Acute Effects of an Inorganic Phosphorus Additive on Mineral Metabolism and Cardiometabolic Risk Factors in Healthy Subjects

• Published in: The journal of clinical endocrinology and metabolism Vol. 107; no. 2; pp. e852 - e864
• Main Authors: Volk, Christin, Schmidt, Benjamin, Brandsch, Corinna, Kurze, Tabea, Schlegelmilch, Ulf, Grosse, Ivo, Ulrich, Christof, Girndt, Matthias, Stangl, Gabriele I
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 18.01.2022
• Subjects: Administration, Oral; Adolescent; Adult; Cardiac patients; Cardiometabolic Risk Factors; Chronic kidney failure; Cross-Over Studies; Dextrose; Dietary Supplements; Double-Blind Method; Female; Fibroblast Growth Factor-23 - blood; Fibroblast growth factors; Glucose; Healthy Volunteers; Humans; Lipids; Male; Phosphates; Phosphates - administration & dosage; Phosphates - adverse effects; Phosphates - blood; Postprandial Period; Risk factors; Young Adult; Germany; human study; PTH; FGF23; phosphorus intake; postprandial metabolism
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/clinem/dgab635

Hyperphosphatemia and high levels of fibroblast growth factor 23 (FGF23) are risk factors for cardiovascular events in patients with chronic kidney diseases. However, the impact of an inorganic phosphorus additive in healthy people is largely unknown. We aimed to investigate the acute effect of excessive dietary phosphorus administered as sodium dihydrogen phosphate on the postprandial levels of Pi and FGF23 and the response to food. This study was a double-blind placebo-controlled crossover study with 29 healthy male and female participants from the general community who were administered a single dose of either 700 mg phosphorus (NaH2PO4) or a sodium-adjusted placebo in combination with a test meal. Postprandial plasma levels of Pi and FGF23 were measured. Compared with placebo, oral phosphorus increased the plasma Pi level, which remained elevated during the ensuing 8 hours (at 480 minutes: 1.31 vs 1.16 mmol/l; P < 0.001), increased urinary Pi (iAUC0-480 789 vs 95 mmol/mmol; P < 0.001), reduced tubular Pi reabsorption (iAUC0-480 -31.5 vs -6.2; P < 0.001), decreased urinary calcium (iAUC0-240 30.6 vs 53.0 mmol/mmol; P = 0.009), and stimulated the release of parathyroid hormone (iAUC0-480 2212 vs 768 ng/l; P < 0.001). However, the FGF23 levels did not change. Postprandial levels of glucose, insulin, and lipids were not substantially affected by phosphorus vs placebo. An oral phosphorus load can induce elevated postprandial levels of circulating Pi for hours in healthy subjects, despite rapid homeostatic counterreactions. FGF23 levels and the postprandial response to food were not affected.