title: Use of a standard urine assay for measuring the phosphate content of beverages.
abstract: Hyperphosphatemia is strongly associated with cardiovascular morbidity and mortality in patients with chronic kidney disease. Phosphate in beverages is readily absorbed and could have a significant impact on serum phosphate levels. Patients are routinely warned about the phosphoric acid in colas, but information on the phosphate content of other beverages is difficult to find. We have shown that the phosphomolybdate method, which is used in the vast majority of hospital laboratories for measuring phosphate in urine, can give an accurate measurement of the phosphate content of beer, cider, wine, and soft drinks. No change to the standard assay protocol is required. There was considerable variation between different types of wine and beer, probably due to the methods of production. The information the assay provides could enable staff providing dietary advice to compare locally available beverages and help patients to avoid or limit their intake of those with high phosphate content.
authors.affiliation: Department of Renal Medicine, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom; Department of Medical Physics, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom. Electronic address: Elizabeth.Lindley@nhs.net.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lindley
authors.affiliation: Department of Blood Sciences, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Seán
authors.initials: S
authors.lastname: Costelloe
authors.affiliation: Department of Blood Sciences, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Mike
authors.initials: M
authors.lastname: Bosomworth
authors.affiliation: Department of Nephrology, Centre Hospitalier Lyon-Sud, Carmen Cens Université Claude Bernard Lyon 1, Lyon, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Fouque
authors.affiliation: Department of Blood Sciences, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Julienne
authors.initials: J
authors.lastname: Freeman
authors.affiliation: Department of Renal Medicine, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom; Department of Medical Physics, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Keane
authors.affiliation: Department of Blood Sciences, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Douglas
authors.initials: D
authors.lastname: Thompson
mesh_terms: D001515:Beer / Q000032:analysis*; D001628:Beverages / Q000032:analysis*; D002253:Carbonated Beverages / Q000032:analysis*; D006801:Humans; D054559:Hyperphosphatemia / Q000652:urine; D008982:Molybdenum / Q000652:urine*; D010756:Phosphoric Acids / Q000652:urine*; D051436:Renal Insufficiency, Chronic / Q000652:urine; D015203:Reproducibility of Results; D016482:Urinalysis; D014920:Wine / Q000032:analysis*
chemical_list: D010756:Phosphoric Acids; D008982:Molybdenum; C003125:phosphomolybdic acid