Importance: Severe hypertriglyceridemia is associated with increased risk of acute pancreatitis. However, the threshold above which triglycerides are associated with acute pancreatitis is unclear.

Objective: To test the hypothesis that nonfasting mild-to-moderate hypertriglyceridemia (177-885 mg/dL; 2-10 mmol/L) is also associated with acute pancreatitis.

Design, Setting, and Participants: This prospective cohort study examines individuals from the Copenhagen General Population Study in 2003 to 2015 and the Copenhagen City Heart Study initiated in 1976 to 1978 with follow-up examinations in 1981 to1983, 1991 to 1994, and in 2001 to 2003. Median follow-up was 6.7 years (interquartile range, 4.0-9.4 years); and includes 116 550 individuals with a triglyceride measurement from the Copenhagen General Population Study (n = 98 649) and the Copenhagen City Heart Study (n = 17 901). All individuals were followed until the occurrence of an event, death, emigration, or end of follow-up (November 2014), whichever came first.

Exposures: Plasma levels of nonfasting triglycerides.

Main Outcomes and Measures: Hazard ratios (HRs) for acute pancreatitis (n = 434) and myocardial infarction (n = 3942).

Results: Overall, 116 550 individuals were included in this study (median [interquartile range] age, 57 [47-66] years). Compared with individuals with plasma triglyceride levels less than 89 mg/dL (<1 mmol/L), the multivariable adjusted HRs for acute pancreatitis were 1.6 (95% CI, 1.0-2.6; 4.3 events/10 000 person-years) for individuals with triglyceride levels of 89 mg/dL to 176 mg/dL (1.00 mmol/L-1.99 mmol/L), 2.3 (95% CI, 1.3-4.0; 5.5 events/10 000 person-years) for 177 mg/dL to 265 mg/dL (2.00 mmol/L-2.99 mmol/L), 2.9 (95% CI, 1.4-5.9; 6.3 events/10 000 person-years) for 366 mg/dL to 353 mg/dL (3.00 mmol/L-3.99 mmol/L), 3.9 (95% CI, 1.5-10.0; 7.5 events/10 000 person-years) for 354 mg/dL-442 mg/dL (4.00 mmol/L-4.99 mmol/L), and 8.7 (95% CI, 3.7-20.0; 12 events/10 000 person-years) for individuals with triglyceride levels greater than or equal to 443 mg/dL (≥5.00 mmol/L) (trend, P = 6 × 10-8). Corresponding HRs for myocardial infarction were 1.6 (95% CI, 1.4-1.9; 41 events/10 000 person-years), 2.2 (95% CI, 1.9-2.7; 57 events/10 000 person-years), 3.2 (95% CI, 2.6-4.1; 72 events/10 000 person-years), 2.8 (95% CI, 2.0-3.9; 68 events/10 000 person-years), and 3.4 (95% CI, 2.4-4.7; 78 events/10 000 person-years) (trend, P = 6 × 10-31), respectively. The multivariable adjusted HR for acute pancreatitis was 1.17 (95% CI, 1.10-1.24) per 89 mg/dL (1 mmol/L) higher triglycerides. When stratified by sex, age, education, smoking, hypertension, statin use, study cohort, diabetes, body mass index (calculated as weight in kilograms divided by height in meters squared), alcohol intake, and gallstone disease, these results were similar with no statistical evidence of interaction.

Conclusions and Relevance: Nonfasting mild-to-moderate hypertriglyceridemia from 177 mg/dL (2 mmol/L) and above is associated with high risk of acute pancreatitis, with HR estimates higher than for myocardial infarction.