Primary Aldosteronism: Changing Definitions and New Concepts of Physiology and Pathophysiology Both Inside and Outside the Kidney

Optimizing the aldosterone-to-renin ratio cut-off for screening primary aldosteronism based on cardiovascular risk: a collaborative study

OBJECTIVES

Aldosterone-to-renin ratio (ARR) based screening is the first step in the diagnosis of primary aldosteronism (PA). However, the guideline-recommended ARR cutoff covers a wide range, from the equivalent of 1.3 to 4.9 ng·dl-1/mIU∙l-1. We aimed to optimize the ARR cutoff for PA screening based on the risk of cardiovascular diseases (CVD).

METHODS

Longitudinally, we included hypertensive participants from the Framingham Offspring Study (FOS) who attended the sixth examination cycle and followed up until 2014. At baseline (1995-1998), we used circulating concentrations of aldosterone and renin to calculate ARR (unit: ng·dl-1/mIU∙l-1) among 1,433 subjects who were free of CVD. We used spline regression to calculate the ARR threshold based on the incident CVD. We used cross-sectional data from the Chongqing Primary Aldosteronism Study (CONPASS) to explore whether the ARR cutoff selected from FOS is applicable to PA screening.

RESULTS

In FOS, CVD risk increased with an increasing ARR until a peak of ARR 1.0, followed by a plateau in CVD risk (hazard ratio 1.49, 95%CI 1.19-1.86). In CONPASS, when compared to essential hypertension with ARR < 1.0, PA with ARR ≥ 1.0 carried a higher CVD risk (odds ratio 2.24, 95%CI 1.41-3.55), while essential hypertension with ARR ≥ 1.0 had an unchanged CVD risk (1.02, 0.62-1.68). Setting ARR cutoff at 2.4 ~ 4.9, 10% ~30% of PA subjects would be unrecognized although they carried a 2.45 ~ 2.58-fold higher CVD risk than essential hypertension.

CONCLUSIONS

The CVD risk-based optimal ARR cutoff is 1.0 ng·dl-1/mIU∙l-1 for PA screening. The current guideline-recommended ARR cutoff may miss patients with PA and high CVD risk.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT03224312).

A Randomized trial assessing Efficacy and safety of Mineralocorticoid receptor Antagonist therapy compared to Standard antihypertensive Therapy in hypErtension with low Renin (REMASTER): rationale and study design

Low-renin hypertension affects 1 in 4 people with hypertension, but the optimal management of this condition is not known. We hypothesize that a large proportion of people with low-renin hypertension is mediated by excess mineralocorticoid receptor (MR) activation and that targeted treatment with an MR antagonist (MRA) will be beneficial. This randomized, single-blinded, titration-to-effect aims to investigate whether targeted treatment in low-renin hypertension with MRA is better compared to standard antihypertensives in terms of blood pressure control and end-organ protection. Adults with hypertension, who are treatment naïve or are receiving up to two antihypertensive agents and have a low direct renin concentration <10 mU/L will be included. Participants with severe hypertension, a secondary cause of hypertension, pregnant, breastfeeding, with moderate-severe cardiovascular and chronic kidney disease, or on medications that confound interpretation of the plasma direct renin or aldosterone concentrations will be excluded. Eligible participants will be randomized 1:1 to either MRA therapy (spironolactone) or standard anti-hypertensive therapy (perindopril+/- amlodipine) for 48 weeks. Anti-hypertensives will be up-titrated every 12 weeks until target blood pressure is achieved. The primary objective will be to determine the total defined daily dose of antihypertensives required to achieve the target blood pressure and change in mean clinic systolic blood pressure at week 48. Current hypertension guidelines do not have specific recommendations for the choice of anti-hypertensive medications for people with low-renin hypertension. The results of this trial could guide future hypertension guidelines.

Selective venous sampling for secondary hypertension

Selective venous sampling (SVS), an invasive radiographic procedure that depends on contrast media, holds a unique role in diagnosing and guiding the treatment of certain types of secondary hypertension, particularly in patients who may be candidates for curative surgery. The adrenal venous sampling (AVS), in particular, is established as the gold standard for localizing and subtyping primary aldosteronism (PA). Throughout decades of clinical practice, AVS could be applied not only to PA but also to other endocrine diseases, such as adrenal Cushing syndrome (ACS) and Pheochromocytomas (PCCs). Notably, the application of AVS in ACS and PCCs remains less recognized compared to PA, with the low success rate of catheterization, the controversy of results interpretation, and the absence of a standardized protocol. Additionally, the AVS procedure necessitates enhancements to boost its success rate, with several helpful but imperfect methods emerging, yet continued exploration remains essential. We also observed renal venous sampling (RVS), an operation akin to AVS in principle, serves as an effective means of diagnosing renin-dependent hypertension, aiding in the identification of precise sources of renin excess and helping the selection of surgical candidates with renin angiotensin aldosterone system (RAAS) abnormal activation. Nonetheless, further basic and clinical research is needed. Selective venous sampling (SVS) can be used in identifying cases of secondary hypertension that are curable by surgical intervention. Adrenal venous sampling (AVS) and aldosterone measurement for classificatory diagnosis of primary aldosteronism (PA) are established worldwide. While its primary application is for PA, AVS also holds the potential for diagnosing other endocrine disorders, including adrenal Cushing's syndrome (ACS) and pheochromocytomas (PCCs) through the measurements of cortisol and catecholamine respectively. In addition, renal venous sampling and renin measurement can help to diagnose renovascular hypertension and reninoma.

Screening and diagnosis of primary aldosteronism. Consensus document of all the Spanish Societies involved in the management of primary aldosteronism

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension (HT), and is associated with a higher cardiometabolic risk than essential HT. However, PA remains underdiagnosed, probably due to several difficulties clinicians usually find in performing its diagnosis and subtype classification. The aim of this consensus is to provide practical recommendations focused on the prevalence and the diagnosis of PA and the clinical implications of aldosterone excess, from a multidisciplinary perspective, in a nominal group consensus approach by experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology, Spanish Association of Surgeons (AEC).

Challenges in Diagnosing and Managing the Spectrum of Primary Aldosteronism

Primary aldosteronism, characterized by the dysregulated production of aldosterone from 1 or both adrenal glands, is the most common endocrine cause of hypertension. It confers a high risk of cardiovascular, renal, and metabolic complications that can be ameliorated with targeted medical therapy or surgery. Diagnosis can be achieved with a positive screening test (elevated aldosterone to renin ratio) followed by confirmatory testing (saline, captopril, fludrocortisone, or oral salt challenges) and subtyping (adrenal imaging and adrenal vein sampling). However, the diagnostic pathway may be complicated by interfering medications, intraindividual variations, and concurrent autonomous cortisol secretion. Furthermore, once diagnosed, careful follow-up is needed to ensure that treatment targets are reached and adverse effects, or even recurrence, are promptly addressed. These challenges will be illustrated in a series of case studies drawn from our endocrine hypertension clinic. We will offer guidance on strategies to facilitate an accurate and timely diagnosis of primary aldosteronism together with a discussion of treatment targets which should be achieved for optimal patient outcomes.

Imaging Concordance With Vein Sampling for Primary Aldosteronism: A Cohort Study and Literature Review

INTRODUCTION

Adrenal venous sampling (AVS) is used to distinguish unilateral from bilateral aldosterone hypersecretion as a cause of primary aldosteronism (PA). Unilateral disease is treated with adrenalectomy and bilateral hypersecretion managed medically.

METHODS

We performed a single institution retrospective cohort study of adult patients undergoing adrenalectomy for PA from July 2013 to June 2022. Concordance of imaging findings with AVS was evaluated. Statistical analysis was performed with Mann-Whitney U and chi-squared Fisher's exact. Literature review performed via triple method search strategy.

RESULTS

Twenty-one patients underwent AVS and adrenalectomy for PA. Two patients did not have imaging findings and 19 were localized with an adenoma. For patients with image localization, AVS was concordant in nine, discordant in four, and nondiagnostic in six. For patients with discordant findings, age range was 35.8 to 72.4 y compared with concordant patient age range of 49.8 to 71.7 y. Overall discordance between imaging results and AVS was 40%. The aldosterone level was associated with concordance with a median of 52 ng/dL compared with 26 ng/dL if discordant (P = 0.002). There was a significant reduction in antihypertensive medications for the entire cohort from a median of three medications (interquartile range 2-4) to 1 medication (interquartile range 1-2), P < 0.001.

CONCLUSIONS

In this cohort, 40% of patients with selective AVS had discordant imaging and AVS results. Aldosterone level was associated with concordance. Hypertension was significantly improved with a median decrease of two antihypertensives. Our results support performance of AVS on all candidates for adrenalectomy for PA.

Familial hyperaldosteronism: an European Reference Network on Rare Endocrine Conditions clinical practice guideline

We describe herein the European Reference Network on Rare Endocrine Conditions clinical practice guideline on diagnosis and management of familial forms of hyperaldosteronism. The guideline panel consisted of 10 experts in primary aldosteronism, endocrine hypertension, paediatric endocrinology, and cardiology as well as a methodologist. A systematic literature search was conducted, and because of the rarity of the condition, most recommendations were based on expert opinion and small patient series. The guideline includes a brief description of the genetics and molecular pathophysiology associated with each condition, the patients to be screened, and how to screen. Diagnostic and treatment approaches for patients with genetically determined diagnosis are presented. The recommendations apply to patients with genetically proven familial hyperaldosteronism and not to families with more than one case of primary aldosteronism without demonstration of a responsible pathogenic variant.

Association of adrenal steroids with metabolomic profiles in patients with primary and endocrine hypertension

Introduction

Endocrine hypertension (EHT) due to pheochromocytoma/paraganglioma (PPGL), Cushing's syndrome (CS), or primary aldosteronism (PA) is linked to a variety of metabolic alterations and comorbidities. Accordingly, patients with EHT and primary hypertension (PHT) are characterized by distinct metabolic profiles. However, it remains unclear whether the metabolomic differences relate solely to the disease-defining hormonal parameters. Therefore, our objective was to study the association of disease defining hormonal excess and concomitant adrenal steroids with metabolomic alterations in patients with EHT.

Methods

Retrospective European multicenter study of 263 patients (mean age 49 years, 50% females; 58 PHT, 69 PPGL, 37 CS, 99 PA) in whom targeted metabolomic and adrenal steroid profiling was available. The association of 13 adrenal steroids with differences in 79 metabolites between PPGL, CS, PA and PHT was examined after correction for age, sex, BMI, and presence of diabetes mellitus.

Results

After adjustment for BMI and diabetes mellitus significant association between adrenal steroids and metabolites - 18 in PPGL, 15 in CS, and 23 in PA - were revealed. In PPGL, the majority of metabolite associations were linked to catecholamine excess, whereas in PA, only one metabolite was associated with aldosterone. In contrast, cortisone (16 metabolites), cortisol (6 metabolites), and DHEA (8 metabolites) had the highest number of associated metabolites in PA. In CS, 18-hydroxycortisol significantly influenced 5 metabolites, cortisol affected 4, and cortisone, 11-deoxycortisol, and DHEA each were linked to 3 metabolites.

Discussions

Our study indicates cortisol, cortisone, and catecholamine excess are significantly associated with metabolomic variances in EHT versus PHT patients. Notably, catecholamine excess is key to PPGL's metabolomic changes, whereas in PA, other non-defining adrenal steroids mainly account for metabolomic differences. In CS, cortisol, alongside other non-defining adrenal hormones, contributes to these differences, suggesting that metabolic disorders and cardiovascular morbidity in these conditions could also be affected by various adrenal steroids.

Hypertension in the emergency department: A missed opportunity to screen for primary aldosteronism?

OBJECTIVES

Primary aldosteronism (PA) is a common but underdiagnosed secondary cause of hypertension. Emergency departments (EDs) often assess patients with severe hypertension or its sequelae, some of whom have underlying PA. We aimed to determine the proportion of patients presenting to the ED with hypertension who meet the Endocrine Society criteria for PA testing and the proportion who were screened.

METHODS

We performed a structured retrospective chart review of adults who presented to three EDs in an Australian tertiary health network between August 2019 and February 2020, with a coded presenting complaint of hypertension. Clinical parameters to determine whether the patients met the criteria for PA testing were extracted from electronic medical records.

RESULTS

Of the 418 patients who presented to the EDs with documented elevated blood pressure (BP), 181 patients (43.3%) fulfilled PA screening criteria and nine patients (2.2%) underwent PA testing. Individuals who fulfilled screening criteria were older; had higher prevalence of Type 2 diabetes, coronary artery disease, and congestive heart failure; took more antihypertensive medications; and had lower estimated glomerular filtration rate. Individuals who were tested for PA were younger and had higher BP on presentation. Screening for PA was more frequent in patients who were referred to medical teams.

CONCLUSIONS

As far as we are aware, our study is the first to evaluate PA testing in hypertensive patients who present to ED. More than 40% of adults presenting to the EDs with hypertension met the current criteria for testing for PA but only few were tested. These results emphasize that increased awareness of PA in the ED is needed to encourage opportunistic testing, referral, and treatment, especially in patients who present with hypertensive emergencies. Prospective studies are required to determine the feasibility and effectiveness of this.

Treating Primary Aldosteronism-Induced Hypertension: Novel Approaches and Future Outlooks

Primary aldosteronism (PA) is the most common cause of secondary hypertension and is associated with increased morbidity and mortality when compared with blood pressure-matched cases of primary hypertension. Current limitations in patient care stem from delayed recognition of the condition, limited access to key diagnostic procedures, and lack of a definitive therapy option for nonsurgical candidates. However, several recent advances have the potential to address these barriers to optimal care. From a diagnostic perspective, machine-learning algorithms have shown promise in the prediction of PA subtypes, while the development of noninvasive alternatives to adrenal vein sampling (including molecular positron emission tomography imaging) has made accurate localization of functioning adrenal nodules possible. In parallel, more selective approaches to targeting the causative aldosterone-producing adrenal adenoma/nodule (APA/APN) have emerged with the advent of partial adrenalectomy or precision ablation. Additionally, the development of novel pharmacological agents may help to mitigate off-target effects of aldosterone and improve clinical efficacy and outcomes. Here, we consider how each of these innovations might change our approach to the patient with PA, to allow more tailored investigation and treatment plans, with corresponding improvement in clinical outcomes and resource utilization, for this highly prevalent disorder.

Revealing Structure and Localization of Steroid Regioisomers through Predictive Fragmentation Patterns in Mass Spectrometry Imaging

Identifying and mapping steroids in tissues can provide opportunities for biomarker discovery, the interrogation of disease progression, and new therapeutics. Although separation coupled to mass spectrometry (MS) has emerged as a powerful tool for studying steroids, imaging and annotating steroid isomers remains challenging. Herein, we present a new method based on the fragmentation of silver-cationized steroids in tandem MS, which produces distinctive and consistent fragmentation patterns conferring confidence in steroid annotation at the regioisomeric level without using prior derivatization, separation, or instrumental modification. In addition to predicting the structure of the steroid with isomeric specificity, the method is simple, flexible, and inexpensive, suggesting that the wider community will easily adapt to it. We demonstrate the utility of our approach by visualizing steroids and steroid isomer distributions in mouse brain tissue using silver-doped pneumatically assisted nanospray desorption electrospray ionization mass spectrometry imaging.

RAS-challenge as a first-look test for detection of primary aldosteronism in patients with treatment-resistant hypertension

PURPOSE

Primary aldosteronism (PA), characterised by low-renin hypertension, confers a high cardiovascular risk and is the most common cause of secondary hypertension, with an increased prevalence in patients with treatment-resistant hypertension. However, it is estimated that only a small percentage of affected patients are identified in routine clinical practice. Inhibitors of the renin-angiotensin system cause an increase in renin levels in patients with intact aldosterone regulation, and inadequate low renin with concurrent RAS inhibition (RASi) may therefore indicate PA, which could serve as a first look screening test for selection for formal work-up.

METHODS

We analysed patients between 2016-2018 with treatment-resistant hypertension who had inadequate low renin in the presence of RASi (i. e. at risk for PA) and who were offered systematic work-up with adrenal vein sampling (AVS).

RESULTS

A total of 26 pts were included in the study (age 54.8 ± 11, male 65%). Mean office blood pressure (BP) was 154/95 mmHg on 4.5 antihypertensive drug classes. AVS had a high technical success rate (96%) and demonstrated unilateral disease in the majority of patients (57%), most of which (77%) were undetected by cross-sectional imaging.

CONCLUSION

In patients with resistant hypertension, low renin in the presence of RASi is a strong indicator for autonomous aldosterone secretion. It may serve as an on-medication screening test for PA to select for formal PA work up.

2023 Korean Endocrine Society Consensus Guidelines for the Diagnosis and Management of Primary Aldosteronism

Primary aldosteronism (PA) is a common, yet underdiagnosed cause of secondary hypertension. It is characterized by an overproduction of aldosterone, leading to hypertension and/or hypokalemia. Despite affecting between 5.9% and 34% of patients with hypertension, PA is frequently missed due to a lack of clinical awareness and systematic screening, which can result in significant cardiovascular complications. To address this, medical societies have developed clinical practice guidelines to improve the management of hypertension and PA. The Korean Endocrine Society, drawing on a wealth of research, has formulated new guidelines for PA. A task force has been established to prepare PA guidelines, which encompass epidemiology, pathophysiology, clinical presentation, diagnosis, treatment, and follow-up care. The Korean clinical guidelines for PA aim to deliver an evidence-based protocol for PA diagnosis, treatment, and patient monitoring. These guidelines are anticipated to ease the burden of this potentially curable condition.

Cyclovirobuxine D alleviates aldosterone-induced myocardial hypertrophy by protecting mitochondrial function depending on the mutual regulation of Nrf2-SIRT3

BACKGROUND

Cyclovirobuxine D (CVB-D) is a natural alkaloid that exhibits multiple pharmacological activities, such as anti-inflammatory, anti-oxidative stress, and anti-cancer properties. However, its specific protective mechanism of action for myocardial hypertrophy remains unresolved.

PURPOSE

This work was to investigate the ameliorative impact of CVB-D in myocardial hypertrophy, and to elucidate aldosterone (ALD)-induced myocardial hypertrophy by inhibiting the SIRT3 mediated Nrf2 activation.

METHODS

The myocardial hypertrophy model was reproduced by ALD both in vitro and in vivo, and the protective effect of CVB-D on myocardium and mitochondria was evaluated by TEM, H&E, qPCR, Western blot and ChIP. An immunoprecipitation experiment was adopted to evaluate the acetylation level of Nrf2 and the binding between SIRT3 and Nrf2. Additionally, bardoxolone-methyl (BAR, an Nrf2 agonist), ML385 (an Nrf2 inhibitor), resveratrol (RES, a SIRT3 agonist), and 3-TYP (a SIRT3 inhibitor) were used to confirm the molecular mechanism of CVB-D. Lastly, a molecular docking technique was employed to predict the binding site of SIRT3 and Nrf2 proteins.

RESULTS

Our findings suggested that CVB-D improved mitochondrial function, leading to a reduction in ALD-induced cardiomyocyte hypertrophy. By CVB-D treatment, there was an activation of mutual regulation between Nrf2 and SIRT3. Specifically, CVB-D resulted in the increase of Nrf2 protein in the nucleus and activated Nrf2 signaling pathway, thus up-regulating SIRT3. The activation of SIRT3 and the protective action of mitochondrion disappeared because of the intervention of ML385. After CVB-D activated SIRT3, the acetylation level of Nrf2 decreased, followed by activating the Nrf2 pathway. The activation of Nrf2 and mitochondrial protection by CVB-D were reversed by 3-TYP. Our results are also supported by Co-IP and molecular docking analysis, revealing that CVB-D promotes SIRT3-mediated Nrf2 activation.

CONCLUSION

Thus, CVB-D ameliorates ALD-induced myocardial hypertrophy by recovering mitochondrial function by activating the mutual regulation of Nrf2 and SIRT3. Thus, CVB-D could be a beneficial drug for myocardial hypertrophy.

Validation of the Aldosteronoma Resolution Score as a Predictive Resolution Score of Hypertension After Unilateral Adrenalectomy for Primary Aldosteronism in a North-African Population

BACKGROUND

Unilateral primary aldosteronism (UPA) is the most frequent surgically curable form of endocrine hypertension. Adrenalectomy is the cornerstone of treatment for UPA, but outcomes after surgery are variable. Aldosteronoma Resolution Score (ARS) is a four-item predictive score for the cure of hypertension after adrenalectomy for UPA and has been demonstrated to be valid in different populations. We aimed in this study to validate the accuracy of this score in a North-African population.

METHODS

Between 2000 and 2021, the charts of 71 Tunisian patients who underwent laparoscopic adrenalectomy for UPA were retrospectively reviewed. Postoperative outcomes were assessed using the primary aldosteronism surgical outcome (PASO) criterion. The accuracy of the ARS was determined retrospectively by receiver operating characteristic curve and area under the curve.

RESULTS

Thirty-four patients (48%) had complete clinical success according to the PASO criteria. Multivariate regression analysis revealed that the main determinants of complete clinical success were the absence of diabetes (OR: 5.205), a BMI <30 (OR: 4.930), a number of antihypertensive medications ≤2 (OR: 8.667), a plasma ARR >332 (OR: 4.554) and an ARS score ≥3 (OR: 2.056). Cure rates were, respectively, 21.1, 51.6, and 66.6% for patients with a score ARS 0-1, 2-3, and 4-5. The AUC of the ARS was 0.837.

CONCLUSION

The ARS is a sufficiently predictive score in our North-African population. It may be used preoperatively to predict the outcome after adrenalectomy in these populations.

Willingness to be tested for a secondary cause of hypertension: a survey of the Australian general community

BACKGROUND

Primary aldosteronism (PA) represents the most common and potentially curable cause of secondary hypertension. However, PA is not commonly screened for, and up to 34% of patients who screen positive do not complete the full diagnostic process. This suggests that the diagnostic process may pose a barrier to patients and may contribute to the under-diagnosis of PA.

AIMS

To evaluate the willingness of the Australian general public to undergo testing for secondary causes of hypertension and identify enablers or barriers to testing from the patients' perspective.

METHODS

An online survey containing questions on knowledge and attitudes towards hypertension, willingness to be tested and enablers/barriers towards testing was distributed to the Australian community.

RESULTS

Of 520 adult respondents (mean age 50.4 years, SD 27.3 years; 28.8% hypertensive; 56.0% female), the majority of non-hypertensive and hypertensive respondents (82.7% vs 70.0%; P = 0.03) were willing to undergo testing for a secondary cause of hypertension that involved blood and urine tests. Greater knowledge of hypertensive risk modification strategies and complications was predictive of willingness to be tested, whereas age, sex, education level, geographic location, socio-economic status and cardiovascular comorbidities were not. The top three barriers to testing included fear of a serious underlying condition, lack of belief in further testing and increased stress associated with further testing.

CONCLUSION

A high proportion of patients are willing to engage in testing for a secondary cause of hypertension. Education about the risks associated with hypertension and the testing process may overcome several barriers to testing.

Aldosterone and renin concentrations and blood pressure in young Indigenous and non-Indigenous adults in the Northern Territory: a cross-sectional study

OBJECTIVES

To evaluate aldosterone and renin levels and aldosterone-to-renin ratios (ARRs) in young Indigenous and non-Indigenous adults in the Northern Territory, and their association with blood pressure levels.

DESIGN

Cross-sectional study; single time point sub-study of two prospective birth cohort studies.

SETTING, PARTICIPANTS

Participants in the Aboriginal Birth Cohort (ABC) - born to Indigenous mothers at the Royal Darwin Hospital during 1987-1990 - and the Top End Cohort (TEC) - people born to non-Indigenous mothers in Darwin, recruited during 2007-2009 - aged 32-35 years at the time of this sub-study.

MAIN OUTCOME MEASURES

Plasma aldosterone and direct renin concentrations; ARRs (positive screening test result for primary aldosteronism defined as > 70 pmol/mU); systolic and diastolic blood pressure.

RESULTS

A total of 255 ABC (205 in remote, 50 in urban locations) and 76 TEC members participated. Median aldosterone concentration was similar for all three groups. The median renin concentration was 7.5 mU/L (interquartile range [IQR], 4.1-12.4 mU/L) in the TEC group, 12.4 mU/L (IQR, 5.1-19 mU/L) in the urban ABC group, and 29.3 mU/L (IQR, 15.0-52.9 mU/L) in the remote ABC group. The median ARR was 10 pmol/mU (IQR, 6-19 pmol/mU) in the remote ABC group, 28 pmol/mU (IQR, 16-70 pmol/mU) in the urban ABC group, and 43 pmol/mU (IQR, 26-74 pmol/mU) in the TEC group. Thirteen urban ABC participants (26%), 21 TEC participants (28%), and six people in the remote ABC group (3%) had ARR values above 70 pmol/mU. Adjusted for age and body mass index (BMI), mean systolic and diastolic blood pressure were lower for women than men in all participant groups; after adjusting for age, sex, and BMI, larger ARR was associated with higher systolic blood pressure in the TEC group but not the two ABC groups.

CONCLUSION

Screening test results for primary aldosteronism were positive for about one-quarter of urban Indigenous and non-Indigenous participants. A prospective study that includes confirmatory testing would more accurately assess the prevalence of primary aldosteronism among Indigenous Australians in the Northern Territory.

Identifying KCNJ5 Mutation in Aldosterone-Producing Adenoma Patients With Baseline Characteristics Using Machine Learning Technology

Background

Primary aldosteronism is characterized by inappropriate aldosterone production, and unilateral aldosterone-producing adenoma (uPA) is a common type of PA. KCNJ5 mutation is a protective factor in uPA; however, there is no preoperative approach to detect KCNJ5 mutation in patients with uPA.

Objectives

This study aimed to provide a personalized surgical recommendation that enables more confidence in advising patients to pursue surgical treatment.

Methods

We enrolled 328 patients with uPA harboring KCNJ5 mutations (n = 158) or not (n = 170) who had undergone adrenalectomy. Eighty-seven features were collected, including demographics, various blood and urine test results, and clinical comorbidities. We designed 2 versions of the prediction model: one for institutes with complete blood tests (full version), and the other for institutes that may not be equipped with comprehensive testing facilities (condensed version).

Results

The results show that in the full version, the Light Gradient Boosting Machine outperformed other classifiers, achieving area under the curve and accuracy values of 0.905 and 0.864, respectively. The Light Gradient Boosting Machine also showed excellent performance in the condensed version, achieving area under the curve and accuracy values of 0.867 and 0.803, respectively.

Conclusions

We simplified the preoperative diagnosis of KCNJ5 mutations successfully using machine learning. The proposed lightweight tool that requires only baseline characteristics and blood/urine test results can be widely applied and can aid personalized prediction during preoperative counseling for patients with uPA.

Biochemical Evaluation by Confirmatory Tests after Unilateral Adrenalectomy for Primary Aldosteronism

Primary aldosteronism (PA) is the most common cause of endocrine hypertension. Unilateral PA can be cured using unilateral adrenalectomy (Adx). PA surgery outcome (PASO) criteria, which include clinical and biochemical outcomes, have been proposed to evaluate PA cure after Adx. However, clinical outcomes are often inconsistent with biochemical outcomes. In addition, although confirmatory tests are included as endpoints of biochemical outcomes in the PASO criteria, their clinical usefulness has not yet been established. We evaluated clinical parameters and confirmatory test results before and after Adx in 16 patients with PA and assessed the usefulness of the confirmatory tests. The following were the clinical outcomes after Adx: 37.5% complete success, 62.5% partial success, and 0% absent success. The ratio of biochemical complete success was as follows: 69% aldosterone/renin ratio and basal plasma aldosterone concentration, 19% as assessed by the captopril challenge test, 47% as assessed by the saline infusion test, 30% as assessed by the furosemide upright test, and 100% urine aldosterone. Of these, biochemical complete success was judged in four cases by aldosterone/renin ratio and basal plasma aldosterone concentration, one case by captopril challenge test, five cases by saline infusion test, and one case by furosemide upright test. Although clinical outcomes and urine aldosterone levels improved after Adx, confirmatory tests failed to improve in some cases. The current criteria are not considered useful for biochemical evaluation after Adx. To determine whether additional treatment with mineralocorticoid receptor antagonists is required, more accurate biochemical criteria should be established after Adx.

Aldosterone: Renal Action and Physiological Effects

Aldosterone exerts profound effects on renal and cardiovascular physiology. In the kidney, aldosterone acts to preserve electrolyte and acid-base balance in response to changes in dietary sodium (Na+ ) or potassium (K+ ) intake. These physiological actions, principally through activation of mineralocorticoid receptors (MRs), have important effects particularly in patients with renal and cardiovascular disease as demonstrated by multiple clinical trials. Multiple factors, be they genetic, humoral, dietary, or otherwise, can play a role in influencing the rate of aldosterone synthesis and secretion from the adrenal cortex. Normally, aldosterone secretion and action respond to dietary Na+ intake. In the kidney, the distal nephron and collecting duct are the main targets of aldosterone and MR action, which stimulates Na+ absorption in part via the epithelial Na+ channel (ENaC), the principal channel responsible for the fine-tuning of Na+ balance. Our understanding of the regulatory factors that allow aldosterone, via multiple signaling pathways, to function properly clearly implicates this hormone as central to many pathophysiological effects that become dysfunctional in disease states. Numerous pathologies that affect blood pressure (BP), electrolyte balance, and overall cardiovascular health are due to abnormal secretion of aldosterone, mutations in MR, ENaC, or effectors and modulators of their action. Study of the mechanisms of these pathologies has allowed researchers and clinicians to create novel dietary and pharmacological targets to improve human health. This article covers the regulation of aldosterone synthesis and secretion, receptors, effector molecules, and signaling pathways that modulate its action in the kidney. We also consider the role of aldosterone in disease and the benefit of mineralocorticoid antagonists. © 2023 American Physiological Society. Compr Physiol 13:4409-4491, 2023.

The adrenal vein sampling outcomes study (AVOS): success rates following adrenalectomy for unilateral primary aldosteronism

The objective was to determine the clinical and biochemical success rates and assess the nature of follow-up after adrenalectomy in patients with unilateral primary aldosteronism (PA), subtyped by adrenal vein sampling (AVS) in West Australia (WA) using the Primary Aldosteronism Surgical Outcome (PASO) criteria. Clinical and biochemical outcomes were retrospectively evaluated in patients with unilateral PA who underwent adrenalectomy according to AVS between September 2017 and September 2020. Pre- and post-surgical data were collected using a standardised questionnaire, review of clinic letters and examination of private and public pathology results and radiological reports. Follow-up data were available for 47 patients post-adrenalectomy; biochemical outcome data were available for 37 patients, clinical outcome data for 40 patients, with 30 patients having both outcomes available. Final assessment was performed between 0 to 3 months in 23/37 (62.2%) patients with biochemical outcomes, 15/40 (37.5%) with clinical outcomes, and 17/30 (56.7%) with both clinical and biochemical outcomes. Complete biochemical success was achieved in 83.8% (31/37) of patients, with 26.7% (8/30) obtaining both complete clinical and biochemical success. Complete clinical success was achieved in 35.0% (14/40) of patients, with 47.5% (19/40) obtaining partial clinical success. Overall, 93.6% (44/47) of patients derived benefit from adrenalectomy. The outcomes of adrenalectomy for unilateral PA in Western Australian using standardised PASO criteria demonstrate highly comparable clinical and biochemical success rates to international data. However, further standardisation of post-operative follow-up care needs to be implemented to ensure the recommended repeat follow-up assessment criteria are collected.

Adrenal Vein Sampling Results and Surgical Outcomes in Patients with a Normal Plasma Aldosterone Concentration

PURPOSE

To determine the utility of adrenal vein sampling (AVS) and outcomes after adrenalectomy in patients with normal plasma aldosterone concentration (PAC) and elevated aldosterone-to-renin ratio (ARR).

MATERIALS AND METHODS

The study sample included 106 patients with ARR greater than 20 and PAC between 5 and 15 ng/dL (normal PAC group) who underwent AVS from 2005 to 2021. These patients were compared with a cohort of 106 patients with ARR >20 and PAC >15 ng/dL (high PAC group) who underwent AVS during the same period. Data regarding baseline clinical characteristics, lateralization indices from AVS, and outcomes after adrenalectomy were analyzed.

RESULTS

AVS was technically successful in 210 patients (210/212, 99%). A smaller proportion of patients in the normal PAC group showed a lateralization index of >4 compared with those in the high PAC group (44% vs 64%, P <.01). A similar proportion of patients in the normal PAC group experienced improved or cured hypertension after adrenalectomy compared with that in the high PAC group (94% vs 88%, P =.31). Hypokalemia was cured in all patients in the normal PAC group after adrenalectomy compared with 98% of patients in the high PAC group (100% vs 98%, P = 1).

CONCLUSIONS

Although lateralization is less frequent for patients with normal PAC, patients who do lateralize show similar blood pressure response and correction of hypokalemia after adrenalectomy, regardless of initial plasma aldosterone levels. Therefore, patients with PAC <15 ng/dL should still be considered for AVS provided the ARR is elevated.

Laboratory medicine in arterial hypertension

In the initial diagnostics of arterial hypertension (AH) laboratory medicine is a cornerstone, along with a blood pressure (BP) measurement and an electrocardiogram. It mainly refers to routine blood and urine tests for diagnosis and monitoring primary hypertension and its associated conditions such as asymptomatic hypertension-mediated organ damage, chronic kidney disease and hypertensive disorders of pregnancy. In addition, long term non-fatal and fatal risks for cardiovascular (CV) events in hypertension are assessed based on clinical and laboratory data. Furthermore, laboratory medicine is involved in the management of hypertension, especially in monitoring the disease progression. However, antihypertensive drugs may interfere with laboratory test results. Diuretics, especially thiazides, can affect blood and urine sodium concentrations, or angiotensin-converting enzyme inhibitors and angiotensin receptor blockers can affect the blood biomarkers of the renin-angiotensin-aldosterone system (RAAS). It's dysfunction plays a critical role in primary aldosteronism (PA), the most common endocrine disorder in secondary hypertension, which accounts for only small proportion of AH in relative terms but substantial proportion of hypertensives in absolute terms, affecting younger population and carrying a higher risk of CV mortality and morbidity. When screening for PA, aldosterone-to-renin ratio still contributes massively to the increased incidence of the disease, despite certain limits. In conclusion, laboratory medicine is involved in the screening, diagnosis, monitoring and prognosis of hypertension. It is of great importance to understand the preanalytical and analytical factors influencing final laboratory result.

TSPAN12 (Tetraspanin 12) Is a Novel Negative Regulator of Aldosterone Production in Adrenal Physiology and Aldosterone-Producing Adenomas

BACKGROUND

Aldosterone-producing adenomas (APAs) are a major cause of primary aldosteronism, a condition of low-renin hypertension, in which aldosterone overproduction is usually driven by a somatic activating mutation in an ion pump or channel. TSPAN12 is differentially expressed in different subgroups of APAs suggesting a role in APA pathophysiology. Our objective was to determine the function of TSPAN12 (tetraspanin 12) in adrenal physiology and pathophysiology.

METHODS

APA specimens, pig adrenals under dietary sodium modulation, and a human adrenocortical cell line HAC15 were used for functional characterization of TSPAN12 in vivo and in vitro.

RESULTS

Gene ontology analysis of 21 APA transcriptomes dichotomized according to high versus low TSPAN12 transcript levels highlighted a function for TSPAN12 related to the renin-angiotensin system. TSPAN12 expression levels in a cohort of 30 APAs were inversely correlated with baseline plasma aldosterone concentrations (R=-0.47; P=0.009). In a pig model of renin-angiotensin system activation by dietary salt restriction, TSPAN12 mRNA levels and TSPAN12 immunostaining were markedly increased in the zona glomerulosa layer of the adrenal cortex. In vitro stimulation of human adrenocortical human adrenocortical cells with 10 nM angiotensin II for 6 hours caused a 1.6-fold±0.13 increase in TSPAN12 expression, which was ablated by 10 μM nifedipine (P=0.0097) or 30 μM W-7 (P=0.0022). Gene silencing of TSPAN12 in human adrenocortical cells demonstrated its inverse effect on aldosterone secretion under basal and angiotensin II stimulated conditions.

CONCLUSIONS

Our findings show that TSPAN12 is a negative regulator of aldosterone production and could contribute to aldosterone overproduction in primary aldosteronism.

Renal Artery Stenosis Complicated with Primary Aldosteronism

Primary aldosteronism (PA) is a typical example of low renin hypertension, whereas renal artery stenosis (RAS) is a classic form of high renin hypertension. PA and RAS occurring simultaneously in a patient is challenging to diagnose. We report a 32-year-old woman with a 12-year history of resistant hypertension. She was identified to have elevated plasma aldosterone and renin levels with normal aldosterone/renin ratio (ARR). Imaging examinations identified bilateral adrenal thickening and subtotal occlusion of the anterior segment of the left renal artery. Adrenal venous sampling was performed and indicated the existence of unilateral aldosterone over-secretion. It may suggest that even though RAS led to non-suppressed renin, adrenal venous sampling remains to be an applicable approach to establish the diagnosis of aldosterone-producing adenomas, although the diagnostic value of ARR may be compromised due to non-suppressed renin level. The patient underwent a two-stage treatment. First, stenosis of the left renal artery was dilated by percutaneous transluminal renal balloon angioplasty. Two months later, laparoscopic complete left adrenalectomy was performed. Hematoxylin-eosin staining and CYP11B2 immunostaining suggested that this tumor was an aldosterone-producing adenoma. After the two-stage treatment, her blood pressure decreased to a normal level without antihypertensive drugs. This case report raises our awareness of the simultaneous occurrence of RAS and PA. Under this condition, ARR could lead to a false-negative PA. Adrenal venous sampling is warranted to achieve a confirmed diagnosis. For subjects with complex etiologies of secondary hypertension, multi-stage treatment may be required.

Ambulatory fludrocortisone suppression test in the diagnosis of primary aldosteronism: Safety, accuracy and cost-effectiveness

OBJECTIVE

The aims of this study were to explore if the ambulatory fludrocortisone suppression test (FST) was safe, accurate and cost-effective.

CONTEXT

The diagnosis of primary aldosteronism (PA) remains time-consuming and complex. The FST is used to confirm PA, but it is an in-patient test due to potentially serious complications such as hypokalemia. In Stockholm, FST has been performed since 2005 as an ambulatory procedure.

DESIGN

This is a retrospective study including all patients investigated with FST in four hospitals in Stockholm, Sweden, during 2005-2019.

PATIENTS/MEASUREMENTS

In total, 156 cases of ambulatory FST (FSTamb) and 15 cases of in-patient FST (FSTin) were included. FSTamb and FSTin were compared regarding health costs, clinical characteristics and laboratory results.

RESULTS

No difference was found in the outcomes of FSTamb and FSTin. No severe complications were reported in FSTamb patients. No difference was found in the median value for plasma potassium on Day 5 between the two groups. Only three patients (1.9%) in the FSTamb had to repeat the test due to incomplete intake of medications. FSTamb and FSTin were equally accurate. The cost of performing FSTamb was at least 50% lower compared with FSTin ($2400 vs. $5200 per patient). The time needed for FSTamb was 60 min of physician's time and 150 min of nurse's time which were lower than the 5 days in FSTin.

CONCLUSIONS

Ambulatory FST is safe and accurate and can be performed with significantly less healthcare costs compared to FSTin.

Whole blood methylome-derived features to discriminate endocrine hypertension

Background

Arterial hypertension represents a worldwide health burden and a major risk factor for cardiovascular morbidity and mortality. Hypertension can be primary (primary hypertension, PHT), or secondary to endocrine disorders (endocrine hypertension, EHT), such as Cushing's syndrome (CS), primary aldosteronism (PA), and pheochromocytoma/paraganglioma (PPGL). Diagnosis of EHT is currently based on hormone assays. Efficient detection remains challenging, but is crucial to properly orientate patients for diagnostic confirmation and specific treatment. More accurate biomarkers would help in the diagnostic pathway. We hypothesized that each type of endocrine hypertension could be associated with a specific blood DNA methylation signature, which could be used for disease discrimination. To identify such markers, we aimed at exploring the methylome profiles in a cohort of 255 patients with hypertension, either PHT (n = 42) or EHT (n = 213), and at identifying specific discriminating signatures using machine learning approaches.

Results

Unsupervised classification of samples showed discrimination of PHT from EHT. CS patients clustered separately from all other patients, whereas PA and PPGL showed an overall overlap. Global methylation was decreased in the CS group compared to PHT. Supervised comparison with PHT identified differentially methylated CpG sites for each type of endocrine hypertension, showing a diffuse genomic location. Among the most differentially methylated genes, FKBP5 was identified in the CS group. Using four different machine learning methods—Lasso (Least Absolute Shrinkage and Selection Operator), Logistic Regression, Random Forest, and Support Vector Machine—predictive models for each type of endocrine hypertension were built on training cohorts (80% of samples for each hypertension type) and estimated on validation cohorts (20% of samples for each hypertension type). Balanced accuracies ranged from 0.55 to 0.74 for predicting EHT, 0.85 to 0.95 for predicting CS, 0.66 to 0.88 for predicting PA, and 0.70 to 0.83 for predicting PPGL.

Conclusions

The blood DNA methylome can discriminate endocrine hypertension, with methylation signatures for each type of endocrine disorder.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01347-y.

Stroke Risks in Primary Aldosteronism with Different Treatments: A Systematic Review and Meta-Analysis

Background: Primary aldosteronism (PA) is a common cause of secondary hypertension and confers a higher risk of stroke. The treatment strategies of PA mainly include medical and adrenalectomy treatment, while there is still no solid conclusion on how these two different treatment strategies mitigate the detrimental effect of PA on stroke. Methods: PubMed, Embase, and Cochrane Library were searched for studies comparing stroke events in patients with PA receiving medical treatment versus adrenalectomy treatment published up to 19 March 2022, including patients with essential hypertension as a control group. We used either fixed or random effect models according to the heterogeneities. Sensitivity analysis was conducted by deleting each study one at a time. Results: We reviewed 201 articles, and three studies met the final criteria, including 3244 PA patients with medical treatment, 1611 PA patients with adrenalectomy treatment, and 20,568 EH patients. Patients with PA post adrenalectomy were observed with a significantly decreased risk of stroke compared to patients receiving medical treatment (OR: 0.57, 95% CI: 0.35−0.93, p = 0.03), and with no difference when compared to patients with essential hypertension. Patients with PA receiving medical treatment were still observed with higher stroke risks (OR: 1.88, 95% CI: 1.68−2.11, p < 0.00001) than patients with essential hypertension. Conclusion: PA is a critical modifiable risk factor for stroke. Adrenalectomy has a superior performance in the mitigation of stroke risks among patients with PA.

In Primary Aldosteronism Acute Potassium Chloride Supplementation Suppresses Abundance and Phosphorylation of the Sodium-Chloride Cotransporter

Background

Elevated abundance of sodium-chloride cotransporter (NCC) and phosphorylated NCC (pNCC) are potential markers of primary aldosteronism (PA), but these effects may be driven by hypokalemia.

Methods

We measured plasma potassium in patients with PA. If potassium was <4.0 mmol/L, patients were given sufficient oral potassium chloride (KCl) over 24 hours to achieve as close to 4.0 mmol/L as possible. Clinical chemistries were assessed, and urinary extracellular vesicles (uEVs) were examined to investigate effects on NCC.

Results

Among 21 patients with PA who received a median total dose of 6.0 g (2.4-16.8 g) of KCl, increases were observed in plasma potassium (from 3.4 to 4.0 mmol/L; P<0.001), aldosterone (from 305 to 558 pmol/L; P=0.01), and renin (from 1.2 to 2.5 mIU/L; P<0.001), whereas decreases were detected in uEV levels of NCC (median fold change_(post/basal) [FC]=0.71 [0.09-1.99]; P=0.02), pT60-NCC (FC=0.84 [0.06-1.66]; P=0.05), and pT55/60-NCC (FC=0.67 [0.08-2.42]; P=0.02). By contrast, in 10 patients with PA who did not receive KCl, there were no apparent changes in plasma potassium, NCC abundance, and phosphorylation status, but increases were observed in plasma aldosterone (from 178 to 418 pmol/L; P=0.006) and renin (from 2.0 to 3.0 mU/L; P=0.009). Plasma potassium correlated inversely with uEV levels of NCC (R ²=0.11; P=0.01), pT60-NCC (R ²=0.11; P=0.01), and pT55/60-NCC (R ²=0.11; P=0.01).

Conclusions

Acute oral KCl loading replenished plasma potassium in patients with PA and suppressed NCC abundance and phosphorylation, despite a significant rise in plasma aldosterone. This supports the view that potassium supplementation in humans with PA overrides the aldosterone stimulatory effect on NCC. The increased plasma aldosterone in patients with PA without KCl supplementation may be due to aldosterone response to posture challenge.

Pathophysiology of bilateral hyperaldosteronism

PURPOSE OF REVIEW

Renin-independent aldosterone production from one or both affected adrenal(s), a condition known as primary aldosteronism (PA), is a common cause of secondary hypertension. In this review, we aimed to summarize recent findings regarding pathophysiology of bilateral forms of PA, including sporadic bilateral hyperaldosteronism (BHA) and rare familial hyperaldosteronism.

RECENT FINDINGS

The presence of subcapsular aldosterone synthase (CYP11B2)-expressing aldosterone-producing micronodules, also called aldosterone-producing cell clusters, appears to be a common histologic feature of adrenals with sporadic BHA. Aldosterone-producing micronodules frequently harbor aldosterone-driver somatic mutations. Other potential factors leading to sporadic BHA include rare disease-predisposing germline variants, circulating angiotensin II type 1 receptor autoantibodies, and paracrine activation of aldosterone production by adrenal mast cells. The application of whole exome sequencing has also identified new genes that cause inherited familial forms of PA.

SUMMARY

Research over the past 10 years has significantly improved our understanding of the molecular pathogenesis of bilateral PA. Based on the improved understanding of BHA, future studies should have the ability to develop more personalized treatment options and advanced diagnostic tools for patients with PA.

Primary Aldosteronism and Resistant Hypertension: A Pathophysiological Insight

Primary aldosteronism (PA) is a pathological condition characterized by an excessive aldosterone secretion; once thought to be rare, PA is now recognized as the most common cause of secondary hypertension. Its prevalence increases with the severity of hypertension, reaching up to 29.1% in patients with resistant hypertension (RH). Both PA and RH are "high-risk phenotypes", associated with increased cardiovascular morbidity and mortality compared to non-PA and non-RH patients. Aldosterone excess, as occurs in PA, can contribute to the development of a RH phenotype through several mechanisms. First, inappropriate aldosterone levels with respect to the hydro-electrolytic status of the individual can cause salt retention and volume expansion by inducing sodium and water reabsorption in the kidney. Moreover, a growing body of evidence has highlighted the detrimental consequences of "non-classical" effects of aldosterone in several target tissues. Aldosterone-induced vascular remodeling, sympathetic overactivity, insulin resistance, and adipose tissue dysfunction can further contribute to the worsening of arterial hypertension and to the development of drug-resistance. In addition, the pro-oxidative, pro-fibrotic, and pro-inflammatory effects of aldosterone may aggravate end-organ damage, thereby perpetuating a vicious cycle that eventually leads to a more severe hypertensive phenotype. Finally, neither the pathophysiological mechanisms mediating aldosterone-driven blood pressure rise, nor those mediating aldosterone-driven end-organ damage, are specifically blocked by standard first-line anti-hypertensive drugs, which might further account for the drug-resistant phenotype that frequently characterizes PA patients.

Concurrent Primary Aldosteronism and Renal Artery Stenosis: An Overlooked Condition Inducing Resistant Hypertension

To explore the clinical features of coexisting primary aldosteronism (PA) and renal artery stenosis (RAS), we retrospectively analyzed records from 71 patients with PA with RAS and a control group of 121 patients with PA without RAS. Aldosterone-to-renin concentration ratio tests and computerized tomography (CT) scanning of the adrenal and renal arteries were routinely conducted to screen for PA and RAS. Color Doppler flow and/or magnetic resonance imaging were used as substitute testing of patients for whom CT was contraindicated. Standard percutaneous renal arteriography (PTRA) was considered for patients with RAS exceeding 70% based on non-invasive tests and for those without PTRA contraindications. The patients with PA with RAS were further divided into severe (RAS>70%) and moderate (50% < RAS <70%) RAS groups. The prevalence of RAS among PA patients was 6.9% (71/1,033), including 3.2% (33/1,033) with severe RAS. Compared with the PA without RAS group, the severe RAS group showed higher levels of systolic blood pressure (SBP) (171.82 ± 18.24 vs. 154.11 ± 18.96 mmHg; P < 0.001) and diastolic BP(DBP) (110.76 ± 15.90 vs. 91.73 ± 12.85 mmHg; P < 0.001) and prevalence of resistant hypertension (RH) (90.9 vs. 66.9%; P = 0.008), whereas the moderate RAS group merely showed higher DBP (98.63 ± 14.90 vs. 91.73 ± 12.85 mmHg; P = 0.006). The direct renin concentrations (DRCs) (5.37 ± 3.94 vs. 3.71 ± 2.10 μU/mL; P < 0.001) and false-negative rate (33.8 vs. 3.3%; P < 0.01) of PA screening tests were significantly higher in the PA with RAS group than in the control group, but only in severe RAS group, in subgroup analysis. Among patients who underwent successful treatment for severe RAS, mean DRC decreased from 11.22 ± 9.10 to 3.24 ± 2.69 μIU/mL (P < 0.001). Overall, the prevalence of RH decreased from 81.7 to 2.8% (P < 0.001) when both PA and RAS were treated with standard methods. PA with concurrent severe RAS is a condition that induces RH. PA can be easily missed in patients with coexisting RAS. RAS patients with RH after successful revascularization for RAS should be evaluated for coexisting PA.

Prognosis of adrenalectomy guided by computed tomography versus adrenal vein sampling in patients with primary aldosteronism: A systematic review and meta‐analysis

Adrenal vein sampling (AVS) is recommended to be the gold standard for patients with unilateral subtypes of primary aldosteronism to clinical diagnosis and surgery therapy. However, it is uncertain whether AVS is better for prognosis than computed tomography (CT), which is the most widely used. Pubmed, Embase, and Cochrane Library were searched for articles with no start date restriction. The last search was conducted on Jun 15, 2021. Eligible studies compared the distinct subtypes of primary aldosteronism by AVS with CT (as a control group) and reported the prognosis at follow‐up. Evaluation of cohort studies referred to Newcastle ‐ Ottawa Quality Assessment Scale, and randomized controlled trials referred to Updated Cochrane Collaboration tool. A random‐effect model or fixed‐effect model was chosen according to the heterogeneity test. All processes were performed following the PRISMA 2020 statement. Eleven studies were identified, including 1325 patients based on AVS and 907 patients based on CT. Compared with patients guided by CT, patients who underwent AVS had an increased possibility of complete biochemical success (odds ratio [OR] 2.78, 95% CI 1.88–4.12) and a decreased chance of absent biochemical success (OR 0.23, 95% CI 0.13–0.40) at follow‐up. Nevertheless, the rate of complete clinical success (OR 1.09, 95% CI 0.89–1.35) and absent clinical success (OR 0.96, 95% CI 0.68–1.33) had no significant difference. Therefore, distinguishing subtypes by AVS for early treatment may be crucial since it can promote biochemical improvement.

Pathophysiology and histopathology of primary aldosteronism

Primary aldosteronism (PA) can be sporadic or familial and classified into unilateral and bilateral forms. Sporadic PA predominates with excessive aldosterone production usually arising from a unilateral aldosterone-producing adenoma (APA) or bilateral adrenocortical hyperplasia. Familial PA is rare and caused by germline variants, that partly correspond to somatic alterations in APAs. Classification into unilateral and bilateral PA determines the treatment approach but does not accurately mirror disease pathology. Some evidence indicates a disease continuum ranging from balanced aldosterone production from each adrenal to extreme asymmetrical bilateral aldosterone production. Nonetheless, surgical removal of the overactive adrenal in unilateral PA achieves highly successful outcomes and almost all patients are biochemically cured of their aldosteronism.

Preoperative mineralocorticoid receptor antagonist reduces postoperative hyperkalaemia in patients with Conn syndrome

BACKGROUND

The preoperative use of mineralocorticoid receptor antagonists (MRA) in patients with unilateral forms of primary aldosteronism (PA) is not standardized. The current Endocrine Society Guidelines do not specifically recommend MRA treatment before surgery. It is unclear whether preoperative MRA can optimize perioperative blood pressure and potassium control, and reduce the incidence of postoperative hyperkalaemia.

OBJECTIVE

This study aimed to investigate the effect of MRA on the incidence of postoperative hyperkalaemia in addition to perioperative blood pressure and potassium concentration in patients undergoing unilateral adrenalectomy for the treatment of PA.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral centres, Victoria, Australia.

PATIENTS

A total of 96 patients who were diagnosed with unilateral forms of PA: 73 patients ('MRA' group) received preoperative MRA while 23 patients ('No-MRA' group) did not.

RESULTS

The prevalence of postoperative hyperkalaemia was significantly higher in the 'No-MRA' group at 2-4 weeks after surgery, compared to the 'MRA' group (35% vs. 11%, p = .014). In a logistic regression, the use of MRA significantly predicted a lower incidence of postoperative hyperkalaemia after adjusting for age, sex, baseline aldosterone-to-renin ratio, potassium and preoperative eGFR. Before surgery, patients in the 'MRA' group had normalized blood pressure and potassium concentration requiring fewer antihypertensive medications and no potassium supplements.

CONCLUSION

Preoperative MRA use was associated with optimal perioperative blood pressure and normalized serum potassium in addition to a lower incidence of postoperative hyperkalaemia. MRA should be considered standard treatment for patients awaiting surgery for PA.

Adrenal venous sampling in the diagnostic workup of primary aldosteronism

Primary aldosteronism (PA) is the primary cause of secondary hypertension. The prevalence of PA has probably been underestimated in the past and recent studies suggest that PA could be present in up to 10% of patients suffering from hypertension. Aldosterone excess in PA can be caused by unilateral adrenal disease, usually adrenal adenoma, or bilateral adrenal hyperplasia. Differentiation between unilateral and bilateral disease is clinically important as the former can effectively be treated by removal of the affected adrenal. CT or MRI cannot reliably distinguish unilateral from bilateral disease. Therefore, adrenal vein sampling (AVS) is an important step of the diagnostic work-up in patients with PA. Current guidelines recommend PA in virtually all patients with biochemically diagnosed PA who would undergo adrenal surgery if unilateral PA was diagnosed. In this narrative review, we give an overview of the current technique used for AVS with a focus on the experience with this technique at the University Hospital Basel, Switzerland.

KCNJ5 Somatic Mutation Is Associated With Higher Aortic Wall Thickness and Less Calcification in Patients With Aldosterone-Producing Adenoma

OBJECTIVE

Primary aldosteronism (PA) is the most common type of secondary hypertension, and it is associated with a higher rate of cardiovascular complications. KCNJ5 somatic mutations have recently been identified in aldosterone-producing adenoma (APA), however their influence on vascular remodeling and injury is still unclear. The aim of this study was to investigate the association between KCNJ5 somatic mutation status and vascular status.

METHODS

We enrolled 179 APA patients who had undergone adrenalectomy from a prospectively maintained database, of whom 99 had KCNJ5 somatic mutations. Preoperative clinical, biochemical and imaging data of abdominal CT, including abdominal aortic calcification (AAC) score, aortic diameter and wall thickness at levels of superior (SMA) and inferior (IMA) mesenteric arteries were analyzed.

RESULTS

After propensity score matching for age, sex, body mass index, triglycerides and low-density lipoprotein, there were 48 patients in each KCNJ5 (+) and KCNJ5 (-) group. Mutation carriers had a lower AAC score (217.3 ± 562.2 vs. 605.6 ± 1359.1, P=0.018), higher aortic wall thickness (SMA level: 2.2 ± 0.6 mm vs. 1.8 ± 0.6 mm, P=0.006; IMA level: 2.4 ± 0.6 mm vs. 1.8 ± 0.7 mm, P<0.001) than non-carriers. In multivariate analysis, KCNJ5 mutations were independently associated with AAC score (P=0.014) and aortic wall thickness (SMA level: P<0.001; IMA level: P=0.004). After adrenalectomy, mutation carriers had less aortic wall thickness progression than non-carriers (Δthickness SMA: -0.1 ± 0.8 mm vs. 0.9 ± 0.6 mm, P=0.024; IMA: -0.1 ± 0.6 mm vs. 0.8 ± 0.7 mm, P=0.04).

CONCLUSION

KCNJ5 mutation carriers had less calcification burden of the aorta, thickened aortic wall, and less wall thickness progression than non-carriers.

Heightened Cardiovascular Risk in Hypertension Associated With Renin-Independent Aldosteronism Versus Renin-Dependent Aldosteronism: A Collaborative Study

Background While both renin-dependent and renin-independent aldosterone secretion contribute to aldosteronism, their relative associations with cardiovascular disease (CVD) risk has not been investigated. Methods and Results A total of 2909 participants from the FOS (Framingham Offspring Study) with baseline, serum aldosterone concentration, and plasma renin concentration who attended the sixth examination cycle and were followed up until 2014 and who were free of CVD were included. We further recruited 2612 hypertensive participants from the CONPASS (Chongqing Primary Aldosteronism Study). Captopril challenge test was performed to confirm renin-dependent or -independent aldosteronism in CONPASS. Among 1433 hypertensive subjects of FOS, when compared with those with serum aldosterone concentration <10 ng dL^-1 (normal aldosterone), participants who had serum aldosterone concentration ≥10 ng dL^-1 and plasma renin concentration ≤15 mIU L^-1 (identified as renin-independent aldosteronism) showed a higher risk of CVD (hazard ratio, 1.40 [95% CI, 1.08-1.82]), while those who had serum aldosterone concentration ≥10 ng dL^-1 and plasma renin concentration >15 mIU L^-1 (identified as renin-dependent aldosteronism) showed an unchanged CVD risk. In CONPASS, renin-independent aldosteronism carried a significantly higher risk of CVD than normal aldosterone (odds ratio, 2.57 [95% CI, 1.13-5.86]), while the CVD risk remained unchanged in renin-dependent aldosteronism. Elevation of the urinary potassium-to-sodium excretion ratio, reflective of mineralocorticoid receptor activity, was only observed in participants with renin-independent aldosteronism. Conclusions Among patients with hypertension, renin-independent aldosteronism is more closely associated with CVD risk than renin-dependent aldosteronism.

Diagnosis and treatment of primary aldosteronism

Primary aldosteronism is a common cause of secondary hypertension associated with excess cardiovascular morbidities. Primary aldosteronism is underdiagnosed because it does not have a specific, easily identifiable feature and clinicians can be poorly aware of the disease. The diagnostic investigation is a multistep process of screening, confirmatory testing, and subtype differentiation of unilateral from bilateral forms for therapeutic management. Adrenal venous sampling is key for reliable subtype identification, but can be bypassed in patients with specific characteristics. For unilateral disease, surgery offers the possibility of cure, with total laparoscopic unilateral adrenalectomy being the treatment of choice. Bilateral forms are treated mainly with mineralocorticoid receptor antagonists. The goals of treatment are to normalise both blood pressure and excessive aldosterone production, and the primary aims are to reduce associated comorbidities, improve quality of life, and reduce mortality. Prompt diagnosis of primary aldosteronism and the use of targeted treatment strategies mitigate aldosterone-specific target organ damage and with appropriate patient management outcomes can be excellent. Advances in molecular histopathology challenge the traditional concept of primary aldosteronism as a binary disease, caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia. Somatic mutations drive autonomous aldosterone production in most adenomas. Many of these same mutations have been identified in nodular lesions adjacent to an aldosterone-producing adenoma and in patients with bilateral disease. In addition, germline mutations cause rare familial forms of aldosteronism (familial hyperaldosteronism types 1-4). Genetic testing for inherited forms in suspected cases of familial hyperaldosteronism avoids the burdensome diagnostic investigation in positive patients. In this Review, we discuss advances and future management approaches in the diagnosis of primary aldosteronism.

Tolerability and Efficacy of Long-Term Medical Therapy in Primary Aldosteronism

INTRODUCTION

Patients with primary aldosteronism (PA) have increased cardiovascular risk, and there are concerns about the efficacy of medical therapy.

OBJECTIVE

We aimed to assess long-term tolerability and efficacy of medical therapy in PA patients.

METHODS

We conducted a retrospective study on 201 PA patients treated with medical therapy (spironolactone, eplerenone, or amiloride) from 2000 to 2020 at 2 tertiary centers. Clinical and biochemical control and side effects were assessed.

RESULTS

Among 155 patients on long-term medications, 57.4% achieved blood pressure (BP) <140/90 mmHg, 90.1% achieved normokalemia (48.0% potassium ≥4.3 mmol/L), and 63.2% achieved renin >1 ng/mL/h. Concordance of biochemical control using potassium and renin levels was 49.1%. Side effects were experienced by 52.3% of patients, with 10.3% switching, 22.6% decreasing dose, and 11.0% stopping medications. Risk factors for side effects were spironolactone use, dose ≥ 50 mg, treatment duration ≥1 year, male gender, and unilateral PA. Patients with unilateral PA used higher spironolactone doses vs bilateral (57 vs 50 mg, P < 0.001) and had more side effects (63.2% vs 41.8%, P = 0.008). Forty-six unilateral PA patients who underwent surgery after initial medical therapy experienced improved BP (systolic from 141 to 135 mmHg, P = 0.045; diastolic from 85 to 79 mmHg, P = 0.002).

CONCLUSION

Dose-dependent side effects limit efficacy of medical therapy in PA. Future prospective studies should assess the best monitoring strategy for biochemical control during long-term medical therapy. For unilateral PA, surgery remains preferable, yielding better control with less long-term side effects.

Immunohistochemical Analysis of CYP11B2, CYP11B1 and β-catenin Helps Subtyping and Relates With Clinical Characteristics of Unilateral Primary Aldosteronism

Background: Primary aldosteronism is caused by aldosterone overproduction. While conventional hematoxylin-eosin staining can demonstrate morphological abnormality, it cannot provide any functional histopathological information. We aimed to identify the diagnostic, functional and prognostic value of CYP11B2, CYP11B1, and β-catenin immunostaining in unilateral hyperaldosteronism.

Method: A total of 134 patients with unilateral hyperaldosteronism were recruited in our study. The expression of CYP11B2, CYP11B1, and β-catenin was evaluated semiquantitatively on 134 patients’ sections using immunohistochemistry technology and the relationship with clinical data was assessed.

Results: Patients were classified into four subtypes based on CYP11B2 staining as below: (1)118 patients with unilateral single aldosterone-producing adenoma (APA), (2)11 with unilateral multiple APA, (3)four with aldosterone-producing cell cluster (APCC), and (4)one with an undefined source. Adjusted CYP11B2 H-score was correlated with serum aldosterone, aldosterone to renin ratio (ARR), and serum potassium. In the abnormal β-catenin staining group, hypertension duration, aldosterone, ARR, cortisol, tumor diameter, tumor area, and CYP11B2 H-score were significantly higher than those of the wild-type group. Serum potassium level was significantly lower in the abnormal β-catenin staining group. Age, gender, BMI, family history of hypertension, adjusted CYP11B2 and CYP11B1 H-scores differed significantly between complete clinical success and incomplete clinical success groups. Age, gender and family history of hypertension were independently associated with complete clinical success based on multivariate logistic regression analysis.

Conclusion: CYP11B2 immunostaining could improve the differential diagnosis of unilateral hyperaldosteronism. Adjusted CYP11B2 H-score could be used as a histopathological marker to reflect the severity of unilateral APA. Dysregulation of Wnt/β-catenin signaling and impaired β-catenin degradation may provoke the proliferation and enhance the steroidogenic ability of APA tumor cells, indicating that the Wnt pathway might be a potential, actionable, therapeutic target in the treatment of hyperaldosteronism. Age, sex and family history of hypertension were independent predictors of clinical outcome after adrenalectomy for unilateral hyperaldosteronism.

Associations of trauma and posttraumatic stress disorder with aldosterone in women

BACKGROUND

Posttraumatic stress disorder (PTSD) has been associated with increased cardiovascular risk, however, underlying mechanisms have not been fully specified. PTSD is associated with stress-related hormones, including dysregulated glucocorticoid activity. Dysregulation of aldosterone, a mineralocorticoid activated by psychological stress and implicated in cardiovascular damage, may be a relevant pathway linking PTSD and cardiovascular risk. Few studies to date have evaluated the association between PTSD and aldosterone, none with repeated measures of aldosterone. We examined if trauma and PTSD were associated with altered aldosterone levels relative to women unexposed to trauma.

METHODS

The association of trauma exposure and chronic PTSD with plasma aldosterone levels was investigated in 521 middle-aged women in the Nurses' Health Study II. Aldosterone was assessed at two time points, 10-16 years apart, and trauma exposure and PTSD were also ascertained for both time points. Regarding exposure assessment, women were characterized based on a structured diagnostic interview as: having chronic PTSD (PTSD at both time points; n = 174); being trauma-exposed (trauma exposure at first time point but no PTSD; n = 174); and being unexposed (no trauma exposure at either time point; reference group for all analyses; n = 173). Linear mixed models examined associations of trauma and PTSD status with log-transformed aldosterone levels, adjusting for covariates and health-related variables that may confound or lie on the pathway between PTSD and altered aldosterone levels.

RESULTS

Across the sample, mean aldosterone concentration decreased over time. Adjusting for covariates, women with chronic PTSD had significantly lower aldosterone levels averaged over time, compared to women unexposed to trauma (β = - 0.08, p = 0.04). Interactions between trauma/PTSD group and time were not significant, indicating change in aldosterone over time did not differ by trauma/PTSD status. Post-hoc exploratory analyses suggested that menopausal status partially mediated the relationship between chronic PTSD status and aldosterone level, such that postmenopausal status explained 7% of the effect of PTSD on aldosterone.

CONCLUSIONS

These findings indicate that PTSD is associated with lower levels of aldosterone. Further work is needed to understand implications of this type of dysregulation in a key biological stress system for cardiovascular and other health outcomes previously linked with PTSD.

Mineralocorticoid receptors in pulmonary hypertension and right heart failure: From molecular biology to therapeutic targeting

Pulmonary hypertension (PH) is a devastating condition characterized by pulmonary vascular remodelling, leading to progressive increase in pulmonary artery pressure and subsequent right ventricular failure. Aldosterone and the mineralocorticoid receptor (MR), a nuclear transcription factor, are key drivers of cardiovascular disease and MR antagonists are well-established in heart failure. Now, a growing body of evidence points at a detrimental role of MR in PH. Pharmacological MR blockade attenuated PH and prevented RV failure in experimental models. Mouse models with cell selective MR deletion suggest that this effect is mediated by MR in endothelial cells. While the evidence from experimental studies appears convincing, the available clinical data on MR antagonist use in patients with PH is more controversial. Integrated analysis of clinical data together with MR-dependent molecular alterations may provide insights why some patients respond to MRA treatment while others do not. Potential ways to identify MRA 'responders' include the analysis of underlying PH causes, stage of disease, or sex, as well as new biomarkers.

Hypertension Management in Stroke Prevention: Time to Consider Primary Aldosteronism

Primary aldosteronism confers a higher risk of stroke, atrial fibrillation, and cardiovascular disease than blood pressure matched essential hypertension. It is the most common endocrine cause of secondary hypertension with prevalence estimates of up to 13% in primary care and 30% in referral centers around the world. Unlike essential hypertension, primary aldosteronism has targeted medical treatment and potentially curative surgical solutions which can ameliorate the associated cardiovascular risks. This narrative review highlights an evidence gap in the optimal diagnosis and targeted treatment of primary aldosteronism in secondary stroke prevention. Over half of the patients suffering a stroke have blood pressure in the hypertensive range and less than a third achieve optimal blood pressure control. There are no guideline recommendations to test for primary aldosteronism in these patients, although up to 30% of patients with resistant hypertension may have this disease. The accurate diagnosis of primary aldosteronism could significantly improve blood pressure, simplify the medication regimen and reduce the overall cardiovascular risk in these patients. The challenges associated with screening for primary aldosteronism following stroke may be overcome by novel blood tests which are less affected by antihypertensive medications routinely used in stroke care. Approximately one-quarter of all strokes occur in patients who have previously had a stroke. Modifying hypertension, the leading modifiable risk factor, would, therefore, have significant public health implications. As clinicians, we must increase our awareness of primary aldosteronism in patients with stroke, particularly in those with resistant hypertension, to enable targeted therapy and reduce the risk of stroke recurrence.

Urinary proteomics for kidney dysfunction: insights and trends

Introduction: Kidney dysfunction poses a high burden on patients and health care systems. Early detection and accurate prediction of kidney disease progression remains a major challenge. Compared to existing clinical parameters, urinary proteomics has the potential to reveal molecular alterations within the kidney that may alter its function before the onset of clinical symptoms. Thus, urinary proteomics has greater prognostic potential for assessment of kidney dysfunction progression.Areas covered: Advances in urinary proteomics for major causes of kidney dysfunction are discussed. The application of urinary extracellular vesicles for studying kidney dysfunction are discussed. Technological advances in urinary proteomics are discussed. The literature was identified using a database search for titles containing 'proteom*' and 'urin*' and published within the past 5 years. Retrieved literature was manually filtered to retain kidney dysfunctions-related studies.Expert opinion: Despite major advances, diagnosis by urinary proteomics has not been fully applied in any clinical settings. This could be attributed to the complex nature of kidney diseases, in addition to the constraints on study power and feasibility of incorporating mass spectrometry techniques in daily routine analysis. Nevertheless, we are confident that advances in urinary proteomics will soon provide superior insights into kidney disease beyond existing clinical parameters.

Primary Aldosteronism: a Continuum from Normotension to Hypertension

PURPOSE OF REVIEW

Primary aldosteronism (PA) is the most common cause of secondary hypertension. Emerging evidence suggests that PA is associated with cardiovascular, metabolic, and renal complications, that likely develop insidiously, due to prolonged inappropriate mineralocorticoid receptor activation. In this review, we discuss the expanding clinical and pathological spectrum of PA.

RECENT FINDINGS

Clinical and molecular studies conducted over the recent years reveal that PA traverses a series of contiguous stages. Pre-clinical, but hormonally overt PA has been identified in patients with normal blood pressure, and such patients harbor an increased risk of developing hypertension. Similarly, genetic and histopathological advancements have exposed a spectrum of PA pathology that corresponds to a continuum that spans from pre-clinical stages to florid PA. PA evolves from pre-hypertensive stages to resistant hypertension, along with serious cardiovascular and renal consequences. Early recognition of PA and targeted therapy will be essential for cardiovascular morbidity and mortality prevention in a large number of patients.

Re-evaluating absent clinical success after adrenalectomy in unilateral primary aldosteronism

BACKGROUND

Adrenalectomy cures unilateral primary aldosteronism, and it improves or cures hypertension. However, a significant proportion of patients are classified with absent clinical success postsurgery, suggesting that surgery was ineffective.

METHODS

We assessed all patients 6 to 12 months post-surgery for clinical outcomes using Primary Aldosteronism Surgical Outcomes (PASO), AVIS-2, and CONNsortium criteria. We estimated blood pressure changes after adjustment for changes in defined daily dosages of antihypertensive medications. We also reassessed all patients using PASO at their recent clinical visit.

RESULTS

A total of 104 patients with unilateral primary aldosteronism underwent adrenalectomy at 2 tertiary centers from 2000 to 2019; 24 (23%), 31 (30%), and 54 (52%) patients were classified with absent clinical success using PASO, AVIS-2, and CONNsortium criteria, respectively. Among 24 patients with absent clinical success using PASO criteria, 10 had complete biochemical cure, 3 partial, 2 absent, and 9 had resolution of hypokalemia. On multivariable analysis, absent clinical success was associated with presence of hyperlipidemia, diabetes mellitus, and lower defined daily dosages at baseline. After adjustment for changes in defined daily dosages, 7 of 24 patients showed blood pressure improvement ≥20/10 mm Hg post-surgery. After a follow-up of mean 5.6 years, 12 of 24 patients showed partial or complete clinical success when reassessed using PASO criteria. Only 6 of 104 (5.8%) patients failed to show clinical improvement post-surgery using any of the 3 mentioned criteria or using PASO criteria at their recent clinical visit.

CONCLUSION

Although some patients may be classified with absent clinical success post-surgery, the assessment of clinical outcomes remains subject to many variables. In patients with unilateral primary aldosteronism, evidenced by lateralization on AVS, unilateral adrenalectomy should remain the recommended treatment.