Association Between Aldosterone and Parathyroid Hormone Levels in Patients With Adrenocortical Tumors

Bilateral or Unilateral Aldosterone Hypersecretion and Responsiveness to Therapy Are Associated with Differences in Calcium/Phosphate Homeostasis in Patients with Primary Aldosteronism

Introduction Primary aldosteronism is characterized by the autonomous excretion of aldosterone, which may induce bone mineral disorders. Methods A total of 96 patients with primary aldosteronism were analyzed to identify differences in the regulation of serum calcium/phosphate balance between patients with unilateral and bilateral aldosterone hypersecretion and to determine whether or not adrenalectomy or mineralocorticoid receptor blockers affected such differences. Results Serum phosphate concentrations were significantly lower in patients with unilateral aldosterone hypersecretion than in patients with bilateral aldosterone hypersecretion (2.96±0.45 vs. 3.36±0.55 mg/dL, p<0.05), and recovered after adrenalectomy (2.96±0.45 vs. 3.49±0.32 mg/dL, p<0.01). In patients with bilateral aldosterone hypersecretion, the baseline serum phosphate levels were significantly lower in responders to mineralocorticoid receptor blocker treatment, defined as post-treatment plasma renin activity ≥1 ng/mL/h, than in non-responders. In responders, these levels tended to recover after treatment. A weak negative correlation between the plasma aldosterone concentration (PAC) and serum phosphate was observed, but there were no associations between the PAC and serum calcium concentration or between the aldosterone renin ratio and serum calcium and phosphate concentrations. Conclusion The effects on calcium/phosphate homeostasis may differ according to the primary aldosteronism subtype.

Hyperaldosteronism and hyperparathyroidism. A disturbing friendship

Classically, aldosterone actions are associated with the stability of the effective circulating volume and with blood pressure control, while parathormone actions are linked to bone mineral metabolism, calcium, and phosphate homeostasis. Nevertheless, the relationship between these two hormonal axes surpasses these areas. A bidirectional interrelation between calcium-phosphorus metabolism and blood pressure control can lead to alterations in both. This can have significant implications for the evolution and treatment of patients. To illustrate this relationship, we present two clinical cases that demonstrate the pathophysiology involved.).

Evaluating the clinical and mechanistic effects of eplerenone and amiloride monotherapy, and combination therapy with cinacalcet, in primary hyperparathyroidism: A placebo-controlled randomized trial

OBJECTIVES

Human physiology and epidemiology studies have demonstrated complex interactions between the renin-angiotensin-aldosterone system, parathyroid hormone and calcium homeostasis. Several of these studies have suggested that aldosterone inhibition may lower parathyroid hormone (PTH) levels. The objective of this study was to assess the effect of 4 weeks of maximally tolerated mineralocorticoid receptor antagonist therapy with eplerenone on PTH levels in patients with primary hyperparathyroidism (P-HPT) when compared to amiloride and placebo. We also investigated the synergistic effect of these interventions when combined with cinacalcet for an additional 2 weeks.

DESIGN

Randomized, double-blinded, three parallel-group, placebo-controlled trial.

PATIENTS

Patients with P-HPT.

RESULTS

Most patients were women (83%) and White (76%). Maximally tolerated doses of eplerenone and amiloride induced significant reductions in blood pressure and increases in renin and aldosterone production; however, despite these physiologic changes, neither intervention induced significant changes in PTH or calcium levels when compared to the placebo. Both eplerenone and amiloride therapy induced significant reductions in procollagen type 1 N-terminal propeptide levels when compared to placebo. When cinacalcet therapy was added, PTH and calcium levels were markedly reduced in all groups; however, there was no significant difference in PTH or serum calcium reductions between groups.

CONCLUSIONS

Although maximally tolerated therapy with eplerenone and amiloride induced expected changes in renin, aldosterone and blood pressure, there were no meaningful changes in PTH or serum calcium levels in P-HPT patients. These results suggest that inhibition of aldosterone action does not have a clinically meaningful role in medical therapy for P-HPT.

Bone and mineral metabolism in patients with primary aldosteronism: A systematic review and meta-analysis

PURPOSE

Patients with primary aldosteronism (PA) tend to exhibit a high prevalence of osteoporosis (OP) that may vary by whether PA is unilateral or bilateral, and responsive to PA treatment. To explore relationships between bone metabolism, PA subtypes, and treatment outcomes, we performed a systematic review and meta-analysis.

METHODS

The PubMed, Embase, and Cochrane databases were searched for clinical studies related to PA and bone metabolism markers. Articles that met the criteria were screened and included in the systematic review; the data were extracted after evaluating their quality. R software (ver. 2022-02-16, Intel Mac OS X 11.6.4) was used for the meta-analysis.

RESULTS

A total of 28 articles were subjected to systematic review, of which 18 were included in the meta-analysis. We found that PA patients evidenced a lower serum calcium level (mean difference [MD] = -0.06 mmol/L, 95% confidence interval [CI]: -0.10 ~ -0.01), a higher urine calcium level (MD = 1.29 mmol/24 h, 95% CI: 0.81 ~ 1.78), and a higher serum parathyroid hormone (PTH) level (MD = 2.16 pmol/L, 95% CI: 1.57 ~ 2.75) than did essential hypertension (EH) subjects. After medical treatment or adrenal surgery, PA patients exhibited a markedly increased serum calcium level (MD = -0.08 mmol/L, 95% CI: -0.11 ~ -0.05), a decreased urine calcium level (MD = 1.72 mmol/24 h, 95% CI: 1.00 ~ 2.44), a decreased serum PTH level (MD = 2.67 pmol/L, 95% CI: 1.73 ~ 3.62), and an increased serum 25-hydroxyvitamin D (25-OHD) level (MD = -6.32 nmol/L, 95% CI: -11.94 ~ -0.70). The meta-analysis showed that the ser um PTH level of unilateral PA patients was significantly higher than that of bilateral PA patients (MD = 0.93 pmol/L, 95% CI: 0.36 ~ 1.49) and the serum 25-OHD lower than that of bilateral PA patients (MD = -4.68 nmol/L, 95% CI: -7.58 ~ 1.77). There were, however, no significant differences between PA and EH patients of 25-OHD, or BMD of femoral neck and lumbar spine. BMDs of the femoral neck or lumbar spine did not change significantly after treatment. The meta-analytical results were confirmed via sensitivity and subgroup analyses.

CONCLUSION

Excess aldosterone was associated with decreased serum calcium, elevated urinary calcium, and elevated PTH levels; these effects may be enhanced by low serum 25-OHD levels. The risks of OP and fracture might be elevated in PA patients, especially unilateral PA patients, but could be reduced after medical treatment or adrenal surgery. In view, however, of the lack of BMD changes, such hypothesis needs to be tested in further studies.