Patients with severe psoriasis were nearly 70% more likely to develop abdominal aortic aneurysms compared with the general population, according to a Danish population-based cohort study.
The findings augment existing evidence linking psoriasis and cardiovascular diseases, wrote Dr. Usman Khalid of Copenhagen University Herlev and Gentofte Hospital, Denmark. The report was published online April 14 in Arteriosclerosis, Thrombosis, and Vascular Biology.
While the mechanisms for the link are unclear, “emerging evidence suggests that AAA is a focal representation of a systemic disease with a distinct inflammatory component, rather than a mere consequence of atherosclerosis,” wrote Dr. Khalid and his associates.
Several case series have linked AAA with other autoimmune disorders, including systemic lupus erythematosus and rheumatoid arthritis, they noted. Their study comprised nearly 5.5 million adults in Denmark between 1997 and 2011. The researchers identified 59,423 patients with mild psoriasis and 11,566 patients with severe psoriasis (Arterioscler Thromb Vasc Biol. 2016 April 14. doi: 10.1161/ATVBAHA.116.307449).
The incidence of AAA in the reference population was 3.72 cases per 10,000 person-years, with an average follow-up period of 14.4 years. In contrast, the incidence of AAA in patients with mild psoriasis was 7.30 cases per 10,000 person-years, and the rate in patients with severe psoriasis was 9.87 cases of per 10,000 person-years, with average follow-up periods of 5.7 years. Both mild and severe psoriasis were significantly associated with AAA after the researchers accounted for age, sex, comorbidities, medications, socioeconomic status, and smoking, with adjusted incidence rate ratios of 1.20 (95% confidence interval, 1.03-1.39) and 1.67 (95% CI, 1.21-2.32), respectively.
The historical view that AAA is caused mainly by atherosclerosis has largely been upended, the researchers noted. Instead, AAA appears to be a multifactorial process involving inflammation, matrix degradation, thrombosis, and aortic wall stress. Furthermore, inflammation in both AAA and psoriasis is centrally mediated by T-helper-17 cells and interleukin-17. Together, the data suggest that shared inflammatory mechanisms link psoriasis and AAA, especially because the association correlates with psoriatic disease activity, they said. “This finding clearly requires independent replication, and the clinical consequences are unclear at present.”
The LEO Foundation and the Novo Nordisk Foundation funded the study. Dr. Khalid had no disclosures. Four coinvestigators reported financial ties with Abbott, Pfizer, AstraZeneca, Bayer, and several other pharmaceutical companies.