Effect of treatment with methotrexate and coal tar on adipokine levels and indices of insulin resistance and sensitivity in patients with psoriasis vulgaris

Background and objectives: Recent studies have implicated adipokines in the pathogenesis of the immune-mediated inflammatory disease, psoriasis and its associated comorbidities. Hence, we undertook to study adipokine levels and indices of insulin resistance and sensitivity in patients with psoriasis vulgaris, in comparison with controls and their association with disease severity and response to therapy.

Methods: Sixty cases of psoriasis vulgaris and 60 age- and gender-matched healthy controls were included in this study. Severity grading according to psoriasis area severity index scoring was done in all psoriatics. Serum levels of adipokines [leptin, adiponectin, resistin and interleukin-6 (IL-6)] and insulin were estimated in all psoriatics at baseline and at 12 weeks on follow-up and in controls.

Results: Baseline levels of the inflammatory adipokines (leptin, resistin and IL-6) and insulin resistance indices were significantly higher in psoriatics, as compared to controls, while that of the anti-inflammatory adipokine, adiponectin and insulin sensitivity indices were significantly lower in psoriatics, as compared with controls. Baseline inflammatory adipokines, serum insulin level and insulin resistance indices demonstrated a significant positive correlation with the severity of psoriasis, while the anti-inflammatory adipokine, adiponectin and insulin sensitivity indices demonstrated a significant negative correlation with the disease severity. After 12 weeks of therapy (both topical and systemic), there was a significant reduction in the levels of inflammatory adipokines and a significant increase in the levels of anti-inflammatory adipokine-adiponectin. However, a significant decrease in insulin levels and insulin resistance indices were observed only with systemic therapy with methotrexate.

Conclusion: The present results implicate that adipokines are significantly associated with pathogenesis of psoriasis and hence adequate and early control of psoriasis may contribute to the decreased development of metabolic syndrome, including the risk of cardiovascular disease.