To evaluate whether statins are associated with a protective effect on the development of rheumatoid arthritis (RA).
A nested case-control study was conducted using data from the General Practice Research Database. A study population consisting of three groups of subjects aged 40-89 years was identified: (1) patients exposed to a statin or other lipid-lowering agent (LLA); (2) patients with a diagnosis of hyperlipidaemia in the absence of lipid-lowering drug treatment and (3) a random sample of 25 000 individuals with no diagnosis of hyperlipidaemia nor a prescription for a LLA. From this population incident cases of RA and up to four controls for each case were identified, matched on age, sex, general practice, number of years of recorded history in the database and index date. The independent effects of hyperlipidaemia and statins on the development of RA were evaluated using conditional logistic regression.
313 cases of RA and 1252 matched controls were identified. Compared with patients with untreated hyperlipidaemia, or hyperlipidaemia treated with LLA other than statins, the adjusted odds ratio for patients with no hyperlipidaemia was 0.68 (95% CI 0.50 to 0.91). When those with hyperlipidaemia who received statins were compared with those with hyperlipidaemia who did not use statins (ie, untreated hyperlipidaemia patients or those treated with non-statin LLA) the OR was 0.59 (95% CI 0.37 to 0.96).
These data provide evidence to support the hypothesis that statins may be protective against the development of RA in patients with hyperlipidaemia.