Association between Serum Uric Acid and Impaired Endothelial Function: The Circulatory Risk in Communities Study

Aims: Higher serum uric acid (UA) may impair endothelial function. However, population-based evidence examining the association between serum UA levels and endothelial function remains to be limited. Thus, in this study, we aimed to investigate this in the general population. Methods: In this cross-sectional study, 1000 participants (496 males and 504 females), aged 30–79 years, free from a history of gout, have undergone both serum UA and brachial artery flow-mediated dilation (FMD) measurements. Participants were divided into four groups based on serum UA quartiles. Logistic regression models were used to calculate odds ratios (ORs) for low FMD according to the serum UA levels. Results: In total, 203 participants (138 males and 65 females) with %FMD ≤ 5.0% were identified to have endothelial dysfunction. The multivariable OR of low FMD for highest quartiles vs. lowest quartiles was 2.39 (95% confidence interval [CI]: 1.32–4.34), while OR per 1-standard deviation (SD) increment was 1.28 (95% CI: 1.04–1.56). The positive association was noted to be more evident in females (OR per 1-SD increment: 1.46; 95% CI: 1.08–1.96) than in males and confined to individuals not using antihypertensive medications. The ORs per 1-SD increment were 1.01 (95% CI: 0.68–1.50) among individuals using antihypertensive medications and 1.43 (95% CI: 1.12–1.81) among individuals not using antihypertensive medications. Conclusion: Higher serum UA was positively associated with the prevalence of endothelial dysfunction in samples of the general Japanese population and that positive association was confined to individuals not using antihypertensive medications.