A greater increase in bone mineral density (BMD) at the femoral neck may be seen after parathyroidectomy for sporadic primary hyperparathyroidism in men compared with women, according to study results published in Endocrinology, Diabetes & Metabolism.
Primary hyperparathyroidism is a known secondary cause of osteoporosis and increases predisposition toward fractures. Previous studies have shown that surgery in these cases is associated with an increase in BMD. The goal of this study was to investigate for differences in the increase in BMD after parathyroidectomy between sexes.
The retrospective study included 80 adult patients with a diagnosis of primary hyperparathyroidism, who underwent parathyroidectomy at the University of Texas MD Anderson Cancer Center between 1990 and 2013. The participants were divided into 4 study groups: men, women overall, and pre- and postmenopausal women. All patients had available dual-energy X-ray absorptiometry scan results in the lumbar spine, femoral neck, total hip, and distal one-third of the nondominant radius, both at baseline and after surgery.
Overall, z scores at lumbar spine before parathyroidectomy were lower in men compared with women (P =.06). In addition, z scores at femoral neck, total hip, and distal one-third of the radius were lower in men compared with women overall (P ≤.05) and compared with postmenopausal women (P ≤.05), and z scores at femoral neck were also lower in men compared with premenopausal women. There was no difference between preoperative z scores of premenopausal and postmenopausal women.
One year after parathyroidectomy, men had a greater BMD increase in the femoral neck compared with women overall (2.77%; P =.04) and postmenopausal women (2.98%; P =.03). As the change in BMD was not different between premenopausal and postmenopausal women, the researchers suspect that differences in estrogen levels do not explain the observed changes in BMD postoperatively.
The researchers emphasized this study had limitations expected of a retrospective study. Additional limitations result from the small cohort and missing data regarding other factors that affect bone metabolism.
“[O]ur study showed that men had a greater significant BMD increase at the femoral neck compared with women after [parathyroidectomy]. Beyond treatment of hypercalcemia and reduction of nephrolithiasis incidence, this amount of improved BMD could translate to reduction of risk for fracture in the male population,” concluded the researchers.
Vodopivec DM, Silva AM, Garcia-Banigan DC, et al. Gender differences in bone mineral density in patients with sporadic primary hyperparathyroidism. Endocrinol Diabetes Metab. 2018;1(4):e00037.