S1317 Effect of GLP-1 Receptor Agonists on Quality of Bowel Preparation for Colonoscopy: A Systematic Review, Meta-Analysis, and Meta-Regression Analysis

Introduction: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used to manage diabetes and obesity, but their effect on bowel preparation quality for colonoscopy is unclear. Inadequate preparation can reduce polyp detection and necessitate repeat procedures, affecting outcomes. This study evaluates the effect of GLP-1 RAs on bowel prep quality, measured by the Boston Bowel Preparation Score (BBPS), and related colonoscopy outcomes. Methods: A systematic review was performed following PRISMA guidelines, searching PubMed, Embase, and Cochrane databases for studies comparing bowel prep outcomes in GLP-1 RA users versus non-users. Eligible studies were prospective or retrospective cohorts reporting BBPS or related metrics. Statistical analysis was done using R. Risk of bias was assessed via the Newcastle-Ottawa Scale. Meta-regression analyzed the impact of age and sex on BBPS. Random-effects meta-analyses assessed BBPS, BBPS <5, BBPS <1 in any segment, inadequate bowel prep, and polyp detection rate. Results: Thirteen studies involving 167,235 patients (64,346 GLP-1 RA users; 102,889 non-users) were included. GLP-1 RA users had significantly lower BBPS (MD -0.36, 95% CI [-0.66, -0.07], P = 0.019, I² = 71.4%) and higher BBPS <1 in any segment (MD 9.03%, 95% CI [3.45, 14.61], P = 0.02, I² = 0%). No significant differences were found in BBPS <5 (MD 5.40%, 95% CI [-17.16, 27.97], P = 0.202, I² = 23.1%) or inadequate bowel prep (MD 4.00%, 95% CI [-0.41, 8.41], P = 0.068, I² = 54.0%). Polyp detection rate was higher among GLP-1 RA users (MD 6.69%, 95% CI [0.01, 13.38], P = 0.0499, I² = 0%). Despite slightly lower BBPS, the improved detection rate may reflect clinical benefit from reduced motility, less spasm, and better luminal insufflation. Meta-regression showed no significant effect of age (P = 0.5509) or sex (P = 0.5373) on BBPS. Leave-one-out sensitivity confirmed robustness (MD -0.46 to -0.35, P < 0.05). Conclusion: GLP-1 RA use is linked to mildly reduced bowel prep quality and segmental cleaning, likely due to altered gut motility. Yet, increased polyp detection suggests clinical benefit, potentially from reduced spasm and keeping the lumen better insufflated. Future studies should explore optimized prep protocols for GLP-1 RA users.