COPENHAGEN – The increased risk of MI and stroke in patients who develop psoriasis as young adults is essentially confined to those having a positive family history of cardiovascular disease, according to a Danish national study presented at the annual congress of the European Academy of Dermatology and Venereology.
“We found a significantly increased risk of MACE [major adverse cardiovascular events] in patients with psoriasis only when a family history of cardiovascular disease was present. This just highlights why it’s important that future studies of cardiovascular risk in psoriasis should include family history. Also, an increased focus on cardiovascular disease in relatives may be appropriate in the cardiovascular risk assessment of patients with psoriasis,” said Dr. Alexander Egeberg of the University of Copenhagen.
He presented a population-based study involving 15 years of follow-up of 30,278 Danes diagnosed with psoriasis in their 20s and a control group consisting of nearly 2.7 million of their Danish contemporaries who were not. None had personal history of acute MI or stroke at baseline. Family medical history, including whether cardiovascular disease occurred in first-degree relatives, was available for all subjects.
Dr. Egeberg and coinvestigators mapped the incidence of acute MI, ischemic stroke, or cardiovascular death in psoriasis patients and the general population controls during follow-up.
“When you look at the patients who developed psoriasis and didn’t have a positive family history of cardiovascular disease, there are almost no cardiovascular events for the entire country,” Dr. Egeberg observed.
In contrast, in a multivariate analysis adjusted for age, gender, socioeconomic status, comorbid cardiovascular disease, smoking, and the use of cardiovascular medications, patients with mild psoriasis and a positive family history for cardiovascular disease had a 28% greater risk of a premature cardiovascular event than the general population during follow-up out to roughly age 40. Those with a positive family history and severe psoriasis as defined by the use of systemic therapies had a 62% increase in risk. Both of these elevated risks were statistically significant.
Among young adult Danes with a positive family history for cardiovascular disease, there were 222 MACE events during 62,225 person-years of follow-up in the mild psoriasis group and 31 events during 6,848 person-years in the 4,504 subjects with severe psoriasis. The resultant incidence rates in both groups were significantly higher than in the control group, who experienced 28,846 MACE events during 16.1 million person-years of follow-up.
In contrast, fewer than 10 MACE events occurred in Danish psoriasis patients without a family history of cardiovascular disease.
A positive family history was also associated with increased MACE in the nonpsoriatic general population, although it didn’t confer as great a risk as in the Danes with psoriasis.
A point worthy of consideration, Dr. Egeberg noted, is that the epidemiology of psoriasis in Denmark apparently differs in several important ways from psoriasis in the United States and some other countries. For one, the prevalence is higher in Scandinavian countries – 7.1% in a Danish national cross-sectional study (Int J Dermatol. 2013 Jun;52[6]:681-3) and 8% in neighboring Norway – as compared with 2%-3% in much of the rest of the world.
Moreover, according to the same cross-sectional study, the prevalence of traditional cardiovascular risk factors, such as smoking and the components of the metabolic syndrome, isn’t higher in Danish psoriasis patients than in the country’s general population. That’s in contrast to the situation in the United Kingdom, where Dr. Joel M. Gelfand of the University of Pennsylvania and associates reported a decade ago in a landmark study that the prevalence of hypertension, obesity, hyperlipidemia, diabetes, and smoking were all higher in persons with psoriasis than in the general population (J Am Acad Dermatol. 2006 Nov;55[5]:829-35). Similar findings were subsequently reported in U.S. psoriasis patients.
Despite their absence of elevated levels of the standard cardiovascular risk factors, Danish psoriasis patients as a group do face a clinically significant increase in cardiovascular risk, compared with the general population, as shown in yet another Danish national cohort study in which the rate ratios for cardiovascular death for mild and severe psoriasis were 1.14 and 1.57, respectively, compared with controls (J Intern Med. 2011 Aug;270[2]:147-57).
In an even more recent Danish nationwide study, the overall death rate was found to be 25.4 per 1,000 person-years in patients with severe psoriasis, 17.0 in those with mild psoriasis, and 13.8 per 1,000 person-years in the general population (J Eur Acad Dermatol Venereol. 2015 May;29[5]:1002-5).
Dr. Egeberg said his new Danish findings suggest that even in psoriasis patients with a greater burden of systemic inflammation as expressed in severe disease, that burden alone doesn’t translate into increased cardiovascular risk. Rather, elevated cardiovascular risk appears to be a consequence of heritable factors, Dr. Egeberg said.