Triglyceride–glucose index, fluid accumulation and subsequent acute respiratory distress syndrome in acute pancreatitis: A two-centre retrospective landmark study

Background Fluid accumulation may carry different pulmonary risks across metabolic profiles in acute pancreatitis. We examined whether the triglyceride–glucose (TyG) index modified the association between first-day fluid accumulation and subsequent acute respiratory distress syndrome (ARDS). Methods We analysed two retrospective hospital cohorts using a 24-hour landmark. Eligible adults had fasting triglyceride and glucose measurements within 24 hours, complete first-day fluid records, and were alive and free of ARDS at the landmark. Fluid accumulation was defined as a net balance of at least 10% of ideal body weight. Multivariable logistic regression assessed its interaction with continuous TyG for ARDS occurring after hour 24 through hour 48, adjusting for centre, age, sex, body mass index, Acute Physiology and Chronic Health Evaluation II score, diabetes and hypertriglyceridaemic aetiology. Results Among 2235 source records, 1326 patients met the eligibility criteria; 442 (33.3%) had fluid accumulation and 85 (6.4%) developed subsequent ARDS. The interaction ratio of odds ratios was 2.59 (95% confidence interval [CI] 1.65–4.07) per unit higher TyG. Estimates were similar after adjustment for transfer and fluid indication (2.64; 95% CI 1.69–4.11) and for early physiological measurements (2.51; 95% CI 1.62–3.88). Excluding hypertriglyceridaemic pancreatitis left 891 patients and 58 events, with an interaction estimate of 1.54 (95% CI 0.55–4.27). Post-landmark ARDS incidence was 3.0% in Nanning and 11.3% in Guilin. Conclusions Among patients alive and free of recorded ARDS at 24 hours, the odds ratio for subsequent ARDS associated with fluid accumulation increased with TyG. The attenuated estimate after excluding hypertriglyceridaemic pancreatitis suggests that aetiology may contribute to this pattern. Prospective evaluation could clarify whether TyG adds useful information to early fluid and respiratory assessment. Registration The original project is listed in the Chinese Clinical Trial Registry as ChiCTR2600122934, registered on 20 April 2026. The clinical observation periods preceded registration; the current two-centre landmark analysis was specified subsequently.