Aldosterone and cardiovascular risk

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).

Follow-up care and assessment of comorbidities and complications in patients with primary aldosteronism: The clinical practice guideline of the Taiwan Society of aldosteronism

Primary aldosteronism (PA) is the most common form of endocrine hypertension, characterized by excess aldosterone production that leads to an increased risk of cardiovascular events and target organ damage. Both adrenalectomy and medical treatment have shown efficacy in improving clinical outcomes and comorbidities associated with PA, including a specific subtype of PA with autonomous cortisol secretion (ACS). Understanding the comorbidities of PA and establishing appropriate follow-up protocols after treatment are crucial for physicians to enhance morbidity and mortality outcomes in patients with PA. Additionally, the screening for hypercortisolism prior to surgery is essential, as the prognosis of patients with coexisting PA and ACS differs from those with PA alone. In this review, we comprehensively summarize the comorbidities of PA, encompassing cardiovascular, renal, and metabolic complications. We also discuss various post-treatment outcomes and provide insights into the strategy for glucocorticoid replacement in patients with overt or subclinical hypercortisolism. This clinical practice guideline aims to equip medical professionals with up-to-date information on managing concurrent hypercortisolism, assessing treatment outcomes, and addressing comorbidities in patients with PA, thereby improving follow-up care.

Effect of Obesity on Clinical Characteristics of Primary Aldosteronism Patients at Diagnosis and Postsurgical Response

CONTEXT

Patients with obesity have an overactivated renin-angiotensin-aldosterone system (RAAS) that is associated with essential hypertension. However, the influence of obesity in primary aldosteronism (PA) is unknown.

OBJECTIVE

We analyzed the effect of obesity on the characteristics of PA, and the association between obesity and RAAS components.

METHODS

A retrospective study was conducted of the Spanish PA Registry (SPAIN-ALDO Registry), which included patients with PA seen at 20 tertiary centers between 2018 and 2022. Differences between patients with and without obesity were analyzed.

RESULTS

A total of 415 patients were included; 189 (45.5%) with obesity. Median age was 55 years (range, 47.3-65.2 years) and 240 (58.4%) were male. Compared to those without obesity, patients with obesity had higher rates of diabetes mellitus, chronic kidney disease, obstructive apnea syndrome, left ventricular hypertrophy, prior cardiovascular events, higher means of systolic blood pressure, and required more antihypertensive drugs. Patients with PA and obesity also had higher values of serum glucose, glycated hemoglobin A1c, creatinine, uric acid, and triglycerides, and lower levels of high-density lipoprotein cholesterol. Levels of blood aldosterone (PAC) and renin were similar between patients with and without obesity. Body mass index was not correlated with PAC nor renin. The rates of adrenal lesions on imaging studies, as well as the rates of unilateral disease assessed by adrenal vein sampling or I-6β-iodomethyl-19-norcholesterol scintigraphy, were similar between groups.

CONCLUSION

Obesity in PA patients involves a worse cardiometabolic profile, and need for more antihypertensive drugs but similar PAC and renin levels, and rates of adrenal lesions and lateral disease than patients without obesity. However, obesity implicates a lower rate of hypertension cure after adrenalectomy.

Cerebro-Cardiovascular Risk, Target Organ Damage, and Treatment Outcomes in Primary Aldosteronism

Primary aldosteronism (PA) is the most common type of endocrine hypertension, and numerous experimental and clinical evidence have verified that prolonged exposure to excess aldosterone is responsible for an increased risk of cerebro-cardiovascular events and target organ damage (TOD) in patients with PA. Therefore, focusing on restoring the toxic effects of excess aldosterone on the target organs is very important to reduce cerebro-cardiovascular events. Current evidence convincingly demonstrates that both surgical and medical treatment strategies would benefit cerebro-cardiovascular outcomes and mortality in the long term. Understanding cerebro-cardiovascular risk in PA would help clinical doctors to achieve both early diagnosis and treatment. Therefore, in this review, we will summarize the cerebro-cardiovascular risk in PA, focusing on the TOD of aldosterone, including brain, heart, vascular system, renal, adipose tissues, diabetes, and obstructive sleep apnea (OSA). Furthermore, the various treatment outcomes of adrenalectomy and medical treatment for patients with PA will also be discussed. We hope this knowledge will help improve cerebro-cardiovascular prognosis and reduce the incidence and mortality of cerebro-cardiovascular events in patients with PA.

Primary Hyperaldosteronism: When to Suspect It and How to Confirm Its Diagnosis

The definition of primary hyperaldosteronism (PA) has shifted, as progress has been made in understanding the disease. PA can be produced by unilateral or bilateral cortical adrenal hyperproduction of aldosterone, due to hyperplasia, aldosterone-secreting cell clusters, aldosterone-producing macro or micro adenoma/s, and combinations of the above, or by an aldosterone-producing carcinoma. PA is a highly prevalent disease, affecting close to 10% of the hypertensive population. However, PA is clearly underdiagnosed. The purpose of this review is to address current knowledge of PA’s clinical manifestations, as well as current methods of diagnosis. PA is associated with a higher cardiovascular morbidity and mortality than essential hypertension with similar blood pressure control. Young hypertensive patients, those with a first-degree relative with PA or ictus, and/or those with apnea/hypopnea syndrome, moderate/severe/resistant hypertension, adrenal incidentaloma, and/or hypokalemia should be screened for PA. PA can induce atrial fibrillation (AF), and those patients should also be screened for PA. We propose the use of the Captopril challenge test (CCT), oral salt loading, or intravenous salt loading for PA diagnosis, given their availability in the majority of hospital centers. CCT could be first-line, since it is safe and easy to perform.

A clinical trial to evaluate the effect of statin use on lowering aldosterone levels

BACKGROUND

Statins are the first-line pharmaceutical agent in the management of hypercholesterolemia and cardiovascular (CV) risk reduction, and the most commonly prescribed class of drugs worldwide. Studies describing CV risk reduction independent of LDL-cholesterol lowering have evoked an interest in the pleiotropic mechanisms of statins' benefits. We recently demonstrated that administration of statins in animal models lowers aldosterone levels and observed an association between statin use and reduced aldosterone levels in two human cohorts, with lipophilic statins displaying a greater effect than hydrophilic statins. Therefore, we designed a randomized, placebo-controlled, double-blinded intervention study to assess whether statin treatment lowers aldosterone in a type-dependent manner in humans, with simvastatin (lipophilic) showing a greater effect than pravastatin (hydrophilic).

METHODS/DESIGN

One hundred five healthy participants will be recruited from the general population to enroll in a 12-week, randomized, placebo-controlled, double-blinded, 3-arm clinical trial. Ninety participants are anticipated to complete the protocol. After baseline assessment of aldosterone levels, participants will be randomized to daily simvastatin, pravastatin, or placebo. Aldosterone levels will be assessed after 2 days on study drug and again after 6 weeks and 12 weeks on study drug. Prior to each aldosterone assessment, participants will consume an isocaloric sodium and potassium-controlled run-in diet for 5 days. Assessments will occur on an inpatient research unit to control for diurnal, fasting, and posture conditions. The primary outcome will compare 12-week angiotensin II-stimulated serum aldosterone by study drug. Secondary outcomes will compare baseline and 12-week 24-h urine aldosterone by study drug.

DISCUSSION

Results from this rigorous study design should provide strong support that statins lower aldosterone levels in humans. These results may explain some of the beneficial effects of statins that are not attributed to the LDL-lowering effect of this important class of medications. Results would demonstrate that statin lipophilicity is an important attribute in lowering aldosterone levels. The outcomes of this program will have implications for the design of studies involving statin medications, as well as for the differential use of classes of statins.

TRIAL REGISTRATION

ClinicalTrials.gov; NCT02871687 ; First Posted August 18, 2016.

Enteric Microbiota⁻Gut⁻Brain Axis from the Perspective of Nuclear Receptors

Nuclear receptors (NRs) play a key role in regulating virtually all body functions, thus maintaining a healthy operating body with all its complex systems. Recently, gut microbiota emerged as major factor contributing to the health of the whole organism. Enteric bacteria have multiple ways to influence their host and several of them involve communication with the brain. Mounting evidence of cooperation between gut flora and NRs is already available. However, the full potential of the microbiota interconnection with NRs remains to be uncovered. Herewith, we present the current state of knowledge on the multifaceted roles of NRs in the enteric microbiota–gut–brain axis.

Aldosterone and Insulin Resistance: Vicious Combination in Patients on Maintenance Hemodialysis

Recently, we demonstrated that plasma aldosterone contributed to insulin resistance in chronic kidney disease. The aim of this study is the clinical impact of this relationship in hemodialysis patients. In a cross section study using a total of 128 hemodialysis patients, multiple regression analysis revealed that plasma aldosterone levels were independently associated with HOMA-IR, insulin resistance index. This association was found to be more stringent in diabetic patients than in non-diabetic patients. Aldosterone levels were associated with cardiac hypertrophy and carotid artery stenosis. HOMA-IR was associated with cardiac hypertrophy. The patients whose aldosterone and HOMA-IR were above the top tertile of each parameter in this cohort showed more severe cardiac hypertrophy and lower contractile function as compared with the patients whose aldosterone levels and HOMA-IR are below the lowest tertile of each parameter. In conclusion, in hemodialysis patients, aldosterone levels and insulin resistance are closely interrelated and the constellation of the two is related to severe cardiovascular tissue damages.

Hypertension: The role of biochemistry in the diagnosis and management

Hypertension is defined as a persistently elevated blood pressure ≥140/90mmHg. It is an important treatable risk factor for cardiovascular disease, with a high prevalence in the general population. The most common cause, essential hypertension, is a widespread disease - however, secondary hypertension is under investigated and under diagnosed. Collectively, hypertension is referred to as a "silent killer" - frequently it displays no overt symptomatology. It is a leading risk factor for death and disability globally, with >40% of persons aged over 25 having hypertension. A vast spectrum of conditions result in hypertension spanning essential through resistant, to patients with an overt endocrine cause. A significant number of patients with hypertension have multiple cardiovascular risk factors at the time of presentation. Both routine and specialised biochemical investigations are paramount for the evaluation of these patients and their subsequent management. Biochemical testing serves to identify those hypertensive individuals who are at higher risk on the basis of evidence of dysglycaemia, dyslipidaemia, renal impairment, or target organ damage and to exclude identifiable causes of hypertension. The main target of biochemical testing is the identification of patients with a specific and treatable aetiology of hypertension. Information gleaned from biochemical investigation is used to risk stratify patients and tailor the type and intensity of subsequent management and treatment. We review the approach to the biochemical investigation of patients presenting with hypertension and propose a diagnostic algorithm for work-up.

Establishment of reference intervals for aldosterone and renin in a Caucasian population using the newly developed Immunodiagnostic Systems specialty immunoassay automated system

BACKGROUND

Measurement of aldosterone and/or renin is essential to aid the differential diagnosis of secondary hypertension, guide strategy for therapeutic management of hypertension and assess adequacy of mineralocorticoid replacement.

AIM

The objective was to establish normative data for aldosterone and renin using the Immunodiagnostic Systems specialty immunoassay system platform in a Caucasian population.

METHODS

Following informed consent, 365 subjects were recruited to this study. Subjects were ambulatory and attended clinic for blood pressure measurement and phlebotomy between the hours of 7:00 and 11:00. Blood pressure was measured according to the 2013 European Society of Hypertension/Cardiology guidelines. The inclusion criteria: age ≥18 years, BMI <30 kg/m(2), non-pregnant, blood pressure <140/90, normal electrolytes and kidney function and not taking prescribed/over the counter medications. Ninety-four subjects were excluded based on these criteria. A total of 271 volunteers (females n = 145), aged 18-65 years formed the reference cohort. Blood for aldosterone/renin was collected into ethylenediaminetetraacetic acid specimen tubes. Samples were kept at room temperature and transported within 30 min of blood draw to the laboratory for immediate processing (centrifugation, separation and freezing of plasma). Plasma was stored at -20℃ prior to analysis on the Immunodiagnostic Systems specialty immunoassay system instrument.

RESULTS

The established reference intervals in an Irish Caucasian population for renin: females: 6.1-62.7 mIU/L, males: 9.0-103 mIU/L, for aldosterone: females: <138-1179 pmol/L, males: <138-670 pmol/L, respectively.

CONCLUSION

This study demonstrates that reference intervals for aldosterone and renin should be gender specific. These automated immunoassays offer rapid stratification of patients with refractory hypertension and will better facilitate the optimization of therapeutic management.

Effect of Treatment on Body Fluid in Patients with Unilateral Aldosterone Producing Adenoma: Adrenalectomy versus Spironolactone

Aldosterone affects fluid retention in the body by affecting how much salt and water that the kidney retains or excretes. There is limited information about the effect of prolonged aldosterone excess and treatment on body fluid in primary aldosteronism (PA) patients. In this study, body composition changes of 41 PA patients with unilateral aldosterone producing adenoma (APA) were assessed by a bio-impedance spectroscopy device. Patients with APA receiving adrenalectomy, as compared with those treated with spironolactone, had significantly lower relative overhydration (OH) and urine albumin excretion, and significantly higher urine sodium excretion four weeks after treatment. These differences dissipated 12 weeks after the initial treatment. Independent factors to predict decreased relative OH four weeks after treatment were male patients and patients who experienced adrenalectomy. Patients who underwent adrenaelctomy had significantly decreased TNF-α and increased serum potassium level when compared to patients treated with spironolactone 4 and 12 weeks after treatment. In this pilot study, we found that adrenalectomy leads to an earlier increase in renal sodium excretion and decreases in body fluid content, TNF-α, and urine albumin excretion. Adrenalectomy yields a therapeutic effect more rapidly, which has been shown to ameliorate overhydration in PA patients.

The multifaceted mineralocorticoid receptor

The primary adrenal cortical steroid hormones, aldosterone, and the glucocorticoids cortisol and corticosterone, act through the structurally similar mineralocorticoid (MR) and glucocorticoid receptors (GRs). Aldosterone is crucial for fluid, electrolyte, and hemodynamic homeostasis and tissue repair; the significantly more abundant glucocorticoids are indispensable for energy homeostasis, appropriate responses to stress, and limiting inflammation. Steroid receptors initiate gene transcription for proteins that effect their actions as well as rapid non-genomic effects through classical cell signaling pathways. GR and MR are expressed in many tissues types, often in the same cells, where they interact at molecular and functional levels, at times in synergy, others in opposition. Thus the appropriate balance of MR and GR activation is crucial for homeostasis. MR has the same binding affinity for aldosterone, cortisol, and corticosterone. Glucocorticoids activate MR in most tissues at basal levels and GR at stress levels. Inactivation of cortisol and corticosterone by 11β-HSD2 allows aldosterone to activate MR within aldosterone target cells and limits activation of the GR. Under most conditions, 11β-HSD1 acts as a reductase and activates cortisol/corticosterone, amplifying circulating levels. 11β-HSD1 and MR antagonists mitigate inappropriate activation of MR under conditions of oxidative stress that contributes to the pathophysiology of the cardiometabolic syndrome; however, MR antagonists decrease normal MR/GR functional interactions, a particular concern for neurons mediating cognition, memory, and affect.

Effects of intermedin1-53 on myocardial fibrosis

Intermedin (IMD) is a member of the calcitonin/calcitonin gene-related peptide (CGRP) family and has similar or more potent cardiovascular actions than adrenomedullin (ADM) and any other CGRP. The aim of the present work is to study the effects of IMD1-53 on cardiac fibroblast fibrosis in vivo and in vitro. Myocardial infarction model was prepared by ligating rats' left anterior descending coronary artery. Mesenchymal collagen contents in the left ventricle were accessed by Sirius-red stain. Heart functions were explored by hemodynamic changes. Expression of I and III type collagens, IMD1-53, receptor activity-modifying proteins (RAMP)1/2/3, and calcitonin receptor-like receptor (CRLR) in left ventricle were detected by western blot analysis. Cardiac fibroblasts (CFbs) fibrosis was induced by treating the cells with aldosterone (ALD). CFbs proliferation and the hydroxyproline contents in supernatants were determined by 3-[4,5-dimehyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide assay and enzyme-linked immunosorbent assay. Heart function was decreased in myocardial infarction model rats. Expression of type I and type III collagens in infarcted zone in myocardial rats was higher than those in the sham-operated group. IMD1-53, RAMP, and CRLR in left ventricle were also up-regulated. In vitro experiment showed that ALD was a powerful stimulator of CFbs activation. IMD1-53 decreased ALD-induced CFbs proliferation in a dose-dependent manner. Moreover, CGRP8-37 and ADM22-52 remarkably blocked the effect of IMD1-53 on ALD-induced myocardial cell fibrosis. IMD could be involved in the onset of cardiac fibrosis. Like ADM, IMD1-53 exerts an antifibrotic effect on CFbs, which might be mediated by CRLR/RAMP complex and ADM receptor.

Endocrine hypertension: then and now

OBJECTIVE

To review the first reported cases of successfully treated pheochromocytoma and primary aldosteronism and to document the diagnostic and therapeutic advances that have occurred since the initial descriptions.

METHODS

The original case descriptions and the subsequent pertinent literature were reviewed.

RESULTS

The successful management of the initial cases of pheochromocytoma in 1926 and primary aldosteronism in 1954 was highlighted by keen clinical observation, clinical intuition, and application of scientific principles. Since those prismatic case descriptions, the technological advances in laboratory-based diagnosis, radiology-based tumor localization, and surgical approaches to the adrenal glands have been truly remarkable.

CONCLUSIONS

The evolution in the diagnosis and treatment of pheochromocytoma will continue to progress as we identify more genetic causes, develop biochemical markers for "preclinical" pheochromocytoma, identify better markers for malignant disease, and develop more effective treatment options for malignant pheochromocytoma. Over the next decade, we hope to determine the pathophysiology for bilateral idiopathic hyperaldosteronism, develop less invasive and less technically demanding tests to distinguish between unilateral aldosterone-producing adenoma and bilateral idiopathic hyperaldosteronism, determine where low renin hypertension stops and primary aldosteronism starts, and determine the impact of genetic and environmental factors on aldosterone secretion in patients with and without primary aldosteronism.

Aldosterone and aldosterone receptor antagonists in patients with chronic heart failure

Aldosterone is a mineralocorticoid hormone synthesized by the adrenal glands that has several regulatory functions to help the body maintain normal volume status and electrolyte balance. Studies have shown significantly higher levels of aldosterone secretion in patients with congestive heart failure compared with normal patients. Elevated levels of aldosterone have been shown to elevate blood pressure, cause left ventricular hypertrophy, and promote cardiac fibrosis. An appreciation of the true role of aldosterone in patients with chronic heart failure did not become apparent until the publication of the Randomized Aldactone Evaluation Study. Until recently, the use of aldosterone receptor antagonists has been limited to patients with severe heart failure and patients with heart failure following myocardial infarction. The Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure (EMPHASIS-HF) study added additional evidence to support the expanded use of aldosterone receptor antagonists in heart failure patients. The results of the EMPHASIS-HF trial showed that patients with mild-to-moderate (New York Heart Association Class II) heart failure had reductions in mortality and hospitalizations from the addition of eplerenone to optimal medical therapy. Evidence remains elusive about the exact mechanism by which aldosterone receptor antagonists improve heart failure morbidity and mortality. The benefits of aldosterone receptor antagonist use in heart failure must be weighed against the potential risk of complications, ie, hyperkalemia and, in the case of spironolactone, possible endocrine abnormalities, in particular gynecomastia. With appropriate monitoring, these risks can be minimized. We now have evidence that patients with mild-to-severe symptoms associated with systolic heart failure will benefit from the addition of an aldosterone receptor antagonist to the standard therapies of angiotensin-converting enzyme inhibitors and beta-blockers. This review will address the pharmacologic basis of aldosterone receptor antagonists in patients with heart failure and the clinical impact of this therapy.

Evidence-based diuretic therapy for improving cardiovascular prognosis in systemic hypertension

Diuretics are among the most commonly prescribed cardiovascular (CV) medications. The strength of evidence supporting the effectiveness of diuretics in lowering blood pressure and for preventing major adverse CV events in patients with hypertension varies considerably among diuretic classes and even among agents within the same class. Unfortunately, common prescribing habits among American physicians, including specialists in CV diseases, are not in line with the existing evidence regarding diuretic therapy for improving CV prognosis. In conclusion, although hydrochlorothiazide is the standard diuretic used for hypertension, the outcomes data suggest that chlorthalidone, indapamide, and possibly even the aldosterone receptor blockers (spironolactone and eplerenone) may be superior agents.

Aliskiren and valsartan combination therapy for the management of hypertension

Combination therapy is necessary for most patients with hypertension, and agents that inhibit the renin-angiotensin-aldosterone system (RAAS) are mainstays in hypertension management, especially for patients at high cardiovascular and renal risk. Single blockade of the RAAS with an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) confers some cardiorenal protection; however, these agents do not extinguish the RAAS as evidenced by a reactive increase in plasma renin activity (PRA), a cardiovascular risk marker, and incomplete cardiorenal protection. Dual blockade with an ACE inhibitor and an ARB offers no additional benefit in patients with hypertension and normal renal and left ventricular function. Indeed, PRA increases synergistically with dual blockade. Aliskiren, the first direct renin inhibitor (DRI) to become available has provided an opportunity to study the merit of DRI/ARB combination treatment. By blocking the first and rate-limiting step in the RAAS, aliskiren reduces PRA by at least 70% and buffers the compensatory increase in PRA observed with ACE inhibitors and ARBs. The combination of a DRI and an ARB or an ACE inhibitor is an effective approach for lowering blood pressure; available data indicate that such combinations favorably affect proteinuria, left ventricular mass index, and brain natriuretic peptide in patients with albuminuria, left ventricular hypertrophy, and heart failure, respectively. Ongoing outcome studies will clarify the role of aliskiren and aliskiren-based combination RAAS blockade in patients with hypertension and those at high cardiorenal risk.

Aldosterone and mineralocorticoid receptor antagonists modulate elastin and collagen deposition in human skin

We have shown that the steroid hormone aldosterone, recognized for its action on the kidney and the cardiovascular system, also modulates deposition of extracellular matrix in human skin. We have shown that treatment of primary cultures of normal skin fibroblasts with aldosterone (10 n-1 μM), in addition to stimulation of collagen type I expression, induces elastin gene expression and elastic fiber deposition. We have further shown that the elastogenic effect of aldosterone, which can be enhanced in the presence of mineralocorticoid receptor (MR) antagonists spironolactone and eplerenone, is executed in a MR-independent manner via amplification of IGF-I receptor-mediated signaling. Because aldosterone applied alone stimulates both collagen and elastin deposition in cultures of fibroblasts and in cultures of skin explants derived from dermal stretch marks, we postulate that this steroid should be used in the treatment of damaged skin that loses its volume and elasticity. Moreover, aldosterone applied in conjunction with spironolactone or eplerenone induces matrix remodeling and exclusively enhances elastogenesis in cultures of fibroblasts and explants derived from dermal scars and keloids. We therefore propose that intra-lesional injection of these factors should be considered in therapy for disfiguring dermal lesions and especially in prevention of their recurrence after surgical excision.