Effects of successful parathyroidectomy on altered arterial reactivity in patients with hypercalcaemia: results of a 3-year follow-up study.

OBJECTIVE

Serum calcium was found to be an independent, prospective risk factor for myocardial infarction. We have previously shown that altered arterial reactivity in the course of primary hyperparathyroidism, a disease characterized by hypercalcaemia, may predominantly involve the arterial media and not the endothelium as observed in patients with various stages of atherosclerosis. The present study was performed to test whether successful parathyroidectomy can improve vascular reactivity in patients with primary hyperparathyroidism.

SUBJECTS AND

DESIGN

Endothelium-dependent, flow-mediated and endothelium-independent, nitroglycerin-induced dilatation were assessed by brachial artery ultrasound (7 MHz) in 18 patients with primary hyperparathyroidism (mean +/- SD; age, 55.1 +/- 12.6) prior to and 3 years after successful parathyroidectomy.

RESULTS

Parathyroidectomy resulted in significant decreases of PTH (242 +/- 186 vs. 34 +/- 24 ng/l, P = 0. 0001) and serum calcium levels (2.8 +/- 0.3 vs. 2.4 +/- 0.1 mm/l, P = 0.00001) and in an increase of serum phosphate levels (0.78 +/- 0. 23 vs. 1.17 +/- 0.18 mm/l, P = 0.00001). However, normalization of hormone and electrolyte levels did not lead to an improvement of flow-mediated dilatation (12.1 +/- 3.1 vs. 11.0 +/- 5.4&, P = 0.49) or nitroglycerin-induced dilatation (12.5 +/- 3.1 vs. 13.2 +/- 6.8%, P = 0.68) within the follow-up period. No changes were observed with respect to the risk factor profile, vessel size and blood flow.

CONCLUSION

These data suggest that restoration of normocalcaemia by parathyroidectomy cannot improve vascular reactivity in patients with primary hyperparathyroidism but may prevent further progression of vascular disease within this period of time.