Relationship Between Inflammatory Markers (IL-6, Neutrophil-Lymphocyte Ratio, and C-Reactive Protein-Albumin Ratio) and Diabetic Ketoacidosis Severity: Correlation with Clinical Outcomes.

Background and Objectives: The use of additional biomarkers to predict clinical course in diabetic ketoacidosis (DKA) is becoming increasingly important. The aim of this study was to investigate the relationship between interleukin-6 (IL-6) levels and the length of stay in the intensive care unit (ICU) in patients with DKA without signs of infection and to investigate the relationship between the neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) albumin ratio (CAR). Materials and Methods: This retrospective, single-center study included 78 patients with DKA without infection who were treated in the Medical ICU between July 2022 and June 2024. The patients were divided into two groups: moderate DKA (Group 1) and severe DKA (Group 2). The patients' IL-6 levels, peripheral blood inflammatory markers (CAR, NLR), Acute Physiology and Chronic Health Evaluation (APACHE) II scores, and the duration of ICU stay were recorded. Results: The median duration of stay in the ICU was 2.00 (1-6) days in group 1 and 3.00 (1-26) days in group 2 (p = 0.001). The mean pH, HCO₃, and CO₂ values in Group 1 were 7.20 ± 0.07, 13.58 ± 2.11 mEq/L, and 29.45 ± 6.27 mmHg, while the mean pH, HCO₃, and PCO₂ values in Group 2 were 7.01 ± 0.11, 7.11 ± 1.91 mEq/L, and 20.35 ± 4.91 mmHg (p < 0.001, p < 0.001, p < 0.001, respectively). There was a strong positive correlation between IL-6 levels and the length of stay in the ICU (r = 0.813, p < 0.001). Additionally, there was a moderate positive correlation between the length of stay in the ICU with the severity of DKA (r = 0.475, p < 0.001), CAR (r = 0.336, p < 0.001), and NLR (r = 0.562, p < 0.001). Conclusions: Inflammatory markers such as NLR and CAR, and more specifically IL-6, were found to be associated with the clinical course and duration of stay in the ICU in patients with DKA.