Long-term diabetes outcomes after bariatric surgery-managing medication withdrawl

Bariatric surgery leads to type 2 diabetes mellitus (T2DM) remission, but recurrence can ensue afterwards. However, literature provides heterogenous remission/recurrence criteria and there is no consensus on long-term T2DM management after surgery. We aim to assess T2DM remission/recurrence rates using standardized criteria and to identify relapse predictors. We also intend to analyze the management of residual T2DM and the impact of maintaining/withdrawing metformin in avoiding future relapse.

We investigated a cohort of 110 obese patients with T2DM who underwent bariatric surgery and were followed for 5 years (Y0-Y5). Patients who ever attained remission were accounted for cumulate remission, while prevalent remission was considered for individuals who were on remission in a specific visit.

A complete prevalent remission of 47.3% was reached at Y1 and it remained stable till Y5 (46.4-48.2%). Complete cumulative rate was of 57.3% at Y5. Five-year T2DM recurrence rate was 15.9% and it was associated with higher pre-operative HbA1c levels (β = 1.06; p < 0.05) and a milder excess body weight loss (EBWL) (β = 0.49; p < 0.05). Glucose-lowering agents were fully stopped in 51.4% of the patients till Y1 and in 16.2% of them afterwards. Medication withdrawal was mainly attempted in patients with a lower baseline HbA1c (β = 0.54; p < 0.01) and higher first-year EBWL (β = 1.04; p < 0.01). Patients that kept metformin after reaching a HbA1c in the complete remission range (<6.0%) did not have greater odds of avoiding relapse in the next visit (OR = 0.33; p = 0.08).

Baseline HbA1c and EBWL were the main variables driving both T2DM relapse after bariatric surgery and the attempt to withdrawal anti-diabetic medication. In our population keeping metformin once an HbA1c < 6.0% is achieved did not seem to diminish relapse but further studies on this matter are needed.