title: Renal Clearance of Mineral Metabolism Biomarkers.
abstract: CKD leads to disturbances in multiple interrelated hormones that regulate bone and mineral metabolism. The renal handling of mineral metabolism hormones in humans is incompletely understood. We determined the single-pass renal clearance of parathyroid hormone, fibroblast growth factor 23, vitamin D metabolites, and phosphate from paired blood samples collected from the abdominal aorta and renal vein in 17 participants undergoing simultaneous right and left heart catheterization and estimated associations of eGFR with the renal elimination of metabolites. The mean age ±SD of the study population was 71.4±10.0 years and 11 participants (65%) were male. We found a relatively large mean±SD single-pass renal extraction of parathyroid hormone (44.2%±10.3%) that exceeded the extraction of creatinine (22.1%±7.9%). The proportionate renal extraction of parathyroid hormone correlated with eGFR. The renal extraction of fibroblast growth factor 23 was, on average, lower than that of parathyroid hormone with greater variability across individuals (17.1%±19.5%). There were no differences in the mean concentrations of vitamin D metabolites across the renal vein and artery. In summary, we demonstrate substantial single-pass renal extraction of parathyroid hormone at a rate that exceeds glomerular filtration. Impaired renal clearance of parathyroid hormone may contribute to secondary hyperparathyroidism in CKD.
authors.affiliation: University of Washington, Kidney Research Institute, Seattle, Washington; hvb2@uw.edu.
authors.forename: Adriana J
authors.initials: AJ
authors.lastname: van Ballegooijen
authors.affiliation: Nephrology Division and Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts; and.
authors.forename: Eugene P
authors.initials: EP
authors.lastname: Rhee
authors.affiliation: Cardiology Division, Massachusetts General Hospital and Harvard Clinical Research Institute, Boston, Massachusetts.
authors.forename: Sammy
authors.initials: S
authors.lastname: Elmariah
authors.affiliation: University of Washington, Kidney Research Institute, Seattle, Washington;
authors.forename: Ian H
authors.initials: IH
authors.lastname: de Boer
authors.affiliation: University of Washington, Kidney Research Institute, Seattle, Washington;
authors.forename: Bryan
authors.initials: B
authors.lastname: Kestenbaum
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008903:Minerals / Q000097:blood / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000097:blood / Q000378:metabolism; D010710:Phosphates / Q000097:blood / Q000378:metabolism
chemical_list: D015415:Biomarkers; D008903:Minerals; D010281:Parathyroid Hormone; D010710:Phosphates; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23
keywords: extraction; mineral metabolism biomarkers; renal clearance