Post-pancreatitis diabetes mellitus is common in chronic pancreatitis and is associated with adverse outcomes.

BACKGROUND
Post-pancreatitis diabetes mellitus (PPDM) is a common consequence of chronic pancreatitis (CP). We aimed to determine the incidence and predictors of PPDM after CP onset, as well as complications and antidiabetic therapy requirements, in a high-volume tertiary center.


METHODS
We did a cohort study with retrospectively collected data from patients with definite CP seen at the Karolinska University Hospital between January 1999 and December 2020. Cause-specific Cox regression analysis was used to assess PPDM predictors. To estimate risk of complications and need for therapy the Fine-Gray subdistribution hazard model was employed, accounting for death as a competing risk.


RESULTS
We identified 481 patients with CP. The cumulative incidence of PPDM was 5.1%, 13.2%, 27.5% and 38.9% at 5, 10, 15 and 20 years, respectively. Compared to CP patients without diabetes, patients with PPDM were predominantly male (55% vs. 75%), had more frequently alcoholic etiology (44% vs. 62%) and previous acute pancreatitis. The only independent predictor of PPDM was presence of pancreatic calcifications (aHR = 2.45, 95% CI 1.30-4.63). Patients with PPDM had higher rates of microangiopathy (aSHR = 1.59, 95% CI 1.02-2.52) and infection (aSHR = 4.53, 95% CI 2.60-9.09) compared to CP patients who had type 2 diabetes (T2DM). The rate of insulin use was three-fold higher, whereas metformin use rate was two-fold higher in the same comparison.


CONCLUSIONS
Patients with PPDM have a higher frequency of clinically significant complications and were more commonly prescribed insulin and metformin, suggesting a more aggressive phenotype than that of T2DM. Greater PPDM awareness is needed to optimize disease management.