Blockade of the interleukin-6 signaling pathway in rheumatoid arthritis: Effects on obesity, adipocytokines and glucose metabolism

Interleukin (IL) 6 is one of the key cytokines whose role in the inflammation development in rheumatoid arthritis (RA), is well proven. The pleiotropic effects of the cytokine and biologic agents that inhibit its action have been studied much worse. The review provides information on the effects of IL-6 and blocking its signaling pathway on adipose tissue, glucose metabolism and adipocytokine levels in RA. It has been shown that prolonged blockade of IL-6 receptors does not lead to the adipose tissue accumulation and improves glycemic control, although it is not clear whether such effect is associated only with the anti-inflammatory properties of tocilizumab and sarilumab. Moreover, the mechanism of this beneficial effect is not fully understood, since the data on increased sensitivity of peripheral tissues to insulin during tocilizumab treatment are ambiguous. Perhaps changes in the relationship of adipocytokines or hormones play a certain role.