Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Glucose Transporter 1 (GLUT-1) as Predictors of Insulin Resistance in Patients With Rheumatoid Arthritis: A Cross-Sectional Study

Rheumatoid arthritis is a chronic systemic inflammatory disorder associated with increased cardiometabolic risk, including insulin resistance. Persistent immune activation and metabolic reprogramming of inflammatory cells are considered key mechanisms linking inflammation to impaired insulin signaling. Hematological inflammatory indices and glucose transporter 1 (GLUT-1) expression may serve as accessible biomarkers of this interaction. This study aimed to evaluate the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and GLUT-1 expression on circulating immune cells as predictors of insulin resistance in patients with rheumatoid arthritis. It also assessed their association with inflammatory status, compared these biomarkers between patients with and without metabolic involvement, and determined their correlation with insulin resistance indices to identify independent predictors of metabolic dysfunction.

A cross-sectional study was conducted among 100 patients with rheumatoid arthritis. Clinical evaluation and fasting laboratory investigations were performed. Insulin resistance was estimated using the homeostatic model assessment of insulin resistance (HOMA-IR). NLR and PLR were calculated from complete blood counts. Flow cytometry was used to quantify GLUT-1 expression on monocytes and granulocytes. Statistical analyses included correlation and multivariate regression models.

Patients with insulin resistance demonstrated significantly higher NLR, PLR, and GLUT-1 expression compared to those without insulin resistance. HOMA-IR showed positive correlations with these biomarkers. Multivariate analysis identified NLR and monocyte GLUT-1 expression as independent predictors of insulin resistance.

Elevated inflammatory indices and increased GLUT-1 expression in immune cells are significantly associated with insulin resistance in rheumatoid arthritis, supporting their potential role in metabolic risk stratification.