Risk of peripheral arterial occlusive disease in patients with rheumatoid arthritis. A nationwide population-based cohort study.

Rheumatoid arthritis (RA) is associated with atherosclerosis. However, the relationship between RA and peripheral arterial occlusive disease (PAOD) remains unclear. We used a national health insurance database to identify a cohort of 30,812 patients diagnosed with RA between 2000 and 2011. Each RA patient was frequency-matched according to age and sex with a patient without RA from a control cohort. A multivariate Cox proportional hazards model was used to analyse the adjusted risk of PAOD. The incidence of PAOD was 1.73-fold higher (95% confidence interval [CI] = 1.57-1.91) in the RA cohort than in the non-RA cohort. The adjusted risk of PAOD was the highest in the patients with RA aged ≤ 49 years (hazard ratio [HR] = 3.39, 95% CI = 2.66-4.32). Patients with RA and various comorbidities showed a significantly higher risk of PAOD (HR = 9.62, 95% CI = 4.86-19.1) compared with control patients without comorbidity. The risk of PAOD increased during the first year of follow-up. In conclusion, patients with RA have an independently higher risk of PAOD compared with the general population. Patients with RA and various comorbidities and those at a young age and early stage of the disease have an increased risk of PAOD.