Effect of calcitonin on hemodialysis patients with hypercalcemia and renal osteodystrophy

Because calcitonin administration has been shown to decrease the serum calcium level in certain hypercalcemic conditions, 10 patients on maintenance dialysis with renal osteodystrophy and persistent hypercalcemia were treated with salmon calcitonin for 3 months. While plasma calcium concentrations were reduced by calcitonin therapy in four patients, therapy was ceased in two patients due to a worsening of their hypercalcemia, although in another two patients the initial worsening of the hypercalcemia settled with continued therapy. No significant changes in calcium levels occurred in the remaining two patients. Analysis of the data suggests that a hypocalcemic effect of calcitonin was most likely in the presence of osteomalacia, while predominant osteitis fibrosa favored a hypercalcemic response. Calcitonin administration caused a mean increase in parathyroid hormone (PTH) secretion 3.6 +/- 1.5 to 6.5 +/- 1.7 ng/ml; p less than 0.05) after 6 weeks of therapy. Three patients reported improvement in their bone pain. These studies show that despite possible symptomatic and morphological effects of calcitonin, its hypocalcemic effect in patients with renal osteodystrophy and hypercalcemia is inconsistent.