Clinical and biochemical characteristics of post-pancreatitis diabetes mellitus: a cross-sectional study from the Danish nationwide DD2 cohort

Background: Postpancreatitis diabetes mellitus (PPDM) is a common metabolic sequalae of acute and chronic pancreatitis. We conducted a cross-sectional study to examine the proportion of PPDM among patients clinically diagnosed with type 2 diabetes (T2D) in Denmark and their clinical and biochemical characteristics. Methods: We identified all past diagnoses of pancreatitis among patients in the Danish Centre for Strategic Research in Type 2 Diabetes (DD2) cohort through linkage with national health registries. Using International Classification of Diseases, Tenth Revision codes we categorized patients as PPDM and further divided them into acute/chronic subtypes (PPDM-A and PPDM-C). We assessed PPDM prevalence and examined associations with clinical and biochemical parameters using log binomial or Poisson regression to calculate age-/sex-adjusted prevalence ratios (aPRs). Results: Among 5564 patients with a clinical diagnosis of T2D, 78 (1.4%) had PPDM. Compared to T2D, PPDM patients were more often underweight or normal weight (body mass index ≤25.0 kg/m ²: aPR 2.3; 95% confidence interval [CI]: 1.6-3.2) and had lower waist-to-hip ratio (≤0.95/≤0.80 in men/women: aPRs 1.8; 95% CI: 1.2-2.7). PPDM patients had lower plasma amylase levels (<17 U/L: aPRs 2.2; 95% CI: 1.1-4.3), higher insulin sensitivity (homeostatic model assessment 2S [HOMA2S] >63: aPR 2.0; 95% CI: 1.2-3.2) and tended to have worse glycaemic control (HbA1c ≥8.0%: aPRs 1.4; 95% CI: 0.8-2.4). PPDM-A was largely indistinguishable from T2D, whereas PPDM-C had impaired insulin secretion, higher insulin sensitivity, and worse glycemic control. Conclusions: The proportion of PPDM among patients with clinically diagnosed T2D is ~1.5% in an everyday clinical care setting. Glucose metabolism of PPDM-A is largely indistinguishable from T2D, whereas PPDM-C differs in relation to insulin secretion and sensitivity.