Novel finding: Proteinuria in patients with a urinary diversion does not predict renal function decline

Purpose:

Proteinuria is used to track down patients with intrinsic renal disease and increased risk of renal function decline and is seen in up to 5% in the general population. The aim of this study is to investigate the prevalence and clinical relevance of proteinuria regarding renal function in patients with a urinary diversion.

Methods:

Data was collected of patients with a urinary diversion who had a follow-up appointment (T1) in the Urology Department of the University Hospital Utrecht in 2021. Patients were divided into a proteinuria and no proteinuria group. Proteinuria was determined through dipstick urinalysis at T1. Glomerular filtration rate and renal imaging were analysed at T1 and after 11–30 months follow-up (T2).

Results:

A research population of 84 patients was identified, median age was 38 years, 39.3% was male. At T1, 43% had proteinuria. There was no association between proteinuria and glomerular filtration rate nor abnormalities on renal imaging at T1 or T2. No statistically significant difference was seen in the glomerular filtration rate decline after 11–30 months between the group with and without proteinuria, determined at T1 (respectively 1.3 ± 6.9 ml/min/1.73 m² vs 2.3 ± 9.5 ml/min/1.73 m²; $p$-value 0.63).

Conclusion:

The prevalence of proteinuria in patients with a urinary diversion is high. Proteinuria was not associated with renal function or renal function decline over time. These findings illustrate the limitations of proteinuria screening to identify individuals at risk for renal function decline among this population.