The relationship between pre-existing diabetes mellitus and the severity of acute pancreatitis: Report from a large international registry: Diabetes Mellitus in Acute Pancreatitis

Background/Objectives: The relationship between pre-existing diabetes mellitus (DM) and acute pancreatitis (AP) severity has not been established. We assessed the impact of pre-existing DM on AP severity in an international, prospectively ascertained registry. Methods: APPRENTICE registry prospectively enrolled 1543 AP patients from 22 centers across 4 continents (8 US, 6 Europe, 5 Latin America, 3 India) between 2015 and 2018, and collected detailed clinical information. Pre-existing DM was defined a diagnosis of DM prior to AP admission. The primary outcome was AP severity defined by the Revised Atlanta Classification (RAC). Secondary outcomes were development of systemic inflammatory response syndrome (SIRS) or intensive care unit (ICU) admission. Results: Pre-existing DM was present in 270 (17.5%) AP patients, of whom 252 (93.3%) had type 2 DM. Patients with pre-existing DM were significantly (p < 0.05) older (55.8 ± 16 vs. 48.3 ± 18.7 years), more likely to be overweight (BMI 29.5 ± 7 vs. 27.2 ± 6.2), have hypertriglyceridemia as the etiology (15% vs. 2%) and prior AP (33 vs. 24%). Mild, moderate, and severe AP were noted in 66%, 23%, and 11% of patients, respectively. On multivariable analysis, pre-existing DM did not significantly impact AP severity assessed by the RAC (moderate-severe vs. mild AP, OR = 0.86, 95% CI 0.63–1.18; severe vs. mild-moderate AP, OR = 1.05, 95% CI, 0.67–1.63), development of SIRS, or the need for ICU admission. No interaction was noted between DM status and continent. Conclusion: About one in 5 patients with AP have pre-existing DM. Once confounding risk factors are considered, pre-existing DM per se is not a risk factor for severe AP.