Phosphate and Cardiovascular Disease beyond Chronic Kidney Disease and Vascular Calcification

Area of Science:

• Nephrology
• Cardiology
• Biochemistry

Background:

• Phosphate is vital but its excess causes detrimental effects, especially vascular calcification in end-stage renal disease.
• High-normal serum phosphate levels are linked to adverse cardiovascular outcomes in general and early-stage CKD populations.
• Dietary phosphate load exacerbates phosphate accumulation and is associated with cardiovascular aging and dysfunction.

Purpose of the Study:

• To elucidate the detrimental effects of phosphate accumulation on cardiovascular health.
• To investigate the role of fibroblast growth factor-23 (FGF-23) in phosphate-induced cardiovascular complications.
• To understand the mechanisms by which excess phosphate and calciprotein particles (CPPs) contribute to vascular calcification in CKD.

Main Methods:

• Observational studies analyzing serum phosphate levels and cardiovascular outcomes.
• Assessment of dietary phosphate intake and its association with aging and cardiac parameters.
• Investigation of FGF-23 levels in relation to cardiovascular conditions in CKD and general populations.
• In vitro studies on the effects of extracellular phosphate on endothelial cells and vascular smooth muscle cells (VSMCs).
• Characterization of calciprotein particles (CPPs) in CKD.

Main Results:

• High-normal serum phosphate is associated with adverse cardiovascular outcomes, preceding overt hyperphosphatemia.
• Habitual high phosphate diet correlates with aging, cardiac hypertrophy, endothelial dysfunction, and atherosclerosis.
• Increased FGF-23 levels are linked to left ventricular hypertrophy, heart failure, atrial fibrillation, and mortality in CKD and general populations.
• Excess extracellular phosphate induces endothelial cell apoptosis and VSMC osteogenic transformation.
• CKD-associated CPPs are deficient in calcification inhibitors, promote inflammation, and drive VSMC calcification.

Conclusions:

• Phosphate accumulation, even at high-normal levels, poses significant cardiovascular risks, particularly in CKD.
• FGF-23 plays a crucial role in mediating phosphate-induced cardiac and vascular pathology.
• Excess phosphate and altered CPPs are key drivers of vascular calcification and inflammation in CKD, contributing to poor outcomes.