Gender differences in bone mineral density in patients with sporadic primary hyperparathyroidism

Primary hyperparathyroidism reduces bone mineral density, which increases the risk of fracture.

To investigate differences in bone mineral density and clinical characteristics after parathyroidectomy between men and women (premenopausal and postmenopausal) with sporadic primary hyperparathyroidism.

This is a retrospective study of adult patients who underwent parathyroidectomy in a tertiary referral center from 1990 to 2013.

A total of 1529 patients underwent parathyroidectomy during the study period; 80 patients met the inclusion criteria. Of these, 24 were men and 56 were women (10 premenopausal and 46 postmenopausal).

Demographics, preoperative and postoperative biochemical analysis, preoperative and postoperative T-scores, preoperative Z-scores, preoperative and postoperative absolute bone mineral density values, and percentage change in bone mineral density from baseline to 12 ± 6 months after parathyroidectomy in the lumbar spine, femoral neck, total hip and distal one-third of the nondominant radius.

Preoperative 24-hour urinary calcium levels were significantly higher in men than in women overall (P = 0.02) and postmenopausal women (P = 0.01). Men had significantly lower preoperative Z-scores than women overall, premenopausal women and postmenopausal women. Men had greater percentage change of increase in bone mineral density in the femoral neck than did women overall (2.77%; P = 0.04) and postmenopausal women (2.98%; P = 0.03) 1 year after parathyroidectomy.

From this study, men demonstrated a greater improvement of bone mineral density in the femoral neck from baseline after parathyroidectomy compared with women.