Background and aims: Neuromuscular symptoms are frequent features of primary hyperparathyroidism in elderly patients. Whether these symptoms are related to concomitant disorders or to hypercalcemia is of major importance in selecting patients who could benefit by parathyroidectomy. To address this hypothesis, we investigated the effects of transient normalization of calcemia on functional capacity by the administration of a single infusion of the bone resorption inhibitors pamidronate or clodronate.
Methods: Functional capacity was evaluated by the functional independence measure (FIM) in 25 patients aged 87.1+/-0.8 years (means+/-SEM) with primary hyperparathyroidism. Nine patients aged 88.4+/-1.1 with primary hyperparathyroidism, not receiving any bisphosphonate, were used as controls.
Results: By inhibiting bone resorption, bisphosphonate administration caused transient normalization of calcemia, associated with improved FIM, at a significantly higher level than in untreated patients (+16.1+/-6.0 vs +4.2+/-3.2%, p<0.05).
Conclusions: If confirmed in a randomized prospective study, these results indicate that a single bisphosphonate infusion, with consecutive transient improvement of functional capacity in relation to plasma calcium normalization, could help in identifying elderly patients who would benefit by parathyroidectomy.