Comparative Effects of TNF alpha and IL-6 Inhibitors on Glucose and Lipid Metabolism in Patients with Rheumatoid Arthritis (RA)

Association between TNFα and IL-6 and glucose tolerance has been reported. However, it is not clear that TNFα and IL-6 affect on glucose tolerance. Recently, biologic agents such as TNF and IL-6 inhibitors have been appeared in the treatment of RA. We have examined comparative effects of TNF αand IL-6 inhibitors on glucose tolerance and lipid metabolism in patients with rheumatoid arthritis. Registered 589 patients with RA have been screened by HbA1c level (more than 5.6%), treatment with methotrexate (MTX) and treatment with biologic agents with or without MTX. We have excluded the patients with RA who are treated with insulin, and selected 30 cases of RA patients who were able to follow-up for 12 months (M). Patients with RA were divided to 3 groups by the treatments as follows: TNF inhibitors with MTX (TNF+MTX), IL-6 with and without MTX (IL-6±MTX) and MTX alone. Body weight, HbA1c, LDL-C, HDL-C, LDL-C/HDLC(L/H) and disease activity score (DAS) were measured before and after 6 and 12 M. There were no differences of DAS between each group before and after 6 and 12 M. DAS in each group was a significantly decreased compared with before (P < 0.05-0.001). HbA1c levels in TNF+MTX were not significantly different (before 6.08%, 6 M 5.92%, 12M 5.91%), but those in MTX alone and IL-6±MTX were significantly improved (before 6.42% and 6.2%, 6M 5.87% and 5.78%, P< 0.05, 12M 5.82%, P< 0.05 and 5.81%, P< 0.01), respectively. There were no significant differences of body weight between each group. HDL-C and LDL-C in IL-6±MTX were significantly (P< 0.01) increased (before 58.2 mg/dl and 123.2 mg/dl, 6M 71.7 mg/dl and 148.5 mg/dl, 12M 63.4 mg/dl and 144.2 mg/dl), respectively. L/H in TNF+MTX was significantly (P<0.05) decreased. In conclusion, effect of glucose tolerance in IL-6 inhibitors was better than TNF inhibitors in RA patients with glucose intolerance. However, TNF inhibitor in lipid metabolism was better than IL-6 inhibitors. Disclosure T. Ishizuka: None. K. Fujioka: None. I. Mori: None. T. Takeda: None. S. Inui: None.