Heart disease: Why people with severe psoriasis are at higher risk

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Researchers say psoriasis can exacerbate conditions that increase the risk of cardiovascular disease. NICK VEASEY/SCIENCE PHOTO LIBRARY/Getty Images
  • Researchers report that psoriasis is linked to an increased risk of heart disease.
  • They say that inflammation plays a role in this, but the precise mechanisms are unclear.
  • Early intervention and effective treatment plans may help reduce cardiovascular risks.

Globally, psoriasis affects an estimated 125 million people around the world.


Despite its prevalence, this immune-mediated dermatological condition still holds many mysteries.


Aside from psoriatic lesions on the skin, this condition can also influence less visible parts of the body.


One important example is its links to an increased risk of cardiovascular events. This increase in risk is independent of traditional cardiovascular risk factors, such as smoking, age, diabetes, and hypertension.


Medical News Today spoke with Dr. Joel Gelfand, a professor of dermatology and epidemiology at the University of Pennsylvania Perelman School of Medicine about the disease.


“There are many lifestyle, genetic, and immunologic connections between psoriasis and cardiovascular disease,” he explained.


He noted that scientists have known about this link for many years and it is an important area of research.


“The more extensive psoriasis is on the skin, the greater risk the patient has of heart attack, stroke, and mortality,” said Gelfand, who wasn’t involved in the study. “Underdiagnosed and undertreated, traditional cardiovascular risk factors in psoriasis patients are also critical to mediating this relationship.”


A recent study, which appears in the Journal of Investigative Dermatology, uses a new approach to investigate the precise mechanisms behind psoriasis and cardiovascular disease.


Current theories on psoriasis and heart disease

Experts say that the inflammation associated with psoriasis helps drive the development of cardiovascular disease.


This inflammation encourages the growth of plaques in blood vessels and can lead to atherosclerosis, a factor in the risk of cardiovascular diseases.


This includes an increased risk of coronary artery disease, where the blood vessels supplying the heart become narrower.


However, there are still some gaps in our understanding. Studies have shown that people with psoriasis have elevated cardiovascular risk before the appearance of coronary artery disease.


Some scientists believe that this may be due to coronary microvascular dysfunction (CMD). The latest study digs into this theory.


Coronary microvascular dysfunction

CMD affects the tiny blood vessels that supply the cardiac muscle. Like coronary artery disease, inflammation seems to be a driving factor in CMD.


However, while coronary artery disease and CMD are related, according to the authors of the recent paper, they “may play different roles in the pathogenesis of vascular disease.”


Some existing evidence suggests that the increased cardiovascular risk in people with psoriasis may be due to CMD, but previous investigations have been small in scale.


The latest study set out to replicate those findings in a larger group.


Because CMD affects the smallest blood vessels, most standard medical procedures cannot detect it. So, in this study, the researchers used a measure called coronary flow reserve, which can detect both coronary artery disease and CMD.


Coronary flow reserve

Coronary flow reserve is a measure of how much blood flow to the coronary arteries can increase during exertion. In other words, it assess how much the coronary circulation can dilate to increase its capacity.


In healthy people, coronary flow reserve is between 3 and 6. If someone has a score of 3, this means they can triple the blood flow when needed.


A score of 2.5 or lower indicates either CMD or coronary artery disease. So, if a routine coronary angiography reveals no coronary artery disease, this implicates CMD.


The findings from the psoriasis and heart disease study

The researchers included data from 448 people with psoriasis.


Of these, they found that 31% had a coronary flow reserve of 2.5 or lower, but no sign of coronary artery disease in a follow-up scan. So, roughly 1 in 3 had CMD.


Compared with participants without CMD, those with CMD were more likely to:


  • be older
  • have a higher body mass index (BMI)
  • have hypertension
  • have psoriatic arthritis

They were also more likely to have more severe psoriasis and to have lived with the condition for longer. So, as disease duration and severity increased, so did the risk of CMD.


The importance of the psoriasis study

Researchers say the results show that disease duration and severity are linked to CMD. Because CMD is prevalent in people with other inflammatory conditions, this supports the theory that systemic inflammation drives CMD.


Also, their analysis found no association between CMD and conventional cardiovascular risk factors, such as smoking, blood fat levels, or type 2 diabetes, all of which are associated with CMD in the general population.


Studies in the general population and people with psoriasis demonstrate that low coronary flow reserves predict poorer cardiovascular outcomes.


The authors conclude that the high levels of CMD are “likely to contribute significantly to the increased risk of adverse [cardiovascular] outcomes in patients with psoriasis […] independently of traditional [cardiovascular] risk factors.”


The authors also note that some research suggests that treating psoriasis is associated with reduced levels of CMD. With this in mind, they write:


“[W]e might hypothesize that an early and effective treatment of psoriasis would restore a CMD and eventually prevent the future risk of myocardial infarction and heart failure associated with it.”


Other options for assessing cardiovascular risk

Gelfand explained how he and his colleagues are also investigating other ways of assessing cardiovascular risk in people with psoriasis.


“The risk of future cardiovascular events can be further refined with cardiac imaging, such as a coronary artery calcium score,” he said. “We are testing a novel, centralized, care coordination model to help psoriasis patients get better screening for, and management of, traditional cardiovascular risk factors. Our preliminary data is quite promising.”


In the future, using a range of scanning and diagnostic technology might help assess and address cardiac risk earlier in this population.


Beyond inflammation

Because inflammation plays an important role in increasing cardiovascular risk, psoriasis drugs that reduce inflammation may also help reduce this risk.


However, as Gelfand mentioned, the evidence is “quite mixed” at this point.


“To date, TNF [tumor necrosis factor] inhibitors seem to be the most promising for lowering cardiovascular risk in psoriasis, but a causal relationship has not been established,” he said.


Successfully treating psoriasis symptoms can also reduce risk in other ways.


“Improved disease control may change how patients live their lives,” Axel Svedbom, PhD, a researcher at the Karolinska Institutet in Sweden who was not involved in the latest research, told Medical News Today.


“Patients with well-controlled psoriasis may lead healthier lives due to reduced social stigma and their sleep may improve due to reduced itch — poor sleep is a risk factor for cardiovascular disease,” he said.


“Furthermore,” he noted, “psoriasis is associated with lipid dysfunction and it is possible that disease activity modifies lipid composition of function. Another potential mechanism is tryptophan metabolism, which has been implicated in both psoriasis and cardiovascular disease.”


We still have much to learn about psoriasis. This study adds another piece to the puzzle.