Decreases in parathyroid gland volume after cinacalcet treatment in hemodialysis patients with secondary hyperparathyroidism.

BACKGROUND/AIM: Cinacalcet, an allosteric modulator of the calcium-sensing receptor, effectively reduces serum parathyroid hormone (PTH). It was examined whether a regression of parathyroid glands in hemodialysis patients with secondary hyperparathyroidism was induced by cinacalcet treatment.

METHODS

Ultrasonography of the parathyroid glands was performed to examine the changes in the parathyroid gland volumes after cinacalcet treatment in 58 patients.

RESULTS

After cinacalcet treatment, serum calcium, phosphate, alkaline phosphatase, and intact PTH significantly decreased (p < 0.0001). The total volumes of the parathyroid glands were significantly decreased 6 months after cinacalcet treatment (942 +/- 747 vs. 708 +/- 550 mm(3), p < 0.0005). There was a significant positive correlation between the parathyroid gland volumes at the start of cinacalcet treatment and the volume reduction in parathyroid glands (r = 0.716, p < 0.0001). Of the 58 patients, the total parathyroid gland volume was decreased in 42 patients and increased in 16 although the doses of cinacalcet, phosphate binders or vitamin D were not significantly different. In both groups, the intact PTH serum levels were significantly decreased after cinacalcet treatment.

CONCLUSION

Cinacalcet treatment in patients with secondary hyperparathyroidism significantly reduced the total parathyroid gland volume in a short 6-month period. This study suggests that cinacalcet treatment may postpone parathyroidectomy and/or reduce cases.