Patients with Psoriatic Arthritis Also at Higher Risk for Cardiovascular Disease

An analysis of 35 years of cohort data provides fresh information about the biggest risk factors for cardiovascular disease in patients with psoriatic arthritis.

A study team from Toronto used records from 1,091 psoriatic arthritis patients who were recruited and followed between 1978 and 2013. Patient health was assessed every 6 to 12 months as part of the original cohort project and recorded along with information about demographics, lifestyle habits and medication usage.

The authors of the new study then used Cox proportional hazard models to look for relationships between cardiovascular events — myocardial infarction, ischemic stroke, revascularization or cardiovascular death — and all the recorded information, including the activity of their psoriatic arthritis.

Overall, 104 cardiovascular events occurred during the follow-up period. Among patients who reached 70 years of age during the study period, 19.8% of them had suffered a cardiovascular event by that birthday. Among patients who reached 80 years of age during the study period, 30.1% of them had suffered a cardiovascular event by that birthday.

Multivariate analysis found a number of factors, aside from age, that were independent predictors of cardiovascular events: hypertension (relative risk (RR), 1.81; p=0.015), diabetes (RR, 2.72; p<0.001) and the number of dactylitic digits (RR, 1.20; p<0.001). Sedimentation rate was also a significant predictor of cardiovascular events, but only among women (RR, 1.83; p=0.02).

“A significant proportion of patients with PsA develop cardiovascular events during the course of their disease,” the study authors wrote in the Annals of the Rheumatic Diseases. “Increased cardiovascular risk is associated with a combination of traditional cardiovascular risk factors and disease activity.”

The findings of the new study are largely consistent with earlier research, which has found that people with psoriatic arthritis are more prone to cardiovascular events than similar people who do not have the disease.

Some questions remain about why psoriatic arthritis patients suffer unusually high rates of cardiovascular disease, but existing research suggests a number of possible causes. For example, a paper that appeared in the Annals of the Rheumatic Diseases earlier this year compared 338 psoriatic arthritis patients with 50,468 controls in the Nord-Trøndelag Health Study 3. The study authors adjusted for age, gender and all cardiovascular risk factors considered by the SCORE algorithm and then looked for other factors that might explain the higher rate of cardiovascular events in patients with psoriatic arthritis.

They found, among the psoriatic arthritis patients, an increased prevalence of angina pectoris (5.0% vs 3.6%, p=0.01), history of percutaneous coronary intervention (2.4% vs 1.4%, p=0.04), hypertension (45.3% vs 39.3%, p=0.01), obesity (32.0% vs 22.4%) and tobacco smoking (21.3% vs 16.4%, p=0.02). They also found that psoriatic arthritis patients had elevated levels of C reactive protein (p<0.001), higher body mass index (p<0.001) and more triglycerides (p=0.01).

A prospective study that compared 102 consecutive psoriatic arthritis patients with 82 healthy controls found similar results. The body mass index of psoriatic arthritis patients was significantly higher than that of the healthy controls. The study authors, who published their findings in Rheumatology, adjusted for that difference and still found that psoriatic arthritis patients had a higher prevalence of diabetes mellitus [odds ratio (OR), 9.27; 95% confidence interval [CI], 2.09-41.09) and hypertension (OR, 3.37; 95% CI, 1.68-6.72), but a lower prevalence of low high density lipoprotein (HDL) cholesterol (OR, 0.16; 95% CI, 0.07-0.41).

“These data,” the study authors concluded, “support the hypothesis that PsA may be associated with obesity, hypertension, dyslipidemia and insulin resistance because of the shared inflammatory pathway.”