Endocrine Abstracts

Introduction: Primary hyperparathyroidism (pHPT) is the most frequent cause of hypercalcemia in ambulatory patients. Most persons have no symptoms, and pHPT usually is diagnosed after an elevated serum calcium (Ca²⁺) level is found incidentally. Parathyroidectomy is the definitive treatment for pHPT. There have been several different approaches to the medical management of pHPT. Our aim in this study is to compare alendronate sodium (ALN) and raloxifene (RLX) efficiency in postmenopausal female pHPT patients with osteoporosis.

Methods: Twenty postmenopausal patients with osteoporosis that were diagnosed with pHPT and rejected the surgical treatment were included in the study. Patients were sequentially randomized into ALN 70 mg/week (n=10) and RLX 60 mg/day (n=10) treatment groups. Serum and urine laboratory parameters of patients were compared with baseline, 6th and 12th month values. Baseline and 12th month bone density values were compared.

Results: Initial age, total Ca²⁺, phosphorus (P), parathormone (PTH), 25-hydroxyvitamin-D (25-OH-D), 24-h urine Ca²⁺, adenoma volume and bone densitometry T scores among groups taking ALN and RLX treatments demonstrated resemblance. While total Ca²⁺ levels of ALN group were significantly lower compared with baseline at the 6th month, such a difference disappeared at the 12th month (11.2±0.6, 10.3±0.7, and 10.6±0.4 respectively, between baseline and 6th month P=0.003, and between baseline and 12th month P=0.070). However, a significant difference was not observed between baseline, 6th and 12th month P, PTH, 25-OH-D, 24-h urine Ca²⁺ (P>0.05 for all). Although some recovery in lumbar and femur neck T score was observed at the 12th month compared with the beginning, a statistical difference was not established. (−3.6±1.2 vs −2.7±1.7, P=0.202; −1.4±2.02 vs −1.8±0.7, P=0.495, respectively). In the RLX group, a statistical difference was not found between initial, 6th and 12th month total Ca²⁺, P, PTH, 25-OH-D, 24-h urine Ca²⁺ and initial and 12th month bone density (P>0.05 for all).

Conclusion: A positive effect of ALN and RLX on Ca levels and osteoporosis was not observed in postmenopausal female patients with pHPT. However, due to the significant Ca²⁺ decrease in the ALN group in the first 6 months in our study, a short-term oral ALN treatment may be utilized for patients waiting for surgery in order to keep Ca²⁺ levels under control.