Psoriasis as initiator or amplifier of the systemic inflammatory march: impact on development of severe vascular events and implications for treatment strategy.

Background Psoriasis is a systemic disease associated with metabolic disorders and vascular complications. Both psoriasis and metabolic disorders are associated with systemic inflammation. We hypothesized that the sequence of events between the onset of psoriasis and metabolic disorder may affect the risk for subsequent development of vascular complications. Methods Nested case-control study was performed using the Taiwan National Health Insurance database. Accordingly, a total of 8180 psoriatic patients and 163600 controls were included. Psoriasis was considered as the initiator of inflammatory march if metabolic disorder, including hypertension, diabetes mellitus and dyslipidemia, developed after onset of psoriasis. In patients with pre-existing metabolic disorder, psoriasis was considered as the amplifier of inflammatory march. Results In patients whose psoriasis served as the disease initiator, a lower risk for developing vascular disease (HR=1.49; 95% CI=1.11-2.00 and HR=1.64; 95% CI=1.31-2.05 for cerebrovascular and cardiovascular events, respectively) was found compared with patients whose psoriasis served as the disease amplifier (HR=2.26; 95% CI=1.72-2.97 and HR=2.78; 95% CI=2.26-3.42 for cerebrovascular and cardiovascular events, respectively) after adjusting for age and gender. In terms of treatment implications, methotrexate was associated with reduced risk for developing cerebrovascular event (HR=0.22; 95% CI=0.05-0.88) only in patients with psoriasis serving as the disease amplifier. Conclusions Our results suggested that two scenarios of systemic inflammatory marches are present among psoriatic patients with metabolic disorder and judicious use of methotrexate may reduce the risk of cerebrovascular event, especially when psoriasis served as the disease amplifier of the systemic inflammatory march.