ABSTRACT
Epidemiological studies show serum phosphorus levels are independently associated with all-cause and cardiovascular mortality in people with chronic kidney disease. Several observational studies have even reported associations between higher serum phosphorus levels within the normal reference range and cardiovascular events and mortality in people with normal kidney function. Serum phosphorus fulfils many criteria to be defined as a risk factor for cardiovascular disease. The association between serum phosphorus and dietary phosphorus intake, however, is only modest. Urinary excretion of phosphorus is often used as a measure of dietary phosphorus intake, and several observational studies have reported associations with urinary phosphorus and clinical outcomes but with conflicting results. Whether increased dietary phosphorus intake is harmful and associated with cardiovascular disease is unclear, and there are limited observational studies addressing this issue. There is also a paucity of interventional studies evaluating the role of manipulation of dietary phosphorus—either with restricted intake or reduction in absorption through the use of phosphorus binders—and clinical outcomes, especially cardiovascular disease. Disordered regulation of fibroblast growth factor-23 (FGF23) by high dietary phosphorus may be a key factor contributing to atherosclerosis and increased cardiovascular burden. This chapter outlines the current evidence linking phosphorus and adverse outcomes, focusing on associations between dietary phosphorus intake and cardiotoxicity.
