Symptomatic hand osteoarthritis is associated with a significant increase in the risk of coronary heart disease events, although the association was not significant for asymptomatic hand osteoarthritis, according to results from a study presented at the annual European Congress of Rheumatology.
A population-based cohort study of 1,348 participants from the Framingham Heart Study found more than double the incidence of coronary heart disease among individuals with symptomatic hand OA, compared with those without hand OA (hazard ratio, 2.26; 95% confidence interval, 1.22-4.18), Dr. Ida K. Haugen reported.
The study defined symptomatic hand OA as one or more hand joints with Kellgren-Lawrence grade of 2 or above and pain in the same joint. The definition excluded individuals with rheumatoid arthritis (RA).
The association persisted even after adjustment for lower limb pain (HR, 2.00; 95% CI, 0.96-4.15), to account for the physical inactivity potentially associated with OA in lower limb joints, according to Dr. Haugen from Diakonhjemmet Hospital in Oslo, and her associates.
However, individuals with radiographic but not symptomatic hand OA showed a nonsignificant increase in the risk of coronary heart disease (HR, 1.60; 95% CI, 0.96-2.66).
The study set out to examine a possible association between hand OA and cardiovascular disease, based on the premise that hand OA is especially likely to be related to metabolic rather than mechanical causes.
"We hypothesized that the association between hand OA and coronary heart disease could be mediated through metabolic factors, such as hyperlipidemia and diabetes, or a more sedate lifestyle due to generalized OA," Dr. Haugen said in an interview.
"Radiographic hand OA is very prevalent in the general population, and only a proportion of those with radiographic hand OA may experience symptoms," she said. "We believe that symptomatic hand OA represents more severe hand OA and, further, the association between hand OA and coronary heart disease may be mediated through factors associated with pain, such as synovitis."
Synovitis has been shown in other diseases such as RA to increase the risk of cardiovascular disease due to the development of atherosclerosis, Dr. Haugen said.
The study failed to find any significant associations between hand OA – either symptomatic or radiographic only – and cardiovascular events, overall mortality, heart failure, and atherothrombotic stroke.
"[W]e hypothesize that the varying associations may be due to different risk factors for coronary heart disease versus cerebrovascular disease and congestive heart failure; for example, hypertension seems to be more important for cerebrovascular disease than for coronary heart disease," Dr. Haugen said.
While further research is needed to explore the mechanisms of the association, Dr. Haugen suggested that clinicians note that patients with hand OA may be at greater risk of coronary heart disease, and preventive strategies may therefore be of greater importance in this group.
Dr. Haugen reported having no relevant financial disclosures.