Association Between Hemoglobin Glycation Index and Delirium Risk in Sepsis Patients in the Intensive Care Unit

Background: Sepsis-associated encephalopathy is a prevalent complication in the sepsis population, especially in patients in the intensive care unit (ICU). The relationship between the hemoglobin glycation index (HGI) and delirium in sepsis patients in the ICU is not yet clearly established. Aims: To investigate the relationship between HGI and delirium risk in sepsis patients admitted to the ICU. Study Design: Retrospective cohort study. Methods: The data were extracted from the Medical Information Mart for Intensive Care IV 3.1 for the sepsis population in the ICU. The primary outcome was delirium occurrence in the ICU, whereas the secondary outcome was 30-day all-cause mortality (ACM) after ICU admission. The patients were stratified into tertiles according to HGI levels: T1 (HGI < -0.612), T2 (-0.612 ≤ HGI < 0.008), and T3 (HGI ≥ 0.008). The link of HGI to clinical outcomes in ICU patients was examined through logistic regression (LR), Cox proportional hazard models, and restricted cubic spline (RCS) and threshold effect analyses. The robustness of our findings was rated through subgroup analyses and interaction tests. Results: In total, 3,744 patients were encompassed in the final analysis. The LR model showed that delirium risk in the T1 group was 67.7% higher than that in the T2 group [odds ratio (OR) = 1.677, 95% confidence interval (CI): 1.414, 1.992], while that in the T3 group was 24.8% higher than that in the T2 group (OR = 1.248, 95% CI: 1.048, 1.487). The Cox proportional hazard model indicated a 36.2% higher risk of 30-day ACM in T1 compared to T2 (hazard ratio = 1.362; 95% CI: 1.041-1.782). The RCS curve demonstrated an approximately U-shaped relation of HGI to delirium risk. The threshold effect analysis revealed an inflection point at HGI = -0.34. When HGI ≤ -0.34, each one-unit increase in HGI lowered the delirium risk by 36.2% (95% CI: 0.527-0.768). Conclusion: This study suggested an independent association between HGI and both delirium risk and short-term prognosis in particularly in patients admitted to the ICU. HGI may be used as a prognostic risk stratification biomarker.