ESPN 51th Annual Meeting

ESPN 2018


 
Determining normal values of urinary phosphorus excretion in healthy children to aid early diagnosis and treatment for urolithiasis.
KATARZYNA TARANTA-JANUSZ LUKASZ LABIENIEC 2 TADEUSZ POROWSKI 1 KRZYSZTOF SZYMANSKI 2 HALINA POROWSKA 3 ANNA WASILEWSKA 1

1- DEPARTMENT OF PAEDIATRICS AND NEPHROLOGY, MEDICAL UNIVERSITY OF BIALYSTOK, POLAND
2- FACULTY OF PHYSICS, UNIVERSITY OF BIAłYSTOK, POLAND
3- DEPARTMENT OF MEDICAL CHEMISTRY, MEDICAL UNIVERSITY OF BIALYSTOK, POLAND
 
Introduction:

Hyperphosphaturia is a medical condition characterised by the presence of an excessive quantity of phosphorus in the urine. Measurement of urinary phosphorus has great importance in childhood since its excretion correlates directly with the prevalence of metabolic risk factors. Therefore, the interpretation of urine phosphorus excretion in children is difficult, because of a lack of age-specific and sex-specific normative values. This study determined the specific reference values for urinary phosphorus excretion in healthy children and adolescents aged 2-18 years and evaluated whether it changed with age during growth and was gender dependent.

Material and methods:

We enrolled 3,913 healthy children and adolescents aged 2-18 years to this study. The study population was divided into age groups and the analysis was performed in one-year periods, separately for boys and girls. Urinary phosphorus excretion was analysed using four categories: P1 in mmol/24 hours units, P2 in mmol/kg/24 hours, P3 in mmol/1.73m2/24 hours and P4 in mmol/mmol creatinine.

Results:

Clear differences in urinary exertion for girls and boys we observed as well as systematic changes with age. The boys presented with significantly higher daily urinary phosphorus excretion independent of its manner of expression (p <0.001). The median urinary phosphorus (P1) rose with age (p <0.001). Percentile tables of phosphorous exertion are presented.

Conclusions:

This was the largest study of urinary phosphate excretion based on a randomly selected sample of girls and boys aged 2–18 years. It highlighted the importance of determining the phosphorus reference values for children of different ages in order to provide early diagnosis and treatment for urolithiasis.