Circulating adipokine levels in Portuguese patients with psoriasis vulgaris according to body mass index, severity and therapy

Background: Psoriasis vulgaris is associated with overweight/obesity and with increased C-reactive protein (CRP), tumour necrosis factor (TNF)-α, interleukin (IL)-6, leptin and resistin levels and decreased adiponectin levels.

Objectives: To understand the role/relationship of adipokines, as well as CRP, in a Portuguese psoriatic population, by assessing the relationship of their levels with psoriasis severity, defined by Psoriasis Area and Severity Index (PASI), with obesity, defined by body mass index (BMI), and psoriasis therapy.

Methods: A cross-sectional (n=66) and longitudinal study (before and after 12 weeks of therapy; n=44) was performed; 10 patients started topical treatment, 17 narrow-band ultraviolet B (NBUVB) and 17 psolaren associated with UVA (PUVA).

Results: Patients presented significantly higher BMI, leptin, resistin, TNF-α, IL-6 and CRP and significantly lower adiponectin values. CRP and IL-6 correlated with PASI. Adiponectin and leptin were more altered in patients with higher BMI. Concerning severity, CRP, resistin and adiponectin were more altered in the severer forms. After treatment, a significant reduction in PASI, CRP, resistin, TNF-α and IL-6, and a significant rise in adiponectin were observed. Nonetheless, CRP and adiponectin remained different from those of control. Concerning therapies, topical therapy was not associated with any significant change, except for TNF-α. After NBUVB, a significant reduction was observed in TNF-α and in CRP. For PUVA, we observed a significant reduction in TNF-α, IL-6 and CRP, and a significant increase in adiponectin.

Conclusion: In psoriatic patients, increased overweight/obesity was associated with raised leptin levels and decreased adiponectin levels. Leptin may contribute to enhance the inflammatory process in overweight/obese psoriatic patients. Resistin, IL-6, CRP and adiponectin levels appear to be dependent on psoriasis severity. CRP, together with IL-6, appears to be a useful marker of psoriasis severity. Both NBUVB and PUVA were effective; however, PUVA results seem to be more successful. Nonetheless, after NBUVB and PUVA, a low-grade inflammation still persists.