Hemoglobin glycation index predicts reduced mortality in critically ill patients with chronic kidney disease.

BACKGROUND: Chronic Kidney Disease (CKD) is a worldwide health problem. Researchers have reported the close relation of the Hemoglobin Glycation Index (HGI) with metabolism, inflammation, and prognosis of disease. The prognostic value of HGI in CKD patients has not been assessed. This study aims to explore the association between HGI and mortality in critically ill patients with CKD. METHODS: Data on critically ill patients diagnosed with CKD were extracted from the Medical Information Mart for Intensive Care-IV database. The HGI is the difference between an observed glycated hemoglobin A1c(HbA1c) and a predicted HbA1c obtained by inserting Fasting Plasma Glucose (FPG) into a regression equation describing the linear relationship between FPG and HbA1c in a reference population. The follow-up started on the patients' first admission to the Intensive Care Unit (ICU). The primary outcome was 30-day mortality. 90-day and 365-day mortality were the secondary outcomes. Cox proportional hazards models were used to investigate the associations between HGI and mortality of CKD patients. Subgroup analyses were performed to assess the consistency of the association. RESULTS: 1,831 critically ill patients with CKD were included in the present study (64.1 % male, 60.2 % white, 71.93±12.72 years). For 30-day mortality, the Hazard Ratio (HR) value of the high-HGI group was 0.50 and 95 % Confidence Interval (95 % CI) was (0.39, 0.65) compared with the reference of the low-HGI group (p < 0.0001). When adjusted for age, gender and ethnicity, the adjusted HR (95 % CI) value of the high-HGI group was 0.53 (0.41, 0.68). When further adjusted for heart rate, diabetes mellitus, and SOFA score in Model II, the adjusted HR value of the high-HGI group was still statistically significant (HR = 0.57, 95 % CI: 0.44‒0.75, p < 0.0001). Similar results were also shown in the secondary outcomes of 90-day and 365-day mortality. Further subgroup analysis showed the above stable association between HGI and 30-day mortality of CKD patients. CONCLUSIONS: High level of HGI is associated with reduced short- and long-term all-cause mortality of critically ill patients with CKD. HGI can independently predict the prognosis of critically ill patients with CKD.