Prevalence of Primary Aldosteronism among Unselected Hypertensive Patients: A Prospective Study Based on the Use of an Aldosterone/Renin Ratio above 25 as a Screening Test

Improving Detection Rates for Primary Aldosteronism

Primary aldosteronism (PA), once considered a rare disease, is being increasingly recognized as an important cause of hypertension. It is associated with higher rates of cardiovascular complications compared to blood pressure-matched essential hypertension. Targeted treatments are available which can mitigate the excess cardiovascular risks and, in some cases, cure hypertension. Making a timely diagnosis of PA is, therefore, highly beneficial for patients. Furthermore, numerous studies from different parts of the world have found PA to be a relatively common disease that can affect patients in any stage of hypertension, regardless of their age or potassium levels. Despite this well-established data, the current rate of PA detection is appallingly low, much below its actual prevalence. This review explores the challenges that clinicians often face in diagnosing PA and offers strategies that may improve the detection of this potentially curable form of hypertension.

Detecting primary aldosteronism in Australian primary care: a prospective study

OBJECTIVE

To assess the identification of primary aldosteronism (PA) in newly diagnosed, treatment-naïve patients with hypertension by screening in primary care.

DESIGN

Prospective study.

SETTING

General practices in the South Eastern Melbourne Primary Health Network with at least three general practitioners and general practices elsewhere in Victoria that had referred patients to the Endocrine Hypertension Clinic at Monash Health, 2017-2020.

PARTICIPANTS

Adults (18-80 years) with newly diagnosed hypertension (measurements of systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg on at least two occasions) and not taking antihypertensive medications were screened for PA by assessing their aldosterone-to-renin ratio (ARR). Participants with two ARR values exceeding 70 pmol/mU underwent saline suppression testing at the Endocrine Hypertension Service (Monash Health) to confirm the diagnosis of PA.

MAIN OUTCOME MEASURES

Prevalence of PA (number of patients with confirmed PA divided by number screened).

RESULTS

Sixty-two of 247 screened participants had elevated ARR values on screening (25%); for 35 people (14%; 95% CI, 10-19%), PA was confirmed by saline suppression testing. Baseline characteristics (mean age, sex distribution, median baseline blood pressure levels, and serum potassium concentration) were similar for people with or without PA.

CONCLUSION

PA was diagnosed in 14% of patients with newly diagnosed hypertension screened by GPs, indicating a potential role for GPs in the early detection of an important form of secondary hypertension for which specific therapies are available.

Incidence of Primary Aldosteronism in Patients with Hypokalemia (IPAHK+): Study Design and Baseline Characteristics

Hypokalemia plays a central role for case finding, course, treatment decision, and prognosis of patients with primary aldosteronism. However, to date there is a lack of high-level evidence about the incidence of primary aldosteronism in hypokalemic patients. The IPAHK⁺study is an epidemiological, cross-sectional, monocentric study to provide evidence on the incidence of PA in a hypokalemic population. The aim of the current analysis was to describe the baseline characteristics of the first 100 patients eligible for study inclusion. The recruitment of patients with hypokalemia (≤3 mmol/l) is carried out continuously on a referral-basis by the central laboratory of the University Hospital Zurich through an automated suitability testing and data delivery system. The careful evaluation of the first 100 reported patients was based on the available reporting system. Out of 28 140 screened patients, 222 (0.79%) were identified with a serum potassium value of≤3 mmol/l (mean 2.89±0.02 mmol/l). Mean potassium levels were slightly lower in non-hypertensive subjects compared to hypertensive subjects (mean difference 0.07 mmol/l, p=0.033), while no significant difference was found between the sexes and patients with and without the diagnosis of primary aldosteronism, atrial fibrillation, or the use of diuretics. The incidence of PA was 4% in the total population studied and 7.5% in the subgroup of hypertensive patients. In conclusion, the continuous enrollment of patients from the IPHAK⁺hypokalemia registry into the IPAHK⁺trial will provide evidence about the actual incidence of primary aldosteronism in a hypokalemic outpatient population.

Regression of left ventricular hypertrophy in primary aldosteronism after adrenalectomy: a meta-analysis of echocardiographic studies

AIM

Available evidence on regression of left ventricular (LV) hypertrophy in patients with primary aldosteronism after unilateral adrenalectomy is scanty. We performed a systematic meta-analysis of echocardiographic studies to provide an updated and comprehensive information on this issue.

METHODS

The PubMed, OVID-MEDLINE and Cochrane library databases were analyzed to search English-language articles published from 1 January 1990 up to 30 June 2020. Studies were identified by using MeSH terms and crossing the following search items: 'primary aldosteronism' 'Conn's syndrome' 'adrenalectomy', with 'cardiac damage', 'hypertensive heart disease' 'left ventricular mass', 'left ventricular hypertrophy', 'left ventricular hypertrophy regression', 'echocardiography'.

RESULTS

A total of 629 hypertensive patients with primary aldosteronism (mean age 49 years, 45% men) were included in 14 studies. Baseline and postintervention pooled mean LV mass/BSA values were 134 ± 4 and 108 ± 3 g/m2 [standard means difference (SMD) -0.42 ± 0.05, confidence interval (CI) -0.52/-0.32, P < 0.0001]; corresponding values for LV mass/h2.7 were 56 ± 2 and 49 ± 1 g/h2.7 (SMD -0.45 ± 0.06, CI -0.52/-0.36, P < 0.0001). Adrenalectomy, followed by a marked decrease in blood pressure, was associated with a decrease in relative wall thickness (SMD -0.17 ± 0.06, CI -0.31/-0.03, P < 0.01) as well as in the number of antihypertensive drugs (SMD -0.45 ± 0.04, CI -0.50-0.32, P < 0.0001).

CONCLUSION

The present meta-analysis suggests that adrenalectomy in patients with primary aldosteronism exerts a beneficial effect on LV structure and geometry by reducing the burden of LV hypertrophy and LV concentric geometry.

Proteomic Profile of Urinary Extracellular Vesicles Identifies AGP1 as a Potential Biomarker of Primary Aldosteronism

CONTEXT

Primary aldosteronism (PA) represents 6% to 10% of all essential hypertension patients and is diagnosed using the aldosterone-to-renin ratio (ARR) and confirmatory studies. The complexity of PA diagnosis encourages the identification of novel PA biomarkers. Urinary extracellular vesicles (uEVs) are a potential source of biomarkers, considering that their cargo reflects the content of the parent cell.

OBJECTIVE

We aimed to evaluate the proteome of uEVs from PA patients and identify potential biomarker candidates for PA.

METHODS

Second morning spot urine was collected from healthy controls (n = 8) and PA patients (n = 7). The uEVs were isolated by ultracentrifugation and characterized. Proteomic analysis on uEVs was performed using LC-MS Orbitrap.

RESULTS

Isolated uEVs carried extracellular vesicle markers, showed a round shape and sizes between 50 and 150 nm. The concentration of uEVs showed a direct correlation with urinary creatinine (r = 0.6357; P = 0.0128). The uEV size mean (167 ± 6 vs 183 ± 4nm) and mode (137 ± 7 vs 171 ± 11nm) was significantly smaller in PA patients than in control subjects, but similar in concentration. Proteomic analysis of uEVs from PA patients identified an upregulation of alpha-1-acid glycoprotein 1 (AGP1) in PA uEVs, which was confirmed using immunoblot. A receiver operating characteristic curve analysis showed an area under the curve of 0.92 (0.82 to 1; P = 0.0055).

CONCLUSION

Proteomic and further immunoblot analyses of uEVs highlights AGP1 as potential biomarker for PA.

How common is primary aldosteronism?

PURPOSE OF REVIEW

Primary aldosteronism, characterized by renin-independent aldosterone secretion from one or both adrenal glands, is the most common and modifiable form of secondary hypertension. The prevalence of primary aldosteronism is increasingly recognized to be much higher than previously thought with many cases still undetected.

RECENT FINDINGS

Prior prevalence studies on primary aldosteronism have reported a wide range of estimates due to heterogeneity of both disease definitions and study populations such that it is difficult to claim a single point estimate. More recent evidence demonstrates that primary aldosteronism, as defined by conventional biochemical diagnostic criteria, is highly prevalent within populations where it is not typically considered such as mild-to-moderate hypertension, prehypertension, and even normotension. Yet, our current screening approach fails to capture many cases. Furthermore, there is mounting evidence that renin-independent aldosteronism exists as a continuum of disease that extends below the current biochemical diagnostic thresholds used to define primary aldosteronsim and has clinically relevant treatment and outcome implications for a much broader patient population. Indeed, much of what we current label as 'essential hypertension' is, in fact, renin-independent aldosterone-mediated hypertension.

SUMMARY

Primary aldosteronism and milder forms of renin-independent aldosteronism are highly prevalent, yet vastly under-recognized, in the general population.

Hypokalemia and the Prevalence of Primary Aldosteronism

Hypokalemia is closely linked with the pathophysiology of primary aldosteronism (PA). Although hypokalemic PA is less common than the normokalemic course of the disease, hypokalemia is of particular importance for the manifestation and development of comorbidities. Specifically, a growing body of evidence demonstrates that hypokalemia in PA patients is associated with a more severe disease course regarding cardiovascular and metabolic morbidity and mortality. It is also well appreciated that low potassium levels per se can promote or exacerbate hypertension. The spectrum of hypokalemia-related symptoms ranges from asymptomatic courses to life-threatening conditions. Hypokalemia is found in 9-37% of all cases of PA with a predominance in patients with aldosterone producing adenoma. Conversely, hypokalemia resolves in almost 100% of cases after both, specific medical or surgical treatment of the disease. However, to date, high-level evidence about the prevalence of primary aldosteronism in a hypokalemic population is missing. Epidemiological data are expected from the recently launched IPAHK+study ("Incidence of Primary Aldosteronism in Patients with Hypokalemia").

Development of a clinical decision tool to reduce diagnostic testing for primary aldosteronism in patients with difficult-to-control hypertension

BACKGROUND

Satisfactory tools to preclude low-risk patients from intensive diagnostic testing for primary aldosteronism (PA) are lacking. Therefore, we aimed to develop a decision tool to determine which patients with difficult-to-control hypertension have a low probability of PA, thereby limiting the exposure to invasive testing while at the same time increasing the efficiency of testing in the remaining patients.

METHODS

Data from consecutive patients with difficult-to-control hypertension, analysed through a standardized diagnostic protocol between January 2010 and October 2017 (n = 824), were included in this cross-sectional study. PA was diagnosed by a combined approach: 1) elevated aldosterone-to-renin ratio (> 5.0 pmol/fmol/s), confirmed with 2) non-suppressible aldosterone after standardized saline infusion (≥280 pmol/L). Multivariable logistic regression analyses including seven pre-specified clinical variables (age, systolic blood pressure, serum potassium, potassium supplementation, serum sodium, eGFR and HbA1c) was performed. After correction for optimism, test reliability, discriminative performance and test characteristics were determined.

RESULTS

PA was diagnosed in 40 (4.9%) of 824 patients. Predicted probabilities of PA agreed well with observed frequencies and the c-statistic was 0.77 (95% confidence interval (95%CI) 0.70-0.83). Predicted probability cut-off values of 1.0-2.5% prevented unnecessary testing in 8-32% of the patients with difficult-to-control hypertension, carrying sensitivities of 0.98 (95%CI 0.96-0.99) and 0.92 (0.83-0.97), and negative predictive values of 0.99 (0.98-1.00) and 0.99 (0.97-0.99).

CONCLUSIONS

With a decision tool, based on seven easy-to-measure clinical variables, patients with a low probability of PA can be reliably selected and a considerable proportion of patients with difficult-to-control hypertension can be spared intensive diagnostic testing.

Primary aldosteronism is a public health issue: challenges and opportunities

A significant proportion of hypertension (potentially more than 5% in the general population) is due to primary aldosteronism (PA) which carries a worse prognosis when compared with blood pressure-matched essential hypertension. Effective targeted treatments are available which mitigate many of the cardiovascular complications of untreated PA. Despite this, the detection rate of PA in primary care is sub-optimal. In this review, we explore the challenges contributing to the under-diagnosis of PA in the community, including uncertainties regarding its actual prevalence. In order to detect PA early and offer targeted treatment before adverse cardiovascular consequences develop, routine screening for PA at the time of a diagnosis of hypertension would seem desirable. However, this is limited by a lack of studies to establish whether routine screening in primary care is cost-effective. Newer techniques are also being developed which could lessen the complexity of diagnosing PA. Most importantly, a dramatic increase in awareness of PA, as a treatable cause of hypertension, is needed amongst clinicians who manage hypertension.

Prevalence of Hypokalemia and Primary Aldosteronism in 5100 Patients Referred to a Tertiary Hypertension Unit

Primary aldosteronism (PA) was considered a rare disorder almost always associated with hypokalemia. The widespread screening of patients with hypertension unveiled an increased prevalence of PA with normokalemic hypertension the prevailing phenotype. Many studies have reported the prevalence of hypokalemia in patients with PA; conversely, the prevalence of PA in patients with hypokalemia is unknown. In this retrospective observational study, we define the prevalence of hypokalemia in referred patients with hypertension and the prevalence of PA in patients with hypokalemia and hypertension. Hypokalemia was present in 15.8% of 5100 patients with hypertension, whereas 76.9% were normokalemic, and 7.3% hyperkalemic. The prevalence of PA in patients with hypokalemia was 28.1% and increased with decreasing potassium concentrations up to 88.5% of patients with spontaneous hypokalemia and potassium concentrations <2.5 mmol/L. A multivariate regression analysis demonstrated the association of hypokalemia with the occurrence of cardiovascular events independent of PA diagnosis. An association of PA with the occurrence of cardiovascular events and target organ damage independent of hypokalemia was also demonstrated. In conclusion, our results confirm that PA is a frequent cause of secondary hypertension in patients with hypokalemia, and the presence of hypertension and spontaneous hypokalemia are strong indications for PA diagnosis. Finally, we show that PA and hypokalemia are associated with an increased risk of cardiovascular events.

Prevalence, diagnosis and outcomes of treatment for primary aldosteronism

Primary aldosteronism (PA) is the most common potentially curable form of hypertension. The overproduction of aldosterone leads to an increased risk of cardiovascular and cerebrovascular events as well as adverse effects to the heart and kidney and psychological disorders. PA is mainly caused by unilateral aldosterone excess due to an aldosterone-producing adenoma or bilateral excess due to bilateral adrenocortical hyperplasia. The diagnostic work-up of PA comprises three steps: screening, confirmatory testing and differentiation of unilateral surgically-correctable forms from medically treated bilateral PA. These specific treatments can mitigate or reverse the increased risks associated with PA. Herein we summarise the prevalence, outcomes and current and future clinical approaches for the diagnosis of primary aldosteronism.

Primary aldosteronism in a general population sample. The Czech post-MONICA study

Purpose: Primary aldosteronism (PA) is considered the most common form of secondary hypertension, however, its prevalence, particularly in a general population, is still a matter of debate. The aim of our study was to evaluate the prevalence of PA in a randomly selected general population sample.Materials and methods: A total of 1940 individuals (1% population random sample) aged 25-64 years were screened for major cardiovascular risk factors in six districts of the Czech Republic. Hypertension was defined as a mean of two blood pressure readings ≥140/90 mmHg at one visit or taking antihypertensive medication. Within this population, 740 individuals were labelled as hypertensives and 650 of them sampled for the analysis of direct plasma renin and serum aldosterone. The diagnosis of PA was based on elevated serum aldosterone, low plasma renin and high aldosterone/renin (ARR) ratio and was also verified by a confirmatory test with saline infusion.Results: Positive ARR was found in 52 (8%) individuals (64% women, 36% men, however, due to substatntial proportion of reluctatnt participants to undergo a further work-up (27%), we could confirm the diagnosis of PA only in 13 of them (2%). Aldosterone-producing adenoma was found in one case only, seven patients had idiopathic type and five individuals refused potential surgical treatment therefore, adrenal venous sampling was not performed.Conclusion: Elevated serum aldosterone together with low renin and high ARR were found in 52 (8%) of hypertensives selected from a general population sample, however, the diagnosis of PA was confirmed only in 13 of them (2%). This study based on a general population survey highlighted the difficulty of conducting epidemiological studies on primary aldosteronism in a relatively healthy cohort part of whom did not provide the level of collaboration that is necessary to assess the true prevalence of this condition.

Incidence of Acute Kidney Injury after Adrenalectomy in Patients with Primary Aldosteronism

Background

Aldosterone-induced glomerular hyperfiltration can lead to masked preoperative renal dysfunction in primary aldosteronism(PA) patients. We evaluated whether PA patients had a higher prevalence of acute kidney injury (AKI) after unilateral adrenalectomy. In addition, we identified risk factors for AKI in these subjects.

Methods

This retrospective study included 107 PA patients, and 186 pheochromocytoma patients as a control group, all of whom underwent adrenalectomy between January 2006 and November 2017 at Yonsei University Severance Hospital. The primary outcome was AKI within 48 hours after adrenalectomy. Univariate and multivariate logistic regression analyses were performed to identify predictors of AKI after adrenalectomy.

Results

Overall incidence of AKI was 49/293 (16.7%). In PA patients, the incidence of AKI was 29/107 (27.1%). In contrast, incidence of AKI was 20/186 (10.7%) in pheochromocytoma patients. Univariate and multivariate logistic regression analysis both showed a higher risk of postoperative AKI in PA patients compared to pheochromocytoma patients. In addition, old age, diabetes, longer duration of hypertension, lower preoperative estimated glomerular filtration rate, high aldosterone-cortisol ratio (ACR) and lateralization index (LI) were identified as independent risk factors for postoperative AKI in PA patients after unilateral adrenalectomy.

Conclusion

Incidence and risk of postoperative AKI were significantly higher in PA patients after surgical treatment. High ACR on the tumor side and high LI were associated with higher risk of AKI in PA patients compared to pheochromocytoma patients.

[Primary hyperaldosteronism: difficulties in diagnosis]

Primary hyperaldosteronism (PA) - is the clinical syndrome, results from autonomous of the major regulators of secretion, aldosterone overproduction by a tumorous or hyperplastic tissue in adrenal cortex. Being the most frequent cause of secondary hypertension, PA may be represented by disorders with unilateral or bilateral aldosterone overproduction and differential diagnosis between them is crucial for choosing a right therapeutic approache: lifelong medical therapy with mineralocorticoid receptor antagonists or unilateral adrenalectomy. Adrenal venous sampling (AVS) is currently the «gold standard» test for identifying laterality of excess hormone production, unlike imaging tests, sensitivity and specificity of which is not enough, due to inability to evaluate functional activity with confidence, and also to limitations in detecting tiny abnormalities of adrenals, such as microadenoma or hyperplasia. Excluding certain cases, AVS is recommended to patients with confirmed PA, planning surgical treatment, to determine the lateralization of aldosterone hypersecretion. Described clinical case of patient with confirmed lateralization from adrenal without any detected lesions on CT-imaging and nonfunctioning tumour on contralateral side, highlights the importance of using AVS for decision to refer patients for surgery.

Predictors of Clinical Success After Surgery for Primary Aldosteronism in the Japanese Nationwide Cohort

Context

Aldosterone-producing adenomas are a curable subtype of primary aldosteronism (PA); however, hypertension persists in some patients after adrenalectomy.

Objective

To identify factors associated with, and develop prediction models for, blood pressure (BP) normalization or improvement after adrenalectomy.

Design

Retrospective analysis of patients treated between 2006 and 2018, with a 6-month follow-up.

Setting

A nationwide, 29-center Japanese registry encompassing 15 university hospitals and 14 city hospitals.

Patients

We categorized 574 participants in the Japan Primary Aldosteronism Study, who were diagnosed with PA and underwent adrenalectomy, as BP normalized or improved, on the basis of their presentations at 6 months postsurgery.

Main Outcome Measure

The rate of complete, partial, and absent clinical success. Predictive factors related to BP outcomes after PA surgery were also evaluated.

Results

Complete clinical success was achieved in 32.6% and partial clinical success was achieved in 53.0% of the patients at 6 months postsurgery. The following five variables were independent predictors for BP normalization: ≤7 years of hypertension, body mass index ≤25 kg/m², no more than one antihypertensive medication, absence of medical history of diabetes, and female sex. The area under the receiver operator characteristic curve was 0.797 in the BP normalization model.

Conclusion

We established models that predicted postoperative BP normalization in patients with PA. These should be useful for shared decision-making regarding adrenalectomy for PA.

The Prevalence of Primary Aldosteronism and Evolving Approaches for Treatment

Over six decades since primary aldosteronism was first described, much has been learned about its prevalence and optimal treatment. Estimates of the prevalence of primary aldosteronism have increased considerably over the years, even exceeding 20% in some populations of resistant hypertension. Even in patients with normal blood pressures, the prevalence of overt primary aldosteronism and dysregulated aldosterone production may be more common than appreciated. Emerging data support the concept that primary aldosteronism may be better characterized as a continuum of renin-independent aldosterone production, whose severity influences the clinical presentation and risk for incident cardiovascular disease. Mineralocorticoid receptor antagonists and adrenalectomy are the mainstay treatments for primary aldosteronism and have long been considered equally efficacious. However, recent data suggest that while surgical adrenalectomy can effectively reduce cardiovascular risk, mineralocorticoid receptor antagonist therapy may require a physiologic approach to optimize efficacy.

Screening of primary aldosteronism by clinical features and daily laboratory tests: combination of urine pH, sex, and serum K

OBJECTIVE

To develop and validate a scoring system for selection of patients who should proceed to endocrinologic examinations of primary aldosteronism in newly diagnosed hypertensive patients.

METHODS

A multivariate logistic regression analysis for primary aldosteronism was undertaken by use of seven possible primary aldosteronism markers, age less than 40 years, female sex, moderate-to-severe hypertension, hypokalemia, serum Na minus Cl at least 40 mmol/l, serum uric acid 237.92 μmol/l or less (4.0 mg/dl), and urine pH (U-pH) at least 7.0, in consecutive outpatients newly diagnosed with hypertension. The diagnostic criteria of primary aldosteronism were plasma aldosterone concentration-to-plasma renin activity ratio [ARR, (ng/dl)/(ng/ml per h)] at least 20 and at least one positive result in four types of challenge tests.

RESULTS

Of 130 patients, 24 were diagnosed with primary aldosteronism. The area under the receiver operating characteristic curve (AUC) for a logistic model incorporating all possible primary aldosteronism markers was 0.73 [95% confidence interval (CI): 0.61-0.85]. Removing high U-pH, female sex, and hypokalemia from the full model decreased the AUC by 0.059, 0.035, and 0.011, respectively. We devised pH of urine, female sex, low serum K (PFK) score, in which one point each was assigned to high U-pH, female sex, and hypokalemia. The prevalences of primary aldosteronism in patients with 0, 1, 2, and 3 points were 11, 14, 42, and 60%, respectively. In external validation datasets (n = 106), AUC of PFK score was significantly higher than that of hypokalemia alone (0.73, 95% CI: 0.63-0.83 vs. 0.53, 95% CI: 0.44-0.63, P < 0.01).

CONCLUSION

PFK score may be a better parameter than hypokalemia alone for identifying patients with a high probability of having primary aldosteronism.

Change in kidney function after unilateral adrenalectomy in patients with primary aldosteronism: identification of risk factors for decreased kidney function

PURPOSE

Glomerular filtration rate (GFR) has been reported to decrease after unilateral adrenalectomy in patients with primary aldosteronism (PA). The aim of this study was to identify clinical predictors for decreased GFR after adrenalectomy in patients with PA.

METHODS

The records of 187 patients (98 patients with PA and 89 with non-PA adrenal disease) who were followed up for at least 6 months after unilateral adrenalectomy were retrospectively analyzed. Estimated GFR (eGFR) was investigated at 1, 3, and 6 months postoperatively. Preoperative risk factors for eGFR% decline at 1 month ([preoperative eGFR-eGFR at 1 month]/preoperative eGFR × 100) and postoperative CKD development were investigated.

RESULTS

The eGFR decreased significantly at 1 month and remained stable in the PA group. However, there were no significant changes in eGFR in the non-PA group over the 6-month period. In the PA group, a high preoperative eGFR and high aldosterone to renin ratio (ARR) were independently associated with eGFR% decline at 1 month. In patients with PA but without preoperative CKD (n = 68), a low preoperative eGFR and high ARR were independent risk factors for developing postoperative CKD. The best preoperative cut-off values of eGFR and ARR for predicting the development of postoperative CKD were ≤ 102 ml/min/1.73 m² and ≥ 448 ng/dl:ng/ml/h, respectively.

CONCLUSIONS

Renal function deteriorated significantly after unilateral adrenalectomy in patients with PA. Clinicians must pay attention to postoperative renal function in PA patients at elevated risk of developing decreased kidney function.

Should all Hypertensive Patients be Screened for Primary Aldosteronism?

Primary aldosteronism (PA) is not only a leading cause of secondary and resistant hypertension, but is also quite frequent in unselected hypertensive patients. Moreover, PA is associated with increased cardiovascular risk, which is disproportionate to BP levels. In addition, timely diagnosis of PA and prompt initiation of treatment attenuate this increased risk. On the other hand, there are limited data regarding the usefulness of screening for PA in all asymptomatic or normokalemic hypertensive patients. More importantly, until now, no well-organized, large-scale, prospective, randomized controlled trial has proved the effectiveness of screening for PA for improving clinical outcome. Accordingly, until more relevant data are available, screening for PA should be considered in hypertensive patients with spontaneous or diuretic-induced hypokalemia as well as in those with resistant hypertension. However, screening for PA in all hypertensive patients cannot be currently recommended.

Prevalence of primary aldosteronism in primary care: a cross-sectional study

BACKGROUND

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension. Reported prevalences of PA vary considerably because of a large heterogeneity in study methodology.

AIM

To examine the proportion of patients with PA among patients with newly diagnosed, never treated hypertension.

DESIGN AND SETTING

A cross-sectional study set in primary care.

METHOD

GPs measured aldosterone and renin in adult patients with newly diagnosed, never treated hypertension. Patients with elevated aldosterone-to-renin ratio and increased plasma aldosterone concentration underwent a saline infusion test to confirm or exclude PA. The source population was meticulously assessed to detect possible selection bias.

RESULTS

Of 3748 patients with newly diagnosed hypertension, 343 patients were screened for PA. In nine out of 74 patients with an elevated aldosterone-to-renin ratio and increased plasma aldosterone concentration the diagnosis of PA was confirmed by a saline infusion test, resulting in a prevalence of 2.6% (95% confidence interval = 1.4 to 4.9). All patients with PA were normokalaemic and 8 out of 9 patients had sustained blood pressure >150/100 mmHg. Screened patients were younger (P<0.001) or showed higher blood pressure (P<0.001) than non-screened patients.

CONCLUSION

In this study a prevalence of PA of 2.6% in a primary care setting was established, which is lower than estimates reported from other primary care studies so far. This study supports the screening strategy as recommended by the Endocrine Society Clinical Practice Guideline. The low proportion of screened patients (9.2%), of the large cohort of eligible patients, reflects the difficulty of conducting prevalence studies in primary care clinical practice.

The Potential Role of Primary Care in Case Detection/Screening of Primary Aldosteronism

Endocrine hypertension, particularly primary aldosteronism (PA), was previously considered to account for less than 1% of all hypertension and was suspected only when patients presented with spontaneous hypokalemia. However, the last 20 years of PA research has now clearly shown that PA is not a rarity, but rather, may account for up to 13% of unselected hypertensive individuals and between 10% and 20% of those with resistant hypertension. Most of these patients do not have spontaneous hypokalemia. The population prevalence of PA likely far exceeds actual detection rates in routine clinical care. As PA represents one of the most common, potentially reversible causes of hypertension, and is associated with significant cardiovascular complications over the long term, it is clear that a pragmatic strategy for targeted case detection in primary care is needed.

CTNNB1 Mutation in Aldosterone Producing Adenoma

Discoveries of somatic mutations permit the recognition of subtypes of aldosterone-producing adenomas (APAs) with distinct clinical presentations and pathological features. Catenin β1 (CTNNB1) mutation in APAs has been recently described and discussed in the literature. However, significant knowledge gaps still remain regarding the prevalence, clinical characteristics, pathophysiology, and outcomes in APA patients harboring CTNNB1 mutations. Aberrant activation of the Wnt/β-catenin signaling pathway will further modulate tumorigenesis. We also discuss the recent knowledge of CTNNB1 mutation in adrenal adenomas.

Prevalence and Clinical Manifestations of Primary Aldosteronism Encountered in Primary Care Practice

BACKGROUND

Despite being widely recognized as the most common form of secondary hypertension, among the general hypertensive population the true prevalence of primary aldosteronism (PA) and its main subtypes, aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH), remains a matter of debate.

OBJECTIVES

This study sought to determine the prevalence and clinical phenotype of PA in a large cohort of unselected patients with hypertension, consecutively referred to our hypertension unit, by 19 general practitioners from Torino, Italy.

METHODS

Following withdrawal from all interfering medications, patients were screened for PA using the ratio of serum aldosterone to plasma renin activity. PA was diagnosed according to Endocrine Society guidelines. The diagnosis was confirmed or excluded by an intravenous saline infusion test or captopril challenge test and subtype differentiation was performed by adrenal computed tomography scanning and adrenal vein sampling, using strict criteria to define successful cannulation and lateralization of aldosterone production.

RESULTS

A total of 1,672 primary care patients with hypertension (569 newly diagnosed and 1,103 patients already diagnosed with arterial hypertension) were included in the study. A total of 99 patients (5.9%) were diagnosed with PA and conclusive subtype differentiation by adrenal vein sampling was made in 91 patients (27 patients with an APA and 64 patients with BAH). The overall prevalence of PA increased with the severity of hypertension, from 3.9% in stage 1 hypertension to 11.8% in stage 3 hypertension. Patients with PA more frequently displayed target organ damage and cardiovascular events compared with those without PA, independent of confounding variables.

CONCLUSIONS

Our results demonstrated that PA is a frequent cause of secondary hypertension, even in the general population of patients with hypertension, and indicates that most of these patients should be screened for PA.

Safety of Temporary Discontinuation of Antihypertensive Medication in Patients With Difficult-to-Control Hypertension

Successful control of blood pressure relies on identification of secondary causes and contributing factors of hypertension. As antihypertensive medication can interfere with diagnostic investigations, temporary discontinuation of medication is advised. However, there are concerns about the safety of temporary discontinuation of antihypertensive medication in patients with difficult-to-control hypertension. We assessed the occurrence of adverse cardiovascular and cerebrovascular events potentially attributable to temporary discontinuation of antihypertensive medication between February 2010 and March 2016 (n=604) in our Analysis of Complicated Hypertension screening program. A reference group (n=604) was extracted from the SMART study (Second Manifestations of Arterial Disease) cohort (comprising a similar cohort at our hospital in whom medication was not stopped) and individually matched for blood pressure, age, sex, and history of cardiovascular disease. Discontinuation of medication was well tolerated; 62% reported no complaints, 24% had mild discomfort that could be left untreated, and 14% experienced complaints that required prescription of antihypertensive escape medication. Three major adverse events were observed in the Analysis of Complicated Hypertension group between discontinuation of medication and 30 days after restart of medication (event rate=31.2 events per 1000 patient-year). In the reference cohort, 5 cardiovascular events were observed during a similar follow-up period (event rate=51.2 events per 1000 patient-year). In conclusion, discontinuation of antihypertensive medication for the diagnostic evaluation of hypertension does not increase the acute risk of cardiovascular events when performed in a well-controlled setting in specialized hospitals with appropriate protocols for monitoring safety.

Advances in our understanding of the prognosis of adrenal incidentaloma

As cross-sectional abdominal imaging is used increasingly, adrenal incidentaloma (AI) are being found frequently and present a clinical dilemma. The vast majority are benign and non-functioning, but a minority represent incidentally found functional or malignant tumours. In this review we summarise the current clinical, biochemical and radiological investigation of AI and discuss recent advances that differentiate clinically inconsequential lesions from functional and/or malignant AI. Areas covered: Prevalence, natural history, biochemical and radiological assessment, indications for surgery and surgical provision. Expert commentary: Well established work-up of AI usually enables benign, non-functioning lesions to be differentiated from functioning and/or malignant AI. In indeterminate lesions recent advances in work-up such as urine steroid profiles measured by gas chromatography /mass spectrometry and functional imaging with 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) in addition to standard investigations have improved characterisation of these lesions. The management of AI showing mild autonomous hypercortisolism without overt features of Cushing's syndrome remains controversial and is discussed in this review.

Subtype prediction in primary aldosteronism: measurement of circadian variation of adrenocortical hormones and 24-h urinary aldosterone

OBJECTIVE

Currently, adrenal venous sampling (AVS) is the only reliable method to distinguish unilateral from bilateral hyperaldosteronism in primary aldosteronism (PA). However, AVS is costly and time-consuming compared with simple blood tests. In this study, we conducted a retrospective study to determine whether circadian variation in plasma adrenocortical hormone levels (i.e. aldosterone, cortisol and ACTH) and a 24-h urinary aldosterone could contribute to the clinical differentiation between unilateral hyperaldosteronism (UHA) and bilateral hyperaldosteronism (BHA).

DESIGN

In 64 patients who were diagnosed with PA and underwent AVS, 32 and 22 patients were diagnosed with UHA and BHA, respectively. Plasma adrenocortical hormone levels at 0:00, 6:00, 12:00 and 18:00 and 24-h urinary aldosterone under a condition of 6 g daily dietary sodium chloride intake were measured.

RESULTS

Baseline plasma aldosterone concentration (PAC) and 24-h urinary aldosterone level in patients with UHA were significantly higher than in patients with BHA, particularly at 6:00. The area under the ROC curve for PAC at 0:00, 6:00, 12:00 and 18:00 and 24-h urinary aldosterone to discriminate UHA and BHA was 0·839 [95% confidence interval (CI); 0·73-0·95], 0·922 (95% CI; 0·85-1·00), 0·875 (95% CI; 0·78-0·97), 0·811 (95% CI; 0·69-0·93), 0·898 (95% CI; 0·81-0·99), respectively.

CONCLUSIONS

PAC at different blood sampling times and 24-h urinary aldosterone level may be diagnostically helpful in discriminating between UHA and BHA. We believe that these tests could reduce the number of unnecessary AVS procedures.

SFE/SFHTA/AFCE Consensus on Primary Aldosteronism, part 2: First diagnostic steps

In patients with suspected primary aldosteronism (PA), the first diagnostic step, screening, must have high sensitivity and negative predictive value. The aldosterone-to-renin ratio (ARR) is used because it has higher sensitivity and lower variability than other measures (serum potassium, plasma aldosterone, urinary aldosterone). ARR is calculated from the plasma aldosterone (PA) and plasma renin activity (PRA) or direct plasma renin (DR) values. These measurements must be taken under standard conditions: in the morning, more than 2hours after awakening, in sitting position after 5 to 15minutes, with normal dietary salt intake, normal serum potassium level and without antihypertensive drugs significantly interfering with the renin-angiotensin-aldosterone system. To rule out ARR elevation due to very low renin values, ARR screening is applied only if aldosterone is>240pmol/l (90pg/ml); DR values<5mIU/l are assimilated to 5mIU/l and PRA values<0.2ng/ml/h to 0.2ng/ml/h. We propose threshold ARR values depending on the units used and a conversion factor (pg to mIU) for DR. If ARR exceeds threshold, PA should be suspected and exploration continued. If ARR is below threshold or if plasma aldosterone is<240pmol/l (90pg/ml) on two measurements, diagnosis of PA is excluded.

Implication of aortic calcification on persistent hypertension after laparoscopic adrenalectomy in patients with primary aldosteronism

OBJECTIVES

To identify risk factors, including aortic calcification, for persistent hypertension in primary aldosteronism patients undergoing laparoscopic adrenalectomy.

METHODS

Between October 2000 and October 2015, we carried out 101 consecutive laparoscopic adrenalectomies for unilateral primary aldosteronism. Of these, 95 cases with at least 1 year of postoperative follow up were included. These were divided into two study groups based on whether they had normal blood pressure without antihypertensive medications (resolved group) or still required medications (unresolved group) at 1 year after surgery. Variables included age, sex, body mass index, history of hypertension, dosage of antihypertensive medication score, presence of type 2 diabetes, subclinical Cushing syndrome, preoperative renal function, aldosteronoma resolution score and abdominal calcification index. Univariate and multivariate logistic regression analyses were used to assess independent risk factors for persistent hypertension 1 year after surgery.

RESULTS

The complete resolution of hypertension without antihypertensive medication 1 year after adrenalectomy was 36 out of 95 (38%). The preoperative antihypertensive medication score, systolic blood pressure and abdominal calcification index were significantly higher, and the aldosteronoma resolution score were significantly lower in the unresolved group than in the resolved group. Using multivariate logistic regression analysis, independent risk factors significantly correlating with persistent hypertension 1 year after surgery were aldosteronoma resolution score and abdominal calcification index.

CONCLUSIONS

Laparoscopic adrenalectomy for primary aldosteronism is effective in improving blood pressure and reducing the need for antihypertensive medications. Aldosteronoma resolution score and abdominal calcification index represent potential independent risk factors for persistent hypertension 1 year after surgery.

Activating mutations in CTNNB1 in aldosterone producing adenomas

Primary aldosteronism (PA) is the most common cause of secondary hypertension with a prevalence of 5–10% in unreferred hypertensive patients. Aldosterone producing adenomas (APAs) constitute a large proportion of PA cases and represent a surgically correctable form of the disease. The WNT signaling pathway is activated in APAs. In other tumors, a frequent cause of aberrant WNT signaling is mutation in the CTNNB1 gene coding for β-catenin. Our objective was to screen for CTNNB1 mutations in a well-characterized cohort of 198 APAs. Somatic CTNNB1 mutations were detected in 5.1% of the tumors, occurring mutually exclusive from mutations in KCNJ5, ATP1A1, ATP2B3 and CACNA1D. All of the observed mutations altered serine/threonine residues in the GSK3β binding domain in exon 3. The mutations were associated with stabilized β-catenin and increased AXIN2 expression, suggesting activation of WNT signaling. By CYP11B2 mRNA expression, CYP11B2 protein expression, and direct measurement of aldosterone in tumor tissue, we confirmed the ability for aldosterone production. This report provides compelling evidence that aberrant WNT signaling caused by mutations in CTNNB1 occur in APAs. This also suggests that other mechanisms that constitutively activate the WNT pathway may be important in APA formation.

Novel somatic mutations and distinct molecular signature in aldosterone-producing adenomas

Aldosterone-producing adenomas (APAs) are found in 1.5-3.0% of hypertensive patients in primary care and can be cured by surgery. Elucidation of genetic events may improve our understanding of these tumors and ultimately improve patient care. Approximately 40% of APAs harbor a missense mutation in the KCNJ5 gene. More recently, somatic mutations in CACNA1D, ATP1A1 and ATP2B3, also important for membrane potential/intracellular Ca(2) (+) regulation, were observed in APAs. In this study, we analyzed 165 APAs for mutations in selected regions of these genes. We then correlated mutational findings with clinical and molecular phenotype using transcriptome analysis, immunohistochemistry and semiquantitative PCR. Somatic mutations in CACNA1D in 3.0% (one novel mutation), ATP1A1 in 6.1% (six novel mutations) and ATP2B3 in 3.0% (two novel mutations) were detected. All observed mutations were located in previously described hotspot regions. Patients with tumors harboring mutations in CACNA1D, ATP1A1 and ATP2B3 were operated at an older age, were more often male and had tumors that were smaller than those in patients with KCNJ5 mutated tumors. Microarray transcriptome analysis segregated KCNJ5 mutated tumors from ATP1A1/ATP2B3 mutated tumors and those without mutation. We observed significant transcription upregulation of CYP11B2, as well as the previously described glomerulosa-specific gene NPNT, in ATP1A1/ATP2B3 mutated tumors compared to KCNJ5 mutated tumors. In summary, we describe novel somatic mutations in proteins regulating the membrane potential/intracellular Ca(2) (+) levels, and also a distinct mRNA and clinical signature, dependent on genetic alteration.

Development of a novel nomogram to predict hypertension cure after laparoscopic adrenalectomy in patients with primary aldosteronism

BACKGROUND

Primary aldosteronism is the most common curable cause of secondary hypertension. Despite resection, however, many patients with primary aldosteronism continue to require antihypertensive drugs to control their blood pressure. Although many patients with primary aldosteronism want to know the postoperative probability of hypertension cure before surgery, there are no predictive models calculating its probability. We therefore developed a nomogram to predict hypertension cure in patients with primary aldosteronism after laparoscopic adrenalectomy.

METHODS

We retrospectively surveyed 132 Japanese patients with primary aldosteronism who were treated by unilateral laparoscopic adrenalectomy. Hypertension cure was defined as normal blood pressure (<140/90 mmHg) without antihypertensive drugs 6 months postoperatively. We developed a novel nomogram that postoperatively predicted cured hypertension in 105 (80 %) randomly selected patients and validated it with the remaining 27 (20 %).

RESULTS

At 6 months, blood pressure had normalized in 42 % of patients without antihypertensive drugs. Duration of hypertension, preoperative number of antihypertensive drug classes, age, and sex were incorporated into a novel nomogram as independent predictors of hypertension cure. The value of the area under the receiver operating characteristics curve for this nomogram was 0.83-which was significantly higher than that of the Aldosteronoma Resolution Score-on internal validation.

CONCLUSIONS

We developed the first nomogram that can accurately predict postoperative hypertension cure in patients with primary aldosteronism. This nomogram can help clinicians calculate the probability of postoperative hypertension cure in patients with primary aldosteronism and objectively inform them of their hypertension outcome before laparoscopic adrenalectomy.

Role of endogenous ACTH on circadian aldosterone rhythm in patients with primary aldosteronism

We recently reported that stimulation with high-dose ACTH caused different responses in terms of aldosterone secretion in aldosterone-producing adenomas (APAs) and idiopathic hyperaldosteronism (IHA) in patients with primary aldosteronism (PA). However, the role of endogenous ACTH in aldosterone secretion in PA has not been systematically evaluated. In this study, we examined diurnal changes in plasma aldosterone concentration (PAC), and changes in PAC after dexamethasone administration in patients with suspected PA, in order to evaluate the effect of endogenous ACTH on aldosterone secretion. Seventy-three patients admitted to Kyoto University Hospital with suspected PA were included. The patients were classified into non-PA, IHA, and APA groups according to the results of captopril challenge test and adrenal venous sampling. PAC at 0900 h (PAC0900), 2300 h (PAC2300), and after 1-mg dexamethasone suppression test (PACdex) was measured and compared among the three groups. The PAC2300/PAC0900 and PACdex/PAC0900 ratios were also analyzed. PAC2300 and PACdex were lower than PAC0900 in all three groups. There were no significant differences in PAC2300/PAC0900 among the three groups. However, PACdex/PAC0900 was significantly lower in the APA group compared with the non-PA and IHA groups. The results of this study indicate that aldosterone secretion in APA patients is more strongly dependent on endogenous ACTH than in IHA and non-PA patients. The results also suggest that factors other than ACTH, such as clock genes, may cause diurnal changes in aldosterone secretion in IHA and non-PA patients.

The value of losartan suppression test in the confirmatory diagnosis of primary aldosteronism in patients over 50 years old

OBJECTIVE

The diagnosis of primary aldosteronism (PA) among the older-aged population has posed a crucial challenge. Among patients over 50 years old, this trial assessed comparability of the performance of two PA diagnostic tests: losartan and captopril suppression tests.

METHODS

A post-hoc subgroup analysis from a prospective cohort was conducted by the TAIPAI (Taiwan Primary Aldosteronism Investigation) group between July 2003 and July 2006. Of the 160 patients in the cohort, 60 patients over 50 years old received captopril and losartan tests to confirm PA.

RESULTS

Among the 60 patients over 50 years old, 31 patients had PA confirmed by standardized protocol. The area under the receiver-operating characteristic (ROC) curve for post-captopril aldosterone was significantly less than that for post-losartan plasma aldosterone concentration (PAC) (0.87 vs 0.94, p=0.02). Using the aldosterone-renin ratio (ARR)>35 with PAC>10 ng/dl, the specificity was 82.76% vs 93.1% and the sensitivity was 77.42% vs 87.10% for the captopril and losartan tests, respectively. The equivalence between the two tests were confirmed by the exact McNemar's test (p=1.0).

CONCLUSION

The losartan test showed comparable accuracy to confirm PA. Verification of this "elderly-friendly" confirmatory test will be the first step to prepare a specific diagnostic model of PA for the older-aged population.

Adrenal nodularity and somatic mutations in primary aldosteronism: one node is the culprit?

CONTEXT

Somatic mutations in genes that influence cell entry of calcium have been identified in aldosterone-producing adenomas (APAs) of adrenal cortex in primary aldosteronism (PA). Many adrenal glands removed for suspicion of APA do not contain a single adenoma but nodular hyperplasia.

OBJECTIVE

The objective of the study was to assess multinodularity and phenotypic and genotypic characteristics of adrenals removed because of the suspicion of APAs.

DESIGN AND METHODS

We assessed the adrenals of 53 PA patients for histopathological characteristics and immunohistochemistry for aldosterone (P450C18) and cortisol (P450C11) synthesis and for KCNJ5, ATP1A1, ATP2B3, and CACNA1D mutations in microdissected nodi.

RESULTS

Glands contained a solitary adenoma in 43% and nodular hyperplasia in 53% of cases. Most adrenal glands contained only one nodule positive for P450C18 expression, with all other nodules negative. KCNJ5 mutations were present in 22 of 53 adrenals (13 adenoma and nine multinodular adrenals). An ATP1A1 and a CACNA1D mutation were found in one multinodular gland each and an ATP2B3 mutation in five APA-containing glands. Mutations were always located in the P450C18-positive nodule. In one gland two nodules containing two different KCNJ5 mutations were present. Zona fasciculata-like cells were more typical for KCNJ5 mutation-containing nodules and zona glomerulosa-like cells for the other three genes.

CONCLUSIONS

Somatic mutations in KCNJ5, ATP1A1, or CACNA1D genes are not limited to APAs but are also found in the more frequent multinodular adrenals. In multinodular glands, only one nodule harbors a mutation. This suggests that the occurrence of a mutation and nodule formation are independent processes. The implications for clinical management remain to be determined.

Hyperaldosteronism: diagnosis, lateralization, and treatment

Primary hyperaldosteronism is an important and commonly unrecognized secondary cause of hypertension. This article provides an overview of the current literature with respect to screening, diagnosis, and lateralization. Selection and outcomes of medical and surgical treatment are discussed.

Predictors of successful outcome after adrenalectomy for primary aldosteronism

The underlying cause of resistant hypertension after adrenalectomy for primary hyperaldosteronism remains controversial. The objective of this study was to identify preoperative factors predictive of resistant hypertension in patients after undergoing retroperitoneoscopic adrenalectomy. Between 2003 and 2009, 124 patients with unilateral aldosterone-producing adenoma or unilateral adrenal hyperplasia underwent retroperitoneoscopic adrenalectomy at our institution. Clinical and biochemical data were reviewed retrospectively at baseline and after a median follow-up time of 59.2 ± 37.2 months. Adrenalectomy cured hypertension in 68 patients (54.8%) and 43 (34.8%) had persistent hypertension that was much easier to control after surgery, whereas 13 patients (10.4%) had continued hypertension and poor blood pressure control. Multivariate regression analysis revealed that the main determinants of postoperative cure were duration of hypertension less than 5 years [odds ratio (OR): 6.515, 95% confidence interval (CI) 2.278-10.293), number of antihypertensive medications ≤2 (OR: 2.939, 95% CI 1.254-5.235), preoperative response to spironolactone (OR: 3.405, 95% CI 1.681-6.985), the TT genotype of the CYP11B2 gene (344 C/T) (OR: 2.765, 95% CI 1.221-4.986), and the presence of adenoma rather than hyperplasia (OR: 5.274, 95% CI 2.150-8.141). The main determinants of surgical cure or control of hypertension in patients with primary hyperaldosteronism were duration of hypertension, number of antihypertensive medications, preoperative response to spironolactone, the presence of adenoma, and CYP11B2 (344 C/T) genotype. Consideration of these factors may help in the evaluation of patients for surgery and for the identification of patients with continued postoperative hypertension that may require more long-term monitoring and treatment.

Prevalence of and risk factors for primary aldosteronism among patients with resistant hypertension in China

OBJECTIVES

It is estimated that there are more than 16 million adults with drug-resistant hypertension in China. Nevertheless, the prevalence of and risk factors for primary aldosteronism, a highly curable condition among adults with drug-resistant hypertension, has not been fully investigated.

METHODS

Between January 2010 and October 2011, a multicenter epidemiologic study was conducted among 1656 patients with resistant hypertension in 11 provinces of China. Serum aldosterone and plasma renin activity were measured in every participant and aldosterone-to-renin ratio (ARR) was calculated. Patients with ARR more than 20 underwent an intravenous (i.v.) sodium infusion test, and diagnosis of primary aldosteronism was established by the presence of unsuppressed postinfusion aldosterone (>8 ng/dl). Patients with biochemically proved primary aldosteronism then underwent adrenal computed tomography (CT) scanning and adrenal vein sampling (AVS) for subtype classification.

RESULTS

Among the 1656 patients, 494 (29.8%) had ARR greater than 20 and underwent i.v. sodium infusion. Of these 494, 118 were diagnosed as primary aldosteronism, yielding a prevalence of 7.1% (95% confidential interval 5.9-8.3%). Seventy of the 118 patients were categorized into unilateral (39) and bilateral (31) by AVS. Generalized additive regression analysis revealed that among all the factors investigated (age of hypertension onset, BMI, family history of hypertension, cigarette smoking, alcohol consumption, diabetes, serum potassium, hyperlipidemia, and creatinine), only age of hypertension onset and serum potassium were independently associated with the presence of primary aldosteronism.

CONCLUSION

The prevalence of primary aldosteronism among Chinese patients with resistant hypertension is relatively lower than that reported previously for other ethnic populations. The screening for primary aldosteronism should be focused on those with early onset hypertension and/or hypokalemia.

Female sex hormones are associated with the reduction of serum sodium and hypertension complications in patients with aldosterone-producing adenoma

This study was conducted to evaluate gender-related differences in clinical characteristics and vascular complications in patients with aldosterone-producing adenomas (APA). Clinical characteristics, biochemical markers and incidence of vascular complications were compared by gender in 187 consecutive patients with APA confirmed by pathological diagnosis. Patients were separated into two groups based on ages either older or younger than 49 years, the average age of menopause among Chinese women (<49 y and ≥49 y). Males had significantly higher BMI than females in the age group of <49 years (p = 0.017). In the <49 years group, males had significantly higher serum sodium levels (p = 0.003). However, no such gender differences in clinical characteristics were observed in patients ≥49 years. A higher proportion of vascular complications was observed in males as compared to females aged <49 years but the difference was not statistically significant (51.4% vs. 34.8%, p = 0.105). The only gender difference observed in vascular complications between patients aged ≥49 years was that a significantly greater proportion of males had cerebrovascular complication compared to females (p = 0.006). Our data suggest that female sex hormones are implicated in reducing serum sodium concentration and vascular complications in female APA patients.

Hypertension

Hypertension is the most common modifiable risk factor for cardiovascular disease. Antihypertensive treatment substantially reduces the risk of heart failure, stroke, and myocardial infarction. Current guidelines recommend screening all adults for high blood pressure (BP). Lifestyle modifications to help control high BP include weight loss, exercise, moderation of alcohol intake, and a diet low in sodium and saturated fats and high in fruits and vegetables. Out-of-office BP monitoring should be used to confirm suspected white coat effect, especially in patients with apparent resistant hypertension.

Preoperative masked renal damage in Japanese patients with primary aldosteronism: identification of predictors for chronic kidney disease manifested after adrenalectomy

OBJECTIVE

Correct interpretation of renal function in patients with primary aldosteronism is difficult before adrenalectomy, because subtle kidney impairment is often masked by glomerular hyperfiltration peculiar to primary aldosteronism. The aim of this study was to investigate postoperative changes in renal function for patients with primary aldosteronism and to identify clinical predictors of chronic kidney disease manifested postoperatively in the patients without pre-existing chronic kidney disease.

METHODS

Records of 78 Japanese patients who underwent unilateral adrenalectomy for primary aldosteronism were retrospectively surveyed. Patients who had been followed up for <6 months were excluded. Preoperative and postoperative estimated glomerular filtration rate were compared. Furthermore, uni- and multivariate analyses were carried out to identify clinical predictors for chronic kidney disease manifested postoperatively.

RESULTS

Patients with preoperative estimated glomerular filtration rate ≥60 mL/min/1.73 m(2) showed a significant decrease after surgery. Of the 66 patients without pre-existing chronic kidney disease, 24 developed chronic kidney disease postoperatively. Multivariate logistic regression analysis identified a medical history of dyslipidemia as an independent predictor for chronic kidney disease manifested postoperatively. According to univariate analyses, additional factors associated with postoperative manifestation of chronic kidney disease included older age, lower diastolic blood pressure and lower estimated glomerular filtration rate.

CONCLUSIONS

The interpretation of normal or abnormal renal functions by examining estimated glomerular filtration rate heightened by hyperfiltration alone can mislead clinicians before adrenalectomy. Clinicians should pay attention to patients at greater risk of a significant decline in postoperative renal function.

Prevalence of primary aldosteronism in hypertensive subjects with hyperglycemia

The aim of this study was to examine the prevalence of primary aldosteronism (PA) in hypertensive patients with hyperglycemia. Two hundred and thirty-two hypertensive patients with hyperglycemia were screened for PA. Fifty-four subjects with an aldosterone/rennin activity ratio >20 ng/dL per ng/mL/hour underwent a saline loading test. Primary aldosteronism was present in 22.4% of patients with a plasma aldosterone concentration >5 ng/dL and 11.6% of those with plasma aldosterone concentrations >10 ng/dL. There were 14.0%-23.0% patients with PA in the diabetes mellitus group, 2.3%-23.3% in the impaired glucose tolerance group, and 9.1% in the impaired fasting glucose group. Primary aldosteronism is common in hypertensive individuals with hyperglycemia.

Persistent hypertension after adrenalectomy for an aldosterone-producing adenoma: weight as a critical prognostic factor for aldosterone's lasting effect on the cardiac and vascular systems

BACKGROUND

Primary aldosteronism caused by an aldosterone producing adrenal tumor/aldosteronoma (APA), is a potentially curable form of hypertension, via unilateral adrenalectomy. Resolution of hypertension (HTN) is not as prevalent after tumor resection, as are the normalization of aldosterone secretion, hypokalemia, and other metabolic abnormalities. Here, we review the immediate and long-term medical outcomes of laparoscopic adrenalectomy in patients with an APA, and attempt to identify any distinctive sex differences in the management of resistant HTN.

METHODS

We performed a retrospective review of the prospective adrenal database at the University of Wisconsin between January 2001 and October 2010. Of the 165 adrenalectomies performed, 32 were for the resection of an APA. Patients were grouped according to their postoperative HTN status. Those patients with normal blood pressure (≤120/80 mm Hg) and on no antihypertensive medication (CURE) were compared with those who continued to require medication for blood pressure control (HTN). We evaluated sex, age, body mass index, tumor size, duration of time with high blood pressure, and the differences in systolic and diastolic blood pressure following adrenalectomy. Statistical analysis was performed using Student's t-test. Statistical significance was defined as a P value of <0.05.

RESULTS

We identified 32 patients with an APA based on biochemical and radiographic studies, two patients were excluded, due to missing data. There were 19 males (63%) and 11 (37%) females, with a mean age was 48.3 ± 2.1 y, and mean tumor size was 24 ± 3 mm. Postoperatively, patients required significantly fewer antihypertensive medications (1.5 ± 0.2 versus 3.3 ± 0.3, P < 0.001). Nine patients (31%) had complete resolution of their HTN, requiring no postoperative antihypertensive medication. The only significant difference between the sexes, was a lower body mass index in women (27.6 ± 1.7 versus 33.4 ± 2.1 kg/m(2), P = 0.04). Ninety percent of the cohort had at least a 20 mm Hg decline in their systolic blood pressure postoperatively, placing them in the prehypertensive or normal blood pressure categories. Sixty-six percent of the CURE patients required at least 6 mo for resolution of their HTN. All 20 patients who presented with hypokalemia, had immediate resolution postoperatively and did not require continuance of the preoperative spironolactone or potassium supplementation.

CONCLUSIONS

Laparoscopic adrenalectomy for aldosterone producing adenoma results in the normalization of, or more readily manageable blood pressure in 90% of patients, within 6 mo. Metabolic disturbances are immediately corrected with tumor resection. Weight is an important contributing factor in resolving HTN.

Effect of age on aldosterone/renin ratio (ARR) and comparison of screening accuracy of ARR plus elevated serum aldosterone concentration for primary aldosteronism screening in different age groups

The serum aldosterone concentration (SAC)/plasma renin activity (PRA) ratio (ARR) is considered a useful screening test in the differential diagnosis of essential hypertension (EH) and primary aldosteronism (PA). The purpose of this study is to investigate the effect of age on ARR and compare the screening accuracy of ARR plus elevated SAC for PA screening in different age groups. Thirty-nine patients with PA, 274 patients with EH, and 153 healthy volunteers were recruited. Blood was sampled for SAC and PRA measuring under keeping upright posture for 1 h. Levels of SAC, PRA, and ARR were compared at different ages range for the respective three groups of subjects. The screening accuracy of ARR plus elevated SAC was compared in different age groups and PA patients served as the same positive subjects. In the EH group, logarithmically transformed ARR (Log-ARR) increased with advancing age and reached its peak in the ≥ 60 years group; in the normotensives group, Log-ARR reached its peak in the 40-49 years group and slightly declined with advancing age. In the PA group, Log-ARR was not age dependent. Screening accuracy increased when combined index of ARR and SAC was used in the ≥ 40 years group but not in the <40 years group. Although the number of EH patients with elevated ARR increased with advancing age, but the screening accuracy and cutoff values of ARR were not affected by age. Using the combined index of ARR and SAC increased the screening accuracy for the patients older than 40 years, but not necessary for the patients younger than 40 years.