Rheumatoid arthritis versus diabetes as a risk factor for cardiovascular disease: a cross-sectional study, the CARRE Investigation

Objectives: Patients with rheumatoid arthritis (RA) have an increased cardiovascular risk, but the magnitude of this risk is not known precisely. A study was undertaken to investigate the associations between RA and type 2 diabetes (DM2), a well-established cardiovascular risk factor, on the one hand, and cardiovascular disease (CVD) on the other. Methods: The prevalence of CVD (coronary, cerebral and peripheral arterial disease) was determined in 353 randomly selected outpatients with RA (diagnosed between 1989 and 2001, aged 50-75 years; the CARRE study) and in participants of a population-based cohort study on diabetes and CVD (the Hoorn study). Patients with RA with normal fasting glucose levels from the CARRE study (RA, n=294) were compared with individuals from the Hoorn study with normal glucose metabolism (non-diabetic, n=258) and individuals with DM2 (DM2, n=194). Results: The prevalence of CVD was 5.0% (95% CI 2.3% to 7.7%) in the non-diabetic group, 12.4% (95% CI 7.5% to 17.3%) in the DM2 group and 12.9% (95% CI 8.8% to 17.0%) in those with RA. With non-diabetic individuals as the reference category, the age-and gender-adjusted prevalence odds ratio (OR) for CVD was 2.3 (95% CI 1.1 to 4.7) for individuals with DM2 and 3.1 (95% CI 1.6 to 6.1) for those with RA. There was an attenuation of the prevalences after adjustment for conventional cardiovascular risk factors (OR 2.0 (95% CI 0.9 to 4.5) and 2.7 (95% CI 1.2 to 5.9), respectively). Conclusions: The prevalence of CVD in RA is increased to an extent that is at least comparable to that of DM2. This should have implications for primary cardiovascular prevention strategies in RA.