Associations of serum iron and ferritin with hyperuricemia and serum uric acid.

To assess the serum iron and ferritin levels in relation to the prevalence of hyperuricemia (HU) and the serum uric acid (SUA) level. Serum iron and ferritin concentrations were detected by Ferene method and chemiluminescence method, respectively. SUA level was detected by uricase-PAP method. HU was defined as SUA ≥ 416 μmol/L for male and ≥ 357 μmol/L for female. Multivariable-adjusted logistic regressions were constructed to investigate the associations between serum iron/ferritin levels and prevalence of HU. Pearson correlation analysis and multivariable linear regression were performed to examine the correlations between serum iron/ferritin levels and SUA level. A total of 2824 subjects (mean age 52.2 ± 7.2) were included. The overall prevalence of HU was 17.3%. Compared with the lowest quartile, the multivariable-adjusted odds ratios (OR) and its 95% confidence interval (CI) of HU were 1.33 (95%CI 0.97-1.82), 1.17 (95%CI 0.85-1.60), and 1.56 (95%CI 1.14-2.13) in the second, third, and fourth quartiles of serum iron, respectively (P for trend = 0.012), and were 1.29 (95%CI 0.89-1.88) in the second, 2.13 (95%CI 1.47-3.07) in the third, and 2.25 (95%CI 1.54-3.29) in the fourth quartile of serum ferritin (P for trend < 0.001). Pearson correlation coefficient indicated a weak positive correlation between serum iron (r = 0.2, P < 0.001) and ferritin (r = 0.3, P < 0.001) levels and SUA. Such positive correlations were further confirmed by multiple linear regression (serum iron: standardized β = 0.059, P < 0.001; serum ferritin: standardized β = 0.061, P = 0.001). Both serum iron and ferritin showed a positive correlation with the prevalence of HU, and a weak positive correlation with SUA level. Key Points • Subjects with higher levels of serum iron or ferritin had higher prevalence of HU. • There was a weak positive correlation between serum iron/ferritin levels and SUA level.