Immediate Postoperative Hyperglycemia As an Independent Risk Factor for New-Onset Diabetes Mellitus Following Pancreaticoduodenectomy: A Retrospective Cohort Study

Background Pancreaticoduodenectomy (PD) increases risk of new-onset diabetes mellitus (NODM), but early predictive markers remain poorly defined. We investigated whether immediate postoperative hyperglycemia (IPH) predicts long-term NODM development following PD, potentially enabling early risk stratification and intervention. Methods We retrospectively analyzed patients undergoing pancreaticoduodenectomy (2010–2020) without pre-existing diabetes. IPH was defined as glucose ≥200 mg/dL within 24 h postoperatively. The primary endpoint was NODM occurrence following PD > 90 days, defined by ADA criteria. Kaplan-Meier survival analysis and multivariable Cox regression models assessed the association between IPH and NODM following PD, adjusting for demographic and tumor factors. Results Among 1060 patients, 662 (62.5 %) experienced IPH. During median follow-up of 4.8 years, NODM following PD developed in 48.5 % of IPH patients versus 42.5 % of non-IPH patients. IPH patients demonstrated significantly worse diabetes-free survival (log-rank p = 0.003) and earlier onset (median 584 vs 844 days, p < 0.001). After multivariable adjustment, IPH independently predicted NODM (HR 1.28, 95 % CI 1.06–1.56, p = 0.012), along with male (HR 1.32, p = 0.004) and specific tumor types (pancreatic cancer HR 1.73, p = 0.005; duodenal cancer HR 1.85, p = 0.019). Conclusions Immediate postoperative hyperglycemia independently predicts long-term diabetes development after pancreaticoduodenectomy. Incorporating IPH into postoperative risk assessment may enable targeted surveillance and early intervention strategies.