Secondary hyperparathyroidism in human kidney transplant recipients

76 kidney transplant recipients who were up to 4 years post transplant, were studied to assess the incidence of secondary hyperparathyroidism. All patients had good renal function with a mean serum creatinine of 1.4 mg/100 ml. Secondary hyperparathyroidism, as evidenced by increased serum parathyroid hormone levels, was present in 53 of the 76 patients (66%) and radiologic bone disease in 26 of the 76 patients (34%), while hypercalcemia (serum calcium greater than 11.0 mg/100 ml) occurred in only 6 patients (8.5%). The incidence of secondary hyperparathyroidism decreased slightly with time following transplantation, but the degree of secondary hyperparathyroidism as indicated by the levels of serum parathyroid hormone at various times following renal transplantation was essentially similar. The causes for the persistence of this condition are not totally known, but it was found that its incidence was related to the duration of dialysis prior to transplantation.