatric surgery had better long-term blood glucose control than those treated with medication and lifestyle measures alone, with higher remission rates seen out to 12 years in a federally supported study. Other long-term studies have also found that remission rates are highest in patients who have had diabetes for a shorter time, begin surgery with lower HbA1c levels and lose more weight afterwards.