Evidence that endogenous calcitonin protects against renal bone disease.

Plasma concentrations of calcium, phosphate, alkaline phosphatase (A.P.), immunoreactive calcitonin (iC.T.), and immunoreactive parathyroid hormone (iP.T.H.) were measured in fifty-two patients with chronic renal failure on maintenance haemodialysis. On the basis of a bimodal distribution of values for plasma-A.P. the patients were dividied into 2 groups. In those patients with normal A.P. concentratons as well as in twenty-eight normal subjects there was a positive correlation between iP.T.H. and iC.T. which was independent of plasma calcium or phosphate. Patients with increased plasma-A.P. had higher concentrations of iP.T.H., lower concentrations of iC.T., and showed a negative relation between the concentrations of the two hormones. It is suggested that a possible factor in the pathogenesis of renal bone disease is a failure to secrete C.T. in adequate amounts.