An investigation of biochemical and radiographic signs of hyperparathyroidism in chronic renal disease.

One hundred and twelve randomly selected patients with renal disease (22 on conservative treatment, 35 on haemodialysis and 55 with functioning kidney transplants) were subjected to a longitudinal and follow-up study of biochemical and radiographic signs of secondary hyperparathyroidism (HPT). Special interest was directed towards diagnostic criteria leading to the decision to perform parathyroid surgery, which had been undertaken in 18 patients. The five patients selected for parathyroidectomy while on conservative treatment were clearly distinguishable from the rest of the patients in this group, on the basis of hypercalcaemia, massive elevation of serum parathyroid hormone and radiographic abnormalities, findings which did not occur in patients in whom parathyroid surgery had not been considered. Six patients underwent parathyroidectomy while on haemodialysis. Preoperatively hypercalcaemia was observed in five and this was the only finding separating these patients from non-operated patients. Radiographic abnormalities were observed in only one operated patient. After kidney transplantation, long-standing hypercalcaemia was observed in 27% of patients. Seven patients underwent parathyroidectomy, hypercalcaemia being the indication for surgery in all cases. Hypercalcaemic patients could not be separated from normocalcaemic patients regarding any other determined biochemical variable, or regarding the incidence of osteonecrosis of weight-bearing joints, which was found in 18% of transplanted patients, and which was the only cause of major symptomatic bone disease observed in this study. The findings of hypercalcaemia as a major deciding factor for parathyroid surgery, a low incidence of radiographic bone disease, and absence of major symptomatic bone disease referable to HPT, are in keeping with a more liberal attitude to parathyroidectomy in chronic renal disease than has been stated in other recent reports. With a more expectant attitude and with more active medical treatment some of the operations performed on the patients in this study might have been avoided but, in general, the favourable outcome after surgery and the low overall incidence of clinical problems referable to bone disease at our unit would seem to support our active approach to parathyroid surgery.