J Ramalho1, E M Petrillo2, A P M Takeichi2, R M A Moyses2, S M Titan2. 1. Nephrology Division, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, 255 Av Dr Enéas de Carvalho Aguiar, Sao Paulo, SP, 05403-000, Brazil. jana_ramalho@yahoo.com.br. 2. Nephrology Division, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, 255 Av Dr Enéas de Carvalho Aguiar, Sao Paulo, SP, 05403-000, Brazil.
Abstract
PURPOSE: The recent observation that urinary calcium excretion (UCE) drops considerably with CKD and that this effect may occur beyond compensation for reduced intestinal calcium absorption suggests that CKD per se is a state of sustained positive calcium balance, a mechanism likely to contribute to vascular calcification and CVD in CKD. However, the determinants of UCE reduction in CKD are not well understood and there is a lack of clinical studies, particularly in the CKD population. Therefore, in this study, we aimed to evaluate variables associated with UCE in a CKD cohort. METHODS: Baseline data on 356 participants of the Progredir Study, Sao Paulo, Brazil, essentially composed of CKD G3a-G4, were analyzed according to UCE (24 h urine collection). RESULTS: Median 24 h UCE was 38 mg/day (IQR 21-68 mg/day) and 0.48 mg/kg/day (IQR 0.28-0.82 mg/kg/day). In univariate analysis, UCE was inversely related to age, phosphorus, 1-84 PTH, FGF-23 and sclerostin, and positively associated with eGFR, DBP, 1,25(OH)2-vitamin D, calcium, bicarbonate, total calorie intake and spironolactone use. After adjustments for age, sex and eGFR, only 1,25(OH)2-vitamin D, calcium, FGF-23, bicarbonate and total calorie intake remained associated with it, but not PTH nor sclerostin. Lastly, in a multivariable model, eGFR, serum 1,25(OH)2-vitamin D, calcium, and FGF-23 remained associated with UCE. Similar results were observed when calcium fractional excretion was used instead of UCE, with eGFR, 1-25-vitamin D and FGF-23 remaining as independent associations. CONCLUSION: Our results showed that CKD is associated with very low levels of UCE and that 1,25(OH)2-vitamin D, serum calcium and FGF-23 were independently associated with UCE in this population, raising the question whether these factors are modulators of the tubular handling of calcium in CKD.
PURPOSE: The recent observation that urinary calcium excretion (UCE) drops considerably with CKD and that this effect may occur beyond compensation for reduced intestinal calcium absorption suggests that CKD per se is a state of sustained positive calcium balance, a mechanism likely to contribute to vascular calcification and CVD in CKD. However, the determinants of UCE reduction in CKD are not well understood and there is a lack of clinical studies, particularly in the CKD population. Therefore, in this study, we aimed to evaluate variables associated with UCE in a CKD cohort. METHODS: Baseline data on 356 participants of the Progredir Study, Sao Paulo, Brazil, essentially composed of CKD G3a-G4, were analyzed according to UCE (24 h urine collection). RESULTS: Median 24 h UCE was 38 mg/day (IQR 21-68 mg/day) and 0.48 mg/kg/day (IQR 0.28-0.82 mg/kg/day). In univariate analysis, UCE was inversely related to age, phosphorus, 1-84 PTH, FGF-23 and sclerostin, and positively associated with eGFR, DBP, 1,25(OH)2-vitamin D, calcium, bicarbonate, total calorie intake and spironolactone use. After adjustments for age, sex and eGFR, only 1,25(OH)2-vitamin D, calcium, FGF-23, bicarbonate and total calorie intake remained associated with it, but not PTH nor sclerostin. Lastly, in a multivariable model, eGFR, serum 1,25(OH)2-vitamin D, calcium, and FGF-23 remained associated with UCE. Similar results were observed when calcium fractional excretion was used instead of UCE, with eGFR, 1-25-vitamin D and FGF-23 remaining as independent associations. CONCLUSION: Our results showed that CKD is associated with very low levels of UCE and that 1,25(OH)2-vitamin D, serum calcium and FGF-23 were independently associated with UCE in this population, raising the question whether these factors are modulators of the tubular handling of calcium in CKD.
Authors: Maria Alice Muniz Domingos; Alessandra Carvalho Goulart; Paulo Andrade Lotufo; Isabela Judith Martins Benseñor; Silvia Maria de Oliveira Titan Journal: Sao Paulo Med J Date: 2017-04-20 Impact factor: 1.044
Authors: Tamara Isakova; Cheryl A M Anderson; Mary B Leonard; Dawei Xie; Orlando M Gutiérrez; Leigh K Rosen; Jacquie Theurer; Keith Bellovich; Susan P Steigerwalt; Ignatius Tang; Amanda Hyre Anderson; Raymond R Townsend; Jiang He; Harold I Feldman; Myles Wolf Journal: Nephrol Dial Transplant Date: 2011-03-07 Impact factor: 5.992
Authors: Joost G J Hoenderop; Olivier Dardenne; Monique Van Abel; Annemiete W C M Van Der Kemp; Carel H Van Os; René St -Arnaud; René J M Bindels Journal: FASEB J Date: 2002-09 Impact factor: 5.191
Authors: Olena Andrukhova; Alina Smorodchenko; Monika Egerbacher; Carmen Streicher; Ute Zeitz; Regina Goetz; Victoria Shalhoub; Moosa Mohammadi; Elena E Pohl; Beate Lanske; Reinhold G Erben Journal: EMBO J Date: 2014-01-16 Impact factor: 11.598
Authors: Kathleen M Hill; Berdine R Martin; Meryl E Wastney; George P McCabe; Sharon M Moe; Connie M Weaver; Munro Peacock Journal: Kidney Int Date: 2012-12-19 Impact factor: 10.612