High prevalence of cardiovascular comorbidities in patients with rheumatoid arthritis from a population-based cross-sectional study of a Japanese health insurance database

OBJECTIVE: To reveal any association between rheumatoid arthritis (RA) and cardiovascular comorbidities using a Japanese health insurance database. METHOD: This population-based cross-sectional study was conducted using health insurance data provided by the Japan Medical Data Center Co., Ltd. We identified 2762 RA subjects having RA diagnostic codes (ICD10 codes; M05, M060, M062-63, M068-069) with at least two physician visits more than two months apart between June 2011 and May 2012 (RA group, n = 2762). We selected age- (±5 years), sex-, and study period-matched non-RA subjects (non-RA group, n = 27,620). We compared the prevalence of cardiovascular and related comorbidities (ischemic heart diseases [IHD], cerebral infarction, hypertension [HT], dyslipidemia [DL], and diabetes mellitus [DM]) between these groups and investigated the association between RA and cardiovascular comorbidities using a conditional logistic regression analysis. RESULTS: The prevalence of all the investigated comorbidities in the RA group was significantly higher compared to the non-RA group. Odds ratios [95% confidence interval] of RA for IHD and cerebral infarction were 2.0 [1.5-2.5] and 3.1 [2.2-4.2] respectively, after adjusting for HT, DL, and DM. CONCLUSIONS: This study revealed for the first time in the Japanese population that RA was significantly associated with cardiovascular comorbidities.