[Magnesium disorder and its clinical significance in chronic kidney disease].

Disturbance in mineral and bone metabolism is a common complication of chronic kidney disease (chronic kidney disease - mineral and bone disorder ; CKD-MBD) and closely related to morbidity and mortality. Because magnesium (Mg) is mainly excreted by kidney, Mg homeostasis is disturbed in CKD. Therefore Mg abnormalities in CKD may contribute to pathogenesis of CKD-MBD. The association of Mg with bone metabolism in general population has been demonstrated. There were reported an association with dietary Mg intake and bone mineral density (BMD) and an increased rate of bone loss with dietary Mg intake. In animal models, decreased bone formation, increased bone resorption, decreased bone mass, and increased skeletal fragility were reported in Mg deficiency. Although vascular calcification is frequently seen in CKD patients, contributing factors to vascular calcification are not fully clarified. Mg is considered "a natural calcium antagonist" , and Mg deficiency has been reported to be related to progression of atherosclerosis in several studies. In hemodialysis patients, lower Mg levels were also reported to be associated with increased atherosclerosis of the common carotid artery. Lower serum Mg levels were also found in hemodialysis patients with evidence of increasing arterial calcification. Several studies suggested that Mg plays an important role against the development of cardiovascular disease, infectious disease, and malignant neoplasia so that Mg may relate to mortality. In hemodialysis patients, we demonstrated that low serum Mg level was a predictor for increased mortality.