Coronary calcification in patients with end-stage renal disease: a novel endocrine disorder?

Cardiovascular mortality is significantly increased among patients with end-stage renal disease. The commonly observed vascular calcification in such patients has been considered as one of the causative factors. In patients undergoing dialysis, the incidence of coronary artery calcification is 2-5 times higher compared to patients with normal renal function and angiographically demonstrated coronary artery disease. Moreover, epidemiological studies have revealed a significant correlation of the extent of coronary artery calcification with the severity of underlying atherosclerotic lesions. Vascular calcification was initially considered as a passive process of hydroxyapatite deposition due to elevated plasma concentrations of calcium and phosphate. Nevertheless, there is a growing body of evidence that vascular calcification is an actively regulated and cell-mediated process. This phenomenon includes phenotypic alterations of vascular smooth muscle cells mainly resulting from an imbalance between promoters (such as increased Ca x P product) and inhibitors (fetuin-A, GLA protein, osteoprotegerin) of mineral deposition. With regard to the therapeutic approach, despite the evident effectiveness of both traditional and innovative remedies in the management of metabolic and electrolytic abnormalities of patients with end-stage renal disease, an individualized intervention based on etiopathogenesis is really required.