Effect of parathyroidectomy for primary hyperparathyroidism on bone mineral density in postmenopausal women.

BACKGROUND: The bone mineral density (BMD) response to parathyroidectomy is heterogeneous and difficult to predict. Available data come from mixed populations of men and women, of different age and degrees of disease severity, and preoperative BMD loss. METHODS: This was a longitudinal, prospective cohort study of 103 postmenopausal women with osteopenia or osteoporosis at the femoral neck site, successfully operated on for primary hyper parathyroidism. BMD and metabolic variables were recorded before and 1 year after parathyroidectomy. RESULTS: After surgery, there was a 1.3 per cent increase in the median BMD at the femoral neck site (0.615 versus 0.623 g/cm(2); P = 0.001). Overall, positive responses were also observed at total hip (0.4 per cent) and lumbar spine (2.3 per cent) sites. Analysing the individual responses, however, only 45 (46 per cent) of 97 patients showed a significant (at least 3.7 per cent) increase in BMD at the femoral neck site compared with the preoperative value and 52 had a decreased (15) or unchanged (37) femoral neck BMD. Patients who gained BMD were younger, had more severe hyperparathyroidism and better renal function. CONCLUSION: Almost half of the postmenopausal women with hyperparathyroidism and low BMD have a significant remineralization response 1 year after parathyroidectomy. Differential mineralization responses of BMD after surgery appear to be related to severity of primary hyperparathyroidism, age and renal function.