Arthritis that accompanies the skin condition psoriasis may also come with a higher risk of heart problems, according to a Hong Kong study.
In particular, patients with so-called psoriatic arthritis may have a three- to four-fold higher prevalence of plaque in their coronary arteries, which leads to a higher heart attack risk.
Clinicians need to identify patients with high cardiovascular (CV) risk so they can provide lifestyle advice and preventive treatment to those individuals, said study author Lai-Shan Tam of the Chinese University of Hong Kong.
Psoriasis and psoriatic arthritis are related, but not everyone who has the red, scaly skin patches associated with psoriasis will develop the more severe psoriatic arthritis associated with joint swelling and pain.
According to the National Psoriasis Foundation, about 30 per cent of those with psoriasis develop the inflammatory arthritis, which that can cause permanent damage to joints.
Compared to the general population, people with psoriatic arthritis had a 68 per cent higher risk of heart attack and a 43 per cent higher risk of death during previous studies, the authors of the new study point out in the Annals of the Rheumatic Diseases. Although the increased risk and association are known, studies can't yet explain why.
Atherosclerosis, or hardening and narrowing of the arteries, is one risk factor that reliably predicts heart problems. Recent studies of atherosclerosis in patients with psoriatic arthritis have been limited to ultrasound images of the carotid arteries in the neck, however, so Tam and colleagues decided to use CT scans to look at multiple arteries around the heart.
The research team evaluated 90 psoriatic arthritis patients and 205 patients who didn't have this condition but who did have cardiovascular risk factors, such as chest pain.
The psoriatic arthritis patients, who didn't have a prior heart disease diagnosis, had significantly higher amounts of plaques of all kinds, including non-calcified and mixed plaques that are considered more likely to rupture and cause heart attacks.
Sixty per cent of psoriatic arthritis patients had at least one coronary plaque, as compared with 35 per cent of the other patients. In addition, the researchers found three-vessel disease in 13 per cent of psoriatic arthritis patients, compared to 3 per cent of controls, and they found that blood vessels had narrowed by more than 50 per cent in 9 per cent of patients with psoriatic arthritis, versus 3 per cent of controls.
Men over age 55 with longer histories of psoriatic arthritis were more likely to have the plaques most commonly associated with heart problems.
If doctors know to look for signs of heart disease sooner, they may be able to prescribe statins, anti-hypertension drugs and anti-inflammatory drugs before needing more aggressive treatment such as percutaneous coronary intervention or an angioplasty to improve blood flow to the heart, Tam told Reuters Health by email.
This could also be true for patients with other chronic inflammatory diseases such as rheumatoid arthritis, Tam and colleagues reported in another study. The researchers would also like to study atherosclerosis in patients with the milder psoriasis.
"A large proportion of patients could be having silent coronary artery disease," Tam said.
The study focuses on one group of patients at the Prince of Wales Hospital in Hong Kong, and the results might not be applicable everywhere, said Lihi Eder of the University of Toronto, who wasn't involved with the study. The researchers also couldn't study the effect of medications or changes for individual patients.
"The effect of psoriatic disease varies significantly over time," she told Reuters Health. But additional studies "investigating atherosclerosis . . . could assist in understanding a link."