PTH Is a Promising Auxiliary Index for the Clinical Diagnosis of Aldosterone-Producing Adenoma

Cross-Disciplinary Approach of Adrenal Tumors: Insights into Primary Aldosteronism-Related Mineral Metabolism Status and Osteoporotic Fracture Risk

Our objective was to overview the novel aspects in the field of adrenal gland neoplasms, namely, the management of bone status with respect to primary aldosteronism (PA). In the current narrative review, a PubMed study was conducted from inception until June 2023. The inclusion criteria were: human (clinically relevant) studies of any study design (at least 10 patients per study); English papers; and the following combination of key words within the title and/or abstract: "aldosterone" AND "bone", "skeleton", "osteoporosis", "fracture", "calcium", "parathyroid", "DXA", "osteocalcin", "P1NP", "alkaline phosphatase", "bone marker", "trabecular bone score", or "FRAX". The exclusion criteria were in vitro or animal studies, reviews, and case reports/series. We screened 1027 articles and finally included 23 studies (13 of case-control type, 3 cross-sectional, 5 prospective, 1 observational cohort, and 1 retrospective study). The assessments provided in these studies were as follows: nine studies addressed Dual-Energy X-ray Absorptiometry (DXA), another study pointed out a bone microarchitecture evaluation underlying trabecular bone score (TBS), and seven studies investigated the bone turnover markers (BTMs) profile. Moreover, 14 studies followed the subjects after adrenalectomy versus medical treatment, and 21 studies addressed secondary hyperparathyroidism in PA patients. According to our study on published data during a period of almost 40 years (n = 23, N = 3965 subjects aged between 38 and 64, with a mean age 56.75, and a female-to-male ratio of 1.05), a higher PTH in PA versus controls (healthy persons or subjects with essential hypertension) is expected, secondary hyperparathyroidism being associated in almost half of the adults diagnosed with PA. Additionally, mineral metabolism anomalies in PA may include lower serum calcium and higher urinary calcium output, all these three parameters being reversible under specific therapy for PA, regardless medical or surgical. The PA subgroup with high PTH seems at higher cardiovascular risk, while unilateral rather than bilateral disease was prone to this PTH anomaly. Moreover, bone mineral density (BMD) according to central DXA might show a higher fracture risk only in certain adults, TBS being a promising alternative (with a still unknown perspective of diabetes' influence on DXA-TBS results in PA). However, an overall increased fracture prevalence in PA is described in most studies, especially with respect to the vertebral site, the fracture risk that seems correctable upon aldosterone excess remission. These data recommend PA as a cause of secondary osteoporosis, a treatable one via PA intervention. There is still an area of debate the way to address BMTs profile in PA, the case's selection toward specific bone evaluation in every day practice, and further on, the understanding of the potential genetic influence at the level of bone and mineral complications in PA patients.

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.

Vitamin D and adrenal gland: Myth or reality? A systematic review

In recent years, vitamin D has become the protagonist in many studies. From cardiology to oncology the spotlight was on this vitamin. While in the past it was considered for its important role in phospho-calcium metabolism and skeletal disorders; today by studying it better, thousands of scenarios and facets have opened up on this vitamin which is actually a hormone in all respects. There are authoritative studies that demonstrate its activity in vitro and in vivo on: carcinogenesis, inflammation, autoimmunity and endocrinopathies. Its role has been studied in type 1 and type 2 diabetes mellitus, in Hashimoto or Graves' thyroiditis and even in adrenal gland diseases. In fact, there are several studies that demonstrate the possible correlations between vitamin D and: Addison's disease, Cushing disease, hyperaldosteronism or adrenocortical tumors. Moreover, this fascinating hormone and adrenal gland even seem to be deeply connected by common genetic pathways. This review aimed to analyze the works that have tried to study the possible influence of vitamin D on adrenal diseases. In this review we analyze the works that have tried to study the possible influence of vita-min D on adrenal disease.

Abdominal aortic calcification is more severe in unilateral primary aldosteronism patients and is associated with elevated aldosterone and parathyroid hormone levels

Primary aldosteronism (PA) is associated with a higher prevalence of abdominal aortic calcification (AAC). Unilateral and bilateral PA are the most common subtypes of PA. However, no studies have addressed the difference in the prevalence of AAC between the two subtypes. In addition to aldosterone, parathyroid hormone (PTH), an important regulator of calcium metabolism, was also reported to be elevated in individuals with unilateral PA. Therefore, we hypothesized that the prevalence of AAC may be higher in individuals with unilateral PA, which may be related to the plasma aldosterone concentration (PAC) and PTH levels. We included 156 PA patients who underwent adrenal venous sampling and 156 with essential hypertension (EH) matched by age and sex. Of the former, 76 were diagnosed with unilateral PA, and 80 were diagnosed with bilateral PA. The aortic calcification index (ACI) presented the severity of AAC and was measured by adrenal computed tomography scan. Our results showed that compared with the EH group, the prevalence and severity of AAC were higher in PA patients (32.7 vs. 19.6%; 4.32 ± 3.61% vs. 2.53 ± 2.42%, respectively). In the PA subgroup analysis, unilateral PA was associated with a higher and more severe AAC than bilateral PA (40.7 vs. 25.0%; 5.12 ± 4.07% vs. 3.08 ± 2.34%, respectively). Moreover, PAC and PTH levels were higher in individuals with unilateral PA than in those with bilateral PA (P < 0.05). After risk adjustment, multivariate regression analysis revealed that PAC and PTH were positively-associated with AAC in patients with PA (P < 0.05). In conclusion, unilateral PA patients exhibited a higher prevalence of AAC and more severe AAC due to elevated PAC and PTH levels.

Adrenal disorders: Is there Any role for vitamin D?

An emerging branch of research is examining the linkage between Vitamin D and nonskeletal disorders, including endocrine diseases. In this regard, a still little studied aspect concerns the involvement of vitamin D in adrenal gland disorders. Adrenal gland disorders, which might be theoretically affected by vitamin D unbalance, include adrenal insufficiency, Cushing's syndrome, adrenocortical tumors and hyperaldosteronism. In this review, we provide an updated document, which tries to collect and discuss the limited evidence to be found in the literature about the relationship between vitamin D and adrenal disorders. We conclude that there is insufficient evidence proving a causal relationship between vitamin D levels and adrenal disorders. Evidence coming from cross-sectional clinical studies can hardly clarify what comes first between vitamin D unbalance and adrenal disease. On the other hand, longitudinal studies monitoring the levels of vitamin D in patients with adrenal disorders or, conversely, the possible development of adrenal pathologies in subjects affected by impaired vitamin D levels would be able to elucidate this still unclear issue.