Urinary albumin excretion and chronic kidney disease in children with vesicoureteral reflux.
BACKGROUND
Albuminuria is a potential biomarker of chronic kidney disease (CKD) in various glomerular diseases. Vesicoureteral reflux (VUR) often progresses to CKD, and study is required of use of albuminuria as a biomarker for this condition. The aim of this study was to evaluate the association between albuminuria and glomerular filtration rate (GFR) or filtration fraction (FF) in children with VUR.


STUDY DESIGN
In this retrospective study, renal parameters of 141 children with VUR were investigated, using inulin clearance, FF, and albuminuria. The association between urinary albumin to creatinine ratio (ACR), GFR, and FF was analyzed in a continuous manner by calculating the β coefficient, and also in a binary manner by calculating the OR.


RESULTS
Using both continuous and binary analyses, ACR values were negatively and significantly associated to GFR values in patients with low, normal, or high FF values (Table). It was also positively and significantly associated with FF values in patients with low, normal or high GFR values (Table). No association was found between ACR and gender, VUR stages or laterality, number of urinary tract infection, presence of a single functional kidney, history of reflux surgery, or renal scars or hypertension.


DISCUSSION
ACR is associated with CKD in patients with VUR. In addition, increased urinary albumin excretion cannot be completely and solely explained by decreased GFR and/or increased FF values. The two main limitations of this study are the crude assessment of renal scarring, which prevented finer analysis between albuminuria and renal scarring surface area, and that the study cohort may not be representative of the true VUR population.


CONCLUSION
This study shows that albuminuria is associated with decreased renal function in patients with VUR and that it could be used to monitor renal function in this condition.