BACKGROUND: Vitamin D deficiency is widely prevalent in chronic kidney disease [CKD] patients. The aim of our study was to determine whether losses of vitamin D binding protein [VDBP] in urine and dialysate contribute to circulating 25-hydroxyvitamin D [25OHD] levels in chronic peritoneal dialysis [PD] patients. METHODS: Dialysate, serum, and urine VDBP levels were measured in 16 children on PD and compared with serum and urine VDBP in ten CKD4-5 patients. Serum VDBP levels were correlated with total circulating 25OHD and peritoneal VDBP losses. RESULTS: The mean age of the study population was 9.4 ± 3.8 years and the median time on dialysis 7.5 (1-18) months. In CKD4-5 patients, urinary VDBP losses were >300-fold higher than seen in age-matched healthy children and correlated with urinary albumin loss (p = 0.0008). There was a significant correlation between serum VDBP and total dialysate and urine losses of VDBP (p = 0.03, r = -0.53). Dialysate VDBP losses correlate with dialysate albumin loss (p = 0.01). VDBP losses in the long daytime dwell were higher than in the overnight drain (p = 0.04). Serum VDBP levels were lower in children with a longer dialysis vintage (p = 0.0004, r = -0.77). In PD patients, the mean total loss of VDBP in dialysate and urine was 1.91 ± 1.6 μmol/day, equivalent to ~7% of the total circulating level of VDBP in healthy controls. There was no correlation between 25(OH)D and VDBP. CONCLUSIONS: Peritoneal VDBP losses mirror both dialysate and urinary albumin losses, and are associated with a longer dialysis vintage but do not contribute to vitamin D deficiency in children on PD.
BACKGROUND:Vitamin D deficiency is widely prevalent in chronic kidney disease [CKD] patients. The aim of our study was to determine whether losses of vitamin D binding protein [VDBP] in urine and dialysate contribute to circulating 25-hydroxyvitamin D [25OHD] levels in chronic peritoneal dialysis [PD] patients. METHODS: Dialysate, serum, and urine VDBP levels were measured in 16 children on PD and compared with serum and urine VDBP in ten CKD4-5 patients. Serum VDBP levels were correlated with total circulating 25OHD and peritoneal VDBP losses. RESULTS: The mean age of the study population was 9.4 ± 3.8 years and the median time on dialysis 7.5 (1-18) months. In CKD4-5 patients, urinary VDBP losses were >300-fold higher than seen in age-matched healthy children and correlated with urinary albumin loss (p = 0.0008). There was a significant correlation between serum VDBP and total dialysate and urine losses of VDBP (p = 0.03, r = -0.53). Dialysate VDBP losses correlate with dialysate albumin loss (p = 0.01). VDBP losses in the long daytime dwell were higher than in the overnight drain (p = 0.04). Serum VDBP levels were lower in children with a longer dialysis vintage (p = 0.0004, r = -0.77). In PDpatients, the mean total loss of VDBP in dialysate and urine was 1.91 ± 1.6 μmol/day, equivalent to ~7% of the total circulating level of VDBP in healthy controls. There was no correlation between 25(OH)D and VDBP. CONCLUSIONS: Peritoneal VDBP losses mirror both dialysate and urinary albumin losses, and are associated with a longer dialysis vintage but do not contribute to vitamin D deficiency in children on PD.
Authors: A Nykjaer; D Dragun; D Walther; H Vorum; C Jacobsen; J Herz; F Melsen; E I Christensen; T E Willnow Journal: Cell Date: 1999-02-19 Impact factor: 41.582
Authors: Mieczyslaw Litwin; Elke Wühl; Claudia Jourdan; Anna Niemirska; Jens P Schenk; Katarzyna Jobs; Ryszard Grenda; Zbigniew T Wawer; Pawel Rajszys; Otto Mehls; Franz Schaefer Journal: Nephrol Dial Transplant Date: 2008-03-14 Impact factor: 5.992
Authors: Rukshana C Shroff; Rosamund McNair; Nichola Figg; Jeremy N Skepper; Leon Schurgers; Ashmeet Gupta; Melanie Hiorns; Ann E Donald; John Deanfield; Lesley Rees; Catherine M Shanahan Journal: Circulation Date: 2008-10-06 Impact factor: 29.690
Authors: Rukshana Shroff; Helen Aitkenhead; Nikola Costa; Antonella Trivelli; Mieczyslaw Litwin; Stefano Picca; Ali Anarat; Peter Sallay; Fatih Ozaltin; Aleksandra Zurowska; Augustina Jankauskiene; Giovanni Montini; Marina Charbit; Franz Schaefer; Elke Wühl Journal: J Am Soc Nephrol Date: 2015-06-11 Impact factor: 10.121
Authors: Michelle R Denburg; Heidi J Kalkwarf; Ian H de Boer; Martin Hewison; Justine Shults; Babette S Zemel; David Stokes; Debbie Foerster; Benjamin Laskin; Anthony Ramirez; Mary B Leonard Journal: Pediatr Nephrol Date: 2013-06-02 Impact factor: 3.714
Authors: Hwa Young Kim; Young Ah Lee; Hae Woon Jung; Min Jeoung Gu; Ji Young Kim; Gyung Min Lee; Jieun Lee; Ju Young Yoon; Sei Won Yang; Choong Ho Shin Journal: Ann Pediatr Endocrinol Metab Date: 2017-12-31