The Relationship of Parathyroidectomy and Bisphosphonates With Fracture Risk in Primary Hyperparathyroidism: An Observational Study.

BACKGROUND

The comparative effectiveness of surgical and medical treatments on fracture risk in primary hyperparathyroidism (PHPT) is unknown.

OBJECTIVE

To measure the relationship of parathyroidectomy and bisphosphonates with skeletal outcomes in patients with PHPT.

DESIGN

Retrospective cohort study.

SETTING

An integrated health care delivery system.

PARTICIPANTS

All enrollees with biochemically confirmed PHPT from 1995 to 2010.

MEASUREMENTS

Bone mineral density (BMD) changes and fracture rate.

RESULTS

In 2013 patients with serial bone density examinations, total hip BMD increased transiently in women with parathyroidectomy (4.2% at <2 years) and bisphosphonates (3.6% at <2 years) and declined progressively in both women and men without these treatments (-6.6% and -7.6%, respectively, at >8 years). In 6272 patients followed for fracture, the absolute risk for hip fracture at 10 years was 20.4 events per 1000 patients who had parathyroidectomy and 85.5 events per 1000 patients treated with bisphosphonates compared with 55.9 events per 1000 patients without these treatments. The risk for any fracture at 10 years was 156.8 events per 1000 patients who had parathyroidectomy and 302.5 events per 1000 patients treated with bisphosphonates compared with 206.1 events per 1000 patients without these treatments. In analyses stratified by baseline BMD status, parathyroidectomy was associated with reduced fracture risk in both osteopenic and osteoporotic patients, whereas bisphosphonates were associated with increased fracture risk in these patients. Parathyroidectomy was associated with fracture risk reduction in patients regardless of whether they satisfied criteria from consensus guidelines for surgery.

LIMITATION

Retrospective study design and nonrandom treatment assignment.

CONCLUSION

Parathyroidectomy was associated with reduced fracture risk, and bisphosphonate treatment was not superior to observation.

PRIMARY FUNDING SOURCE

National Institute on Aging.