Diabetes remission after bariatric surgery may be more likely in younger patients with shorter disease duration

Patients with severe obesity and diabetes are more likely to achieve diabetes remission after bariatric surgery at younger ages and with shorter diabetes duration, higher beta-cell function, and lower insulin usage at baseline, a study found.

Using data from the Longitudinal Assessment of Bariatric Surgery (LABS) observational cohort study, researchers looked at adults with severe obesity who had Roux-en-Y gastric bypass (RYGB) or laparoscopic gastric banding (LAGB) at 10 U.S. hospitals between 2006 and 2009. Participants completed annual research assessments for up to seven years after RYGB or LAGB. For the current analysis, LABS-2, the primary outcome was diabetes remission (using American Diabetes Association consensus group definitions), and researchers also assessed associations between patient characteristics and remission status. Partial remission was defined as an HbA1c level between 5.7% and 6.5% or, if not available, a fasting glucose level of 5.6 to 6.9 mmol/L (100 to 125 mg/dL) in the absence of diabetes pharmacologic therapy. Complete remission was defined as an HbA1c level less than 5.7%, or if not available, a fasting glucose level less than 5.6 mmol/L (<100 mg/dL) in the absence of diabetes pharmacologic therapy. Results were published online on Dec. 3 by the Journal of Clinical Endocrinology & Metabolism.

Of 2,256 participants, 827 (37%) had diabetes. Of those with diabetes, 645 (78%) had RYGB and 182 (22%) had LAGB. Diabetes remission (including both complete and partial) peaked two to three years after both procedures before declining during the seven-year follow-up period. The percentage achieving total diabetes remission in the RYGB group peaked at 62.7% during year two and decreased to 57.2% by year seven, whereas the percentage in partial remission remained stable at about 11%. In the LAGB group, the percentage who achieved total diabetes remission peaked at 29.0% during year two and decreased to 22.5% by year seven, and the percentage in partial remission declined from 7.4% in year one to 5.6% by year seven. Following both procedures, the likelihood of diabetes remission was greater in younger participants and those with shorter diabetes duration, higher C-peptide levels, higher beta-cell function, lower insulin usage at baseline, and greater postsurgical weight loss. After LAGB, reduced insulin resistance was associated with a greater likelihood of diabetes remission, whereas improved beta-cell secretion and not improved insulin resistance predicted remission after RYGB. When the researchers controlled for weight lost, diabetes remission remained nearly fourfold higher after RYGB compared to after LAGB.

Participants were mostly women, mostly White, and heavier on average than those in nonsurgical weight loss studies of patients with type 2 diabetes, potentially limiting generalizability, the study authors noted. They added that other limitations included the study's nonrandomized, observational design and that it was closed out midway through recruitment for the final study visit, resulting in missing data in about 45% of participants for year seven.

The authors concluded that the likelihood of achieving and sustaining both complete and partial diabetes remission in patients with severe obesity is increased when bariatric surgery is performed on younger individuals, soon after diabetes diagnosis, on those with better diabetes control achieved by fewer medications and no insulin, and on those who undergo RYGB compared to LAGB. “Durable, long-term diabetes remission following bariatric surgery is more likely when performed soon after diagnosis when diabetes medication burden is low and beta-cell function is preserved. … [D]elaying bariatric surgery until patients have ‘failed’ medical therapy is not optimal for patient care and should be reconsidered in current treatment guidelines/algorithms,” they wrote.