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.