Prevalence of risk factors for statin-induced myopathy in rheumatoid arthritis patients

Statins are widely prescribed in patients with rheumatoid arthritis (RA). Although statins offer overwhelming cardiovascular benefits, their use can be associated with the development of a statin-induced myopathy. Several factors increase the risk of developing statin-induced myopathy, including the single nucleotide polymorphism (SNP) rs4149056, located within the gene encoding solute carrier organic anion transporter (SLCO1B1). We aimed to identify the frequency of risk factors for statin-induced myopathy and establish whether the rs4149056 genotype is more prevalent in RA.

A total of 396 RA patients and 438 non-RA controls were studied. DNA samples were obtained from all patients. The SNP rs4149056 was identified using real-time polymerase chain reaction and melting curve analysis. Genotypic and allelic frequencies were calculated using the chi-squared test.

Almost 80% of RA patients had one or more risk factor (range 1-5) for the development of statin-induced myopathy. Of the 74 RA patients treated with statins, 90% had one or more (range 1-4) risk factors. No differences in genotype or allelic frequencies were observed between RA patients and controls.

RA patients harbour multiple risk factors for statin-induced myopathy. However, the frequency of the rs4149056 genotypes does not differ according to the presence of RA. Despite this, no cases of statin-induced myopathy were observed in this cohort over a period of four years of follow-up. Thus, we conclude that statin use among RA patients is probably safe, but large-scale prospective studies are needed to confirm this. In the meantime, it may be good practice systematically to consider and record myopathy risk factors in these patients.