Serum IGF-1 in patients with rheumatoid arthritis: correlation with disease activity

Objective Insulin-like growth factor (IGF)-1 participates in modulating immunity and inflammation. Its bioactivity is controlled by six IGF-binding proteins (IGFBP-1 to IGFBP-6). In particular, the IGFBP-3 level is reportedly linked to the disease activity of rheumatoid arthritis (RA), consistent with our previous study. Therefore, the present study aimed to reproduce the previous results. Results The serum IGFBP-3 level was not significantly different among the three groups according to disease activity based on the DAS28-ESR/CRP ( p > 0.05) but was significantly different between the low- and high-disease-activity groups based on the DAS28-CRP ( p = 0.036). Meanwhile, the interleukin-6 (IL-6) level moderately correlated with DAS28-CRP (Spearman’s rho = 0.583, p < 0.001).