Phosphate, Calcification in Blood, and Mineral Stress: The Physiologic Blood Mineral Buffering System and Its Association with Cardiovascular Risk

Phosphate is an important cardiovascular risk factor and lowering elevated blood phosphate concentrations is a main therapeutic target in kidney patients. Phosphate is subject to the blood mineral buffering system which controls the precipitation of calcium and phosphate. Calciprotein particles (CPP), self-assembling complexes of calcium phosphate and serum proteins, are the nanomorphological correlates of this system. CPP1 are spherical, 50-100 nm in diameter, and contain amorphous mineral. CPP2 are oblongated, 100-200nm in the long axis, and they contain a crystalline mineral core. The relative abundance and biological activity of these particles are a matter of intense research, because they can cause oxidative stress, inflammation, and calcification in cellular assay. Therapeutically reducing this endogenous stressor by prolonging crystal formation time might improve patient outcome. This concise review article summarizes our current knowledge about the blood mineral buffering system and proposes Mineral Stress as a novel modifiable cardiovascular risk factor. It furthermore outlines possible implications this might have for improving patient care.