Examination of sex differences in excretion of uric acid

Abstract

Uric acid levels are much lower in women than men, mainly due to differences in excretion caused by female hormones. It is known that the difference in uric acid levels between men and women becomes smaller after reaching 50 years old, when the influence of female hormones decreases significantly. In this study, we collected and compared data on sex differences in uric acid excretion in men over 50 years old (male group, n=26) and postmenopausal women (female group, n=31). As the results, the significant difference in serum uric acid levels between men and women disappeared in this age group (male group: 5.3±1.1 mg/dL, female group: 4.8±1.2 mg/dL, p=0.110), and uric acid excretion was significantly higher in women even after menopause (uric acid/creatinine ratio: male group: 0.47±0.13, female group: 0.69±0.23, p<0.001; FEUA: 7.7±2.6% in the male group and 9.7±3.2% in the female group, p=0.018). Uric acid excretion was positively correlated with estimated salt intake in both men and women (uric acid/creatinine ratio and estimated salt intake: men R²:0.485, p<0.001, women R²:0.521, p<0.001), but this was stronger in women. In postmenopausal women, salt intake accelerated uric acid excretion and, in some cases, increased the risk of cardiovascular events even with low serum uric acid levels. This may be one of the possible reasons to explain the phenomenon that uric acid levels, which indicate the risk of cardiovascular events, are lower in women than men.