Tominaga N, Yonaha T, Yamanouchi M, et al. - In patients on chronic hemodialysis (HD), a negative correlation was found between bone responsiveness to parathyroid hormone (PTH) and intravenous administration of a calcium-sensing receptor (CaSR) agonist and/or a vitamin D receptor activator (VDRA).

• A wide variation in bone responsiveness to PTH has been seen in patients on dialysis.

• 106 patients receiving chronic HD in Japan were included.

• Exclusion criteria were: cases on HD for less than 6 months, or who received a combination of HD and peritoneal dialysis, or had cancer bone metastases or myeloma.

• TRACP-5b (tartrate-resistant acid phosphatase-5b)/intact PTH (iPTH) ratio, an index of bone responsiveness, was used.

• Single linear regression analysis revealed a significant positive correlation of age, corrected serum calcium level, and of ln [1,25-dihydroxycholecalciferol] with ln [TRACP-5b/iPTH].

• On the other hand, a significant negative correlation was demonstrated by factors such as BMI, use of CaSR agonists, use of VDRAs, and serum phosphorus level.