Long-term control of arterial hypertension and regression of left ventricular hypertrophy with treatment of primary aldosteronism

Progress in the Management of Primary Aldosteronism

Primary aldosteronism (PA) is now considered as one of leading causes of secondary hypertension, accounting for 5-10% of all hypertensive patients and more strikingly 20% of those with resistant hypertension. Importantly, those with the unilateral disease could be surgically cured when diagnosed appropriately. On the other hand, only a very limited portion of those suspected to have PA has been screened, diagnosed, or treated to date. With current advancement in medical technologies and genetic research, expanding knowledge of PA has been accumulated and recent achievements have also been documented in the care of those with PA. This review is aimed to have focused description on updated topics of the following; importance of PA screening both in the general and specialized settings and careful interpretation of screening data, recent achievements in hormone assays and sampling methods and their clinical relevance, and expanding knowledge on PA genetics. Improvement in workup processes and novel treatment options, as well as better understanding of the PA pathogenesis based on genetic research, might be expected to result in increased cure and better care of the patients.

Sphingolipids and Redox Signaling in Renal Regulation and Chronic Kidney Diseases

Significance: Sphingolipids play critical roles in the membrane biology and intracellular signaling events that influence cellular behavior and function. Our review focuses on the cellular mechanisms and functional relevance of the cross talk between sphingolipids and redox signaling, which may be critically implicated in the pathogenesis of different renal diseases. Recent Advances: Reactive oxygen species (ROS) and sphingolipids can regulate cellular redox homeostasis through the regulation of NADPH oxidase, mitochondrial integrity, nitric oxide synthase (NOS), and antioxidant enzymes. Over the last two decades, there have been significant advancements in the field of sphingolipid research, and it was in 2010 for the first time that sphingolipid receptor modulator was exploited as a therapeutic in humans. The cross talk of sphingolipids with redox signaling pathways becomes an important mechanism in the development of many different diseases such as renal diseases. Critical Issues: The critical issues to be addressed in this review are how sphingolipids interact with the redox signaling pathway to regulate renal function and even result in chronic kidney diseases. Ceramide, sphingosine, and sphingosine-1-phosphate (S1P) as main signaling sphingolipids are discussed in more detail. Future Directions: Although sphingolipids and ROS may mediate or modulate cellular responses to physiological and pathological stimuli, more translational studies and mechanistic pursuit in a tissue- or cell-specific way are needed to enhance our understanding of this important topic and to develop effective therapeutic strategies to treat diseases associated with redox signaling and sphingolipid cross talk. Antioxid. Redox Signal. 28, 1008-1026.

Targeted treatment of primary aldosteronism - The consensus of Taiwan Society of Aldosteronism

BACKGROUND/PURPOSE

Even with the increasing recognition of primary aldosteronism (PA) as a cause of refractory hypertension and an issue of public health, the consensus of its optimal surgical or medical treatment in Taiwan has not been reached. Our objective was to develop a clinical practice guideline that is feasible for real-world management of PA patients in Taiwan.

METHODS

The Taiwan Society of Aldosteronism (TSA) Task Force recognized the above-mentioned issues and reached this Taiwan PA consensus at its inaugural meeting, in order to provide updated information of internationally acceptable standards, and also to incorporate our local disease characteristics and constraints into PA management.

RESULTS

In patients with lateralized PA, including aldosterone producing adenoma (APA), laparoscopic adrenalectomy is the 'gold standard' of treatment. Mini-laparoscopic and laparoendoscopic single-site approaches are feasible only in highly experienced surgeons. Patients with bilateral adrenal hyperplasia or those not suitable for surgery should be treated by mineralocorticoid receptor antagonists. The outcome data of PA patient management from the literature, especially from PA patients in Taiwan, are reviewed. Mental health screening is helpful in early detection and management of psychopathology among PA patients.

CONCLUSION

We hope this consensus will provide a guideline to help medical professionals to manage PA patients in Taiwan to achieve a better quality of care.

Hypertensive crisis during catheter ablation of atrial fibrillation in a patient with undiagnosed pheochromocytoma: a case report

Introduction

Pheochromocytoma is an unusual cause of hypertension accounting for 0.1% of cases. As the development of atrial fibrillation (AF) is tightly associated with hypertension, patients with pheochromocytoma are at higher risk for AF.

Case presentation

A 72-year-old woman with undiagnosed pheochromocytoma underwent catheter ablation of drug-resistant AF. Procedure-related external factors, such as prescription of a beta blocker without the preventive administration of an alpha blocker, use of contrast medium, administration of anaesthetics, and emotional and pain-related stress, caused a hypertensive crisis with acute left ventricular dysfunction during ablation procedure. After surgical resection of the adrenal tumour, sinus rhythm was maintained without antiarrhythmic drugs.

Discussion

Because hypertensive crisis can lead to life-threatening organ damage, electrophysiologists seeing patients with AF should always consider pheochromocytoma as a mechanism of hypertension and AF before proceeding to catheter ablation of the AF.

Cardiac magnetic resonance imaging of myocardial mass and fibrosis in primary aldosteronism

BACKGROUND

Primary aldosteronism (PA) is associated with increased cardiovascular morbidity, presumably due to left ventricular (LV) hypertrophy and fibrosis. However, the degree of fibrosis has not been extensively studied. Cardiac magnetic resonance imaging (CMR) contrast enhancement and novel sensitive T1 mapping to estimate increased extracellular volume (ECV) are available to measure the extent of fibrosis.

OBJECTIVES

To assess LV mass and fibrosis before and after treatment of PA using CMR with contrast enhancement and T1 mapping.

METHODS

Fifteen patients with newly diagnosed PA (PA1) and 24 age- and sex-matched healthy subjects (HS) were studied by CMR with contrast enhancement. Repeated imaging with a new scanner with T1 mapping was performed in 14 of the PA1 and 20 of the HS median 18 months after specific PA treatment and in additional 16 newly diagnosed PA patients (PA2).

RESULTS

PA1 had higher baseline LV mass index than HS (69 (53-91) vs 51 (40-72) g/m²; P < 0.001), which decreased significantly after treatment (58 (40-86) g/m²; P < 0.001 vs baseline), more with adrenalectomy (n = 8; -9 g/m²; P = 0.003) than with medical treatment (n = 6; -5 g/m²; P = 0.075). No baseline difference was found in contrast enhancement between PA1 and HS. T1 mapping showed no increase in ECV as a myocardial fibrosis marker in PA. Moreover, ECV was lower in the untreated PA2 than HS 10 min post-contrast, and in both PA groups compared with HS 20 min post-contrast.

CONCLUSION

Specific treatment rapidly reduced LV mass in PA. Increased myocardial fibrosis was not found and may not represent a common clinical problem.

Significance of Computed Tomography and Serum Potassium in Predicting Subtype Diagnosis of Primary Aldosteronism

CONTEXT

The number of centers with established adrenal venous sampling (AVS) programs for the subtype diagnosis of primary aldosteronism (PA) is limited.

OBJECTIVE

Aim was to develop an algorithm for AVS based on subtype prediction by computed tomography (CT) and serum potassium.

DESIGN

A multi-institutional retrospective cohort study in Japan.

PATIENTS

A total of 1591 patients with PA were classified into four groups according to CT findings and potassium status. Subtype diagnosis of PA was determined by AVS.

MAIN OUTCOME MEASURE

Prediction value of the combination of CT findings and potassium status for subtype diagnosis.

RESULTS

The percentages of unilateral hyperaldosteronism on AVS were higher in patients with unilateral disease on CT than those with bilateral normal results on CT (50.8% vs 14.6%, P < 0.01), and these percentages were higher in those with hypokalemia than those with normokalemia (58.4% vs 11.5%, P < 0.01). The prevalence and odds ratio for unilateral hyperaldosteronism on AVS were as follows: bilateral normal on CT with normokalemia, 6.2% (reference); unilateral disease on CT with normokalemia, 23.8% and 4.8 [95% confidence interval (CI), 3.1 to 7.2]; bilateral normal on CT with hypokalemia, 38.1% and 9.4 (95% CI, 6.2 to 14.1), and unilateral disease on CT with hypokalemia, 70.6% and 36.4 (95% CI, 24.7 to 53.5).

CONCLUSIONS

Patients with PA with bilateral normal results on CT and normokalemia likely have a low prior probability of a lateralized form of AVS and could be treated medically, whereas those with unilateral disease on CT and hypokalemia have a high probability of a lateralized form of AVS.

Adrenalectomy Lowers Incident Atrial Fibrillation in Primary Aldosteronism Patients at Long Term

Primary aldosteronism (PA) causes cardiovascular damage in excess to the blood pressure elevation, but there are no prospective studies proving a worse long-term prognosis in adrenalectomized and medically treated patients. We have, therefore, assessed the outcome of PA patients according to treatment mode in the PAPY study (Primary Aldosteronism Prevalence in Hypertension) patients, 88.8% of whom were optimally treated patients with primary (essential) hypertension (PH), and the rest had PA and were assigned to medical therapy (6.4%) or adrenalectomy (4.8%). Total mortality was the primary end point; secondary end points were cardiovascular death, major adverse cardiovascular events, including atrial fibrillation, and total cardiovascular events. Kaplan-Meier and Cox analysis were used to compare survival between PA and its subtypes and PH patients. After a median of 11.8 years, complete follow-up data were obtained in 89% of the 1125 patients in the original cohort. Only a trend (P=0.07) toward a worse death-free survival in PA than in PH patients was observed. However, at both univariate (90.0% versus 97.8%; P=0.002) and multivariate analyses (hazard ratio, 1.82; 95% confidence interval, 1.08-3.08; P=0.025), medically treated PA patients showed a lower atrial fibrillation-free survival than PH patients. By showing that during a long-term follow-up adrenalectomized aldosterone-producing adenoma patients have a similar long-term outcome of optimally treated PH patients, whereas, at variance, medically treated PA patients remain at a higher risk of atrial fibrillation, this large prospective study emphasizes the importance of an early identification of PA patients who need adrenalectomy as a key measure to prevent incident atrial fibrillation.

Quality of Life in Primary Aldosteronism: A Comparative Effectiveness Study of Adrenalectomy and Medical Treatment

CONTEXT

In primary aldosteronism (PA), two subtypes are distinguished: aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH). In general, these are treated by adrenalectomy (ADX) and mineralocorticoid receptor antagonists (MRA), respectively.

OBJECTIVE

To compare the effects of surgical treatment and medical treatment on quality of life (QoL).

DESIGN

Post hoc comparative effectiveness study within the Subtyping Primary Aldosteronism: A Randomized Trial Comparing Adrenal Vein Sampling and Computed Tomography Scan (SPARTACUS) trial.

SETTING

Twelve Dutch hospitals and one Polish hospital.

PARTICIPANTS

Patients with PA (n = 184).

INTERVENTIONS

ADX or MRAs.

MAIN OUTCOME MEASURES

At baseline and 6-month and 1-year follow-up, we assessed QoL by two validated questionnaires: RAND 36-Item Health Survey 1.0 (RAND SF-36) and European Quality of Life-5 Dimensions (EQ-5D).

RESULTS

At baseline, seven of eight RAND SF-36 subscales and both summary scores, as well as three of five EQ-5D dimensions and the visual analog scale, were lower in patients with PA compared with the general population, especially in women. The beneficial effects of ADX were larger than for MRAs for seven RAND SF-36 subscales, both summary scores, and health change. For the EQ-5D, we detected a difference in favor of ADX in two dimensions and the visual analog scale. Most differences in QoL between both treatments exceeded the minimally clinically important difference. After 1 year, almost all QoL measures had normalized for adrenalectomized patients. For patients on medical treatment, most QoL measures had improved but not all to the level of the general population.

CONCLUSION

Both treatments improve QoL in PA, underscoring the importance of identifying these patients. QoL improved more after ADX for suspected APA than after initiation of medical treatment for suspected BAH.

Cardiovascular events and target organ damage in primary aldosteronism compared with essential hypertension: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence, relying on heterogeneous studies, as to whether aldosterone excess is responsible for an increased risk of cardiovascular and cerebrovascular complications in patients with primary aldosteronism. We aimed to assess the association between primary aldosteronism and adverse cardiac and cerebrovascular events, target organ damage, diabetes, and metabolic syndrome, compared with the association of essential hypertension and these cardiovascular and end organ events, by integrating results of previous studies.

METHODS

We did a meta-analysis of prospective and retrospective observational studies that compared patients with primary aldosteronism and essential hypertension, to analyse the association between primary aldosteronism and stroke, coronary artery disease (as co-primary endpoints), atrial fibrillation and heart failure, target organ damage, metabolic syndrome, and diabetes (as secondary endpoints). We searched MEDLINE and Cochrane Library for articles published up to Feb 28, 2017, with no start date restriction. Eligible studies compared patients with primary aldosteronism with patients with essential hypertension (as a control group) and reported on the clinical events or endpoints of interest. We also compared primary aldosteronism subtypes, aldosterone-producing adenoma, and bilateral adrenal hyperplasia.

FINDINGS

We identified 31 studies including 3838 patients with primary aldosteronism and 9284 patients with essential hypertension. After a median of 8·8 years (IQR 6·2-10·7) from the diagnosis of hypertension, compared with patients with essential hypertension, patients with primary aldosteronism had an increased risk of stroke (odds ratio [OR] 2·58, 95% CI 1·93-3·45), coronary artery disease (1·77, 1·10-2·83), atrial fibrillation (3·52, 2·06-5·99), and heart failure (2·05, 1·11-3·78). These results were consistent for patients with aldosterone-producing adenoma and bilateral adrenal hyperplasia, with no difference between these subgroups. Similarly, primary aldosteronism increased the risk of diabetes (OR 1·33, 95% CI 1·01-1·74), metabolic syndrome (1·53, 1·22-1·91), and left ventricular hypertrophy (2·29, 1·65-3·17).

INTERPRETATION

Diagnosing primary aldosteronism in the early stages of disease, with early initiation of specific treatment, is important because affected patients display an increased cardiovascular risk compared with patients with essential hypertension.

FUNDING

None.

Cardiometabolic outcomes and mortality in medically treated primary aldosteronism: a retrospective cohort study

BACKGROUND

Mineralocorticoid receptor (MR) antagonists are the recommended medical therapy for primary aldosteronism. Whether this recommendation effectively reduces cardiometabolic risk is not well understood. We aimed to investigate the risk of incident cardiovascular events in patients with primary aldosteronism treated with MR antagonists compared with patients with essential hypertension.

METHODS

We did a cohort study using patients from a research registry from Brigham and Women's Hospital, Massachusetts General Hospital, and their affiliated partner hospitals. We identified patients with primary aldosteronism using International Classification of Disease, 9th and 10th Revision codes, who were assessed between the years 1991-2016 and were at least 18 years of age. We excluded patients who underwent surgical adrenalectomy, had a previous cardiovascular event, were not treated with MR antagonists, or had no follow-up visits after study entry. From the same registry, we identified a population with essential hypertension that was frequency matched by decade of age at study entry. We extracted patient cohort data and collated it into a de-identified database. The primary outcome was an incident cardiovascular event, defined as a composite of incident myocardial infarction or coronary revascularisation, hospital admission with congestive heart failure, or stroke, which was assessed using adjusted Cox regression models. Secondary outcomes were the individual components of the composite cardiovascular outcome, as well as incident atrial fibrillation, incident diabetes, and death.

FINDINGS

We identified 602 eligible patients with primary aldosteronism treated with MR antagonists and 41 853 age-matched patients with essential hypertension from the registry. The two groups of patients had comparable cardiovascular risk profiles and blood pressure throughout the study. The incidence of cardiovascular events was higher in patients with primary aldosteronism on MR antagonists than in patients with essential hypertension (56·3 [95% CI 48·8-64·7] vs 26·6 [26·1-27·2] events per 1000 person-years, adjusted hazard ratio 1·91 [95% CI 1·63-2·25]; adjusted 10-year cumulative incidence difference 14·1 [95% CI 10·1-18·0] excess events per 100 people). Patients with primary aldosteronism also had higher adjusted risks for incident mortality (hazard ratio [HR] 1·34 [95% CI 1·06-1·71]), diabetes (1·26 [1·01-1·57]), and atrial fibrillation (1·93 [1·54-2·42]). Compared with essential hypertension, the excess risk for cardiovascular events and mortality was limited to patients with primary aldosteronism whose renin activity remained suppressed (<1 μg/L per h) on MR antagonists (adjusted HR [2·83 [95% CI 2·11-3·80], and 1·79 [1·14-2·80], respectively) whereas patients who were treated with higher MR antagonist doses and had unsuppressed renin (≥1 μg/L per h) had no significant excess risk.

INTERPRETATION

The current practice of MR antagonist therapy in primary aldosteronism is associated with significantly higher risk for incident cardiometabolic events and death, independent of blood pressure control, than for patients with essential hypertension. Titration of MR antagonist therapy to raise renin might mitigate this excess risk.

FUNDING

US National Institutes of Health.

Decoding resistant hypertension signalling pathways

Resistant hypertension (RH) is a clinical condition in which the hypertensive patient has become resistant to drug therapy and is often associated with increased cardiovascular morbidity and mortality. Several signalling pathways have been studied and related to the development and progression of RH: modulation of sympathetic activity by leptin and aldosterone, primary aldosteronism, arterial stiffness, endothelial dysfunction and variations in the renin-angiotensin-aldosterone system (RAAS). miRNAs comprise a family of small non-coding RNAs that participate in the regulation of gene expression at post-transcriptional level. miRNAs are involved in the development of both cardiovascular damage and hypertension. Little is known of the molecular mechanisms that lead to development and progression of this condition. This review aims to cover the potential roles of miRNAs in the mechanisms associated with the development and consequences of RH, and explore the current state of the art of diagnostic and therapeutic tools based on miRNA approaches.

Primary aldosteronism patients show skin alterations and abnormal activation of glucocorticoid receptor in keratinocytes

Primary aldosteronism (PA) is a disease characterized by high aldosterone levels caused by benign adrenal tumors being the most frequent cause of secondary hypertension. Aldosterone plays vital physiological roles through the mineralocorticoid receptor (MR) but in certain cell types, it can also activate the glucocorticoid (GC) receptor (GR). Both MR and GR are structurally and functionally related and belong to the same family of ligand-dependent transcription factors that recognize identical GC regulatory elements (GREs) on their target genes. GCs play key roles in skin pathophysiology acting through both GR and MR; however, the effects of aldosterone and the potential association of PA and skin disease were not previously addressed. Skin samples from PA revealed histopathological alterations relative to control subjects, featuring epidermal hyperplasia, impaired differentiation, and increased dermal infiltrates, correlating with increased NF-κB signaling and up-regulation of TNF-A and IL-6 cytokines. PA skin samples also showed significantly higher expression of MR, GR, and HSD11B2. In cultured keratinocytes, aldosterone treatment increased GRE transcriptional activity which was significantly inhibited by co-treatment with GR- and MR-antagonists. This study demonstrates that high levels of aldosterone in PA patients correlate with skin anomalies and inflammatory features associated with abnormal GR/MR activation in epidermal keratinocytes.

Hypertension outcomes of adrenalectomy in patients with primary aldosteronism: a systematic review and meta-analysis

BACKGROUND

The hypertension cure rate of unilateral adrenalectomy in primary aldosteronism (PA) patients varies widely in existing studies.

METHODS

We conducted an observational meta-analysis to summarize the pooled hypertension cure rate of unilateral adrenalectomy in PA patients. Comprehensive electronic searches of PubMed, Embase, Cochrane, China National Knowledge Internet (CNKI), WanFang, SinoMed and Chongqing VIP databases were performed from initial state to May 20, 2016. We manually selected eligible studies from references in accordance with the inclusion criteria. The pooled hypertension cure rate of unilateral adrenalectomy in PA patients was calculated using the DerSimonian-Laird method to produce a random-effects model.

RESULTS

Forty-three studies comprising approximately 4000 PA patients were included. The pooled hypertension cure rate was 50.6% (95% CI: 42.9-58.2%) for unilateral adrenalectomy in PA. Subgroup analyses showed that the hypertension cure rate was 61.3% (95% CI: 49.4-73.3%) in Chinese studies and 43.7% (95% CI: 38.0-49.4%) for other countries. Furthermore, the hypertension cure rate at 6-month follow-up was 53.3% (95% CI: 36.0-70.5%) and 49.6% (95% CI: 40.9-58.3%) for follow-up exceeding 6 months. The pooled hypertension cure rate was 50.9% (95% CI: 40.5-61.3%) from 2001 to 2010 and 50.2% (95% CI: 39.0-61.5%) from 2011 to 2016.

CONCLUSIONS

The hypertension cure rate for unilateral adrenalectomy in PA is not optimal. Large clinical trials are required to verify the utility of potential preoperative predictors in developing a novel and effective prediction model.

Case detection and diagnosis of primary aldosteronism - The consensus of Taiwan Society of Aldosteronism

BACKGROUND/PURPOSE

Even though the increasing clinical recognition of primary aldosteronism (PA) as a public health issue, its heightened risk profiles and the availability of targeted surgical/medical treatment being more understood, consensus in its diagnosis and management based on medical evidence, while recognizing the constraints of our real-world clinical practice in Taiwan, has not been reached.

METHODS

The Taiwan Society of Aldosteronism (TSA) Task Force acknowledges the above-mentioned issues and reached this Taiwan PA consensus at its inaugural meeting, in order to provide updated information of internationally acceptable standards, and also to incorporate our local disease characteristics into the management of PA.

RESULTS

When there is suspicion of PA, a plasma aldosterone to renin ratio (ARR) should be obtained initially. Patients with abnormal ARR will undergo confirmatory laboratory and image tests. Subtype classification with adrenal venous sampling (AVS) or NP-59 nuclear imaging, if AVS not available, to lateralize PA is recommended when patients are considered for adrenalectomy. The strengths and weaknesses of the currently available identification methods are discussed, focusing especially on result interpretation.

CONCLUSION

With this consensus we hope to raise more awareness of PA among medical professionals and hypertensive patients in Taiwan, and to facilitate reconciliation of better detection, identification and treatment of patients with PA.

Outcomes analysis of surgical and medical treatments for patients with primary aldosteronism

Patients with aldosterone-producing adenomas are treated using surgery, and patients with idiopathic hyperaldosteronism receive medical treatment using mineralocorticoid receptor antagonists (MRAs). However, the outcomes of surgical and medical treatment for primary aldosteronism (PA) remain unclear. Therefore, we compared the outcomes of surgical and medical treatment for PA and aimed to identify a specific subgroup that might benefit from medical treatment. We identified 269 patients who were treated for PA (unilateral excess: 221 cases; bilateral excess: 48 cases) during 2000-2015 at the Seoul National University Hospital and two other tertiary centers. The main outcomes were the amelioration of hypertension and hypokalemia. Treatment improved hypertension in the surgical treatment group (78.2%) and the medical treatment group (55.6%) (p = 0.001). At the last follow-up, hypokalemia was normalized in the surgical treatment group (97.1%) and the medical treatment group (93.7%, p = 0.046). Among patients with unilateral aldosterone excess, surgery provided advantages in resolving hypertension without worsening renal function. Among patients who were >60 years old or had impaired renal function, surgical and medical treatment provided similar amelioration of hypokalemia and hypertension. Three patients developed hyperkalemia after surgery, and no patients developed hyperkalemia after initiating medical treatment. The surgical treatment group exhibited a lower postoperative estimated glomerular filtration rate (eGFR) and higher serum potassium levels, compared to the medical treatment group. Surgical treatment provided better hypertension and hypokalemia outcomes among patients with PA, compared to medical treatment. However, MRAs may be appropriate for elderly patients with impaired renal function.

Quantitative Value of Aldosterone-Renin Ratio for Detection of Aldosterone-Producing Adenoma: The Aldosterone-Renin Ratio for Primary Aldosteronism (AQUARR) Study

Background

Current guidelines recommend use of the aldosterone‐renin ratio (ARR) for the case detection of primary aldosteronism followed by confirmatory tests to exclude false‐positive results from further diagnostic workup. We investigated the hypothesis that this could be unnecessary in patients with a high ARR value if the quantitative information carried by the ARR is taken into due consideration.

Methods and Results

We interrogated 2 large data sets of prospectively collected patients studied with the same predefined protocol, which included the captopril challenge test. We used an unambiguous diagnosis of aldosterone‐producing adenoma as reference index. We also assessed whether the post‐captopril ARR and plasma aldosterone concentration fall furnished a diagnostic gain over baseline ARR values. We found that the false‐positive rate fell exponentially, and, conversely, the specificity increased with rising ARR values. At receiver operating characteristics curves and diagnostic odds ratio analysis, the high baseline ARR values implied very high positive likelihood ratio and diagnostic odds ratio values. The baseline and post‐captopril ARR showed similar diagnostic accuracy (area under the receiver operating characteristics curve) in both the exploratory and validation cohorts, indicating lack of diagnostic gain with this confirmatory test (between‐area under the curve difference, 0.005; 95% CI, −0.031 to 0.040; P=0.7 for comparison, and 0.05; 95% CI, −0.061 to 0.064; P=0.051 for comparison, respectively).

Conclusions

These results indicate that the ARR conveys key quantitative information that, if properly used, can simplify the diagnostic workup, resulting in saving of money and resources. This can offer the chance of diagnosis and ensuing adrenalectomy to a larger number of hypertensive patients, ultimately resulting in better control of blood pressure.

Steroid metabolome analysis reveals prevalent glucocorticoid excess in primary aldosteronism

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

FUNDING

Medical Research Council UK, Wellcome Trust, European Commission.

Endocrine Tumors Causing Arterial Hypertension: Pathophysiological Mechanisms and Clinical Implications

Some tumors are a relatively rare and amendable cause of hypertension, often associated with a higher cardiovascular morbidity and mortality, as compared with that of both general population and patients with essential hypertension. This worse prognosis is not entirely related to blood pressure increase, because the release of substances from the tumor can directly influence blood pressure behavior. Diagnostic approach is challenging and needs a deep knowledge of the different neuro-hormonal and genetic mechanisms determining blood pressure increase. Surgical tumor removal can, but not always, cause blood pressure normalization, depending on how early was tumor detection, since a long-standing history of hypertension is often associated with a much weaker effect on blood pressure. Moreover, target organ damage can be affected by the substances themselves released by the tumors as well as by tumor removal. In this review we consider the phenotype and genetic features of patients with tumor-induced hypertension and focus on their diagnostic work-up.

Scoring system for the diagnosis of bilateral primary aldosteronism in the outpatient setting before adrenal venous sampling

OBJECTIVE

The only reliable method for subtyping primary aldosteronism (PA) is adrenal venous sampling (AVS), which is costly and time-consuming. Considering the limited availability of AVS, it would be helpful to obtain information on the diagnosis of bilateral hyperaldosteronism (BHA) from routine tests. We aimed to establish new, simple criteria for outpatients to diagnose BHA from PA before AVS.

DESIGN

We retrospectively analysed 82 patients who were diagnosed with PA and underwent AVS. Thirty-seven patients were diagnosed with unilateral hyperaldosteronism (UHA), and 36 with BHA and nine were undetermined. Among the variables that were significantly different between UHA and BHA in the univariate analysis, we chose three variables to be included in multivariate logistic regression models and constructed a subtype prediction score.

RESULTS

The subtype prediction score was calculated as follows: 3 points for no adrenal nodules on computed tomography imaging, 2 for serum potassium of ≥3·5 mmol/l and 2 for aldosterone-to-renin ratio of <490 after a captopril challenge test. Receiver operating characteristic curve analysis for the ability to discriminate BHA from UHA showed that a score of 7 points had 50% sensitivity and 100% specificity and a score of 5 points had 67% sensitivity and 94% specificity (area under the curve: 0·922; 95% CI: 0·863-0·980).

CONCLUSIONS

Our new, simple criteria specifically distinguished BHA from UHA in the outpatient setting before AVS. Furthermore, not only endocrinologists but also general internists can use this convenient, safe scoring system.

Diastolic Dysfunction and Hypertension

Left ventricular (LV) diastolic dysfunction (LVDD) is characterized by alterations in LV diastolic filling, and is a strong predictor of cardiovascular events and heart failure. Hypertension is the most important risk factor for LVDD in the community and promotes LVDD through several mechanisms, including hemodynamic overload and myocardial ischemia. Associated factors such as age, ethnicity, dietary sodium, obesity, diabetes mellitus, and chronic kidney disease also contribute to LVDD in hypertensive individuals. Blood pressure lowering using antihypertensive medications can improve LVDD; however, it remains unclear whether this improvement in LV diastolic function can improve cardiovascular outcomes.

Mineralocorticoid regulation of cell function: the role of rapid signalling and gene transcription pathways

The mineralocorticoid receptor (MR) and mineralocorticoids regulate epithelial handling of electrolytes, and induces diverse effects on other tissues. Traditionally, the effects of MR were ascribed to ligand-receptor binding and activation of gene transcription. However, the MR also utilises a number of intracellular signalling cascades, often by transactivating unrelated receptors, to change cell function more rapidly. Although aldosterone is the physiological mineralocorticoid, it is not the sole ligand for MR. Tissue-selective and mineralocorticoid-specific effects are conferred through the enzyme 11β-hydroxysteroid dehydrogenase 2, cellular redox status and properties of the MR itself. Furthermore, not all aldosterone effects are mediated via MR, with implication of the involvement of other membrane-bound receptors such as GPER. This review will describe the ligands, receptors and intracellular mechanisms available for mineralocorticoid hormone and receptor signalling and illustrate their complex interactions in physiology and disease.

A Novel Method of Adrenal Venous Sampling via an Antecubital Approach

PURPOSE

Currently, almost all adrenal venous sampling (AVS) procedures are performed by femoral vein access. The purpose of this study was to establish the technique of AVS via an antecubital approach and evaluate its safety and feasibility.

MATERIALS AND METHODS

From January 2012 to June 2015, 194 consecutive patients diagnosed as primary aldosteronism underwent AVS via an antecubital approach without ACTH simulation. Catheters used for bilateral adrenal cannulations were recorded. The success rate of bilateral adrenal sampling, operation time, fluoroscopy time, dosage of contrast, and incidence of complications were calculated.

RESULTS

A 5F MPA1 catheter was first used to attempt right adrenal cannulation in all patients. Cannulation of the right adrenal vein was successfully performed in 164 (84.5%) patients. The 5F JR5, Cobra2, and TIG catheters were the ultimate catheters for right adrenal cannulation in 16 (8.2%), 5 (2.6%), and 9 (4.6%) patients, respectively. For left adrenal cannulation, JR5 and Cobra2 catheters were used in 19 (9.8%) and 10 (5.2%) patients, respectively, while only TIG catheters were used in the remaining 165 (85.1%) patients. The rate of successful adrenal sampling on the right, left, and bilateral sides was 91.8%, 93.3%, and 87.6%, respectively. The mean time of operation was (16.3 ± 4.3) minutes, mean fluoroscopy time was (4.7 ± 1.3) minutes, and the mean use of contrast was (14.3 ± 4.7) ml. The incidence of adrenal hematoma was 1.0%.

CONCLUSIONS

This study showed that AVS via an antecubital approach was safe and feasible, with a high rate of successful sampling.

Cardiac Dysfunction in Association with Increased Inflammatory Markers in Primary Aldosteronism

BACKGROUND

Oxidative stress in primary aldosteronism (PA) is thought to worsen aldosterone-induced damage by activating proinflammatory processes. Therefore, we investigated whether inflammatory markers associated with oxidative stress is increased with negative impacts on heart function as evaluated by echocardiography in patients with PA.

METHODS

Thirty-two subjects (mean age, 50.3±11.0 years; 14 males, 18 females) whose aldosterone-renin ratio was more than 30 among patients who visited Severance Hospital since 2010 were enrolled. Interleukin-1β (IL-1β), IL-6, IL-8, monocyte chemoattractant protein 1, tumor necrosis factor α (TNF-α), and matrix metalloproteinase 2 (MMP-2), and MMP-9 were measured. All patients underwent adrenal venous sampling with complete access to both adrenal veins.

RESULTS

Only MMP-2 level was significantly higher in the aldosterone-producing adenoma (APA) group than in the bilateral adrenal hyperplasia (BAH). Patients with APA had significantly higher left ventricular (LV) mass and A velocity, compared to those with BAH. IL-1β was positively correlated with left atrial volume index. Both TNF-α and MMP-2 also had positive linear correlation with A velocity. Furthermore, MMP-9 showed a positive correlation with LV mass, whereas it was negatively correlated with LV end-systolic diameter.

CONCLUSION

These results suggest the possibility that some of inflammatory markers related to oxidative stress may be involved in developing diastolic dysfunction accompanied by LV hypertrophy in PA. Further investigations are needed to clarify the role of oxidative stress in the course of cardiac remodeling.

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

In the 60 years that have passed since the discovery of the mineralocorticoid hormone aldosterone, much has been learned about its synthesis (both adrenal and extra-adrenal), regulation (by renin-angiotensin II, potassium, adrenocorticotrophin, and other factors), and effects (on both epithelial and nonepithelial tissues). Once thought to be rare, primary aldosteronism (PA, in which aldosterone secretion by the adrenal is excessive and autonomous of its principal regulator, angiotensin II) is now known to be the most common specifically treatable and potentially curable form of hypertension, with most patients lacking the clinical feature of hypokalemia, the presence of which was previously considered to be necessary to warrant further efforts towards confirming a diagnosis of PA. This, and the appreciation that aldosterone excess leads to adverse cardiovascular, renal, central nervous, and psychological effects, that are at least partly independent of its effects on blood pressure, have had a profound influence on raising clinical and research interest in PA. Such research on patients with PA has, in turn, furthered knowledge regarding aldosterone synthesis, regulation, and effects. This review summarizes current progress in our understanding of the physiology of aldosterone, and towards defining the causes (including genetic bases), epidemiology, outcomes, and clinical approaches to diagnostic workup (including screening, diagnostic confirmation, and subtype differentiation) and treatment of PA.

Long term outcome of Aldosteronism after target treatments

There exists a great knowledge gap in terms of long-term effects of various surgical and pharmacological treatments on outcomes among primary aldosteronism (PA) patients. Using a validated algorithm, we extracted longitudinal data for all PA patients diagnosed in 1997–2010 and treated in the Taiwan National Health Insurance. We identified 3362 PA patients for whom the mean length of follow-up was 5.75 years. PA has higher major cardiovascular events (MACE) than essential hypertension (23.3% vs 19.3%, p = 0.015). Results from the Cox model suggest a strong effect of adrenalectomy on lowering mortality (HR = 0.23 with residual hypertension and 0.21 with resolved hypertension). While need for receptor antagonist (MRA) MRA after diagnosis suggests that a defined daily dose (DDD) of MRA between 12.5 and 50 mg may alleviate risk of death in a U-shape pattern. A specificity test identified patients who has aldosterone producing adenoma (HR = 0.50, p = 0.005) also confirmed adrenalectomy attenuated all-cause mortality. Adrenalectomy decreases long-term all-cause mortality independently from PA cure from hypertension. Prescription corresponding to a DDD between 12.5 and 50 mg may decrease mortality for patients needing MRA. It calls for more attention on early diagnosis, early treatment and prescription of appropriate dosage of MRA for PA patients.

Radiofrequency ablation compared with laparoscopic adrenalectomy for aldosterone-producing adenoma

BACKGROUND

Radiofrequency ablation (RFA) is an emerging treatment for primary aldosteronism owing to aldosterone-producing adenoma. Whether RFA could be an alternative treatment to laparoscopic adrenalectomy is unknown.

METHODS

This was a retrospective comparative study in patients with aldosterone-producing adenoma undergoing either laparoscopic adrenalectomy or CT-guided percutaneous RFA between 2004 and 2012. Short-term outcomes and long-term resolution rates of primary aldosteronism (normalized aldosterone to renin ratio), hypokalaemia and hypertension (BP lower than 140/90 mmHg without antihypertensive medical therapy) were evaluated.

RESULTS

Some 63 patients were included, 27 in the laparoscopic adrenalectomy group and 36 in the RFA group. RFA was associated with shorter duration of operation (median 12 versus 124 min; P < 0·001), shorter hospital stay (2 versus 4 days; P < 0·001), lower analgesic requirements (13 of 36 versus 23 of 27 patients; P < 0·001) and earlier resumption of work (median 4 versus 14 days; P = 0·006). Morbidity rates were similar in the two groups. With median follow-up of 5·7 (range 1·9-10·6) years, resolution of primary aldosteronism was seen in 33 of 36 patients treated with RFA and all 27 patients who had laparoscopic adrenalectomy (P = 0·180). Hypertension was resolved less frequently after treatment with RFA compared with laparoscopic adrenalectomy (13 of 36 versus 19 of 27 patients; P = 0·007). Hypokalaemia was resolved in all patients.

CONCLUSION

For patients with aldosterone-producing adenoma the efficacy of resolution of primary aldosteronism and hypertension was inferior after treatment with RFA compared with laparoscopic adrenalectomy.

Cardiac Tissue Injury and Remodeling Is Dependent Upon MR Regulation of Activation Pathways in Cardiac Tissue Macrophages

Macrophage mineralocorticoid receptor (MR) signaling is an important mediator of cardiac tissue inflammation and fibrosis. The goal of the present study was to determine the cellular mechanisms of MR signaling in macrophages that promote cardiac tissue injury and remodeling. We sought to identify specific markers of MR signaling in isolated tissue macrophages (cardiac, aortic) vs splenic mononuclear cells from wild-type and myeloid MR-null mice given vehicle/salt or deoxycorticosterone (DOC)/salt for 8 weeks. Cardiac tissue fibrosis in response to 8 weeks of DOC/salt treatment was found in the hearts from wild-type but not myeloid MR-null mice. This was associated with an increased expression of the profibrotic markers TGF-β1 and matrix metalloproteinase-12 and type 1 inflammatory markers TNFα and chemokine (C-X-C motif) ligand-9 in cardiac macrophages. Differential expression of immunomodulatory M2-like markers (eg, arginase-1, macrophage scavenger receptor 1) was dependent on the tissue location of wild-type and MR-null macrophages. Finally, intact MR signaling is required for the phosphorylation of c-Jun NH2-terminal kinase in response to a proinflammatory stimulus in bone marrow monocytes/macrophages in culture. These data suggest that the activation of the c-Jun NH2-terminal kinase pathway in macrophages after a tissue injury and inflammatory stimuli in the DOC/salt model is MR dependent and regulates the transcription of downstream profibrotic factors, which may represent potential therapeutic targets in heart failure patients.

Clinical Outcomes following Percutaneous Radiofrequency Ablation of Unilateral Aldosterone-Producing Adenoma: Comparison with Adrenalectomy

PURPOSE

To compare adrenal radiofrequency (RF) ablation with adrenalectomy in treating unilateral aldosterone-producing adenoma (APA).

MATERIALS AND METHODS

Between April 2008 and September 2013, 44 patients with adrenal venous sampling-confirmed (lateralization index ≥ 4) unilateral APA underwent adrenal RF ablation (12/44 [27%]) or adrenalectomy (32/44 [73%]). Outcomes of adrenal RF ablation (patient age, 51 y ± 11; 4/12 men) were compared with adrenalectomy (patient age, 50 y ± 11; 19/32 men). Blood pressure (145/94 mm Hg ± 19/13 vs 144/89 mm Hg ± 10/8, P = .92), number of antihypertensives (3.0 ± 1.3 vs 2.7 ± 0.89, P = .38), and serum potassium (3.2 mEq/L ± 0.6 vs 3.5 mEq/L ± 0.6, P = .65) of patients were similar before treatment.

RESULTS

RF ablation and adrenalectomy resulted in normokalemia (RF ablation, 4.2 mEq/L ± 0.1, P = .0004; adrenalectomy, 4.3 mEq/L ± 0.6, P < .0001) and normotension (RF ablation, 129/81 mm Hg ± 11/11, P = .02/P = .001; adrenalectomy, 128/85 mm Hg ± 13/12, P < .0001/P = .07) in all patients. Proportions of RF ablation and adrenalectomy patients cured of hypertension (2/12 [17%] vs 12/32 [38%], P = .28) or requiring fewer antihypertensives (7/12 [58%] vs 13/32 [40%], P = .29) were similar. RF ablation patients had a shorter length of stay (0.6 d ± 0.8 [range, 0-2 d] vs 1.7 d ± 1.4 [range, 0-7 d]; P = .01) and less intraoperative blood loss (1.2 mL ± 3 vs 40 mL ±85; P = .01). Procedural complications occurred in 5/32 (15%) adrenalectomy patients (2 major, 3 minor) and in 0/12 RF ablation patients.

CONCLUSIONS

RF ablation to treat APA can achieve similar clinical outcomes as adrenalectomy and results in shorter hospital stays. Larger, prospective trials are needed to validate these results.

Risk factors for renal impairment revealed after unilateral adrenalectomy in patients with primary aldosteronism

Primary aldosteronism (PA) may induce significant decline of renal function and structural damage of kidney. However, it is difficult to evaluate accurate renal function in patients with PA, because glomerular hyperfiltration and aldosterone escape can conceal renal impairment. In this retrospective cohort study, we compared changes in renal function after unilateral adrenalectomy between patients with PA and patients with other adrenal diseases. Risk factors associated with postoperative renal impairment in patients with PA were analyzed.A total of 558 patients who received unilateral adrenalectomy between January 2002 and June 2013 were included: 136 patients with PA and 422 patients with other adrenal diseases (control). Postoperative serial changes in estimated glomerular filtration rate (eGFR) were analyzed in both groups. Multivariate analyses were performed to identify risk factors of renal impairment after adrenalectomy in all patients and the PA group. Postoperative renal impairment was defined as postoperative eGFR decline of >25% from preoperative eGFR. Chronic kidney disease (CKD) was defined as an eGFR <60 mL/min/1.73 m.There were no differences in preoperative eGFR between groups. The PA group showed a significant decrease in eGFR 3 days, 2 weeks, and 6 months after surgery compared to the control group. The PA group showed significant improvement of hypertension after surgery. In the PA group, 53 (39.0%) patients showed postoperative renal impairment. Multivariate regression analysis identified long-standing hypertension, low body mass index, low serum potassium, and high preoperative eGFR as risk factors for postoperative renal impairment. Among the 89 patients with preoperative eGFR ≥60 mL/min/1.73 m, 29 (32.6%) patients developed CKD postoperatively. Age, low serum potassium, low preoperative eGFR, and high serum cholesterol or uric acid were associated with the postoperative CKD development.Our study demonstrates that patients with PA with old age, low serum potassium, long-standing hypertension, and high serum uric acid or cholesterol are at risk of renal impairment after surgical treatment. High preoperative eGFR was also a risk factor for postoperative renal impairment, whereas low preoperative eGFR was a risk factor for postoperative CKD. Close monitoring of renal function and adequate management are required for patients with these risk factors.

Primary Aldosteronism: Diagnosis and Management

Primary aldosteronism (PA) is an important and commonly unrecognized cause of secondary hypertension. Idiopathic hyperaldosteronism and aldosterone-producing adenomas account for more than 95% of PA and are characterized, respectively, by bilateral or unilateral involvement of the adrenal glands. When there is suspicion for the presence of PA, a plasma aldosterone to renin ratio should be obtained initially. Localization to determine adrenal gland involvement is done by imaging, with computerized tomography or magnetic resonance imaging. After imaging, adrenal vein sampling is done to establish treatment options. Patients with unilateral disease, who are good surgical candidates, are most appropriately managed with adrenalectomy. A biochemical cure is almost certain following adrenalectomy; however, only 30-50% of patients would show adequate blood pressure improvement. Patients with bilateral adrenal disease and those believed not to be surgical candidates are managed with mineralocorticoid antagonists.

Aldosterone Induces Tissue Inhibitor of Metalloproteinases-1 Expression and Further Contributes to Collagen Accumulation

Aldosterone induces myocardial fibrosis. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a key factor of myocardial fibrosis. This study tested the hypothesis that aldosterone induces TIMP-1 expression and contributes to the fibrotic process. We prospectively enrolled 54 patients with primary aldosteronism, and measured plasma TIMP-1 and echocardiographic parameters. In the cell study, we investigated the possible molecular mechanism by which aldosterone induces TIMP-1 secretion and the effects on collagen accumulation. In the animal study, we measured serum TIMP-1 levels, cardiac TIMP-1 levels, and cardiac structure in an aldosterone infusion mouse model using implantation of aldosterone pellets. In patients with primary aldosteronism, plasma TIMP-1 was correlated with 24-hour urinary aldosterone, left ventricular mass, and impairment of left ventricular diastolic function. In human cardiac fibroblasts, TIMP-1 protein and mRNA expressions were significantly increased by aldosterone through the glucocorticoid receptor/PI3K/Akt/nuclear factor-κB pathway. TIMP-1 small-interfering RNA significantly reduced aldosterone-induced collagen accumulation, and aldosterone did not alter the levels of collagen1a1 or matrix metalloproteinase-1 mRNA. The aldosterone-induced TIMP-1 expression was inversely related to matrix metalloproteinase-1 activity. Furthermore, in the animal model, the serum and cardiac levels of TIMP-1 were significantly elevated in the mice that received aldosterone infusion. This elevation was blocked by RU-486 but not by eplerenone, suggesting that the effect was through glucocorticoid receptors. In a long-term aldosterone infusion model, serum TIMP-1 was associated with serum aldosterone level, cardiac structure, and fibrosis. In conclusion, aldosterone induced TIMP-1 expression in vivo and in vitro. This increased TIMP-1 expression resulted in enhanced collagen accumulation via the suppression of matrix metalloproteinase-1 activity.

The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To develop clinical practice guidelines for the management of patients with primary aldosteronism.

PARTICIPANTS

The Task Force included a chair, selected by the Clinical Guidelines Subcommittee of the Endocrine Society, six additional experts, a methodologist, and a medical writer. The guideline was cosponsored by American Heart Association, American Association of Endocrine Surgeons, European Society of Endocrinology, European Society of Hypertension, International Association of Endocrine Surgeons, International Society of Endocrinology, International Society of Hypertension, Japan Endocrine Society, and The Japanese Society of Hypertension. The Task Force received no corporate funding or remuneration.

EVIDENCE

We searched for systematic reviews and primary studies to formulate the key treatment and prevention recommendations. We used the Grading of Recommendations, Assessment, Development, and Evaluation group criteria to describe both the quality of evidence and the strength of recommendations. We used "recommend" for strong recommendations and "suggest" for weak recommendations.

CONSENSUS PROCESS

We achieved consensus by collecting the best available evidence and conducting one group meeting, several conference calls, and multiple e-mail communications. With the help of a medical writer, the Endocrine Society's Clinical Guidelines Subcommittee, Clinical Affairs Core Committee, and Council successfully reviewed the drafts prepared by the Task Force. We placed the version approved by the Clinical Guidelines Subcommittee and Clinical Affairs Core Committee on the Endocrine Society's website for comments by members. At each stage of review, the Task Force received written comments and incorporated necessary changes.

CONCLUSIONS

For high-risk groups of hypertensive patients and those with hypokalemia, we recommend case detection of primary aldosteronism by determining the aldosterone-renin ratio under standard conditions and recommend that a commonly used confirmatory test should confirm/exclude the condition. We recommend that all patients with primary aldosteronism undergo adrenal computed tomography as the initial study in subtype testing and to exclude adrenocortical carcinoma. We recommend that an experienced radiologist should establish/exclude unilateral primary aldosteronism using bilateral adrenal venous sampling, and if confirmed, this should optimally be treated by laparoscopic adrenalectomy. We recommend that patients with bilateral adrenal hyperplasia or those unsuitable for surgery should be treated primarily with a mineralocorticoid receptor antagonist.

Expression and functional role of the prorenin receptor in the human adrenocortical zona glomerulosa and in primary aldosteronism

OBJECTIVES

Prorenin can be detected in plasma of hypertensive patients. If detected in patients with primary aldosteronism could implicate prorenin in the development of primary aldosteronism. To address this issue, we measured the plasma prorenin levels in primary aldosteronism patients, the expression of the prorenin receptor (PRR) in the normal human adrenocortical zona glomerulosa and aldosterone-producing adenoma (APA), and we investigated the functional effects of PRR activation in human adrenocortical cells.

METHOD

Plasma renin activity, aldosterone, and active and total trypsin-activated renin were measured in primary aldosteronism patients, essential hypertensive patients, and healthy individuals, and then prorenin levels were calculated. Localization and functional role of PRR were investigated in human and rat tissues, and aldosterone-producing cells.

RESULTS

Primary aldosteronism patients had detectable plasma levels of prorenin. Using digital-droplet real-time PCR, we found a high PRR-to-porphobilinogen deaminase ratio in both the normal adrenal cortex and APAs. Marked expression of the PRR gene and protein was also found in HAC15 cells. Immunoblotting, confocal, and immunogold electron microscopy demonstrated PRR at the cell membrane and intracellularly. Renin and prorenin significantly triggered both CYP11B2 expression (aldosterone synthase) and ERK1/2 phosphorylation, but only CYP11B2 transcription was prevented by aliskiren.

CONCLUSION

The presence of detectable plasma prorenin in primary aldosteronism patients, and the high expression of PRR in the normal human adrenal cortex, APA tissue, CD56+ aldosterone-producing cells, along with activation of CYP11B2 synthesis and ERK1/2 phosphorylation, suggest that the circulating and locally produced prorenin may contribute to the development or maintenance of human primary aldosteronism.

Aldosterone and type 2 diabetes mellitus

Primary hyperaldosteronism (PA) has recently been demonstrated to be strictly associated to metabolic syndrome as compared with essential hypertension (EH). Besides, the characteristics of metabolic syndrome are different in PA compared to EH, as high fasting glucose is more frequent in the former condition. The adverse effect of excess aldosterone on insulin metabolic signaling has generated increasing interest in the role of hyperaldosteronism in the pathogenesis of insulin resistance and resistant hypertension. Moreover, aldosterone receptor antagonist therapy in diabetic and cardiopathic patients improved coronary flow. The aim of this review is to present recent knowledge about the relationship between aldosterone, insulin resistance and diabetes.

The Relation Between the Degree of Left Ventricular Mass Regression and Serum Potassium Level Change in Patients With Primary Aldosteronism After Adrenalectomy

BACKGROUND

Primary aldosteronism (PA) is one of the major etiologies for secondary hypertension featuring more prominent left ventricular hypertrophy. The purpose of the study was to investigate the predictive factors of left ventricular mass index (LVMI) regression in patients with PA after adrenalectomy.

METHODS

We prospectively analyzed 30 patients with aldosterone-producing adenoma (APA) who received adrenalectomy from October 2006 to September 2008. Echocardiography was performed preoperation and 1 year after operation.

RESULTS

Thirty patients with aldosterone-producing adenoma undergoing adrenalectomy were enrolled. In a 1-year follow-up, LVMI decreased significantly by an average of 18.6%. Net LVMI decrease (ΔLVMI) was associated with preoperative LVMI, preoperative serum potassium level, baseline systolic blood pressure (SBP), baseline diastolic blood pressure, net SBP decrease (ΔSBP), net diastolic blood pressure decrease, preoperative/postoperative change of log-transformed plasma aldosterone concentration, preoperative/postoperative change of log-transformed plasma renin activity, and preoperative/postoperative change of serum potassium level (Δserum potassium level). In a multiple regression analysis, preoperative LVMI (β = -0.287, P = 0.049), ΔSBP (β = 0.518, P = 0.01), and Δserum potassium level (β = -20.471, P = 0.014) were significantly correlated with ΔLVMI.

CONCLUSIONS

The LVMI in patients with PA regressed significantly after adrenalectomy. Preoperative LVMI, ΔSBP, and Δserum potassium levels are independent factors associated with the degree of LVMI regression.

Aldosterone and the Mineralocorticoid Receptor: Risk Factors for Cardiometabolic Disorders

Preclinical studies have convincingly demonstrated a role for the mineralocorticoid receptor (MR) in adipose tissue physiology. These studies show that increased MR activation causes adipocyte dysfunction leading to decreased production of insulin-sensitizing products and increased production of inflammatory factors, creating an environment conducive to metabolic and cardiovascular disease. Accumulating data also suggest that MR activation may be an important link between obesity and metabolic syndrome. Moreover, MR activation may mediate the pathogenic consequences of metabolic syndrome. Recent attempts at reversing cardiometabolic damage in patients with type 2 diabetes using MR antagonists have shown promising results. MR antagonists are already used to treat heart failure where their use decreases mortality and morbidity over and above the use of traditional therapies alone. However, more data are needed to establish the benefits of MR antagonists in diabetes, obesity, and metabolic syndrome.

Cardiovascular Risk in Primary Hyperaldosteronism

After the first cases of primary aldosteronism were described and characterized by Conn, a substantial body of experimental and clinical evidence about the long-term effects of excess aldosterone on the cardiovascular system was gathered over the last 5 decades. The prevalence of primary aldosteronism varies considerably between different studies among hypertensive patients, depending on patient selection, the used diagnostic methods, and the severity of hypertension. Prevalence rates vary from 4.6 to 16.6% in those studies in which confirmatory tests to diagnose primary aldosteronism were used. There is also growing evidence indicating that prolonged exposure to elevated aldosterone concentrations is associated with target organ damage in the heart, kidney, and arterial wall, and high cardiovascular risk in patients with primary aldosteronism. Therefore, the aim of treatment should not be confined to BP normalization and hypokalemia correction, but rather should focus on restoring the deleterious effects of excess aldosterone on the cardiovascular system. Current evidence convincingly demonstrates that both surgical and medical treatment strategies beneficially affect cardiovascular outcomes and mortality in the long term. Further studies can be expected to provide better insight into the relationship between cardiovascular risk and complications and the genetic background of primary aldosteronism.