BACKGROUND: Recent observations suggest that psoriasis is a risk factor for the development of coronary artery calcification which in turn represents an indicator for atherosclerosis. OBJECTIVE: To clarify a possible pathogenetic link between psoriasis and atherosclerosis, we studied the metabolic state of patients with psoriasis. METHODS: Thirty-nine consecutive patients with moderate-to-severe plaque-type psoriasis were enrolled in the study. Detailed information was obtained on the patients' clinical picture and history of psoriasis, smoking habits and medication. The body mass index (BMI) of the patients was calculated. Laboratory investigations focused on values for inflammation, lipid profile and multiple cytokines. The intima-media thickness of the carotid artery was measured by ultrasound, and an oral glucose tolerance test was performed to calculate the homeostasis model assessment of insulin resistance (HOMA). RESULTS: Numerous well-recognized correlations such as between BMI and HOMA (P < 0.02) as well as BMI and vessel wall thickness (P < 0.05) were successfully reproduced, thus confirming consistency of our dataset. With regard to psoriasis, we observed a significant correlation between the Psoriasis Area and Severity Index (PASI) score and insulin secretion. Moreover, the PASI score was significantly correlated with serum resistin levels--a cytokine known to be increased in insulin resistance. CONCLUSIONS: Taken together, several measurements indicative of insulin resistance were found to be significantly correlated with the PASI score. The concept of insulin resistance as a consequence of chronic inflammation and possible pathogenetic cause for comorbidities known to be associated with psoriasis is supported by these data. Our findings validate further studies on larger cohorts as well as interventional studies.