Prevalence and influence of hypouricemia on cardiovascular diseases in patients with rheumatoid arthritis

Serum uric acid (SUA) acts as an antioxidant and abnormally low SUA may raise the risk of developing atherosclerotic disorders. There is a U-shaped association between SUA with cardiovascular diseases (CVDs) in general population. However, the prevalence of hypouricemia and its influence on CVDs in rheumatoid arthritis (RA) remains unclear. This cross-sectional study collected clinical data from a Chinese RA cohort. Hypouricemia was defined as SUA ≤ 3.0 mg/dL, and hyperuricemia was defined as SUA ≥ 7.0 mg/dL. CVDs were defined as a history of angina pectoris, myocardial infarction, heart failure, stroke and peripheral arterial disease. Restricted cubic spline regression and logistic regression analysis were conducted to evaluate the associations between SUA levels and CVDs. Among 1130 RA patients recruited, the mean age was 53.2 years and 79.0% were female. The prevalence of hypouricemia and hyperuricemia were 10.6% and 12.0%, respectively. RA patients with hyperuricemia had a higher rate of CVDs than normouricemic patients (27.9% vs. 7.1%, P