Mineral metabolism management in hemodialysis patients with secondary hyperparathyroidism in Japan: baseline data from the MBD-5D.

BACKGROUND/AIMS: The Mineral and Bone Disorder Outcomes Study for Japanese CKD Stage 5D Patients (MBD-5D) is a multicenter, prospective observational study of hemodialysis patients with secondary hyperparathyroidism (SHPT) in Japan, where the national guideline recommends targets for serum calcium (8.4-10.0 mg/dl), phosphorus (3.5-6.0 mg/dl), and intact parathyroid hormone (PTH) (60-180 pg/ml).

METHODS

The MBD-5D involved patients who were receiving hemodialysis for more than 3 months and met at least one of the following conditions: having intact PTH levels >180 pg/ml, or receiving intravenous vitamin D receptor activators (VDRAs) or oral VDRA analog. This report describes the baseline characteristics of the study participants and examines factors associated with mineral metabolism controllability.

RESULTS

A total of 8,229 patients were registered from 86 facilities as the whole cohort, and 3,276 patients were randomly selected as the subcohort. The severity of SHPT was associated with a lower likelihood of achieving the targets for calcium and phosphorus, whereas patients with a history of parathyroidectomy were more likely to achieve these targets as compared with those who had not undergone surgery despite high PTH levels. The use of 2.5 mEq/l calcium dialysate was also associated with a higher likelihood of achieving the targets compared with the use of 3.0 mEq/l calcium dialysate.

CONCLUSION

The severity of SHPT and the use of dialysate with higher calcium concentration are associated with practical difficulty in managing mineral metabolism in dialysis patients. Further prospective follow-up is needed to confirm our findings and to examine their impact on patient-level outcomes.