[Pathogenesis and therapy for vascular calcification in patients on chronic hemodialysis]

Vascular calcification is a common complication of end-stage renal disease (ESRD) and is likely related to the high incidence of cardiovascular disease in patients with ESRD. Vascular calcification occurs both in the vascular intima and in the tunica media. Intimal calcification is disseminated and is associated with damaged endothelium and macrophage. On the contrary, medial calcification occurs in patchy distribution and the most frequent cells types found in its vicinity are smooth muscle cells (SMC). The uremic state is associated with numerous metabolic abnormalities and endocrine disturbances primarily involving calcium and phosphorus metabolism. In addition, ESRD is considered state of active inflammatory response. These dysfunctions likely contribute to the development and progression of vascular calcification. Recent reports have shown that this is a highly regulated process governed by factors that closely resemble calcium deposition in bone tissue. Vascular calcification requires changes in the phenotype of SMC and the expression of several bone-associated proteins normally involved in bone metabolism. This review is focused on the role of phosphorus in the pathogenesis of vascular calcification and the therapeutic approaches currently available to slow its progression in patients with ESRD.