Endocrine Abstracts

Context: Recent studies showed association between hyperaldosteronism and low bone density among patients with primary aldosteronism (PA) due to secondary hyperparathyroidism.

Objective: To assess bone turnover markers and bone mineral density (BMD) of PA patients compared to essential hypertension.

Design: This was an open label, prospective, case-controlled study, conducted over 12 months.

Setting: Eighteen consecutive out-patients with confirmed PA and seventeen age- and sex-matched controls were recruited.

Patients: All patients had confirmed PA based on Endocrine Society guideline. Controls were patients with essential hypertension.

Intervention: Bone turnover markers (CTX and P1NP), BMD, intact parathyroid hormone (iPTH), and bone profile were assessed at baseline and three months following treatment among 15 PA patients. Calcium intake was assessed using a validated questionnaire.

Main outcome measures: Primary outcomes were the changes of bone turnover markers and BMD following treatment of PA, and their relation to other parameters.

Results: PA patients had significantly lower serum calcium and higher iPTH despite comparable vitamin D levels with control group. Both bone turnover markers were significantly higher among the PA group. BMD of lumbar spine, neck of femur and distal radius did not differ between groups. Three months following treatment, there were significant i) increment of serum 25-OH vitamin D level, ii) reduction in iPTH level, iii) reduction in bone turnover markers and iv) improvement in the lumbar spine BMD.

Conclusion: PA is a state of high bone turnover in the presence of secondary hyperparathyroidism. Treatment of PA improves secondary hyperparathyroidism with reduction in bone turnover markers.