CKD-MBD II

Introduction and Aims: Vascular calcification is an important factor influencing cardiovascular complications and the vital prognosis in hemodialysis patients. However, a target level of PTH and a guide for medical practice to prevent vascular calcification are not clearly defined in the KDIGO's guidelines and are controversial. We investigated the development and progression of aortic calcification in the early stage of hemodialysis initiation. Methods:We performed a retrospective cohort study in 102 patients who initiated hemodialysis for end-stage kidney disease between July 2004 and June 2009 and could be followed-up for three years in our hospital. We compared the extent of calcification in the aortic arch at the time of hemodialysis initiation and three years later by reviewing postero-anterior chest X-ray. We defined an outcome as an increase in the extent of calcification by 50% and examined the factors related to this outcome using multiple logistic regression analysis. Results: Aortic arch calcification was observed 46% of patients at baseline and increased to 80% during the three-year study period. In addition, forty-eight of the 102 patients achieved the outcome. The mean daily dose of calcium carbonate (1,000-mg units) for three years (odds ratio: 2.2 [95% CI 1.5 3.4]), an iPTH level of 180 pg/ml or above (3.9 [1.6 10.6]), and age (1.5 [1.0 2.3]) were significantly associated with progression of aortic calcification. On the other hand, the presence of diabetes, use of activated vitamin D and statin, mean levels of serum calcium and phosphate and factors related to lipid for three years were not associated with the progression of aortic calcification. Conclusions: The KDIGO's guideline recommend PTH level is maintained in the range of two to nine times the upper normal limit in patients with CKD stage5D, regarding the relative risk of death. However, in view of vascular calcification, it is important to control the PTH levels more strictly from the early stage of dialysis initiation, in addition to reducing the doses of calcium-containing phosphate binders as far as possible.