Body composition and serum levels of adiponectin, vascular endothelial growth factor, and interleukin-6 in patients with rheumatoid arthritis

Aim To investigate differences in body composition and body mass index (BMI) in patients with rheumatoid arthritis (RA) and their correlations with serum production of adiponectin, interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF). Methods The study included 83 patients (age 53 ± 5 years) with RA treated with methotrexate. We determined their BMI, fat mass, and fat-free mass using bioimpedance analysis, and serum concentrations of adiponectin, VEGF, and IL-6 using immunoassay analysis. Results Normal BMI was found in 39 (47%), overweight and obesity in 26 (31%), and underweight in 18 (22%) patients. Concentration of adiponectin was lower in overweight/ obese patients than in patients with normal BMI (2.1 [0.8- 3.9] μg/mL vs 8.9 (7.2-11.3) μg/mL). In underweight patients, it was moderately increased (12.7 [9.3-14.8] μg/mL) and the correlation between the concentrations of adiponectin and IL-6 was positive (r = 0.4; P = 0.01). Concentrations of VEGF and IL-6 were increased in all groups with RA. The overweight/obese group showed a negative correlation between the concentrations of adiponectin and VEGF (r = - 0.34; P = 0.04), a positive correlation between VEGF concentration and fat mass (r = 0.39; P = 0.02), and a negative correlation between adiponectin concentration and fat mass (r = - 0.23; P = 0.02). Conclusion Inflammatory and angiogenesis activation was found in RA patients with all types of body composition, but only in those with obesity and overweight there was a direct antagonism between adiponectin and VEGF. Further research is needed to identify possible regimens of metabolic correction in different variations of body composition.