In-Hospital Postoperative Glycemic Trends After Pancreatic Insulinoma Resection

Introduction: Following resection of insulinoma, patients may develop postoperative hyperglycemia in the hospital. Predictors and trends of hyperglycemia immediately following surgery are poorly understood. Methods: We conducted a single-center retrospective study of patients who underwent distal pancreatectomy, enucleation, or ethanol ablation for solitary benign pancreatic insulinoma from 2010 to 2023. In-hospital postoperative glucose trends and predictors of hyperglycemia normalization after surgery were analyzed. Results: We identified 117 patients: 51% distal pancreatectomies, 42% enucleations, and 7% operative ethanol ablations. During their hospitalization, 73% of patients developed hyperglycemia postoperatively that normalized prior to discharge, while 24% had persistent hyperglycemia until discharge and 3% were normoglycemic. Of patients with glucose normalization, median time to normalization was 35 h (interquartile range= [16.3, 81.8]). Patients with glucose normalization within 5 days of surgery had significantly smaller insulinomas (median = 1.5 cm) than those without (median = 1.8 cm, P = 0.02). Predictors of glucose normalization within 5 days of surgery included smaller tumor size (odds ratio = 0.47, 95% confidence interval = [0.21, 0.93]; P = 0.05) and younger age (odds ratio = 0.97, 95% confidence interval = [0.94, 0.99], P = 0.04). Older age (B = 1.2, P = 0.02) and male gender (B = 44.7, P = 0.02) were associated with prolonged time to glucose normalization. Conclusions: Most patients develop transient hyperglycemia immediately after insulinoma resection which resolves, on average, within 35 h of surgery. Smaller tumor size is associated with glucose normalization while older age is associated with prolonged hyperglycemia in the early postoperative period. These findings may enable both patients and surgeons to better anticipate in-hospital glucose trends after surgical management of benign insulinoma.