METHODS: This was an open-label, prospective, case-controlled study, conducted over 12 months. Fifty-two consecutive patients referred for secondary hypertension were screened. Eighteen patients with confirmed PA (diagnosis based on the Endocrine Society clinical guideline) and seventeen matched controls with essential hypertension were recruited. BTM (CTX and P1NP), BMD, intact parathyroid hormone (iPTH), and bone profile were assessed at baseline and three months following treatment among the PA patients. Calcium intake was assessed using a validated questionnaire. Primary outcomes were the changes of bone 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 BTM 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: 1) reduction in BTM; 2) improvement in the lumbar spine BMD; 3) reduction in iPTH level; and 4) increment of serum 25-OH vitamin D level.
CONCLUSIONS: Our findings support that bone loss and potential fracture risk among PA patients are likely a result of aldosterone-mediated secondary hyperparathyroidism. Patients with early PA may already exhibit increased bone turnover despite no significant changes in BMD.
EVIDENCE ACQUISITION: A systematic search of all English-language medical literature published from 1980 till May 2016 using PubMed, Embase and Ovid was performed. Nine observational studies were evaluated after fulfilling the inclusion and exclusion criteria.
EVIDENCE SYNTHESIS: A total of 547 patients were examined. All studies used vitamin D2/D3 or calcifediol (25-hydroxyvitamin D3), There was significant improvement of serum 25(OH)D with unchanged serum iPTH level after vitamin D replacement, with pooled d+: 3.10 (95% CI 2.25 to 3.95), P<0.01 and pooled d+: 0.82 (95% CI -0.35 to 1.98), P=0.16 respectively. There was neither worsening of the pre-existing hypercalcemia (pooled d+: -0.27 [95% CI -1.09 to 0.64, P=0.56]) nor hypercalciuria (pooled d+: 3.64 [95% CI -0.55 to 7.83, P=0.09]). Two studies assessed in this meta-analysis reported unchanged bone density with vitamin D replacement.
CONCLUSIONS: Vitamin D replacement in subjects with mild PHPT and coexistent vitamin D deficiency improved serum 25(OH)D level without worsening of pre-existing hypercalcemia or hypercalciuria. Well-designed multicenter randomized controlled trials examining pre- and postoperative outcomes of vitamin D therapy in patients with different severities of PHPT and vitamin D inadequacy are warranted to elucidate the most appropriate vitamin D treatment protocol and determine the long-term safety concerns.
EVIDENCE ACQUISITION: We conducted a meta-analysis to evaluate the relationship between primary aldosteronism (PA) with bone biochemical markers and to assess bone mineral density in patients with primary aldosteronism.
EVIDENCE SYNTHESIS: A total of 939 subjects were examined (37.5% with PA). Patients with PA had significantly higher serum parathyroid hormone, lower serum calcium, higher urine calcium excretion and higher serum alkaline phosphatase compared to patients without PA, with no significant difference in serum vitamin D between both groups. Bone mineral density of lumbar spine, femoral neck and total neck of femur were similar between two groups. With PA treatment, there was a significant increment in serum calcium and reduction in serum parathyroid hormone.
CONCLUSIONS: PA is associated with hypercalciuria with subsequent secondary hyperparathyroidism. This potentially affects bone health. We recommend this to be part of complication screening among patients with PA.