New concepts in phosphorus homeostasis and its impact on renal health with particular reference to the cat

Elliott, Jonathan; Geddes, Rebecca F

Abstract

New discoveries relating to phosphorus homeostasis include the hormones fibroblast growth factor-23 and klotho produced by bone and kidney. These hormones, together with novel understanding of how calcium and phosphate ions are carried in colloidal form as calciprotein particles, have changed our view of how phosphorus is regulated. Recognition that high dietary intake of inorganic forms of phosphorus in humans is a risk factor for both cardiovascular and renal diseases have led to re-examination of the impact of inorganic sources of phosphorus in prepared cat foods on renal health. Data suggest that when homeostatic mechanisms lead to proximal tubular (S3 segment) phosphate concentrations exceeding 3.25 mmol/L for a significant part of the day, tubular stress and structural kidney damage ensues. Recent experimental rodent studies support the concept that cal-ciprotein particles form in the proximal tubule at these prevailing phosphate concentrations and trigger proximal tubular damage. Long-term feeding studies in cats suggest that carefully formulated prepared diets containing 1 g/Mcal of inorganic phosphorus (in the form of sodium tripolyphosphate or potassium monophosphate and pyrophosphate), resulting in estimated tubular phosphate concentrations < 2.5 mmol/L can be fed to healthy adult cats without detectable adverse effects on renal health.

Citation

Elliott, J., & Geddes, R. F. (2022). New concepts in phosphorus homeostasis and its impact on renal health with particular reference to the cat. The Veterinary Journal, 283-284, Article 105842. https://doi.org/10.1016/j.tvjl.2022.105842

• Journal Article Type: Review
• Acceptance Date: May 10, 2022
• Online Publication Date: May 14, 2022
• Publication Date: May 14, 2022
• Deposit Date: Jun 13, 2022
• Publicly Available Date: Jun 20, 2022
• Journal: The Veterinary Journal
• Print ISSN: 1090-0233
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 283-284
• Article Number: 105842
• DOI: https://doi.org/10.1016/j.tvjl.2022.105842
• Keywords: Calciprotein particles; Fibroblast growth factor-23; Klotho; proximal tubular toxicity
• Publisher URL: www.elsevier.com/locate/tvjl