To explore the predictive value of triglyceride glucose (TyG) index for the severity of acute pancreatitis (AP).

Original studies comparing TyG index between severe acute pancreatitis (SAP) and non-SAP patients were searched from PubMed, CNKI and other databases. Random effect model combined with standardized mean difference (SMD) was used to perform heterogeneity, subgroup, sensitivity and publication bias analyses. The quality of studies was evaluated according to Newcastle-Ottawa Scale (NOS). Publication bias was evaluated by Egger, Begg test and funnel plot.

12 studies comprising 3 407 patients were included. Meta-analysis showed that the TyG index in SAP patients was significantly higher than that in non-SAP counterparts (SMD=1.09, 95%CI: 0.99-1.18, P<0.05). Heterogeneity analysis revealed that high degree of heterogeneity was observed among different studies (I²=93.4%, P<0.001). According to the research quality, the SMD of high-quality studies was 1.13 (95%CI: 1.00-1.26, I²=82.0%),1.04 for medium-quality studies (95%CI: 0.90-1.17, I²=95.8%), and no statistical difference was noted between two groups (P=0.334). According to the average age in the SAP group, the SMD for SAP patients aged<50 years was 1.41 (95%CI: 1.26-1.57, I²=96.9%), and 0.88 for those aged≥50 years (95%CI: 0.76-1.00, I²=0.0%), indicating the prediction performance of TyG index was higher in the young SAP patients (P<0.001). A single study was excluded and the effect value was repeated combined. The results showed that combined SMD caused slight changes, and statistical significance was maintained in all analyses, indicating that the results of this study were robust and not significantly affected by individual studies. The overall distribution of funnel plot was basically symmetrical, with deviations of only a few studies. Egger and Begg regression tests detected no publication bias (t=0.64, Z=0.89; both P>0.05).

The existing evidence suggests that TyG index has certain potential value in predicting the severity of AP, especially in young patients.