Objective To evaluate the impact of dynamic changes in proteinuria on the deterioration of renal function in patients with IgA nephropathy (IgAN).

Methods A total of 105 patients with IgAN were selected as the study subjects, and they had complete 3-year follow-up data. Based on the initial 24 h proteinuria levels, the patients were categorized into mild proteinuria (group A, < 1.0 g), moderate proteinuria (group B, 1.0 to 3.0 g) and severe proteinuria (group C, >3.0 g). The primary endpoint of this study was the incidence of an annual decline rate of ≥30% in the estimated glomerular filtration rate (eGFR), while the secondary endpoint was the occurrence of end-stage renal disease events. Survival analysis was conducted using the Kaplan-Meier method. Cox proportional hazards regression model was employed to assess the impact of different clinical variables on renal function decline. Receiver operating characteristic (ROC) curves were plotted to analyze the predictive efficacy of changes in proteinuria levels on disease progression.

Results Statistically significant differences were observed among the three groups in terms of the proportion of patients with eGFR decline rate of ≥30% and hormone therapy (P < 0.05). The mean survival time was 35.686 months in the group A, 34.644 months in the group B, and 29.760 months in the group C. Both the initial proteinuria level (OR=4.068, P < 0.001) and the change in proteinuria level (OR=3.914, P < 0.001) were significant predictors of renal function decline. The initial proteinuria level area under the curve (AUC)=0.825, P < 0.001 demonstrated higher predictive efficacy for the deterioration of IgAN compared to the change in proteinuria level(AUC=0.643, P < 0.05).

Conclusion The initial proteinuria level and its dynamic changes are important predictors of renal function progression in patients with IgAN. Monitoring the dynamic changes in proteinuria can facilitate early intervention in renal function deterioration.