Cellular Glucose Transport and Inflammatory Blood Markers in Rheumatoid Arthritis Spectrum: An Immunometabolic Perspective

Background: Rheumatoid arthritis (RA) is increasingly recognized as an immunometabolic disorder. This study evaluated whether glucose-handling markers, including glucose transporter 1 (GLUT1) and hexokinase 2 (HK2), and circulating inflammatory markers differed between RA cases and healthy controls and whether these markers were associated with DAS28-based disease activity in an exploratory secondary analysis. Methods: A retrospective secondary analysis was conducted using data from 160 participants, comprising 80 cases and 80 controls. Variables included demographic characteristics, fasting glucose, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), serum amyloid A (SAA), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), Disease Activity Score in 28 joints (DAS28), GLUT1, and HK2. Nonparametric tests were used for group comparisons, and Spearman's correlation was used to assess within-case associations. Results: Cases demonstrated significantly higher GLUT1 and HK2 levels than controls (both p < 0.001), along with elevated ESR, interleukin-6, SAA, NLR, and PLR. HK2 was significantly higher in high-activity than moderate-activity cases (p = 0.037), whereas GLUT1 was not. Within-case correlations were weak and nonsignificant. Conclusion: These findings support a measurable immunometabolic signature in RA. HK2 may show exploratory association with DAS28-based activity categories; however, prospective validation is required before clinical application.