Bone and mineral metabolism in patients with primary aldosteronism

Medullary nephrocalcinois and primary hyperaldosteronism - A rare and under recognised association

ABSTRACT

Medullary nephrocalcinosis is an uncommon manifestation of primary hyperaldosteronism (PHA) and the exact etiology of this association is still debated. Here we report three cases of PHA with medullary nephrocalcinosis and how medullary nephrocalcinosis in one patient led to misdiagnosis as renal tubular acidosis (RTA). Although PHA and RTA can share overlapping symptoms, careful evaluation of clinical presentation, biochemical tests, and imaging studies are essential to differentiate between the two conditions and ensure appropriate management. Also, awareness of this uncommon manifestation of PHA is essential to avoid misdiagnosis as tubulopathy, as this may delay the treatment.

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.

The prevalence of primary and secondary hyperparathyroidism and its cardiometabolic implications in primary aldosteronism

BACKGROUND

The aim of this study was to analyze the prevalence of primary and secondary hyperparathyroidism in patients with primary aldosteronism (PA), and its implication on cardiovascular and metabolic outcomes.

METHODS

A retrospective study of patients with PA (exposed cohort, N.=44) and all hypertensive (EH) patients with adrenal lesions without PA nor other adrenal hypersecretion (non-exposed cohort, N.=41) on follow-up at our center between 2016 and 2020.

RESULTS

The mean age of patients with PA and EH was 55.1±14.13 and 66.3±10.93 (P<0.001), and 50% of PA and 39.0% of EH were women (P=0.309). At diagnosis, the prevalence of primary hyperparathyroidism in PA was of 18.2%, and all were normocalcemic hyperparathyroidism cases. Globally, no differences were found in the prevalence of primary hyperparathyroidism compared to EH (18.2% vs. 29.3%, P=0.229), but hypercalcemic primary hyperparathyroidism was significantly more prevalent in EH patients than in PA (22.0% vs. 0%, P=0.001). There were 47.7% (N.=21) cases of secondary hyperparathyroidism in patients with PA (4 due to chronic kidney disease (CKD) and vitamin D deficiency, and 17 due to vitamin D deficiency alone). The cardiometabolic profile of patients with PA and hyperparathyroidism (N.=29) was similar to of those patients without hyperparathyroidism (N.=15) at diagnosis and after a median follow-up of 3.6 years (interquartile range 1.1-5.9).

CONCLUSIONS

Although primary and secondary hyperparathyroidism are common in patients with PA, their prevalence was similar than the observed in EH patients. Primary hyperparathyroidism is usually mild in PA, appearing as normocalcemic forms. No negative implications of the hyperparathyroidism in the cardiometabolic profile of PA were observed.

Bilateral co-secretory lesions presenting with coexisting Cushing syndrome and primary aldosteronism: a case report

BACKGROUND

There is an increasing number of cases of aldosterone- and cortisol-producing adenomas (A/CPAs) reported in the context of primary aldosteronism (PA). Most of these patients have PA complicated with subclinical Cushing's syndrome; cases of apparent Cushing's syndrome (CS) complicated with aldosteronism are less reported. However, Co-secretory tumors were present in the right adrenal gland, a cortisol-secreting adenoma and an aldosterone-producing nodule (APN) were present in the left adrenal gland, and aldosterone-producing micronodules (APMs) were present in both adrenal glands, which has not been reported. Here, we report such a case, offering profound insight into the diversity of clinical and pathological features of this disease.

CASE PRESENTATION

The case was a 45-year-old female from the adrenal disease diagnosis and treatment centre in West China Hospital of Sichuan University. The patient presented with hypertension, moon-shaped face, central obesity, fat accumulation on the back of the neck, disappearance of cortisol circadian rhythm, ACTH < 5 ng/L, failed elevated cortisol inhibition by dexamethasone, orthostatic aldosterone/renin activity > 30 (ng/dL)/(ng/mL/h), and plasma aldosterone concentration > 10 ng/dL after saline infusion testing. Based on the above, she was diagnosed with non-ACTH-dependent CS complicated with PA. Adrenal vein sampling showed no lateralization for cortisol and aldosterone secretion in the bilateral adrenal glands. The left adrenocortical adenoma was removed by robot-assisted laparoscopic resection. However, hypertension, fatigue and weight gain were not alleviated after surgery; additionally, purple striae appeared in the lower abdomen, groin area and inner thigh, accompanied by systemic joint pain. One month later, the right adrenocortical adenoma was also removed. CYP11B1 were expressed in the bilateral adrenocortical adenomas, and CYP11B2 was also expressed in the right adrenocortical adenomas. APN existed in the left adrenal gland and APMs in the adrenal cortex adjacent to bilateral adrenocortical adenomas. After another surgery, her serum cortisol and plasma aldosterone returned to normal ranges, except for slightly higher ACTH.

CONCLUSIONS

This case suggests that it is necessary to assess the presence of PA, even in CS with apparent symptoms. As patients with CS and PA may have more complicated adrenal lesions, more data are required for diagnosis.

Aldosterone-producing adenoma is associated with urolithiasis in primary aldosteronism

Primary aldosteronism (PA) is associated with urolithiasis as it causes hypercalciuria and hypocitraturia. However, the influence of different subtypes of PA on urinary stone formation remains unclear. This study aimed to evaluate the association between aldosterone-producing adenoma (APA) and the burden of urolithiasis in patients with PA. In the present study, we enrolled 312 patients with PA from a prospectively maintained database, of whom 179 had APA. Clinical, biochemical, and imaging data (including the presence, volume, and density of urinary stones on abdominal computed tomography) were compared between groups, with employment of propensity score matching (PSM) analysis to balance possible confounding factors. Kaplan-Meier analysis was used to estimate the acute renal colic event during follow-up. After PSM for age, sex, serum calcium, phosphate, blood urea nitrogen, creatinine, and uric acid, the APA and non-APA groups had 106 patients each. Patients with APA had higher serum intact parathyroid hormone (iPTH) (79.1 ± 45.0 vs 56.1 ± 30.3, P < 0.001) and a higher prevalence of urolithiasis (27.4% vs 12.3%, P = 0.006) than non-APA patients. During follow-up, a higher incidence of acute renal colic events was noted in the APA group than the non-APA group (P = 0.011); this association remained significant (P = 0.038) after adjustment for age and sex in Cox-regression analysis. Our data suggest that APA is associated with a heavier burden of urolithiasis and higher incidence of renal colic events compared to the non-APA subtype of PA.

Vitamin D regulates insulin and ameliorates apoptosis and oxidative stress in pancreatic tissues of rats with streptozotocin-induced diabetes

This study was designed to evaluate the potential therapeutic efficacy of vitamin D (Vit D) in averting the harmful effects of type 2 diabetes mellitus (T2D). Forty male Wistar rats were allotted into four groups: (1) the control, (2) Vit D, (3) streptozotocin (STZ), and (4) STZ + Vit D groups. Rats co-treated with Vit D had significantly (p < 0.05) decreased levels of cortisol; proinflammatory cytokines, including interleukin-6 (IL-6); and malondialdehyde (MDA). Meanwhile, the levels of insulin significantly (p < 0.05) increased, whereas the activity of the antioxidant system, including glutathione (GSH), superoxide dismutase (SOD), catalase, and total antioxidant capacity (TAC), significantly (p < 0.05) decreased. Histopathological examination revealed the destruction of beta cells in the islets of Langerhans in rats with diabetes. Meanwhile, immunoexpression revealed an increase in the immunoreactivity of caspase-3 and endothelial nitric oxide synthase and a reduction in the immunoreactivity of insulin in rats with diabetes. In conclusion, Vit D ameliorated the harmful biochemical impact of diabetes mellitus, probably by increasing insulin secretion and sensitivity, ameliorating β-cell function, and decreasing cortisol levels; also, the anti-inflammatory effect of Vit D reduces the number of proinflammatory cytokines (e.g., IL-6) and increases the activity of the antioxidant system, such as GSH, SOD, TAC, and catalase while reducing lipid peroxidation enzymes (e.g., MDA).

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.

Risk Factors Associated With Lower Bone Mineral Density in Primary Aldosteronism Patients

PURPOSE

The association between primary aldosteronism (PA) and lower bone mineral density (BMD) has raised a concern, but the contributing factors remain unclear. We aim to explore the risk factors for lower BMD in PA patients.

METHODS

We analyzed and compared the data of 60 PA patients with 60 matched essential hypertension (EH) patients. BMD, bone metabolites, and several oxidative stress and inflammation indicators-including C-reactive protein (CRP), superoxide dismutase (SOD), total bilirubin (TBIL), mean platelet volume (MPV), etc.-were assessed and compared in PA and EH patients. Bivariate correlation analysis and multivariate linear regression analysis were performed to explore the factors associated with BMD in PA patients.

RESULTS

The BMD measured by quantitative computed tomography in PA patients was lower than that in EH patients (141.9 ± 34.0 vs. 158.9 ± 55.9 g/cm³, p = 0.047), especially in patients less than 50 years old. BMD was independently negatively associated with age (standardized β = -0.581, p < 0.001), serum phosphorus (standardized β = -0.203, p = 0.008), urinary calcium excretion (standardized β = -0.185, p = 0.031), and MPV (standardized β = -0.172, p = 0.043) and positively associated with SOD (standardized β = 0.205, p = 0.011) and TBIL (standardized β = 0.212, p = 0.015).

CONCLUSIONS

The PA patients showed a lower BMD than the EH patients, which was associated with age, serum phosphorus, urinary calcium excretion, MPV, SOD, and TBIL. These variables might be potential markers for the assessment of bone loss and efficacy of treatments in PA patients.

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.

Spironolactone Attenuates Methylglyoxal-induced Cellular Dysfunction in MC3T3-E1 Osteoblastic Cells

BACKGROUND

Methylglyoxal (MG) is associated with the pathogenesis of age- and diabetes-related complications. Spironolactone is a competitive antagonist of aldosterone that is widely employed in the treatment of hypertension and heart failure. This study examined the effects of spironolactone on MG-induced cellular dysfunction in MC3T3-E1 osteoblastic cells.

METHODS

MC3T3-E1 cells were treated with spironolactone in the presence of MG. The mitochondrial function, bone formation activity, oxidative damage, inflammatory cytokines, glyoxalase I activity, and glutathione (GSH) were measured.

RESULTS

Pretreatment of MC3T3-E1 osteoblastic cells with spironolactone prevented MG-induced cell death, and improved bone formation activity. Spironolactone reduced MG-induced endoplasmic reticulum stress, production of intracellular reactive oxygen species, mitochondrial superoxides, cardiolipin peroxidation, and inflammatory cytokines. Pretreatment with spironolactone also increased the level of reduced GSH and the activity of glyoxalase I. MG induced mitochondrial dysfunction, but markers of mitochondrial biogenesis such as mitochondrial membrane potential, adenosine triphosphate, proliferator-activated receptor gamma coactivator 1α, and nitric oxide were significantly improved by treatment of spironolactone.

CONCLUSION

Spironolactone could prevent MG-induced cytotoxicity in MC3T3-E1 osteoblastic cells by reduction of oxidative stress. The oxidative stress reduction was explained by spironolactone's inhibition of advanced glycation end-product formation, restoring mitochondrial dysfunction, and anti-inflammatory effect.

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

OBJECTIVE

Patients with primary aldosteronism (PA) can present with high PTH levels and negative calcium balance, with some studies speculating that aldosterone could directly stimulate PTH secretion. Either adrenalectomy or mineralocorticoid receptor blockers could reduce PTH levels in patients with PA. The aim of this study was to assess the relationship between aldosterone levels and parathyroid hormone (PTH)-vitamin D-calcium axis in a cohort of patients with PA, compared with patients with nonsecreting adrenocortical tumors in conditions of vitamin D sufficiency.

METHODS

We enrolled a series of 243 patients retrospectively, of whom 66 had PA and 177 had nonsecreting adrenal tumors, and selected those with full mineral metabolism evaluation and 25(OH) vitamin D levels >20 ng/mL at the time of initial endocrine screening. The final cohort was composed of 26 patients with PA and 39 patients, used as controls, with nonsecreting adrenal tumors. The relationships between aldosterone, PTH levels, and biochemistries of mineral metabolism were assessed.

RESULTS

Aldosterone was positively associated with PTH levels (r = 0.260, P < .05) in the whole cohort and in the PA cohort alone (r = 0.450; P = .02). In the multivariate analysis, both aldosterone concentrations and urinary calcium excretion were significantly related to PTH levels, with no effect of 25(OH) vitamin D or other parameters of bone metabolism.

CONCLUSION

PTH level is associated with aldosterone, probably independent of 25(OH) vitamin D levels and urinary calcium. Whether aldosterone interacts directly with the parathyroid glands remains to be established.

Development and validation of a novel diagnostic nomogram model to predict primary aldosteronism in patients with hypertension

PURPOSE

Primary aldosteronism (PA) remains, to a large extent, an under-diagnosed disease. We aimed to develop and validate a novel clinical nomogram to predict PA based on routine biochemical variables including new ones, calcium-phosphorus product.

METHODS

Records from 806 patients with hypertension were randomly divided into 70% (n = 564) as the training set and the remaining 30% (n = 242) as the validation set. Predictors for PA were extracted to construct a nomogram model based on regression analysis of the training set. An internal validation was performed to assess the nomogram model's discrimination and consistency using the area under the curve for receiver operating characteristic curves and calibration plots. The diagnostic accuracy was compared between nomogram and other known prediction models, using receiver operating characteristics (ROC) and decision curve analyses (DCA).

RESULTS

Female gender, serum potassium, serum calcium-phosphorus product, and urine pH were adopted as predictors in the nomogram. The nomogram resulted in an area under the curve of 0.73 (95% confidence interval: 0.68-0.78) in the training set and an area under the curve of 0.68 (0.59-0.75) in the validation set. Predicted probability and actual probability matched well in the nomogram (p > 0.05). Based on ROC and DCA, 21-70% threshold to predict PA in the nomogram model was clinically useful.

CONCLUSIONS

We have developed a novel nomogram to predict PA in hypertensive individuals based on routine biochemical variables. External validation is needed to further demonstrate its predictive ability in primary care settings.

Aldosterone enhances high phosphate-induced vascular calcification through inhibition of AMPK-mediated autophagy

It remains unclear whether the necessity of calcified mellitus induced by high inorganic phosphate (Pi) is required and the roles of autophagy plays in aldosterone (Aldo)‐enhanced vascular calcification (VC) and vascular smooth muscle cell (VSMC) osteogenic differentiation. In the present study, we found that Aldo enhanced VC both in vivo and in vitro only in the presence of high Pi, alongside with increased expression of VSMC osteogenic proteins (BMP2, Runx2 and OCN) and decreased expression of VSMC contractile proteins (α‐SMA, SM22α and smoothelin). However, these effects were blocked by mineralocorticoid receptor inhibitor, spironolactone. In addition, the stimulatory effects of Aldo on VSMC calcification were further accelerated by the autophagy inhibitor, 3‐MA, and were counteracted by the autophagy inducer, rapamycin. Moreover, inhibiting adenosine monophosphate‐activated protein kinase (AMPK) by Compound C attenuated Aldo/MR‐enhanced VC. These results suggested that Aldo facilitates high Pi‐induced VSMC osteogenic phenotypic switch and calcification through MR‐mediated signalling pathways that involve AMPK‐dependent autophagy, which provided new insights into Aldo excess‐associated VC in various settings.

Role of the renin-angiotensin-aldosterone system in bone metabolism

With the acceleration of population aging, the incidence of osteoporosis has gradually increased, and osteoporosis and fractures caused by osteoporosis have gradually become a serious social public health problem. The classic role of the renin-angiotensin-aldosterone system (RAAS) is to keep blood pressure stable. However, as the components of RAAS were found in bone tissues, their functions of stimulating osteoclast formation and inhibiting osteoblast activity thus inducing bone loss have gradually emerged. RAAS blockers can prevent osteoporotic fractures which may be related to angiotensin type 1 (AT1) receptor, osteoprotegerin (OPG)/nuclear factor-κB ligand (RANKL), and angiotensin-converting enzyme 2 (ACE2)/angiotensin (1-7) (Ang (1-7))/G protein-coupled receptor (Mas) cascade. However, some studies suggest that RAAS blockers do not prevent osteoporotic fractures. This article reviews the effects of RAAS and RAAS inhibitors on bone metabolism and provides new ideas for the prevention of osteoporosis.

Spironolactone reduces biochemical markers of bone turnover in postmenopausal women with primary aldosteronism

CONTEXT

Primary aldosteronism (PA) is the most frequent form of endocrine hypertension. Besides its deleterious impact on cardiovascular target organ damage, PA is considered to cause osteoporosis.

PATIENTS AND METHODS

We assessed bone turnover in a subset of 36 postmenopausal women with PA. 18 patients had unilateral PA and were treated by adrenalectomy, whereas 18 patients had bilateral PA and received mineralocorticoid receptor antagonist (MRA) therapy respectively. 18 age- and BMI-matched females served as controls. To estimate bone remodeling, we measured the bone turnover markers intact procollagen 1 N-terminal propeptide, bone alkaline phosphatase, osteocalcin and tartrate resistant acid phosphatase 5b in plasma by chemiluminescent immunoassays at time of diagnosis and one year after initiation of treatment.

STUDY DESIGN

Observational longitudinal cohort study.

SETTING

Tertiary care hospital.

RESULTS

Compared with controls, patients with PA had mildly elevated osteocalcin at baseline (p = 0.013), while the other bone markers were comparable between both groups. There were no differences between the unilateral and the bilateral PA subgroup. One year after initiation of MRA treatment with spironolactone bone resorption and bone formation markers had significantly decreased in patients with bilateral PA. In contrast, patients adrenalectomized because of unilateral PA showed no significant change of bone turnover markers.

CONCLUSION

This study shows that aldosterone excess in postmenopausal women with PA is not associated with a relevant increase of bone turnover markers at baseline. However, we observed a significant decrease of bone markers in patients treated with spironolactone, but not in patients treated by adrenalectomy.

Disentangling the Relationships Between the Renin-Angiotensin-Aldosterone System, Calcium Physiology, and Risk for Kidney Stones

CONTEXT

Complex relationships between aldosterone and calcium homeostasis have been proposed.

OBJECTIVE

To disentangle the influence of aldosterone and intravascular volume on calcium physiology.

DESIGN

Patient-oriented and epidemiology studies.

SETTING

Clinical research center and nationwide cohorts.

PARTICIPANTS/INTERVENTIONS

Patient-oriented study (n = 18): Participants were evaluated after completing a sodium-restricted (RES) diet to contract intravascular volume and after a liberalized-sodium (LIB) diet to expand intravascular volume. Cross-sectional studies (n = 3755): the association between 24h urinary sodium and calcium excretion and risk for kidney stones was assessed.

RESULTS

Patient-oriented study: compared to a RES-diet, a LIB-diet suppressed renin activity (LIB: 0.3 [0.1, 0.4] vs. RES: 3.1 [1.7, 5.3] ng/mL/h; P < 0.001) and plasma aldosterone (LIB: 2.0 [2.0, 2.7] vs. RES: 20.0 [16.1, 31.0] vs. ng/dL; P < 0.001), but increased calciuria (LIB: 238.4 ± 112.3 vs. RES: 112.9 ± 60.8 mg/24hr; P < 0.0001) and decreased serum calcium (LIB: 8.9 ± 0.3 vs. RES: 9.8 ± 0.4 mg/dL; P < 0.0001). Epidemiology study: mean urinary calcium excretion was higher with greater urinary sodium excretion. Compared to a urinary sodium excretion of < 120 mEq/day, a urinary sodium excretion of ≥220 mEq/day was associated with a higher risk for having kidney stones in women (risk ratio = 1.79 [95% confidence interval 1.05, 3.04]) and men (risk ratio = 2.06 [95% confidence interval 1.27, 3.32]).

CONCLUSIONS

High dietary sodium intake suppresses aldosterone, decreases serum calcium, and increases calciuria and the risk for developing kidney stones. Our findings help disentangle the influences of volume from aldosterone on calcium homeostasis and provide support for the recommendation to restrict dietary sodium for kidney stone prevention.

The effect of vitamin D treatment on clinical and biochemical outcomes of primary aldosteronism

INTRODUCTION

Primary aldosteronism (PA) contributed to the cardiovascular disease and metabolic alterations independent of the blood pressure level. Evidence exists that aldosterone excess also affects calcium and mineral homeostasis. PA subjects have been shown to have greater prevalence of vitamin D deficiency. However, the impact of vitamin D treatment in this population has never been assessed.

OBJECTIVE

This study aimed to evaluate the effect of vitamin D treatment on clinical and biochemical outcomes of PA patients.

METHODS

Two hundred forty hypertensive subjects were screened, 31 had positive ARR, and 17 patients with newly confirmed PA following positive confirmatory test that has not been subjected for definitive treatment were enrolled. Clinical parameter (blood pressure) and biochemical parameters (renal profile, plasma aldosterone concentration, plasma renin activity, serum calcium, vitamin D, intact parathyroid hormone, 24-hour urinary calcium) were measured at baseline and 3 months of treatment with Bio-D3 capsule. Primary outcomes were the changes in the blood pressure and biochemical parameters.

RESULTS

About 70% of our PA subjects have low vitamin D levels at baseline. Three months following treatment, there were significant: (a) improvement in 25(OH)D levels; (b) reduction in systolic blood pressure and plasma aldosterone concentration; and (c) improvement in the eGFR. The vitamin D deficient subgroup has the greatest magnitude of the systolic blood pressure reduction following treatment.

CONCLUSIONS

This study demonstrated significant proportion of PA patients has vitamin D insufficiency. Vitamin D treatment improves these interrelated parameters possibly suggesting interplay between vitamin D, aldosterone, renal function and the blood pressure.

Primary Aldosteronism and Bone Metabolism: A Systematic Review and Meta-Analysis

BACKGROUND

Currently, increasing evidence shows that excess aldosterone may have an impact on bone health, and primary aldosteronism (PA) may be a secondary cause of osteoporosis. This problem is worthy of attention because secondary osteoporosis is always potentially reversible, which affects the selection of treatment for PA to some extent. The present systematic review will assess and summarize the available data regarding the relationship between PA and osteoporosis.

METHODS

Pubmed and Embase were searched for clinical trials related to the association between PA and bone metabolism. The results were limited to full-text articles published in English, without restrictions for the publication time. The quality of clinical trials was appraised, and the data were extracted. Biochemical parameters of bone turnover in PA patients were assessed using random-effect meta-analysis. Descriptive analysis was performed for other parameters, for data is insufficient.

RESULTS

A final total of 15 articles were included in this review. The meta-analysis of six studies showed that subjects with PA had higher serum PTH levels (MD=21.50 pg/ml, 95% CI (15.63, 27.37), P<0.00001) and slightly increased urinary calcium levels (MD = 1.65 mmol/24 h, 95% CI (1.24, 2.06), P < 0.00001) than the EH controls. PA is associated with an increased risk of bone fracture. Bone loss in patients with PA may be reversed by MR antagonists or adrenal surgery.

CONCLUSIONS

PA may be a secondary cause of osteoporosis and is associated with an increased risk of bone fracture. The clarification of the relationships between PA and bone metabolism requires additional prospective randomized controlled studies in a large sample.

Associations between primary aldosteronism and diabetes, poor bone health, and sleep apnea-what do we know so far?

Primary aldosteronism (PA), the most common cause of secondary hypertension, is a well-recognized condition that can lead to cardiovascular and renal complications. PA is frequently left undiagnosed and untreated, leading to aldosterone-specific morbidity and mortality. In this review we highlight the evidence linking PA with other conditions such as (i) diabetes mellitus, (ii) obstructive sleep apnea, and (iii) bone health, along with clinical implications and proposed underlying mechanisms.

The crosstalk between aldosterone and calcium metabolism in primary aldosteronism: A possible calcium metabolism-associated aberrant "neoplastic" steroidogenesis in adrenals

Intracellular calcium (Ca) levels play pivotal roles in aldosterone biosynthesis. Several somatic mutations of ion channels associated with aldosterone over-production were reported to result in over-inflow of Ca ion. Recently, the main regulators of extracellular Ca including VDR, CaSR and PTH1R were also reported to regulate steroidogenesis including aldosterone production. Therefore, not only intracellular but also extracellular Ca levels could regulate aldosterone biosynthesis. In addition, primary aldosteronism (PA) is clinically associated with not only more frequent cardiovascular events but also secondary metabolic disorders including abnormal calcium metabolism, osteoporosis and others. However, the details of Ca metabolic abnormalities associated with, including the potential correlation between those abnormalities and aldosterone overproduction, have remained virtually unknown. Therefore, in this study, we first immunolocalized Ca metabolism-related receptors (CaSR, VDR and PTH1R) in normal adrenal glands (NAs), aldosterone-producing adenomas (APAs) and cortisol-producing adenoma (CPA). We then compared the findings with clinicopathological parameters of these patients and the patterns of KCNJ5 somatic mutation of the tumors among APA patients. In vitro study was also performed to further explore the potential effects of extracellular Ca, PTH, Vitamin D and ionophore on aldosterone production. Ca metabolism-related receptors were predominantly localized in aldosterone-producing cells (ZG and APA) in both immunohistochemistry and qRT-PCR analysis. CYP11B2 mRNA was significantly increased by CaCl₂ treatment and further by adding ionophore. All the key enzymes related to aldosterone and cortisol biosynthesis including CYP11B2, CYP17A1 and CYP11B1 were upregulated by PTH treatment in this model and PTH could serve as a co-stimulator of ANG II to increase CYP11B2 expression. VDR mRNA levels were positively correlated with those of CYP11B2, CYP17A1 and CYP11B1 in APA tumor tissues and significantly higher in KCNJ5 mutated APAs than wild type. CYP11B1 levels were also significantly increased by VitD treatment. PTH1R mRNA levels were positively correlated with those of CYP17A1 and CYP11B1, both involved in cortisol production. In addition, the status of VDR was correlated with TRACP-5b levels, and that of PTH1R with serum Ca levels as well as urinary Ca excretion, respectively. Results of our present study did firstly demonstrate that aldosterone-producing cells were more sensitive to the fluctuations of extracellular Ca levels and Ca metabolism could directly influence steroidogenesis, especially "neoplastic" co-secretion of aldosterone and cortisol in APA patients.

Evaluation of bone health in patients with adrenal tumors

PURPOSE OF REVIEW

Adrenal tumors occur in 5% of population with higher prevalence in elderly. Patients with adrenal tumors present with overt hormonal excess in up to 15% of cases, and mild autonomous cortisol secretion in 30-40% of cases. Overt Cushing syndrome, mild autonomous cortisol secretion, pheochromocytoma, and primary aldosteronism have been associated with higher cardiovascular morbidity and mortality. Increasing experimental and clinical evidence also suggests that adrenal hormone excess is detrimental to bone health. This review aims to discuss the effect of cortisol, aldosterone, and catecholamine excess on bone metabolism, secondary osteoporosis, and fragility fractures.

RECENT FINDINGS

Several studies have reported that patients with hormonally active adrenal tumors demonstrate increased prevalence of fragility fractures incongruous to bone density scan findings. The utility of dual absorptiometry X-ray (DXA) in diagnosing secondary osteoporosis is unclear in patients with cortisol, aldosterone, and catecholamine excess. Trabecular bone score and bone turn over markers could serve as potential diagnostic tools in assessment of severity of bone disease in patients with hormonally active adrenal tumors.

SUMMARY

Adrenalectomy is the mainstay of therapy in patients with overt hormone production. Appropriate case detection strategies to identify patients at risk of fragility fractures are needed in patients not treated with adrenalectomy, such as bilateral primary aldosteronism and mild autonomous cortisol secretion.

Diagnosis and treatment of primary aldosteronism: practical clinical perspectives

Primary aldosteronism (PA), the most common form of secondary hypertension, can be either surgically cured or treated with targeted pharmacotherapy. PA is frequently undiagnosed and untreated, leading to aldosterone-specific cardiovascular morbidity and nephrotoxicity. Thus, clinicians should perform case detection testing for PA at least once in all patients with hypertension. Confirmatory testing is indicated in most patients with positive case detection testing results. The next step is to determine whether patients with confirmed PA have a disease that can be cured with surgery or whether it should be treated medically; this step is guided by computed tomography scan of the adrenal glands and adrenal venous sampling. With appropriate surgical expertise, laparoscopic unilateral adrenalectomy is safe, efficient and curative in patients with unilateral adrenal disease. In patients who have bilateral aldosterone hypersecretion, the optimal management is a low-sodium diet and lifelong treatment with a mineralocorticoid receptor antagonist administered at a dosage to maintain a high-normal serum potassium concentration without the aid of oral potassium supplements.

Adrenocortical incidentalomas and bone: from molecular insights to clinical perspectives

Adrenal incidentalomas constitute a common clinical problem with an overall prevalence of around 2-3%, but are more common with advancing age being present in 10% of those aged 70 years. The majority of these lesions are benign adrenocortical adenomas (80%), characterized in 10-40% of the cases by autonomous cortisol hypersecretion, and in 1-10% by aldosterone hypersecretion. Several observational studies have shown that autonomous cortisol and aldosterone hypersecretion are more prevalent than expected in patients with osteopenia and osteoporosis: these patients have accelerated bone loss and an increased incidence of vertebral fractures. In contrast to glucocorticoid action, the effects of aldosterone on bone are less well understood. Recent data, demonstrating a concomitant co-secretion of glucocorticoid metabolites in patients with primary aldosteronism, could explain some of the metabolic abnormalities seen in patients with aldosterone hypersecretion. In clinical practice, patients with unexplained osteoporosis, particularly when associated with other features such as impaired glucose tolerance or hypertension, should be investigated for the possible presence of autonomous cortisol or aldosterone secretion due to an adrenal adenoma. Randomized intervention studies are needed, however, to investigate the optimum interventions for osteoporosis and other co-morbidities in these patients.

Effects of Altered Calcium Metabolism on Cardiac Parameters in Primary Aldosteronism

BACKGROUND

Increasing evidence supports interplay between aldosterone and parathyroid hormone (PTH), which may aggravate cardiovascular complications in various heart diseases. Negative structural cardiovascular remodeling by primary aldosteronism (PA) is also suspected to be associated with changes in calcium levels. However, to date, few clinical studies have examined how changes in calcium and PTH levels influence cardiovascular outcomes in PA patients. Therefore, we investigated the impact of altered calcium homeostasis caused by excessive aldosterone on cardiovascular parameters in patients with PA.

METHODS

Forty-two patients (mean age 48.8±10.9 years; 1:1, male:female) whose plasma aldosterone concentration/plasma renin activity ratio was more than 30 were selected among those who had visited Severance Hospital from 2010 to 2014. All patients underwent adrenal venous sampling with complete access to both adrenal veins.

RESULTS

The prevalence of unilateral adrenal adenoma (54.8%) was similar to that of bilateral adrenal hyperplasia. Mean serum corrected calcium level was 8.9±0.3 mg/dL (range, 8.3 to 9.9). The corrected calcium level had a negative linear correlation with left ventricular end-diastolic diameter (LVEDD, ρ=-0.424, P=0.031). Moreover, multivariable regression analysis showed that the corrected calcium level was marginally associated with the LVEDD and corrected QT (QTc) interval (β=-0.366, P=0.068 and β=-0.252, P=0.070, respectively).

CONCLUSION

Aldosterone-mediated hypercalciuria and subsequent hypocalcemia may be partly involved in the development of cardiac remodeling as well as a prolonged QTc interval, in subjects with PA, thereby triggering deleterious effects on target organs additively.

Bone health among patients with primary aldosteronism: a systematic review and meta-analysis

INTRODUCTION

Recent studies showed a possible association between hyperaldosteronism and secondary hyperparathyroidism leading to reduced bone health, however results are conflicting.

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.

Bone Health in Adrenal Disorders

Secondary osteoporosis resulting from specific clinical disorders may be potentially reversible, and thus continuous efforts to find and adequately treat the secondary causes of skeletal fragility are critical to ameliorate fracture risk and to avoid unnecessary treatment with anti-osteoporotic drugs. Among the hyperfunctional adrenal masses, Cushing's syndrome, pheochromocytoma, and primary aldosteronism are receiving particularly great attention due to their high morbidity and mortality mainly by increasing cardiovascular risk. Interestingly, there is accumulating experimental and clinical evidence that adrenal hormones may have direct detrimental effects on bone metabolism as well. Thus, the present review discusses the possibility of adrenal disorders, especially focusing on pheochromocytoma and primary aldosteronism, as secondary causes of osteoporosis.

Lower Trabecular Bone Score in Patients With Primary Aldosteronism: Human Skeletal Deterioration by Aldosterone Excess

CONTEXT

Despite the potential detrimental effects of aldosterone excess on bone metabolism, discrepancies exist between fracture risk and bone mass in patients with and without primary aldosteronism (PA).

OBJECTIVE

To clarify the possibility that aldosterone excess might mainly affect bone properties not explained by the bone mineral density (BMD).

DESIGN, SETTING, AND PATIENTS

Among 625 consecutive patients with newly diagnosed adrenal incidentaloma (AI), 72 with biochemically confirmed PA and 335 with nonfunctional AI were defined as cases and controls, respectively.

RESULTS

In women, although no statistically significant differences in lumbar spine BMD were found between groups, the lumbar spine trabecular bone score (TBS) was significantly lower in patients with PA than in controls after adjustment for confounders (P = 0.007). Consistently, the plasma aldosterone concentration (PAC) correlated inversely with the lumbar spine TBS (P = 0.028) but not with bone mass in women. Compared with women in the lowest PAC quartile, those in the highest PAC quartile had significantly lower lumbar spine TBSs (P = 0.004). Importantly, all these observations in women remained statistically significant after additional adjustment for the lumbar spine BMD in the multivariable model. However, BMD and TBS at the lumbar spine did not differ according to the presence of PA and the level of PAC in men.

CONCLUSION

These findings provide clinical evidence that aldosterone excess in PA might contribute to deteriorated bone quality through weak microarchitecture, regardless of bone mass, especially in women.

Vertebral fractures assessed with dual-energy X-ray absorptiometry in patients with Addison's disease on glucocorticoid and mineralocorticoid replacement therapy

PURPOSE

to assess bone damage and metabolic abnormalities in patients with Addison's disease given replacement doses of glucocorticoids and mineralocorticoids.

METHODS

A total of 87 patients and 81 age-matched and sex-matched healthy controls were studied. The following parameters were measured: urinary cortisol, serum calcium, phosphorus, creatinine, 24-h urinary calcium excretion, bone alkaline phosphatase, parathyroid hormone, serum CrossLaps, 25 hydroxyvitamin D, and 1,25 dihydroxyvitamin D. Clear vertebral images were obtained with dual-energy X-ray absorptiometry in 61 Addison's disease patients and 47 controls and assessed using Genant's classification.

RESULTS

Nineteen Addison's disease patients (31.1%) had at least one morphometric vertebral fracture, as opposed to six controls (12.8%, odds ratio 3.09, 95% confidence interval 1.12-8.52). There were no significant differences in bone mineral density parameters at any site between patients and controls. In Addison's disease patients, there was a positive correlation between urinary cortisol and urinary calcium excretion. Patients with fractures had a longer history of disease than those without fractures. Patients taking fludrocortisone had a higher bone mineral density than untreated patients at all sites except the lumbar spine.

CONCLUSIONS

Addison's disease patients have more fragile bones irrespective of any decrease in bone mineral density. Supra-physiological doses of glucocorticoids and longer-standing disease (with a consequently higher glucocorticoid intake) might be the main causes behind patients' increased bone fragility. Associated mineralocorticoid treatment seems to have a protective effect on bone mineral density.

Effect of eplerenone on markers of bone turnover in patients with primary hyperparathyroidism - The randomized, placebo-controlled EPATH trial

Mineralocorticoid receptor (MR) antagonism may affect bone turnover via direct and indirect pathways involving parathyroid hormone, but randomized controlled trials are lacking. In a pre-specified analysis of the "Eplerenone in primary hyperparathyroidism" placebo-controlled, randomized trial (ISRCTN 33941607), effects of eight weeks MR-blockade with eplerenone on bone turnover markers in 97 patients with primary hyperparathyroidism were tested. Mean age was 67.5±9.5years, and 76 (78.4%) were females. In analysis of covariance with adjustment for baseline values, eplerenone had no significant effect on isoform 5b of the tartrate-resistant acid phosphatase (TRAP), beta-crosslaps, N-terminal propeptide of procollagen type 1 (P1NP), osteocalcin and bone-specific alkaline phosphatase. There was no significant cross-sectional correlation between plasma aldosterone concentration or the aldosterone-to-renin ratio and markers of bone turnover in multivariate linear regression models at baseline. These data provide first evidence from a randomized and placebo-controlled trial that short-term MR antagonism may not affect bone turnover, at least in patients with primary hyperparathyroidism.

[Effects of aldosterone on osteoblast proliferation, differentiation and osteogenic gene expressions in vitro]

OBJECTIVE

To study the effect of aldosterone on cell proliferation, alkaline phosphatase (AKP) activity and osteogenic gene expression in rat osteoblasts and explore the mechanisms.

METHODS

Osteoblasts isolated from the skull of neonatal SD rats by enzyme digestion were cultured and treated with different concentrations of aldosterone. The cell proliferation and AKP activity were evaluated using CCK-8 assay kit and AKP assay kit, respectively. The effects of aldosterone on mRNA and protein expressions of the osteogenic genes and epithelial sodium channel (ENaC) gene were investigated using semi-quantitative PCR and Western blotting.

RESULTS

Compared with the control cells, the cells treated with 0.01-1.0 µmol/L aldosterone showed obviously enhanced proliferation while lower (1×10^-3 µmol/L) or higher (10 µmol/L) concentrations of aldosterone did not significantly affect the cell proliferation. Aldosterone within the concentration range of 1×10^-3 to 10 µmol/L did not cause significant changes in AKP activity in the osteoblasts. Treatment with 0.01 to 1.0 µmol/L aldosterone significantly upregulated the expressions of the osteogenic genes and α-ENaC gene at both the mRNA and protein levels.

CONCLUSION

Aldosterone within the concentration range of 0.01-1.0 µmol/L stimulates the proliferation and osteogenic gene expressions and enhances α-ENaC gene expression in rat osteoblasts in vitro, suggesting the possibility that ENaC participates in aldosterone-mediated regulation of osteoblast functions.

[Effects of aldosterone on osteoblast proliferation, differentiation and osteogenic gene expressions in vitro]

OBJECTIVE

To study the effect of aldosterone on cell proliferation, alkaline phosphatase (AKP) activity and osteogenic gene expression in rat osteoblasts and explore the mechanisms.

METHODS

Osteoblasts isolated from the skull of neonatal SD rats by enzyme digestion were cultured and treated with different concentrations of aldosterone. The cell proliferation and AKP activity were evaluated using CCK-8 assay kit and AKP assay kit, respectively. The effects of aldosterone on mRNA and protein expressions of the osteogenic genes and epithelial sodium channel (ENaC) gene were investigated using semi-quantitative PCR and Western blotting.

RESULTS

Compared with the control cells, the cells treated with 0.01-1.0 µmol/L aldosterone showed obviously enhanced proliferation while lower (1×10-3 µmol/L) or higher (10 µmol/L) concentrations of aldosterone did not significantly affect the cell proliferation. Aldosterone within the concentration range of 1×10-3 to 10 µmol/L did not cause significant changes in AKP activity in the osteoblasts. Treatment with 0.01 to 1.0 µmol/L aldosterone significantly upregulated the expressions of the osteogenic genes and α-ENaC gene at both the mRNA and protein levels.

CONCLUSION

Aldosterone within the concentration range of 0.01-1.0 µmol/L stimulates the proliferation and osteogenic gene expressions and enhances α-ENaC gene expression in rat osteoblasts in vitro, suggesting the possibility that ENaC participates in aldosterone-mediated regulation of osteoblast functions.

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.

Steroid metabolome analysis reveals prevalent glucocorticoid excess in primary aldosteronism

BACKGROUND

Adrenal aldosterone excess is the most common cause of secondary hypertension and is associated with increased cardiovascular morbidity. However, adverse metabolic risk in primary aldosteronism extends beyond hypertension, with increased rates of insulin resistance, type 2 diabetes, and osteoporosis, which cannot be easily explained by aldosterone excess.

METHODS

We performed mass spectrometry-based analysis of a 24-hour urine steroid metabolome in 174 newly diagnosed patients with primary aldosteronism (103 unilateral adenomas, 71 bilateral adrenal hyperplasias) in comparison to 162 healthy controls, 56 patients with endocrine inactive adrenal adenoma, 104 patients with mild subclinical, and 47 with clinically overt adrenal cortisol excess. We also analyzed the expression of cortisol-producing CYP11B1 and aldosterone-producing CYP11B2 enzymes in adenoma tissue from 57 patients with aldosterone-producing adenoma, employing immunohistochemistry with digital image analysis.

RESULTS

Primary aldosteronism patients had significantly increased cortisol and total glucocorticoid metabolite excretion (all P < 0.001), only exceeded by glucocorticoid output in patients with clinically overt adrenal Cushing syndrome. Several surrogate parameters of metabolic risk correlated significantly with glucocorticoid but not mineralocorticoid output. Intratumoral CYP11B1 expression was significantly associated with the corresponding in vivo glucocorticoid excretion. Unilateral adrenalectomy resolved both mineralocorticoid and glucocorticoid excess. Postoperative evidence of adrenal insufficiency was found in 13 (29%) of 45 consecutively tested patients.

CONCLUSION

Our data indicate that glucocorticoid cosecretion is frequently found in primary aldosteronism and contributes to associated metabolic risk. Mineralocorticoid receptor antagonist therapy alone may not be sufficient to counteract adverse metabolic risk in medically treated patients with primary aldosteronism.

FUNDING

Medical Research Council UK, Wellcome Trust, European Commission.

Risk of Fracture in Primary Aldosteronism: A Population-Based Cohort Study

Primary aldosteronism (PA) is associated with increased urinary calcium excretion and osteoporosis prevalence. We studied the long-term effect of hyperaldosterone on fracture risk and possible risk mitigation via treatments, by comparing PA patients and their essential hypertension (EH) counterparts extracted by propensity score match. We used a longitudinal population database from the Taiwan National Health Insurance, and used a validated algorithm to identify PA patients diagnosed in 1997-2010. Our sample included 2533 PA patients, including 921 patients with aldosterone-producing adenoma (APA). Our methods for assessing excessive fracture risk included multivariable Cox regression and the competing risk regression. The incidence rate of fracture at any site was 14.4 per 1000 person-years for PA, and 11.2 per 1000 person-years for APA. In contrast, the incidence rate of fracture at any site was 8.3 per 1000 person-years in EH controls for PA, and 6.5 per 1000 person-years in EH controls for APA. Mineralocorticoid receptor antagonist (MRA) treatment might be associated with higher risk of osteoporotic fracture in the whole female PA cohort (subdistribution hazard ratio [SHR] = 2.12, p = 0.008) as well as female APA patients (SHR = 1.15, p = 0.049). As to fracture at any site, MRA treatment was also associated with higher risk; the SHR was 1.88 (p < 0.001) in the whole female PA cohort, and 2.17 (p = 0.019) in female APA patients. PA is tightly associated with higher risk of bone fracture, even in the case where the competing risk of death was controlled. Particularly, female PA patients treated with MRA were confronted with significantly higher risk in bone fracture than their EH controls. © 2017 American Society for Bone and Mineral Research.

Salt, Aldosterone, and Parathyroid Hormone: What Is the Relevance for Organ Damage?

Structured interventions on lifestyle have been suggested as a cost-effective strategy for prevention of cardiovascular disease. Epidemiologic studies demonstrate that dietary salt restriction effectively decreases blood pressure, but its influence on cardiovascular morbidity and mortality is still under debate. Evidence gathered from studies conducted in patients with primary aldosteronism, essential hypertension, or heart failure demonstrates that long-term exposure to elevated aldosterone results in cardiac structural and functional changes that are independent of blood pressure. Animal experiments and initial clinical studies indicate that aldosterone damages the heart only in the context of an inappropriately elevated salt status. Recent evidence suggests that aldosterone might functionally interact with the parathyroid hormone and thereby affect calcium homeostasis with important sequelae for bone mineral density and strength. The interaction between aldosterone and parathyroid hormone might have implications also for the heart. Elevated dietary salt is associated on the one hand with increased urinary calcium excretion and, on the other hand, could facilitate the interaction between aldosterone and parathyroid hormone at the cellular level. This review summarizes the evidence supporting the contribution of salt and aldosterone to cardiovascular disease and the possible cardiac and skeletal consequences of the mutual interplay between aldosterone, parathyroid hormone, and salt.

Hyperaldosteronism and cardiovascular risk in patients with autosomal dominant polycystic kidney disease

Hypertension is commonly associated with autosomal dominant polycystic kidney disease (ADPKD), often discovered before the onset of renal failure, albeit the pathogenetic mechanisms are not well elucidated. Hyperaldosteronism in ADPKD may contribute to the development of insulin resistance and endothelial dysfunction, and progression of cardiorenal disease. The aim of study was to evaluate the prevalence of primary aldosteronism (PA) in ADPKD patients and identify some surrogate biomarkers of cardiovascular risk.We have enrolled 27 hypertensive ADPKD patients with estimated glomerular filtration rate (eGFR) ≥ 60 mL/min, evaluating the renin-angiotensin-aldosterone system (RAAS), inflammatory indexes, nutritional status, homocysteine (Hcy), homeostasis model assessment-insulin resistance (HOMA-IR), mineral metabolism, microalbuminuria, and surrogate markers of atherosclerosis [carotid intima media thickness (cIMT), ankle/brachial index (ABI), flow mediated dilation (FMD), renal resistive index (RRI) and left ventricular mass index (LVMI)]. Furthermore, we have carried out the morpho-functional magnetic resonance imaging (MRI) with high-field 3 T Magnetom Avanto.We have divided patients into group A, with normal plasma aldosterone concentration (PAC) and group B with PA, present in 9 (33%) of overall ADPKD patients. Respect to group A, group B showed a significant higher mean value of LVMI, HOMA-IR and Hcy (P = 0.001, P = 0.004, P = 0.018; respectively), and a lower value of FMD and 25-hydroxyvitamin D (25-OH-VitD) (P = 0.037, P = 0.019; respectively) with a higher prevalence of non-dipper pattern at Ambulatory Blood Pressure Monitoring (ABPM) (65% vs 40%, P < 0.05) at an early stage of the disease.In this study, we showed a high prevalence of PA in ADPKD patients, associated to higher LVMI, HOMA-IR, Hcy, lower FMD, and 25-OH-VitD, considered as surrogate markers of atherosclerosis, compared to ADPKD patients with normal PAC values. Our results indicate a higher overall cardiovascular risk in ADPKD patients with inappropriate aldosterone secretion, and a screening for PA in all patients with ADPKD is recommended.

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

BACKGROUND

Parathyroid hormone (PTH) stimulates aldosterone secretion in human adrenocortex and is regulated by the renin-angiotensin-aldosterone system. We speculated that measurement of PTH may be a valuable aid in the diagnosis of aldosterone-producing adenoma (APA).

METHODS

To test this hypothesis, we recruited 142 patients with adrenal adenoma, of whom 84 had an APA and 58 had a nonfunctioning adrenal adenoma (NFA). Plasma levels of intact PTH, serum potassium, sodium, calcium, phosphate, 25(OH) vitamin D, plasma aldosterone concentration (PAC), plasma renin activity (PRA), and aldosterone to renin ratio (ARR) were measured in every patient. Computed tomography (CT) scanning of the adrenal gland and adrenal hormone levels was used to evaluate the function of the adrenal adenoma. We also evaluated the impact of renin-angiotensin-aldosterone system (RAAS) components on PTH from the recumbent-upright test in 15 patients with APA and 30 patients with NFA.

RESULTS

Compared with NFA, PTH levels were significantly increased in patients with APA, and serum calcium and phosphate were significantly decreased. When position was changed from supine to upright, the variation in PTH levels was significantly higher in APA patients compared with NFA patients. Receiver operator characteristic (ROC) curves identified the Youden index, which corresponded to the best tradeoff of combined marker (ARR and PTH) with a sensitivity and specificity of 89.3% and 93.1%, respectively.

CONCLUSIONS

The baseline and positional variation of serum PTH levels were significant in APA, thus PTH may be a promising auxiliary index for the clinical diagnosis of APA.

Association of Circulating Renin and Aldosterone With Osteocalcin and Bone Mineral Density in African Ancestry Families

Hypertension is associated with accelerated bone loss, and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family members without regard to health status from 6 probands (mean family size: 62 and relative pairs: 1687). Participants underwent a clinical examination, dual-energy x-ray absorptiometry, and quantitative computed tomographic scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone/renin ratio was calculated as aldosterone concentration/renin activity. All models were analyzed using pedigree-based variance components methods. Full models included adjustment for age, sex, body composition, comorbidities, lifestyle factors, blood pressure, and antihypertensive medication. Higher renin activity was significantly associated with lower total osteocalcin and with higher trabecular bone mineral density (both P<0.01). There were also significant genetic correlations between renin activity and whole-body bone mineral density. There were no associations with aldosterone concentration in any model and results for aldosterone/renin ratio were similar to those for renin activity. This is the first study to report a significant association between renin activity and a marker of bone turnover and bone mineral density in generally healthy individuals. Also, there is evidence for significant genetic pleiotropy and, thus, there may be a shared biological mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension.

Association of serum parathyrine and calcium levels with primary aldosteronism: a meta-analysis

Primary aldosteronism (PA) represents major cause of secondary hypertension, strongly associated with high cardiovascular morbidity and mortality. Aldosterone excess may influence mineral homeostasis, through higher urinary calcium (Ca) excretion reducing calcium plasma levels and leading to secondary increase of parathyrine (PTH). The purpose of the present study is to clarify the association of serum PTH and Ca levels with PA using a metaanalysis approach. We searched articles indexed in the PubMed, OVID and Sciencedirect published as of September 2014 that met our predefined criteria. Six articles with 748 subjects from 8 case-control studies were identified. Overall, pooled analysis indicated that subjects with PA had higher serum PTH concentrations and lower Ca levels than controls with essential hypertension (EH) (PTH: SMD = 1.146, 95% CI = [0.774, 1.518]; Ca: SMD = -0.698, 95% CI = [-1.102,-0.294]). Further subgroup analysis stratified by geological location found a similar pattern both in Italy and Austria (Italy: for PTH, SMD = 1.176, 95% CI = [0.758, 1.593], for Ca, SMD = -0.669, 95% CI = [-1.119,-0.219]; Austria: for PTH, SMD = 1.004, 95% CI = [0.359, 1.648], for Ca, SMD = -0.900, 95% CI = [-1.543,-0.257]). In addition, the subgroup analysis stratified by type of Ca measurement also found a similar pattern by spectrophotometry (SMD = -1.078, 95% CI = [-1.532, -0.623]), but not by ion selective electrode (SMD = -0.248, 95% CI = [-0.810, 0.315]). Sensitivity analysis showed that excluding any one study from the pooled analysis did not vary the results substantially. No evidence of publication bias was observed. In conclusion, this meta-analysis supports a significant association of PTH and Ca concentration with PA. Therefore, the high levels of PTH and low Ca concentrations in serum can be used as a variable predictor for PA.

What is the optimal bone-preserving strategy for patients with Addison's disease?

Addison's disease is associated with low bone mineral density and increased risk of hip fractures. Causes are multifactorial, contributed by underlying adrenocortical hormonal deficiency, associated autoimmune endocrinopathies, electrolyte disturbances and, in some patients, supraphysiologic glucocorticoid replacement. Recent realization of physiologic cortisol production rate has revised downwards glucocorticoid replacement dosages. Meanwhile, new research has emerged suggesting complex interplay between sodium and calcium homoeostasis under the influence of mineralocorticoid and parathyroid hormone that may impact bone health. As the prevalence of Addison's disease is rising, and osteoporosis and fractures are associated with significant morbidity and increased mortality, attention to bone preservation in Addison's disease is of clinical relevance and importance. We suggest an approach to bone health in Addison's disease integrating physiologic adrenocortical hormonal replacement with electrolyte and mineral homoeostasis optimization.

Prevalence and clinical correlates of somatic mutation in aldosterone producing adenoma-Taiwanese population

Primary aldosteronism (PA) is a common form of secondary hypertension and has significant cardiovascular consequences. Mutated channelopathy due to the activation of calcium channels has been recently described in aldosterone-producing adenoma (APA). The study involved 148 consecutive PA patients, (66 males; aged 56.3 ± 12.3years) who received adrenalectomy, and were collected from the Taiwan PA investigator (TAIPAI) group. A high rate of somatic mutation in APA was found (n=91, 61.5%); including mutations in KCNJ5 (n=88, 59.5%), ATP1A1 (n=2, 1.4%), and ATP2B3 (n=1, 0.7%); however, no mutations in CACNA1D were identified. Mutation-carriers were younger (<0.001), had lower Cyst C (p=0.042), pulse wave velocity (p=0.027), C-reactive protein (p=0.042) and a lower rate of proteinuria (p=0.031) than non-carriers. After multivariate adjustment, mutation carriers had lower serum CRP levels than non-carriers (p=0.031. Patients with mutation also had a greater chance of recovery from hypertension after operation (p=0.005). A high incidence of somatic mutations in APA was identified in the Taiwanese population. Mutation-carriers had lower CRP levels and a higher rate of cure of hypertension after adrenalectomy. This raises the possibility of using mutation screening as a tool in predicting long-term outcome after adrenalectomy.

Aldosterone, parathyroid hormone, and the use of renin-angiotensin-aldosterone system inhibitors: the multi-ethnic study of atherosclerosis

CONTEXT

Aldosterone and PTH are implicated in the pathogenesis of cardiovascular and skeletal diseases. An expanding body of evidence supports a bidirectional and positive physiologic relationship between aldosterone and PTH. Large population-based studies confirming this relationship, and whether it may be targeted as a potential method to mitigate the clinical consequences associated with excess aldosterone and PTH, are needed.

OBJECTIVE

We hypothesized that higher aldosterone levels would associate with higher PTH, and that the use of renin-angiotensin-aldosterone system (RAAS) inhibitors would predict lower PTH in a large, multi-ethnic, community-based cohort.

DESIGN, SETTING, PARTICIPANTS

We conducted cross-sectional analyses of participants in the Multi-Ethnic Study of Atherosclerosis without apparent primary hyperparathyroidism or chronic kidney disease (n = 5668). We evaluated associations of RAAS inhibitor use with PTH concentration among 1888 treated hypertensive participants. We also tested associations of serum aldosterone concentration with PTH concentration among 1547 participants with these measurements.

OUTCOME

Serum PTH concentration.

RESULTS

Higher aldosterone associated with higher PTH (β = 0.19 pg/ml per 1 ng/dl of aldosterone, P < .0001), and this finding was most pronounced among those with a primary hyperaldosteronism-like phenotype. There was a stepwise increment in PTH when comparing untreated normotensives, hypertensives using RAAS inhibitors, untreated hypertensives, and treated hypertensives using non-RAAS inhibitors (40.8, 45.0, 46.2, 47.1 pg/ml, respectively). The use of any RAAS inhibitor independently associated with lower PTH (β = -2.327 pg/ml per use of RAAS inhibitor, P = .006), when compared with the use of any non-RAAS inhibitor medication.

CONCLUSIONS

Higher serum aldosterone concentration is associated with higher serum PTH concentration, and the use of RAAS inhibitors is associated with lower PTH concentration. These results extend prior evidence from observational and intervention studies suggesting a potentially important and modifiable relationship between the RAAS and PTH in humans.

The renin-angiotensin-aldosterone system and calcium-regulatory hormones

There is increasing evidence of a clinically relevant interplay between the renin-angiotensin-aldosterone system and calcium-regulatory systems. Classically, the former is considered a key regulator of sodium and volume homeostasis, while the latter is most often associated with skeletal health. However, emerging evidence suggests an overlap in regulatory control. Hyperaldosteronism and hyperparathyroidism represent pathophysiologic conditions that may contribute to or perpetuate each other; aldosterone regulates parathyroid hormone and associates with adverse skeletal complications, and parathyroid hormone regulates aldosterone and associates with adverse cardiovascular complications. As dysregulation in both systems is linked to poor cardiovascular and skeletal health, it is increasingly important to fully characterize how they interact to more precisely understand their impact on human health and potential therapies to modulate these interactions. This review describes the known clinical interactions between these two systems including observational and interventional studies. Specifically, we review studies describing the inhibition of renin activity by calcium and vitamin D, and a potentially bidirectional and stimulatory relationship between aldosterone and parathyroid hormone. Deciphering these relationships might clarify variability in outcomes research, inform the design of future intervention studies and provide insight into the results of prior and ongoing intervention studies. However, before these opportunities can be addressed, more effort must be placed on shifting observational data to the proof of concept phase. This will require reallocation of resources to conduct interventional studies and secure the necessary talent.