1 Pediatric Nephrology Ward with Dialysis Division for Children, Public Clinical Hospital No. 1 in Zabrze, Poland, ul. 3 Maja 13/15, 41-800, Zabrze, Poland.
2 Department of Pediatrics, Faculty of Medical Sciences in Zabrze, Medical University of Silesia in Katowice, Poland, ul. 3 Maja 13/15, 41-800, Zabrze, Poland.
3 Department of Pediatrics, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Poland, ul. Medyków 16, 40-752, Katowice, Poland.
4 Intensive Therapy And Neonatal Pathology Ward, Public Clinical Hospital No. 1 in Zabrze, Poland, ul. 3 Maja 13/15, 41-800, Zabrze, Poland.
5 Pediatric Endocrinology Ward, Public Clinical Hospital No. 1 in Zabrze, Poland, ul. 3 Maja 13/15, 41-800, Zabrze, Poland.
6 Department of Pediatrics, Faculty of Medical Sciences in Zabrze, Medical University of Silesia in Katowice, Poland, ul. 3 Maja 13/15, 41-800, Zabrze, Poland. szczep57@poczta.onet.pl.