Purpose of review
The concepts of steady state, external balance, total body status and internal distribution are not always appreciated or even considered in clinical practice. The current tests available for clinical assessment
physiology and pathophysiology are valid in some aspects, but also have many limitations. The purpose of this review is to clarify the above concepts and discuss the utility of the currently available tests to assess phosphorus
Both epidemiologic and preclinical data have shown that disturbances in mineral metabolism contribute significantly to the morbidity and mortality in chronic kidney disease
. There are also emerging data supporting the notion that phosphotoxicity may exist even in individuals with normal renal function. In chronic kidney disease
(CKD), hyperphosphatemia is a relative late event and is a suboptimal indicator of phosphorus
balance and status. The judicious use of plasma and urine chemistry and hormonal biomarkers such as fibroblast growth factor 23
should be considered.
There is a dire need to increase awareness of what physiologic parameters should be monitored in terms of phosphorus
pathophysiology. Although the current available tests in the clinical armamentarium are not ideal, understanding their implications and limitations will improve patient care and motivate practitioners and investigators to develop better tests.