Early postkidney transplantation hypophosphatemia

Abstract

Background: As hypophosphatemia is a common multifactorial problem of kidney transplantation (Tx), this research aimed at studying the frequency of posttransparent hypophosphatemia in the early postkidney Tx period and investigating the risk components associated with the situation. Materials and Methods: In this study, 50 renal transplant recipients on the day before (-1) and on days 10 (+10) and 30 (+30) days after kidney Tx were examined for the levels of serum phosphate (Pi). Levels of serum creatinine (Cr), Pi, 25-hydroxyvitamin D (25[OH] D), intact parathyroid hormone (iPTH) and fbroblast growth factor 23 (FGF-23), the 24 h urinary excretion of Pi and Cr, estimated glomerular fltration rate (eGFR), and the ratio of transport maximum of Pi (TMP) to eGFR (TMP/GFR) were evaluated on the same days. Results: Hypophosphatemia (serum Pi <2.5 mg/dl) was seen in 0%, 40%, and 42% of the patients on days-1, +10, and +30, respectively. Te levels of 25(OH)D and iPTH were not signifcantly di?erent in patients with and without hypophosphatemia on days +10 and +30. Compared to those with normophosphatemia, pre-Tx FGF-23 level was signifcantly higher in patients with hypophosphatemia on days +10 and +30, respectively. Te regression coefcient of TMP/GFR and Cr was positive on days-1, +10, and +30. Te coefcient of pre-Tx FGF-23 on post-Tx serum Pi was negative on days +10 (P < 0.03) and +30 (P < 0.003), and the coefcient of post-Tx FGF-23 was negative just on day +10 with serum Pi (P < 0.008). Conclusion: Te main causes of post-Tx hypophosphatemia in the multivariate linear analysis were pre-Tx FGF-23 and post-Tx FGF-23 levels on days +10, post-Tx Cr, and TMP/GFR.