Preventive Strategies for Vascular Calcification in Patients with Chronic Kidney Disease.

BACKGROUND: Vascular calcification is significant because of the close association between the degree of vascular calcification and cardiovascular mortality in chronic kidney disease (CKD) patients. SUMMARY: There are 2 types of vascular calcification in CKD patients. One is endothelial vascular calcification, a common type of vascular calcification. Another is medial vascular calcification, a specific type that is common in CKD patients. The former is mainly associated with atherosclerosis due to hyperlipidemia, especially hypercholesterolemia. The latter CKD-specific type is called Moenckeberg's arteriosclerosis. A known risk factor for this type of vascular calcification is hyperphosphatemia. In this review article, we mainly discuss a preventive strategy for Moenckeberg type vascular calcification in CKD, primarily involving the treatment of hyperphosphatemia. Several possible modalities are considered. However, at present, dietary restriction of phosphate is not recommended so as to avoid malnutrition in CKD patients. The first consideration is the enhancement of phosphate removal by renal replacement therapy in dialysis patients. Various phosphate binder therapies can be beneficial and effective. Surgical and pharmacological parathyroidectomies are also useful for treating secondary hyperparathyroidism. Good quality bone provides a good pool of calcium and phosphate. Thus, bone protection is another option for preventing vascular calcification. Several therapeutic agents have been developed to manage osteoporosis. These trial agents may be reasonably effective in impeding the progression of vascular calcification in CKD patients. Key Messages: We should make full use of several modalities so as to completely prevent vascular calcification.

Safety and efficacy evaluation of lanthanum carbonate for hyperphosphatemia in end-stage renal disease patients.

In end-stage renal disease patients, various abnormalities of bone mineral metabolism adversely affect mortality. Hyperphosphatemia is known to adversely affect mortality and quality of life in chronic kidney disease patients and has been shown to be involved not only in the onset and progression of secondary hyperparathyroidism but also in vascular calcification. Thus, hyperphosphatemia is the main treatment target indicated in several guidelines for chronic kidney disease-mineral and bone disorder treatment. Phosphate binders are typically required for the management of hyperphosphatemia because dietary phosphorus restriction and phosphorus removal by hemodialysis alone are insufficient. We are able to prescribe five phosphate binders (calcium carbonate, sevelamer HCl, lanthanum carbonate (LaC), bixalomer, and ferric citrate) to Japanese hemodialysis patients. LaC is the most powerful noncalcium-containing phosphate binder for the treatment of hyperphosphatemia. In this chapter, we discuss the efficacy and safety of LaC, the safety of which has been under debate. In particular, we consider its toxic effects on the skeletal system. LaC is effective for hyperphosphatemia treatment in end-stage renal failure patients. It has been shown to be able to decrease serum fibroblast growth factor-23 levels. This result suggests that it may have beneficial effects on the cardiovascular system in patients undergoing renal replacement therapy. However, the effects of LaC remain obscure. Further investigations are required. No negative effects of LaC on bone metabolism or bone morphometry have been reported, but long-term clinical data are needed.