1. Urinary and dialysate losses of vitamin D-binding protein in children on chronic peritoneal dialysis.
- Author
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Prytuła, Agnieszka, Wells, David, McLean, Timothy, Balona, Filipa, Gullett, Ambrose, Knott, Craig, Cantwell, Michelle, Hassen, Kimberly, Ledermann, Sarah, Rees, Lesley, and Shroff, Rukshana
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DRUG analysis , *CARRIER proteins , *CHRONIC kidney failure , *DIALYSIS (Chemistry) , *PERITONEAL dialysis , *REGRESSION analysis , *STATISTICS , *T-test (Statistics) , *U-statistics , *VITAMIN D , *DATA analysis , *ALBUMINS , *DATA analysis software , *DESCRIPTIVE statistics - Abstract
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. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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