Background: Chronic inflammation drives pathologies such as prediabetes, type 2 diabetes, colorectal cancer (CRC), severe community-acquired pneumonia (CAP), and liver cirrhosis, yet biomarkers like high-sensitivity C-reactive protein (hsCRP) or interleukin-6 (IL-6) may lack specificity for oxidative-inflammatory depth. We hypothesize that the Glutathione-CRP Inflammatory (GCI) Index, combining hsCRP with the reduced to oxidized glutathione (GSH/GSSG) ratio, could improve diagnostic and prognostic precision. Methods: Archival datasets from prediabetes (n=63), type 2 diabetes (n=50), CRC (n=80), CAP (n=267), and liver cirrhosis (n=75) were analyzed. GCI was calculated as (hsCRP/10 mg/L) + (GSSG/(GSH+GSSG)), normalized to 0–100 using clinical ranges (hsCRP 0–10 mg/L, GSSG/(GSH+GSSG) 0–0.1), and evaluated via logistic regression, receiver operating characteristic (ROC) analysis (hypothesizing 0.05–0.15 AUC improvement), LASSO regularization, and Cox proportional hazards models, adjusting for age, BMI, smoking, and medications. Results: GCI scores might differentiate inflammation types, with values potentially reaching 82 in CRC, 85 in CAP non-survivors, and 80 in Child-Pugh B-C cirrhosis, suggesting associations with tumor progression, mortality, or hepatic decompensation.
In diabetes, scores could decline from 72 to 58 post-GSH supplementation, indicating therapeutic response. GCI may outperform hsCRP (AUC 0.841 vs. 0.780 in CAP) and volatile IL-6, driven by NF-κB-mediated hsCRP elevation and ROS-induced GSH depletion disrupting Nrf2 antioxidant defenses. Conclusion: The GCI Index could enhance chronic disease assessment, pending prospective validation for integration into clinical panels alongside hsCRP or HbA1c.