ABSTRACT
Objective:To investigate the effects of hyperuricemia on the prognosis of IgA nephropathy (IgAN) using propensity score matching (PSM) method.Methods:IgAN patients proven by biopsy were included. PSM was used to match patients. Kaplan-Meier method was used for survival analysis, and Cox regression analysis was used to analyze the effects of hyperuricemia on IgAN prognosis. Primary outcome events were defined as death, or end-stage renal disease (dialysis, transplantation), or a decrease in estimated glomerular filtration rate (eGFR) greater than 40%. Renal outcome was defined as end-stage renal disease (dialysis, transplantation), or a decrease in eGFR greater than 40%.Results:A total of 1 454 IgAN patients were included in this study, including 850 females and 604 males. Uric acid level was (368.26±92.87) μmol/L in the males, and (277.23±92.71) μmol/L in the females. The median follow-up time was 85.00(56.10, 106.33) months. During the follow-up period, a total of 134 patients reached the primary outcome events, including 5 deaths, 24 dialysis patients, 5 kidney transplant patients, and 100 patients with eGFR decreased by more than 40%. After 1∶1 matching, 131 males and 159 females in the hyperuricemia group were successfully matched with 131 males and 159 females in the normal uric acid group, and there was no significant statistical difference in each parameter in baseline between the hyperuricemia group and normal uric acid group after matching. Kaplan-Meier survival analysis showed that either before or after matching, the incidence of primary outcome events in male or female patients with hyperuricemia was higher than those with normal uric acid, but there was no statistically significant difference in incidence of primary outcome events between female hyperuricemia group and female normal uric acid group after matching (Log-rank test, χ2=3.586, P=0.058). Cox proportional hazard regression model showed that, in the pre-match fully adjusted model, the hazard ratio ( HR) of entering primary outcome events was 2.29-fold (95% CI 1.27-4.11, P=0.006) for men with hyperuricemia and 1.85-fold (95% CI 1.01-3.37, P=0.045) for women with hyperuricemia compared with those with normal uric acid. In the post-match fully adjusted model, the HR of entering primary outcome events was 2.41-fold (95% CI 1.18-4.93, P=0.016) for men with hyperuricemia and 1.83-fold (95% CI 0.91-3.67, P=0.091) for women with hyperuricemia compared with those with normal uric acid. In the pre-match fully adjusted model, the HR of entering renal outcome events was 2.68-fold (95% CI 1.47-4.88, P=0.001) for men with hyperuricemia and 1.81-fold (95% CI 0.99-3.33, P=0.056) for women with hyperuricemia compared with those with normal uric acid. In the post-match fully adjusted model, the HR of entering renal outcome events was 2.89-fold (95% CI 1.36-6.15, P=0.006) for men with hyperuricemia and 1.81-fold (95% CI 0.88-3.72, P=0.106) for women with hyperuricemia compared with those with normal uric acid. Conclusion:Hyperuricemia may be associated with IgAN progression, and it has a more significant effect on male IgAN patients.