Impact of Treatment with Methotrexate and TNF Alpha Inhibitors on Insulin Resistance in Patients with Psoriasis

ABS TRACT Objective: A strong link between psoriasis and obesity, type 2 diabetes, insulin resistance dyslipidaemia and metabolic syndrome has been documented. The aim of this study was to investigate the effects of methotrexate (MTX), a conventional antipsoriatic agent, and tumour necrosis factor (TNF)-alpha inhibitors (TNFi) on insulin resistance in pa- tients with psoriasis. Material and Methods: Thirty-one patients with psoriasis treated with MTX and TNFi were prospectively evaluated. Se- venteen patients received MTX, while 14 received the TNFi treatment. At the baseline and at week 12 values of serum C-reactive protein (CRP), the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and lipid parameters were evaluated. Results: The decrease in CRP le- vels after the treatment was significantly higher in the TNFi group than in the MTX group (-1.76 vs. -0.1, p = 0.005; respectively). The levels of serum glucose showed increases in both therapy groups, which was statistically significant in only TNFi group (p = 0.012). Although it was not statistically significant, increases in the HOMA-IR values were noted in MTX and TNFi therapy groups (0.26 ± 1.77 vs. 0.59±1.81, p = 0.558, p = 249; respectively). Conclusion: In the present study, a significant increase in the levels of fasting serum glucose was observed in TNFi group, and an increase in HOMA-IR values was noted in both therapy groups, which is not consistent with the literature. Despite the short follow-up pe- riod and small sample size, we believe that the effects of the TNFi and MTX demand caution for the follow-up of psoriasis, which is already an insulin-resistant condition.