Prevalence and predictors of residual gastric content in patients with type 2 diabetes on GLP-1 receptor agonists: A prospective observational study.

AIMS: To assess the prevalence and risk factors of increased residual gastric content (RGC) under fasting conditions in patients with type 2 diabetes mellitus (T2DM) treated with glucagon-like peptide-1 receptor agonists (GLP-1 RAs), providing evidence for peri-procedural medication management.

MATERIALS AND

METHODS

This single-centre prospective cohort study enrolled inpatients with T2DM at the Endocrinology Department of Ningbo No.2 Hospital between April and December 2024. Patients aged 18-80 years with BMI <40 kg/m2 were categorized as GLP-1 RA users or non-users. Those with conditions known to affect gastric motility were excluded. After a standard overnight fast, bedside gastric ultrasonography was performed. The primary outcome was the prevalence of increased RGC, defined as solid content or clear fluid volume >1.5 mL/kg. Secondary analyses explored associated risk factors.

RESULTS

Of 390 patients included (237 [60.8%] male), 224 (57.4%) were GLP-1 RA users. After propensity score matching, the prevalence of increased RGC remained significantly higher in GLP-1 RA users compared with non-users (53.3% vs. 32.1%; p < 0.001). In multivariate logistic regression adjusted by inverse probability of treatment weighting (IPTW), GLP-1 RA use was robustly associated with increased RGC (OR 2.52; 95% CI 1.84-3.45). Notably, diabetic retinopathy (OR 1.84; 95% CI 1.14-2.99) and diabetic kidney disease (OR 1.67; 95% CI 1.17-2.39) emerged as independent risk factors, identifying a high-risk microvascular phenotype. Furthermore, among GLP-1 RA users, each additional day since the last GLP-1 RA dose reduced the odds of increased RGC by 23% (adjusted OR 0.77; 95% CI 0.65-0.90).

CONCLUSIONS

GLP-1 RA therapy is a potent, independent driver of significant gastric retention in patients with T2DM, persisting despite standard fasting. Crucially, the presence of diabetic retinopathy or nephropathy identifies a "double-hit" high-risk phenotype, where pharmacological delay interacts with microvascular burden. These findings suggest that current fasting protocols may be insufficient for these patients, necessitating individualized preoperative assessment based on microvascular status and dosing timing.