Studies Differ on Arthritic and Cardiovascular Comorbidity

A study of nearly half a million people indicates that psoriatic arthritis patients suffer significantly elevated levels of cardiovascular and pulmonary disease — though not quite so elevated as patients with other rheumatic diseases.

Published late last year, the study examined data from 498,611 people aged 40-70 from the UK Biobank. Participants completed a touchscreen questionnaire on lifestyle, socio-demographics, current health and medical history. They also underwent verbal interviews with research nurses.

Investigators tabulated the prevalence of cardiovascular, pulmonary, allergic and metabolic comorbidities in patients with psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis and systemic lupus erythematosus. The researchers then divided actual comorbidity figures for each patient group by the “expected” comorbidity figures for age-and-sex-matched controls to calculate a Standardized Incident Ration (SIR) for each disease-comorbidity combination.

Cardiovascular comorbidities: Patients with psoriatic arthritis suffered significantly elevated rates of angina (SIR, 1.50; 95% confidence interval [CI], 1.08-2.03) and hypertension (SIR, 1.43; 95% CI, 1.28-1.59), but — unlike patients with the other 3 rheumatic diseases — they did not suffer significantly elevated rates of heart attack (SIR, 1.27; 95% CI, 0.83-1.87) or stroke (SIR, 0.97; 95% CI, 0.52-1.67).

Rheumatoid arthritis patients suffered elevated rates of heart attack (SIR, 1.86), angina (SIR, 1.87), stroke (SIR, 1.78) and hypertension (SIR, 1.24), as did patients with ankylosing spondylitis (heart attack SIR, 1.34; angina SIR, 1.34; stroke SIR 1.47; hypertension SIR, 1.17). Patients with systemic lupus erythematosus fared the worst (heart attack SIR, 3.35; angina SIR, 2.94; stroke SIR, 5.21; hypertension SIR, 1.42).

Pulmonary comorbidities: Patients with psoriatic arthritis suffered more emphysema/chronic bronchitis than expected but the numbers did not quite reach statistical significance (SIR, 1.54; 95% CI, 0.97-2.34). Their tendency to asthma was slightly (but not significantly) below normal (SIR, 0.91; 95% CI, 0.74-1.11).

Asthma rates were also about normal in patients with ankylosing spondylitis and systemic lupus erythematosus. They were elevated, however, in rheumatoid arthritis patients (SIR, 1.33; 95% CI, 1.24-1.42).

Emphysema rates were significantly elevated among patients with rheumatoid arthritis (SIR, 2.48; 95% CI, 2.18-2.81), ankylosing spondylitis (SIR, 2.37; 95% CI, 1.78-3.08) and systemic lupus erythematosus (SIR, 2.28; 95% CI, 1.37-3.56).

Patients with psoriatic arthritis were the only ones to suffer from significantly elevated rates of hay fever, eczema and/or allergic rhinitis (SIR, 1.19; 95% CI, 1.05-1.34).

Patients with rheumatoid arthritis were the only ones to suffer from significantly elevated rates of diabetes (SIR 1.49; 95% CI, 1.35-1.63).

“This study is unique in that it captures morbidities in a similar way across several rheumatic conditions in a large national-based study,” the investigators wrote in Arthritis & Rheumatology. “Prevalence rates of cardiovascular diseases and lung disorders are especially increased in people with rheumatoid arthritis, ankylosing spondylitis and systemic lupus erythematosus.”

Other researchers have looked for a link between psoriatic arthritis and cardiovascular disease. Some have found it, while others haven’t.

A study just published in Rheumatology matched 4 otherwise similar to people to all patients diagnosed with psoriatic arthritis, psoriasis or ankylosing spondylitis at a British primary care practice between 1999 and 2009. They then used Fisher’s exact test to compare cardiovascular outcomes between the matched patients and the 106 psoriatic arthritis patients, 290 psoriasis patients and 94 ankylosing spondylitis patients.

Psoriatic arthritis and ankylosing spondylitis patients did suffer significantly higher rates of hypertension than their matched cohorts. None of the study patients experienced significantly elevated rates of ischemic heart disease, hyperlipidemia or diabetes mellitus.

A number of other studies have reached somewhat ambiguous conclusions but the balance of evidence indicates a link between psoriatic arthritis and cardiovascular co-morbidity and disease, according to a 2011 research review that appeared in Annals of the Rheumatic Diseases.