Association between hemoglobin glycation index and delirium after gastric surgery: Based upon the MIMIC-IV

Defined as the observed hemoglobin A1c minus the expected hemoglobin A1c calculated from glucose level, the hemoglobin glycation index (HGI) quantifies the mismatch between chronic glycation status and contemporaneous glucose level. This research sought to ascertain whether HGI is associated with postoperative delirium (POD) after gastric surgery by analyzing data from the Medical Information Mart for Intensive Care IV database. We implemented a retrospective cohort study utilizing data from the Medical Information Mart for Intensive Care IV database (v3.1) on patients who underwent gastric surgery. The patients were categorized into 3 HGI tertile groups: T1, T2, and T3. The primary outcome was POD after gastric surgery. The logistic regression models were utilized to estimate the interrelation between HGI and POD after gastric surgery. A potential nonlinear relationship between HGI and POD was assessed by restricted cubic spline. A threshold effect analysis was conducted utilizing piecewise logistic models. This study included 1133 patients. The median age was 65.78 (range: 18.43-95.06 years), with 60.10% patients being male. Among included patients, POD occurred in 687 patients (60.64%). Compared to T2 (reference), T1 (low HGI) was independently associated with higher odds of POD (odds ratio [OR] 1.433; 95% confidence interval [CI] 1.015, 2.028; P = .042), whereas T3 (high HGI) exhibited no significant association with POD (OR 1.224; 95% CI 0.846-1.772; P = .284) in the fully adjusted logistic regression model. An L-shaped relationship was observed, with inflection point at -0.226. Below this threshold, every unit elevation in HGI was associated with a 31.3% decrease in the odds of POD after gastric surgery (OR 0.687; 95% CI 0.489, 0.935; P = .023). Among individuals who underwent gastric surgery, lower HGI is independently associated with greater odds of POD, indicating a higher risk for patients with low HGI. As a parameter that identifies the mismatch between long-term glycation status and contemporaneous glucose, HGI could be utilized in the risk stratification of patients for POD after gastric surgery.