Abstract: Objective To investigate the association between preoperative hemoglobin glycation index (HGI) and postoperative complications in diabetic patients undergoing elective surgery. Methods This single-center retrospective cohort study included adult diabetic patients who underwent elective non-cardiac surgery between January 2013 and June 2024. Preoperative fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), and perioperative clinical data were collected. HGI was calculated as the difference between observed HbA1c and HbA1c predicted from FPG using a linear regression model. The primary outcome was postoperative complications during hospitalization. Multivariable logistic regression was used to evaluate the independent association between HGI and postoperative complications, and restricted cubic splines were applied to assess potential non-linear relationships. Results Total of 9 249 diabetic patients undergoing elective surgery were included, among whom 761 patients (8.2%) developed postoperative complications. Higher preoperative HGI was independently associated with an increased risk of postoperative complications (OR:1.099, 95% CI: 1.029-1.171; P=0.004). Restricted cubic spline analysis suggested a linear association between HGI and complication risk. Conclusions Preoperative HGI is an independent risk factor for in-hospital postoperative complications in diabetic patients following elective non-cardiac surgery. The linear dose-response relationship identified highlights its potential as a supplementary tool for perioperative risk assessment.

Key words: hemoglobin glycation index, postoperative complications, diabetes, non-cardiac surgery