Changes in bone mineral density after surgical intervention for primary hyperparathyroidism.

Background: Patients with primary hyperparathyroidism often lack classic symptoms but can have reductions in bone mineral density and increased fracture risk. We sought to determine bone mineral density improvement after successful surgery and associated factors.

Methods: A review of patients with osteopenia or osteoporosis with curative parathyroidectomy and both pre- and postoperative dual-energy X-ray absorptiometry bone mineral density scans was conducted. We compared patients with declining (<0%), moderate improvement (0.1-5%), and significant improvement (>5%) on dual-energy X-ray absorptiometry bone mineral density scans.

Results: We identified 420 patients who underwent a dual-energy X-ray absorptiometry bone mineral density scan preoperatively and within 36 months postoperatively. At the most affected site, 38% had significant improvement, 31% moderate improvement, and 31% declining bone mineral density. Patients who significantly improved were younger (P = .01), had lesser preoperative dual-energy X-ray absorptiometry (P = .001), and had greater preoperative levels of parathyroid hormone (P = .04), serum calcium (P = .03), and preoperative urinary calcium. There was no difference in outcomes between sex and with preoperative bisphosphonate use. Average hip and spine bone mineral density had similar responses to surgery.

Conclusion: Bone mineral density improves in up to 75% of patients after curative parathyroidectomy for primary hyperparathyroidism. The hip and lumbar spine responded similarly. Younger patients and those with severe primary hyperparathyroidism may derive the most skeletal benefits from parathyroidectomy, but the uniform positive response supports parathyroidectomy in patients with osteoporosis and possibly osteopenia.