Clinical Journal of the American Society of Nephrology. 2015. 10(4):571-577.
In children with nonglomerular chronic kidney disease (CKD), baseline proteinuria and systolic blood pressure levels are independently associated with progression of CKD. That was the conclusion of a study conducted recently by Sahar A. Fathallah-Shaykh, MD, and colleagues.
Most cases of CKD in children are causes by congenital anomalies of the kidney and urinary tract or genetic disorders. The researchers in this study aimed to evaluate the relationships between baseline proteinuria and blood pressure and longitudinal changes in glomerular filtration rate (GFR) in children with nonglomerular causes of CKD.
The prospective CKD in Children study assessed the urine protein-to-creatinine ratio, casual systolic and diastolic blood pressure (normalized for age, sex, and height), and GFR decline in 522 children with nonglomerular CKD. Median age was 10 years and median follow-up was 4.4 years. Mean baseline eGFR of 52 mL/min/1.73 m2 declined 1.3 mL/min/1.72 m2 on average.
There was an association between a 2-fold higher baseline urine protein-to-creatinine ratio and an accelerated decline in GFR of 0.3 mL/min/1.73 m2 per year (95% CI, 0.4-0.1). Among normotensive children, there was an association between larger declines in GFR and larger baseline urine protein-to-creatinine ratios; estimated GFR declines of 0.8 and 1.8 mL/min/1.73 m2 per year were associated with urine protein-to-creatinine ration <0.5 and ≥0.5 mg/mg, respectively. Among children with elevated blood pressure, average GFR declines were evident but were not larger in children with higher levels of proteinuria.