Bone mineral density evolution after successful parathyroidectomy in patients with normocalcemic primary hyperparathyroidism.

CONTEXT It is unclear whether bone mineral density (BMD) improves in patients with normocalcemic primary hyperparathyroidism (PHPT) after parathyroidectomy (PTX). OBJECTIVE The objective of the study was to evaluate and compare the impact of PTX on BMD change at 1 year in normocalcemic vs hypercalcemic PHPT. DESIGN This was a longitudinal cohort study. SETTING The study took place at a referral center. PATIENTS We included 60 PHPT patients (mean age 64.0 ± 10.1 years), successfully treated by PTX by the same surgeon. Two groups were individualized according to baseline serum total (albumin corrected) calcium: 39 patients with normal baseline serum total calcium (normocalcemic group) and 21 patients with hypercalcemia at baseline (hypercalcemic group). MAIN OUTCOME MEASURE BMD changes 1 year after PTX were measured. RESULTS In the normocalcemic group, BMD increased significantly by +2.3 ± 5.0% at the spine (P = .016) and +1.9 ± 5.7% at the hip (P = .048). In the hypercalcemic group, BMD increased significantly by +4.0 ± 3.8% at the spine (P = .0003) and +3.2 ± 4.2% at the hip (P = .003). There was no difference in these BMD gains between both groups (P > .1). The presence of multiple adenomas or hyperplasia was more frequent in the normocalcemic group than in the hypercalcemic group (P = .04). CONCLUSION Our results indicate for the first time that successful PTX in normocalcemic PHPT patients with osteoporosis is followed with mild but significant BMD improvement at the spine and hip at 1 year, comparable with that observed in hypercalcemic PHPT, suggesting that PTX may be beneficial in normocalcemic PHPT.