Objective:To explore the effects of serum triglyceride (STAG) level within 48 hours after hospitalization on the complications of acute pancreatitis (AP).Methods:From January 2012 to June 2016, 1 006 hospitalized patients diagnosed with AP at the Third People′s Hospital of Chengdu were collected. According to the STAG level within 48 hours after hospitalization, AP patients were divided into normal to mild hypertriglyceridemia (HTG) group(STAG <2.3 mmol/L, 877 cases), moderate HTG group(STAG: 2.3 to <8.5 mmol/L, 82 cases) and severe HTG group (≥8.5 mmol/L, 47 cases). The general clinical data and the incidence of local complications of AP including acute necrotizing pancreatitis, pancreatic necrosis, acute peripancreatic fluid collection (APFC) and acute necrotic collection (ANC) and AP-associated gastrointestinal abnormal changes were compared in the three groups. The severity of the complications of AP was scored by modified-magnetic resonance severity index (M-MRSI). Wilcoxon rank sum test and chi-square test were used for statistical analysis, and multivariate logistic regression analysis was used to analyze the correlation between STAG level and persistent organ failure (POF).Results:Compared with that of the normal to mild HTG group and moderate HTG group, the age of the patients of the severe HTG group was the youngest (52 years old, 19 to 82 years old and 47 years old, 21 to 62 years old vs. 35 years old, 18 to 43 years old), the proportion of male was the highest (46.3%, 406/877 and 64.6%, 53/82 vs. 85.1%, 40/47), and the differences were statistically significant( Z=3.943, 2.841, χ2=26.912, 6.224, all P<0.017). The proportion of body mass index (BMI)≥30 kg/m 2 in severe HTG group was higher than that in normal to mild HTG group (38.3%, 18/47 vs. 20.2%, 177/877), and the difference was statistically significant ( χ2=8.792, P=0.003). The proportions of patients with history of diabetes and severe alcohol intake of moderate HTG group and severe HTG group were all higher than those of normal to mild HTG group (31.7%, 26/82 and 29.8%, 14/47 vs. 15.4%, 135/877; 37.8%, 31/82 and 46.8%, 22/47 vs. 9.6%, 84/877), and the differences were statistically significant ( χ2=14.286, 6.833, 56.613 and 60.844, all P<0.017). Compared with those of the normal to mild HTG group and moderate HTG group, the incidences of pancreatic necrosis, APFC, and the M-MRSI score of the severe HTG group were all the highest (8.2%, 72/877 and 15.9%, 13/82 vs. 38.3%, 18/47; 17.8%, 156/877 and 36.6%, 30/82 vs. 59.6%, 28/47; 2, 0 to 10 and 3, 0 to 10 vs. 5, 0 to 10), and the differences were statistically significant( χ2=45.936, 8.244, 48.842 and 6.381, Z=2.711 and 3.049, all P<0.017). The incidence rates of acute necrotizing pancreatitis and ANC of moderate HTG group and severe HTG group were all higher than those of normal to mild HTG group(28.0%, 23/82 and 48.9%, 23/47 vs. 13.3%, 117/877; 26.8%, 22/82 and 42.6%, 20/47 vs. 13.3%, 117/877), and the differences were statistically significant ( χ2=13.011, 43.965, 11.008 and 30.144, all P<0.017). The incidence rate of POF of severe HTG group was higher than those of normal to mild HTG group and moderate HTG group (46.8%, 22/47 vs.14.8%, 130/877 and 24.4%, 20/82), and the differences were statistically significant ( χ2=33.205 and 6.838, both P<0.017). The results of multivariate logistic regression analysis showed that age ≥ 60 years old (odds ratio ( OR)=1.84, 95% confidence interval ( CI) 1.26 to 3.03), BMI≥30 kg/m 2 ( OR=2.41, 95% CI 1.61 to 3.77), alcohol intake ( OR=3.81, 95% CI 2.09 to 5.47), moderate HTG( OR=1.89, 95% CI 1.78 to 5.23) and severe HTG ( OR=3.65, 95% CI 1.98 to 6.49) were independent risk factors of POF(all P<0.05). Conclusion:The STAG level is related to the complications of AP, and moderate HTG and severe HTG(STAG ≥2.3 mmol/L) are independently associated with the risk of POF.