Background: GLP1RAs are an increasingly common treatment in the setting of type 2 diabetes mellitus (T2DM). One hypothesized mechanism by which bariatric surgery contributes to T2DM remission is by increasing intestinal GLP-1 secretion. We aimed to evaluate the association of the response to GLP1RA pre-operatively on hemoglobin A1c (HbA1c) level and weight loss after bariatric surgery.
Methods: The NorthShore bariatric surgery database was retrospectively queried for patients with T2DM who had taken a GLP1RA prior to Roux-en-Y gastric bypass (N=38) or gastric sleeve surgery (N=9). GLP1RA response was measured by change in HbA1c from initiation of therapy to 6mo. Outcomes included HbA1c level and percent total body weight loss (TBWL) at 6mo, 1 and 2yr post-op. The association between GLP1RA response and post-operative outcomes was evaluated with partial correlation coefficients adjusted for baseline HbA1c with/without baseline weight.
Results: The average HbA1c at initiation of therapy was 8.3±1.4% and decreased by 1.1±1.5% on GLP1RA treatment with liraglutide being most commonly prescribed (44.7%). A greater decrease in HbA1c from GLP1RA was correlated with a lower HbA1c at 6mo (r=0.38, p=0.02), and 2yr (r=0.43, p=0.03), but not 1yr (r=0.35, p=0.06) or TBWL. After adjustment for baseline weight, the association remained at 6mo (r=0.37, p=0.02). Stratification by procedure noted a strong association between GLP1RA response and reduced post-operative HbA1c at 6mo (r=0.99, p<0.01) and TBWL at 1yr (r=0.82, p=0.02) and 2yrs (r=0.99, p=0.01) for patients who had undergone gastric sleeve, but not gastric bypass.
Conclusion: To our knowledge, this is the first study examining the association of GLP1RA response on glycemic and weight outcomes post-bariatric surgery in people with T2DM. Despite a number of limitations, results from this small cohort suggest the need for further evaluation of this relationship as a potentially useful predictor of surgical outcomes.
D. Amusin: None. K. Kuchta: None. T. Ewing: None. L. Tucker: None. M. Campbell: None. M. Ujiki: Advisory Panel; Self; Boston Scientific Corporation, Consultant; Self; Cook Medical, Speaker’s Bureau; Self; Medtronic. L. K. Billings: Advisory Panel; Self; Bayer Inc., Lilly Diabetes, Novo Nordisk, Sanofi.