IGF1 and rheumatoid arthritis: There were studies which reported high IGFBP and IGF-Ι levels in both synovial fluid (SF) and serum of RA patients when compared to healthy group.21 There are also studies on the contrary reporting similar or reduced IGF-I and IGFBP levels in RA patients compared to controls.22 In RA, IGF-1 protein expression is deranged, which results in decreased blood levels of IGF-1 acting on the regulatory T-cells (Treg) and decreased suppression of inflammation.