The risk for cardiovascular disease in those with rheumatoid arthritis (RA) could be estimated through genetic screening, say scientists who found that mutations in the gene for interleukin (IL)-6 link these conditions.
"Mounting evidence associates RA with increased cardiovascular morbidity and mortality which cannot be explained solely by an increased prevalence of traditional cardiovascular disease risk factors," write George Kitas (University of Manchester, UK) and colleagues in the journal Atherosclerosis.
"The increased inflammatory load of these patients has been recently incorporated in the panel of the major risk factors for CVD development in RA," note the researchers.
They add: "Genes encoding pro-inflammatory cytokines are therefore candidates for predisposing to cardiovascular disease in RA."
For the current study, Kitas et al looked at variations in the IL-6 gene in 383 individuals aged an average of 61.3 years.
Genotyping results in these patients were compared with results from 422 control individuals of similar age who did not have RA.
Comparison revealed that cardiovascular disease was significantly more common in those with the IL6-174C allele than in those with other alleles, at a prevalence of 26.2% versus 17.0%.
Importantly, after adjustment for traditional cardiovascular disease risk factors and RA characteristics, patients with the IL6-174C allele still had almost twice the risk for cardiovascular disease (odds ratio = 1.92) of those without it, although smoking status had a small but insignificant effect on the relationship.
Discussing their work, the researchers note that their results are limited by the fact that they examined the effects of only one polymorphism on the presence of cardiovascular disease.
They therefore recommend haplotype analysis to elucidate the pathways linking IL-6 with cardiovascular disease in those with RA.
If such studies are performed and the current findings replicated, the authors argue that the "IL6 -174G>C polymorphism could be incorporated in the panel of a DNA microarray, which, alongside traditional risk factors, would help clinicians identify RA patients at higher risk for future development of CVD."
They believe this would allow "early, aggressive risk factor management including relevant education, smoking cessation, weight control and exercise."