Polymyalgia rheumatica patients aged 50-59 had a fivefold increased risk of vascular disease, compared with a threefold increased risk among patients aged 80 and older.
Several inflammatory rheumatological disorders, including rheumatoid arthritis, systemic lupus erythematosus, gout, psoriatic arthritis and ankylosing spondilitis, are associated with an increased risk of cardiovascular disease.
However, evidence has been mixed as to whether one of the most common inflammatory rheumatological conditions - polymyalgia rheumatica - is linked to increased risk of cardiovascular disease. Although there are "a number of biologically plausible mechanisms between polymyalgia rheumatica and vascular disease," studies that have investigated a potential association have been small or have not been of good quality.
In the new study, UK-based researchers examined the data of 3,249 patients with polymyalgia rheumatica and 12,735 patients who did not have this condition. Both groups were being treated by primary care physicians in England and Wales, and none of the patients had history of vascular disease.
Following the participants for up to 12 years, the researchers found that the polymyalgia rheumatica patients had a higher risk of all vascular diseases, including angina, heart attack, atherosclerosis and stroke. The risk was similar for men and women, and was highest in the 6-12 months after being diagnosed with polymyalgia rheumatica.
Age also influenced risk - patients aged 50-59 had a fivefold increased risk of vascular disease, compared with a threefold increased risk among patients aged 80 and older.
The authors explain their findings:
"Our results showed that patients with polymyalgia rheumatica had an increased risk of all types of vascular events, even after traditional risk factors for vascular disease were controlled for. This excess risk was present soon after diagnosis, was present in both men and women, and was largest in younger (< 60 yr) patients.
This early excess risk provides insight into potential mechanisms and supports the link between inflammation and vascular disease, given that the inflammatory burden in polymyalgia rheumatica...is highest in early disease."
In their conclusion, the authors recommend "aggressive management" of vascular risk factors in patients with polymyalgia rheumatica but say that further research is needed to investigate the mechanisms behind the association.
Polymyalgia rheumatica 'difficult to diagnose'
The researchers say that one potential confounding factor in their research could be "surveillance bias." Patients newly diagnosed with polymyalgia rheumatica are known to consult more regularly with physicians, so it is possible that their doctors were more vigilant in identifying emerging risk factors than would otherwise be the case.
Also, the authors acknowledge that polymyalgia rheumatica is a difficult condition to diagnose accurately, as a single diagnostic test does not exist. Therefore, it is possible that some participants in the study could have been misdiagnosed.
However, in an attempt to avoid this misclassification problem, the researchers limited their polymyalgia rheumatica participants to patients in a primary care setting who were receiving steroids for their condition.
The first classification criteria for polymyalgia rheumatica were released by the American College of Rheumatology in 2012. Under those criteria, a patient can be categorized with having polymyalgia rheumatica if they present with:
- Shoulder pain on both sides
- Morning stiffness that lasts at least 45 minutes
- High levels of inflammation measured by protein in blood and erythrocyte sedimentation
- Reported new hip pain
- Absence of swelling in the small joints of the hands and feet, and absence of positive blood tests for rheumatoid arthritis.