<scp>GLP</scp> ‐1 Receptor Agonists and Weight Loss Among Suboptimal Responders to Metabolic Bariatric Surgery: A Target Trial Emulation

ABSTRACT Importance Suboptimal weight loss affects 20%–35% of patients after metabolic bariatric surgery (MBS). Randomised evidence on glucagon‐like peptide‐1 receptor agonist (GLP‐1 RA) pharmacotherapy in this population is limited to small, single‐center Western trials. No data exist from Chinese populations. Objective To emulate a target trial comparing GLP‐1 RA initiation with standard care among suboptimal responders to MBS in a Chinese multicenter cohort. Design, Setting, and Participants Target trial emulation using electronic health record (EHR) data from two Tertiary A teaching hospitals in China (March 2019 to June 2024). Eligible adults aged 18–65 years had undergone sleeve gastrectomy (SG) or Roux‐en‐Y gastric bypass (RYGB), were 12–36 months post‐surgery with body mass index (BMI) ≥ 28 kg/m 2 and suboptimal weight loss. The clone‐censor‐weight approach handled the 30‐day grace period. 1:5 propensity score matching yielded 624 patients (104 GLP‐1 RA, 520 standard care). Interventions Strategy A: GLP‐1 RA initiated within 30 days. Strategy B: standard post‐MBS care without GLP‐1 RA. Main Outcome Percentage of total body weight loss (%TBWL) at 12 months. Results Mean age was 36.4 years; 66% were female; mean BMI was 33.7 kg/m 2 . At 12 months, mean %TBWL was 7.5% in the GLP‐1 RA group versus 1.2% in the standard care group (difference, 6.28 percentage points; 95% CI, 5.50 to 7.07; p < 0.001). The ≥ 5% TBWL responder rate was 75% versus 7%. The per‐protocol effect was 6.44 percentage points (95% CI, 5.65 to 7.23). Results were consistent across surgery types, BMI thresholds, diabetes status, and all sensitivity analyses. Conclusions and Relevance In this target trial emulation, GLP‐1 RA initiation was associated with clinically meaningful weight loss among Chinese suboptimal responders to MBS. These findings extend Western randomised trial evidence to a Chinese multicenter real‐world setting and support the integration of GLP‐1 RA pharmacotherapy into post‐bariatric care pathways in China.