Blood soluble receptor for advanced glycation end products (sRAGE) levels in age-matched groups of rheumatoid arthritis (RA) patients and healthy controls. Box plots show the 25th and 75th percentiles. Horizontal lines within boxes in bold indicate medians, and dashed lines indicate means. Vertical bars indicate the 5th and 95th percentiles. Statistical differences with respect to sRAGE levels between groups were calculated using the Mann–Whitney U test.