MONTREAL — Psoriasis is an independent risk factor for increased cardiovascular morbidity and mortality, according to a growing number of studies and new guidelines from the American Academy of Dermatology.
Based on this evidence, it is important to screen and regularly monitor psoriasis patients for cardiovascular disease risk factors, said Dr. Lyn C. Guenther, professor and chair of the division of dermatology at the University of Western Ontario, London.
An increased prevalence of cardiovascular disease among people with psoriasis—especially more severe forms—is not new. “I thought it was all related to their [increased] weight,” Dr. Guenther said. “Psoriasis appears to be an independent risk factor now.”
The American Academy of Dermatology addressed increased cardiovascular risk among people with psoriasis in guidelines released in May.
Studies also have suggested that the increased prevalence of hypertension and diabetes among people with psoriasis (J. Am. Acad. Derm. 2006;55:829–35) contributes to the risk, as does a typically atherogenic lipoprotein profile at the onset of skin disease (J. Am. Acad. Dermatol. 2007;56:629–34).
“This is something we cannot ignore any longer,” Dr. Guenther said during a symposium sponsored by Abbott at the annual conference of the Canadian Dermatology Association. “I am not necessarily suggesting we are the ones who have to address this, but [we should] make sure these comorbidities are addressed.”
Psoriasis is associated not only with increased cardiovascular morbidity, but also with increased mortality. “This theme comes up repeatedly,” said Dr. Guenther, who has worked as a researcher, consultant, and speaker for Abbott, Amgen/Wyeth, Schering Plough, Astellas, and Leo Pharma. People with severe psoriasis have a 50% increased risk of death and tend to die earlier than do those without psoriasis (males 3.5 years earlier, females 4.4 years earlier). These figures do not apply to mild disease, she noted.
Not surprisingly, people with psoriasis also have an increased prevalence of metabolic syndrome, Dr. Guenther said.
In one case-control study, 30% of 338 adults with chronic plaque psoriasis and 21% of 334 adults with other skin diseases met criteria for metabolic syndrome—a difference that was statistically significant (Br. J. Dermatol. 2007;157:68–73).
In addition, younger patients with more severe psoriasis appear to be the group at greatest relative risk for a myocardial infarction (JAMA 2006;296:1735–41). Those with severe psoriasis at age 30 years had more than three times the risk (relative risk, 3.1) of having a myocardial infarction, compared with the general population. Risk was lower but still elevated for 30-year-olds with mild psoriasis (RR, 1.29). In 60-year-olds, however, severe psoriasis conferred a 1.36 relative risk for an MI and mild psoriasis conferred a 1.08 relative risk.
Inflammation may be the common culprit in both psoriasis and increased cardiovascular disease. “Tumor necrosis factor-α [TNF-α] is involved in cardiovascular disease and is a target for many of our therapies. High TNF levels are an independent predictor of cardiovascular morbidity and mortality, and TNF levels are high in psoriasis,” Dr. Guenther said.
Elevated C-reactive protein levels may be an important link between psoriasis and cardiovascular disease as well, as was suggested in an editors' roundtable in the American Journal of Cardiology (Am. J. Cardiol. 2008;101:1119–26). “C-reactive protein is something we are starting to measure in our patients,” said Dr. Guenther, who called the marker a very sensitive indicator of inflammation.
There are also immunologic similarities between atherosclerosis and psoriasis. Cell activation, inactive immunity, and adaptive immunity indicate that pathogenesis is similar between these two diseases, she said.
The good news is that treatment of psoriasis might reduce cardiovascular disease and death. “If you reduce inflammation, CRP, and TNF, it might reduce cardiovascular morbidity and mortality,” Dr. Guenther said, citing as an example, a study of rheumatoid arthritis patients, in which methotrexate decreased the incidence of cardiovascular disease and mortality (Lancet 2002:359:1173–7).