Primary aldosteronism

Investigating secondary hypertension in cerebrovascular disease

Hypertension is the leading cause of stroke in the UK and worldwide. In recent years, stroke incidence has increased by 30%-41.5% in people aged under 64 years, with the prevalence of hypertension increasing by 4%-11%. Given that 5%-10% of people with hypertension in the general population have an underlying cause for their elevated blood pressure, it is important that all clinicians should maintain a high clinical suspicion for secondary hypertension. This review provides a clinical perspective of when to consider the underlying causes of secondary hypertension, with investigation algorithms for patients presenting with stroke and hypertension. Early involvement of hypertension specialist services is important to identify secondary causes of hypertension, as its effective control reduces cardiovascular-associated morbidity.

Insight into the status of plasma renin and aldosterone measurement: findings from 526 clinical laboratories in China

OBJECTIVES

Accurate measurements of renin and aldosterone levels play an important role in primary aldosteronism screening, which is of great importance in the management and categorization of hypertension. The objective of this study is to investigate the current status of plasma renin and aldosterone measurements in China, which is achieved by analyzing the results of 526 clinical laboratories nationwide for three pooled fresh plasma samples derived from more than 2,000 patients.

METHODS

Renin and aldosterone in three pooled plasma samples were measured four times in 526 laboratories employing various measurement systems. The inter- and intra-laboratory %CV were calculated and compared. To determine the source of the substantial inter-laboratory %CV, laboratories were categorized according to the measurement systems they are using, and both the inter- and intra-measurement-system %CV were calculated and compared.

RESULTS

Regarding renin, the majority of laboratories use four primary commercial immunoassays. However, for aldosterone, in addition to commercial immunoassays, laboratory-developed liquid chromatography-tandem mass spectrometry (LC-MS) methods are also used by laboratories. The median values of intra-laboratory %CVs, intra-measurement-system %CVs, inter-laboratory %CVs, and inter-measurement systems %CVs varied between 1.6 and 2.6 %, 4.6 and 14.9 %, 8.3 and 25.7 %, and 10.0 and 34.4 % for renin, respectively. For aldosterone, these values ranged from 1.4 to 2.2 %, 2.5-14.7 %, 9.9-31.0 %, and 10.0-35.5 %, respectively.

CONCLUSIONS

The precision within laboratories and measurement systems for plasma renin and aldosterone measurements is satisfactory. However, the comparability between laboratories using different measurement systems remains lacking, indicating the long way to achieve standardization and harmonization for these two analytes.

Aldosterone, Renin, and Aldosterone-to-Renin Ratio Variability in Screening for Primary Aldosteronism

CONTEXT

The plasma aldosterone concentration (PAC), renin, and aldosterone-to-renin ratio (ARR) are used to screen for primary aldosteronism (PA). Substantial intra-individual variability of PAC and ARR using plasma renin activity in the context of usual antihypertensive therapy has been described, but there is no data on ARR variability calculated using direct renin concentration (DRC).

OBJECTIVE

To describe the intra-individual variability of PAC, DRC, and ARR in the absence of interfering medications in patients with and without PA.

DESIGN

Retrospective cohort study.

PATIENTS

Hypertensive patients referred for investigation of PA, with at least 2 ARR measurements while off interfering medications.

SETTING

Endocrine hypertension service of a tertiary center, from May 2017 to July 2021.

MAIN OUTCOME MEASURES

PAC, DRC, and ARR variability was calculated as coefficient of variation (CV) and percent difference (PD).

RESULTS

Analysis of 223 patients (55% female, median age 52 years), including 162 with confirmed PA, demonstrated high variability with a sample CV of 22-25% in the PAC and sample CV of 41% to 42% in the DRC and ARR in both the PA and non-PA groups. The degree of variability was substantially higher than the assays' analytical CV. Sixty-two patients (38%) with PA had at least one ARR below 70 pmol/L:mU/L (2.4 ng/dL:mU/L), a cut-off for first-line screening of PA.

CONCLUSIONS

Significant intra-individual variability in PAC, DRC, and hence ARR occurs in a large proportion of patients being investigated for PA. These findings support the need for at least 2 ARR before PA is excluded or further investigated.

Plasma and serum prorenin concentrations in diabetes, hypertension, and renal disease

Although the renin-angiotensin-aldosterone system plays a crucial role in fluid homeostasis and cardiovascular disease pathophysiology, measurements of plasma prorenin levels are still unavailable in clinical practice. We previously found that prorenin molecules in human blood underwent significant posttranslational modifications and were undetectable using immunological assays that utilized antibodies specifically recognizing unmodified recombinant prorenin. Using a sandwich enzyme-linked immunosorbent assay that captures posttranslationally modified prorenins with their prosegment antibodies, we measured plasma and serum prorenin concentrations in 219 patients with diabetes mellitus, hypertension and/or renal disease and compared them with those of 40 healthy controls. The measured values were not significantly different from those of the healthy controls and were 1,000- to 100,000-fold higher than previously reported levels determined using conventional assay kits. Multiple regression analyses showed that body weight, serum albumin levels, and serum creatinine levels negatively correlated with plasma prorenin levels, while the use of loop diuretics was associated with elevated plasma prorenin levels. Blood pressure, HbA1c, and plasma renin activity were not independent variables affecting plasma prorenin levels. In contrast, serum prorenin levels were unaffected by any of the above clinical parameters. The association of the plasma prorenin concentration with indices reflecting body fluid status suggests the need to scrutinize its role as a biomarker, while serum prorenins are less likely to have immediate diagnostic value.

Screening for primary aldosteronism is underutilised in patients with chronic kidney disease

BACKGROUND

Primary aldosteronism (PA) is the most common and potentially curable endocrine cause of secondary hypertension, and carries a worse prognosis than essential hypertension. Despite the high prevalence of hypertension in patients with chronic kidney disease (CKD), the screening rates for primary aldosteronism in CKD are unknown.

METHODS

In this study, we retrospectively reviewed medical records of 1627 adults who presented to the nephrology clinics of 2 tertiary hospitals in Melbourne, Australia, between 2014 and 2019. In addition to assessing the pattern of screening, we also evaluated patient-specific factors associated with the decision to test for primary aldosteronism. Patients were excluded from the final analysis if they did not have CKD, had an organ transplant, had end stage renal failure, or had insufficient data or follow-up.

RESULTS

Of the 600 patients included in the analysis, 234 (39%) had an indication for screening for primary aldosteronism based on recommendations made by the Endocrine Society. However, only 33 (14%) were tested. They were younger, had a higher mean systolic blood pressure, better renal function, and lower mean serum potassium than those who were indicated but not screened. Of the 33 screened patients, an elevated aldosterone-to-renin ratio was noted in 8 patients and a diagnosis of primary aldosteronism was made in 4 patients.

CONCLUSIONS

The screening rate for primary aldosteronism is low in a CKD population, especially in patients who are older, have a lower eGFR and normal serum potassium. The consequences of undiagnosed primary aldosteronism in this select population may be substantial due to the cardiovascular and renal sequelae associated with untreated disease.

Aldosterone Reduction Rate After Saline Infusion Test May Be a Novel Prediction in Patients With Primary Aldosteronism

OBJECTIVE

Accurate assessment and localization of aldosterone-producing adenomas (APAs) are essential for the treatment of primary aldosteronism (PA). Although adrenal venous sampling (AVS) is the standard method of reference for subtype diagnosis in PA, controversy exists concerning the criteria for its interpretation. This study aims to determine better indicators that can reliably predict subtypes of PA.

METHOD

Retrospective, single-cohort analysis including 209 patients with PA who were subjected to AVS. Eighty-two patients whose plasma aldosterone concentrations (PAC) were normalized after surgery were histopathologically or genetically diagnosed with APA. The accuracy of image findings was compared to AVS results. Receiver operating characteristic (ROC) curve analysis between the operated and the no-apparent laterality groups was performed using AVS parameters and loading test for diagnosis of PA.

RESULT

Agreement between image findings and AVS results was 56.3%. ROC curve analysis revealed that the lateralization index (LI) after adrenocorticotropin stimulation cutoff was 2.40, with 98.8% sensitivity and 97.1% specificity. The contralateral suppression index (CSI) cutoff value was 1.19, with 98.0% sensitivity and 93.9% specificity. All patients over the LI and CSI cutoff values exhibited unilateral subtypes. Among the loading test, the best classification accuracy was achieved using the PAC reduction rate after a saline infusion test (SIT) >33.8%, which yielded 87.2% sensitivity or a PAC after a SIT <87.9 pg/mL with 86.2% specificity for predicting bilateral PA.

CONCLUSION

The combined criteria of the PAC reduction rate and PAC after the SIT can determine which subset of patients with APA who should be performed AVS for validation.

Resistant Hypertension: Novel Insights

Hypertension is the most common chronic disease and the leading risk factor for disability and premature deaths in the world, accounting for more than 9 million deaths annually. Resistant hypertension is a particularly severe form of hypertension. It was described 50 years ago and since then has been a very active field of research. This review aims at summarizing the most recent findings on resistant hypertension. The recent concepts of apparent- and true-resistant hypertension have stimulated a more precise definition of resistant hypertension taking into account not only the accuracy of blood pressure measurement and pharmacological class of prescribed drugs but also patient adherence to drugs and life-style recommendations. Recent epidemiological studies have reported a 10% prevalence of resistant hypertension among hypertensive subjects and demonstrated the high cardiovascular risk of these patients. In addition, these studies identified subgroups of patients with even higher morbidity and mortality risk, probably requiring a more aggressive medical management. In the meantime, guidelines provided more standardized clinical work-up to identify potentially reversible causes for resistant hypertension such as secondary hypertension. The debate is however still ongoing on which would be the optimal method(s) to screen for non-adherence to hypertension therapy, recognized as the major cause for (pseudo)-resistance to treatment. Recent randomized clinical trials have demonstrated the strong benefit of anti-aldosterone drugs (mostly spironolocatone) as fourth-line therapies in resistant hypertension whereas clinical trials with device-based therapies displayed contrasting results. New trials with improved devices and more carefully selected patients with resistant hypertension are ongoing.

A short review of primary aldosteronism in a question and answer fashion

OBJECTIVES

The aim of this study was to present up to date information concerning the diagnosis and treatment of primary aldosteronism (PA). PA is the most common cause of endocrine hypertension. It has been reported up to 24% of selective referred hypertensive patients.

METHODS

We did a search in Pub-Med and Google Scholar using the terms: PA, hyperaldosteronism, idiopathic adrenal hyperplasia, diagnosis of PA, mineralocorticoid receptor antagonists, adrenalectomy, and surgery. We also did cross-referencing search with the above terms. We had divided our study into five sections: Introduction, Diagnosis, Genetics, Treatment, and Conclusions. We present our results in a question and answer fashion in order to make reading more interesting.

RESULTS

PA should be searched in all high-risk populations. The gold standard for diagnosis PA is the plasma aldosterone/plasma renin ratio (ARR). If this test is positive, then we proceed with one of the four confirmatory tests. If positive, then we proceed with a localizing technique like adrenal vein sampling (AVS) and CT scan. If the lesion is unilateral, after proper preoperative preparation, we proceed, in adrenalectomy. If the lesion is bilateral or the patient refuses or is not fit for surgery, we treat them with mineralocorticoid receptor antagonists, usually spironolactone.

CONCLUSIONS

Primary aldosteronism is the most common and a treatable case of secondary hypertension. Only patients with unilateral adrenal diseases are eligible for surgery, while patients with bilateral and non-surgically correctable PA are usually treated by mineralocorticoid receptor antagonist (MRA). Thus, the distinction between unilateral and bilateral aldosterone hypersecretion is crucial.

The aldosterone to renin ratio in the diagnosis of primary aldosteronism: Promises and challenges

The complexity of evaluating patients for secondary treatable causes of hypertension is underappreciated. Primary aldosteronism (PA) is the most prevalent cause of secondary hypertension (3%-32% of hypertensive patients). The recent endocrine society clinical practice guideline (ESCPG), "The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment", differs from the previous version in the explicit recognition of PA as a major public health issue. Despite this, PA is underdiagnosed. The guidelines call on physicians to substantially ramp up the screening of hypertensive patients at risk of PA. Further, it recommends the plasma aldosterone to renin ratio (ARR), as the test of choice for screening for PA. However, the ARR is a highly variable test with reported diagnostic sensitivities and specificities ranging from 66% to 100% and 61% to 100%, respectively. Variability of the ARR can be attributed to the high degree of within-subject variation, differences in sampling protocols, laboratory assays, reporting units, the effect of medications and the population characteristics used to establish the decision thresholds. These factors render the possibility of false positive and false negative results-which have the potential to adversely impact patients. The limitations and caveats to the use of the ARR necessitate an effective clinic-laboratory interface, with specialist physician and clinical scientist collaboration for ARR result interpretation. Improvement in the diagnostic sensitivity and specificity of the ARR is predicated on harmonisation of pretesting patient preparation criteria, knowledge of the analytical methods used to derive the ratio and the method-specific threshold for PA.

Criteria for diagnosing primary aldosteronism on the basis of liquid chromatography-tandem mass spectrometry determinations of plasma aldosterone concentration

BACKGROUND

Primary aldosteronism is affecting about 10% of hypertensive patients. Primary aldosteronism should be diagnosed by screening tests based on plasma aldosterone concentration (PAC) and aldosterone-to-renin ratio (ARR), followed by confirmatory test. The cutoff values for PAC and ARR depend on PAC and plasma renin measurement methods. Liquid chromatography-tandem mass spectrometry (LC-MS/MS), the new gold standard method for aldosterone determination, is now widespread but shows lower values than immunoassays. New cutoff values have yet to be determined with LC-MS/MS PAC.

METHODS

In a retrospective cohort, we measured PAC by LC-MS/MS in 93 healthy volunteers, 77 patients with essential hypertension and 82 primary aldosteronism patients (42 lateralized, 24 bilateral, 16 primary aldosteronism without adrenal vein sampling) after 30 min in a seated position.

RESULTS

PAC ranged from 42 to 309 pmol/l in healthy volunteers and from 63 to 362 pmol/l in essential hypertensive patients. A cutoff value of 360 pmol/l for basal PAC had a sensitivity of 90.5% and a specificity of 95.1% to differentiate lateralized primary aldosteronism from essential hypertensive patients. ARR ranged from 2.3 to 22.3 in healthy volunteers and from 3.2 to 55.6 pmol/mU in essential hypertensive patients. Using ROC curves, we selected an ARR of 46 pmol/mU, which provided a sensitivity of 100% and a specificity of 93.4% to distinguish between essential hypertensive and lateralized primary aldosteronism patients (sensitivity 94.4%, specificity 93.9% for the overall primary aldosteronism population).

CONCLUSION

Criteria for primary aldosteronism screening need to be adapted, given the increasing use of LC-MS/MS to determine PAC. We suggest to use 360 pmol/l and 46 pmol/mU as cutoff values, respectively, for basal PAC and ARR after 30 min of seated rest.

Effect of Combined Hormonal Replacement Therapy on the Aldosterone/Renin Ratio in Postmenopausal Women

BACKGROUND

Plasma aldosterone/renin ratio (ARR) is the most popular screening test for primary aldosteronism (PA). Because both estrogen and progesterone (including in oral contraceptive agents) affect aldosterone and renin levels, we studied the effects of combined hormonal replacement therapy (HRT) on ARR; renin was measured as both direct renin concentration (DRC) and plasma renin activity (PRA).

METHODS

Fifteen normotensive, healthy postmenopausal women underwent measurement (seated, midmorning) of plasma aldosterone, DRC, PRA, electrolytes, and creatinine and urinary aldosterone, cortisol, electrolytes, and creatinine at baseline and after 2 weeks and 6 weeks of treatment with combined HRT (conjugated estrogens 0.625 mg and medroxyprogesterone 2.5 mg daily).

RESULTS

Combined HRT was associated with statistically significant increases in aldosterone [median (range): baseline, 150 (85 to 600); 2 weeks, 230 (129 to 790); 6 weeks, 434 (200 to 1200) pmol/L; P < 0.001 (Friedman test)] and PRA [2.3 (1.2 to 4.3), 3.8 (1.4 to 7.0), 5.1 (1.4 to 10.8) ng/mL/h, respectively; P < 0.001] but decreases in DRC [21 (10 to 31), 21 (10 to 39), and 14 (8.0 to 30) mU/L, respectively; P < 0.01], leading to increases in ARR calculated by DRC [7.8 (3.6 to 34.8), 11.4 (5.4 to 48.5), and 30.4 (10.5 to 90.2), respectively; P < 0.001]. The ARR calculated by DRC exceeded the cutoff value (70) in three patients after 6 weeks. There were no significant changes in ARR calculated by PRA [79 (26 to 184), 91 (23 to 166), and 88 (50 to 230), respectively; P = 0.282], plasma electrolytes and creatinine, or any urinary measurements.

CONCLUSION

The combined oral HRT used in this study is capable of significantly increasing ARR with a risk of false-positive results during screening for PA but only if DRC (and not PRA) is used to calculate the ratio.

11-Deoxycortisol may be superior to cortisol in confirming a successful adrenal vein catheterization without cosyntropin: a pilot study

AIM

We aimed to compare the performance of nine adrenal steroids in confirming the correct catheter position during adrenal venous sampling (AVS) without cosyntropin in patients with primary hyperaldosteronism.

MATERIALS & METHODS

A successful adrenal vein catheterization without cosyntropin was defined as the ratio of steroids from adrenal to peripheral veins being >3:1. AVS samples from four patients with primary hyperaldosteronism were analyzed.

RESULTS

Compared with the mean ratio of cortisol without cosyntropin, the ratios of 11-deoxycortisol (p = 0.008), dehydroepiandrosterone (p = 0.01) and androstenedione (p = 0.008) were significantly higher. None of the ratios (n = 8) of cortisol from adrenal to peripheral veins exceeded 3:1, while all ratios of 11-deoxycortisol (p < 0.001) were >3.

CONCLUSION

Cosyntropin infusion during AVS may not be necessary if 11-deoxycortisol is used to confirm catheter position.

Lower physical fitness in patients with primary aldosteronism is linked to the severity of hypertension and kalemia

Hypokalemia as a typical feature of primary aldosteronism (PA) is associated with muscle weakness and could contribute to lower cardiopulmonary fitness. The aim of this study was to describe cardiopulmonary fitness and exercise blood pressure and their determinants during a symptom-limited exercise stress test in patients with PA. We performed a cross-sectional study of patients with confirmed PA who were included before adrenal vein sampling on whom a symptom-limited exercise stress test with expired gas analysis was performed. Patients were switched to the treatment with doxazosin and verapamil at least two weeks before the study. In 27 patients (17 male) the VO(2peak) was 25.4+/-6.0 ml/kg/min which corresponds to 80.8+/-18.9 % of Czech national norm. Linear regression analysis shows that VO(2peak) depends on doxazosin dose (DX) (p=0.001) and kalemia (p=0.02): VO(2peak) = 4.2 - 1.0 * DX + 7.6 * Kalemia. Patients with higher doxazosin doses had a longer history of hypertension and had used more antihypertensives before examination, thus indicating that VO(2peak) also depends on the severity of hypertension. In patients with PA, lower cardiopulmonary fitness depends inversely on the severity of hypertension and on lower plasma potassium level.

A cross-sectional study of the effects of β-blocker therapy on the interpretation of the aldosterone/renin ratio: can dosing regimen predict effect?

CONTEXT AND AIM

Aldosterone/renin ratio (ARR) is used as the primary screening tool for primary aldosteronism. Its interpretation is often challenging because of the interference of antihypertensive medication. β-blocker therapy suppresses renin production by inhibiting β-adrenergic receptors in the juxtaglomerular apparatus of the kidney and consequently aldosterone secretion (to a lesser extent). Therefore, β-blocker therapy has the potential to elevate the ARR. The aim of this study was to investigate whether or not the effect of β-blocker therapy on the ARR could be predicted from the dosing regimen.

METHODS

A prospective cross-sectional study was conducted. Participants were stratified into one of four groups (control/low/medium/high) based on the quantity of β-blocker prescribed. ARR was calculated from renin/aldosterone, measured using two assay systems.

RESULTS

Eighty-nine volunteers were recruited to our study. In the control group, zero patients had a positive ARR using plasma renin activity (PRA)/direct renin concentration (DRC). In the low, medium, and high-dose β-blocker groups between 8-25% of patients demonstrated screen positive ARR results for primary aldosteronism using DRC and PRA. DRC was significantly lower in patients in the medium/high-dose groups and PRA significantly lower in the low/medium/high-dose groups compared with controls. ARR using DRC was significantly higher in the medium/high-dose groups and ARR using PRA was significantly higher in the low/medium/high-dose groups compared with controls.

CONCLUSION

Our study suggests that β-blocker therapy is associated with an increased risk of positive ARR screens for primary aldosteronism irrespective of the dose of β-blocker prescribed, in patients in whom it is clinically reasonable to expect that primary aldosteronism may be present.

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.

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.

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.

Role of D2 dopamine receptor in adrenal cortical cell proliferation and aldosterone-producing adenoma tumorigenesis

Aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia are the two characteristic types of primary aldosteronism. Dysregulation of adrenal cortical cell proliferation contributes to both diseases. We previously demonstrated that APA expressed less dopamine D2 receptor than the respective non-tumor tissue and might contribute to the overproduction of aldosterone. As activation of D2 receptor inhibits the proliferation of various cells, downregulation of D2 receptor in APA may play a role in the tumorigenesis of APA. In this study, we demonstrate that D2 receptor plays a role in angiotensin II (AII)-stimulated adrenal cortical cell proliferation. The D2 receptor agonist, bromocriptine, inhibited AII-stimulated cell proliferation in primary cultures of the normal human adrenal cortex and APA through attenuating AII-induced phosphorylation of PK-stimulated cyclin D1 protein expression and cell proliferation. D2 receptor also inhibited AII-induced ERK1/2 phosphorylation. Our results demonstrate that, in addition to inhibiting aldosterone synthesis/production, D2 receptor exerts an anti-proliferative effect in adrenal cortical and APA cells by attenuating PKCμ and ERK phosphorylation. The lower level of expression of D2 receptor in APA may augment cell proliferation and plays a crucial role in the tumorigenesis of APA. Our novel finding suggests a new therapeutic target for primary aldosteronism.

Right adrenal venography findings correlated with C-arm CT for selection during C-arm CT-assisted adrenal vein sampling in primary aldosteronism

PURPOSE

This study was designed to evaluate retrospectively the efficacy of C-arm CT to confirm right adrenal vein catheterization during adrenal vein sampling (AVS) and to correlate adrenal venography findings with C-arm CT and/or biochemical results for right adrenal vein selection.

METHODS

Forty-two consecutive primary aldosteronism patients (M:F = 21:21; age: 29-70 years) underwent C-arm CT assisted sequential AVS. After catheterization of right adrenal vein, C-arm CT was performed to confirm catheter position. Catheter was repositioned when right adrenal gland was not opacified. Radiological images, medical records, and biochemical results were reviewed for technical/biochemical success rates and complications. Right adrenal venography findings of pinnate pattern, visualization of renal capsular vein, and retroperitoneal vein other than renal capsular vein were correlated with C-arm CT and/or biochemical results for right adrenal vein selection.

RESULTS

Both the technical and biochemical success of AVS was achieved in 40 patients (95.2%). C-arm CT failed due to catheter instability in one, and adrenal/vena cava cortisol gradient was <3 in one patient. Catheter was repositioned in four patients (9.5%) according to C-arm CT findings. Right adrenal venography finding of renal capsular vein significantly correlated with C-arm CT and/or biochemical results (100%) for right adrenal vein selection (p = 0.011, χ(2) test), whereas pinnate pattern (p = 0.099) and other retroperitoneal veins (p = 0.347) did not. There was no procedure-related complication.

CONCLUSIONS

C-arm CT increases confidence of right adrenal vein catheterization during AVS. Visualization of renal capsular vein on adrenal venography suggests right adrenal vein catheterization and C-arm CT may not be required.

A case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated and cured

A 45-year-old female went into cardiopulmonary arrest. She was in ventricular fibrillation (VF) and was defibrillated using an automated external defibrillator. After arrival at our hospital, electrocardiography monitoring showed QT prolongation. Serum potassium was low at 2.2 mEq/L, and hypokalemia-induced long QT syndrome was considered to be the cause of this patient's VF. An intravenous infusion of potassium and magnesium sulphate was started, which normalized her serum potassium and QTc interval, with no recurrence of ventricular arrhythmias. Endocrinological investigations showed a plasma renin activity of <0.1 ng/(mL h) and a plasma aldosterone concentration 258 pg/mL. Computed tomography scanning revealed a low signal area 16 mm × 20 mm in size of the right adrenal gland. From the above findings, this patient was diagnosed with a right adrenal tumor and primary aldosteronism. We concluded that the right adrenal tumor was excreting excess amounts of aldosterone from adrenal vein sampling, and performed laparascopic right adrenalectomy. Serum potassium levels rose immediately to normal levels postoperatively. We were able to withdraw her antihypertensive medication 3 months after adrenalectomy. We report a case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated, and cured. <Learning objective: When you come across ventricular fibrillation, please consider one of the reasons is caused by hypokalemia due to primary aldosteronism. After an appropriate resuscitation, both hypokalemia and hypertension are completely curable by removing the adrenal tumor.>.

Long-term re-evaluation of primary aldosteronism after medical treatment reveals high proportion of normal mineralocorticoid secretion

OBJECTIVE

In most cases of primary aldosteronism (PA), An adrenal aldosterone-secreting tumor cannot be reasonably proven, so these patients undergo medical treatment. Controversial data exist about the evolution of PA after medical therapy: long-term treatment with mineralocorticoid antagonists has been reported to normalize aldosterone levels but other authors failed to find remission of mineralocorticoid hypersecretion. Thus, we planned to retest aldosterone secretion in patients with medically treated PA diagnosed at least 3 years before.

DESIGN

Retrospective, cross-sectional study.

METHODS

The same workup for PA as at diagnosis (basal aldosterone to renin activity ratio (ARR) and aldosterone suppression test) was performed after stopping interfering drugs and low-salt diet, in 34 subjects with PA diagnosed between 3 and 15 years earlier, by case finding from subgroups of hypertensive patients at high risk for PA. Criteria for persistence of PA were the same as at diagnosis (ARR (pg/ml per ng per ml per h) >400, aldosterone >150 pg/ml basally, and >100 pg/ml after saline infusion) or less restrictive.

RESULTS

PA was not confirmed in 26 (76%) of the patients and also not in 20 (59%) using the least restrictive criteria suggested by international guidelines. Unconfirmed PA was positively associated with female sex, higher potassium levels, longer duration of hypertension, and follow-up, but not with adrenal mass, aldosterone levels at diagnosis, and treatment with mineralocorticoid antagonists.

CONCLUSIONS

This study suggests that mineralocorticoid hyperfunction in patients with PA after medical treatment may decline spontaneously. Higher potassium concentration and duration of treatment seem to increase the probability of this event.

A novel point mutation in the KCNJ5 gene causing primary hyperaldosteronism and early-onset autosomal dominant hypertension

CONTEXT

Aldosterone production in the adrenal zona glomerulosa is mainly regulated by angiotensin II, [K(+)], and ACTH. Genetic deletion of subunits of K(+)-selective leak (KCNK) channels TWIK-related acid sensitive K(+)-1 and/or TWIK-related acid sensitive K(+)-3 in mice results in primary hyperaldosteronism, whereas mutations in the KCNJ5 (potassium inwardly rectifying channel, subfamily J, member 5) gene are implicated in primary hyperaldosteronism and, in certain cases, in autonomous glomerulosa cell proliferation in humans.

OBJECTIVE

The objective of the study was to investigate the role of KCNK3, KCNK5, KCNK9, and KCNJ5 genes in a family with primary hyperaldosteronism and early-onset hypertension.

PATIENTS AND METHODS

Two patients, a mother and a daughter, presented with severe primary hyperaldosteronism, bilateral massive adrenal hyperplasia, and early-onset hypertension refractory to medical treatment. Genomic DNA was isolated and the exons of the entire coding regions of the above genes were amplified and sequenced. Electrophysiological studies were performed to determine the effect of identified mutation(s) on the membrane reversal potentials.

RESULTS

Sequencing of the KCNJ5 gene revealed a single, heterozygous guanine to thymine (G → T) substitution at nucleotide position 470 (n.G470T), resulting in isoleucine (I) to serine (S) substitution at amino acid 157 (p.I157S). This mutation results in loss of ion selectivity, cell membrane depolarization, increased Ca(2+) entry in adrenal glomerulosa cells, and increased aldosterone synthesis. Sequencing of the KCNK3, KCNK5, and KCNK9 genes revealed no mutations in our patients.

CONCLUSIONS

These findings explain the pathogenesis in a subset of patients with severe hypertension and implicate loss of K(+) channel selectivity in constitutive aldosterone production.

Primary aldosteronism: from bench to bedside

Primary aldosteronism is now thought to be the commonest potentially curable and specifically treatable form of hypertension. The detection of primary aldosteronism is of utmost importance not only because it provides an opportunity for a targeted treatment, but also because it has been demonstrated that patients with primary aldosteronism are more prone to cardiovascular events and target organ damage than essential hypertensives. Normalization of blood pressure and hypokalemia should not be the only goal of treatment. Normalization of circulating aldosterone or mineralocorticoid blockade is necessary to prevent aldosterone-induced tissue damage that occurs independent of blood pressure. This review will focus on the current understanding and comprehensive management review of primary aldosteronism, highlighting the new evidence that has become recently available.

Endocrine hypertension--current understanding and comprehensive management review

Hypertension is a very common disease, leading to significant morbidity with reduction in quality of life. In addition to being a major cause of morbidity and mortality, hypertension places a heavy burden on health care systems, families, and society as a whole. In patients with hypertension, the ability to identify a contributing or secondary cause that is potentially curable or amenable to specific forms of management is of great importance. Endocrine hypertension has emerged as one of the common forms of secondary hypertension. Primary aldosteronism, pheochromocytoma and Cushing's syndrome are among the common causes of endocrine hypertension. The application of new clinical, biochemical, and radiologic approaches has significantly advanced our understanding of the pathophysiology and clinical spectrum of these diseases and improved the management strategies of these challenging conditions.

Cardiac dimensions are largely determined by dietary salt in patients with primary aldosteronism: results of a case-control study

CONTEXT

Animal studies have demonstrated that dietary sodium intake is a major influence in the pathogenesis of aldosterone-induced effects in the heart such as left ventricular (LV) hypertrophy and fibrosis. LV hypertrophy is an important predictor for cardiovascular morbidity and mortality.

OBJECTIVE

We aimed to investigate the relationships between aldosterone and dietary salt and LV dimensions in patients with primary aldosteronism (PA).

DESIGN AND PARTICIPANTS

This case-control study included 21 patients with confirmed PA and 21 control patients with essential hypertension matched for age, gender, duration of hypertension, and 24-h systolic and diastolic blood pressure.

MAIN OUTCOME MEASURES

Patients were evaluated by echocardiography and 24-h urinary sodium (UNa) excretion while consuming their usual diets.

RESULTS

Patients with PA had significantly greater mean LV end-diastolic diameter, interventricular septum and posterior wall thicknesses, LV mass (LVM) and LV mass index, and end systolic and diastolic volumes than control patients. UNa significantly positively correlated with interventricular septum, posterior wall thicknesses, and LVM in the patients with PA but not in control patients. In a multivariate analysis, UNa was an independent predictor for LV wall thickness and LV mass among the patients with PA but not in patients with essential hypertension.

CONCLUSIONS

These findings emphasize the importance of dietary sodium in determining the degree of cardiac damage in those patients with PA, and we suggest that aldosterone excess may play a permissive role. In patients with PA, because a high-salt diet is associated with greater LVM, dietary salt restriction might reduce cardiovascular risk.

Diagnosis and treatment of primary aldosteronism

A few simple rules can allow physicians to successfully identify many patients with arterial hypertension caused by PA among the so-called essential hypertensive patients. The hyperaldosteronism and the hypokalemia can be cured with adrenalectomy in practically all of these patients. Moreover, in a substantial proportion of them, the blood pressure can be normalized or markedly lowered if a unilateral cause of PA is discovered. Hence, the screening for PA can be rewarding both for the patient and for the clinician, particularly in those cases where hypertension is severe and/or resistant to treatment, in which the removal of an APA can allow blood pressure to be brought under control despite withdrawal of, or a prominent reduction in, the number and doses of antihypertensive medications.

A comprehensive review of the clinical aspects of primary aldosteronism

Primary aldosteronism is much more common than previously thought. The high prevalence of primary aldosteronism, the damage this condition does to the heart, blood vessels and kidneys (which causes a high rate of cardiovascular events), along with the notion that a timely diagnosis followed by an appropriate therapy can correct the arterial hypertension and hypokalemia, justify efforts to search for primary aldosteronism in many patients with hypertension. Most centers can use a cost-effective strategy to screen for patients with primary aldosteronism. By contrast, the identification of primary aldosteronism subtypes, which involves adrenal-vein sampling, should only be undertaken at tertiary referral centers that have experience in performing and interpreting this test. The identification of a curable form of primary aldosteronism can be beneficial for the patient. In some subgroups of patients with hypertension who are at high risk of primary aldosteronism or can benefit most from an accurate diagnosis, an aggressive diagnostic approach is necessary.

Adrenal Venous Sampling

In patients with primary aldosteronism, adrenal venous sampling is helpful to distinguish between unilateral and bilateral adrenal diseases. However, the procedure is technically challenging, and selective bilateral catheterization often fails. The aim of this analysis was to evaluate success rate in a retrospective analysis and compare data with procedures done prospectively after introduction of measures designed to improve rates of successful cannulation. Patients were derived from a cross-sectional study involving 5 German centers (German Conn's registry). In the retrospective phase, 569 patients with primary aldosteronism were registered between 1990 and 2007, of whom 230 received adrenal venous sampling. In 200 patients there were sufficient data to evaluate the procedure. In 2008 and 2009, primary aldosteronism was diagnosed in 156 patients, and adrenal venous sampling was done in 106 and evaluated prospectively. Retrospective evaluation revealed that 31% were bilaterally selective when a selectivity index (cortisol adrenal vein/cortisol inferior vena cava) of ≥2.0 was applied. Centers completing <20 procedures had success rates between 8% and 10%. Overall success rate increased in the prospective phase from 31% to 61%. Retrospective data demonstrated the pitfalls of performing adrenal venous sampling. Even in specialized centers, success rates were poor. Marked improvements could be observed in the prospective phase. Selected centers that implemented specific measures to increase accuracy, such as rapid-cortisol-assay and introduction of standard operating procedures, reached success rates of >70%. These data demonstrate the importance of throughput, expertise, and various potentially beneficial measures to improve adrenal vein sampling.

Diagnosis and treatment of primary aldosteronism

Primary aldosteronism involves more than 11% of hypertensive patients who are referred to specialized centers for the diagnosis and treatment of hypertension. If not diagnosed early it causes an excess damage to the heart, vessels and kidney, which translates into an cardiovascular events. Since these ominous consequences can be corrected with a timely diagnosis and an appropriate therapy, physicians should exercise a high degree of alert concerning the possibility that primary aldosteronism is present in hypertensive patients. The purpose of this review is to provide up-dated information on the strategy for case detection, the subtype differentiation and the management of primary aldosteronism.

Effect of atenolol on aldosterone/renin ratio calculated by both plasma Renin activity and direct Renin concentration in healthy male volunteers

BACKGROUND

The most popular screening test for primary aldosteronism (PAL) is the plasma aldosterone to renin ratio (ARR). Medications, dietary sodium, posture, and time of day all affect renin and aldosterone levels and can result in false-negative or -positive ARR if not controlled. Opinions are divided on whether beta-adrenoreceptor blockers significantly affect the ARR.

METHODS

Normotensive, nonmedicated male volunteers (n = 21) underwent measurement (seated, midmorning) of plasma aldosterone (by HPLC-tandem mass spectrometry), direct renin concentration (DRC), renin activity (PRA), cortisol, electrolytes, and creatinine and urinary aldosterone, cortisol, electrolytes, and creatinine at baseline, and after 1 wk (25 mg daily) and 4 wk (50 mg daily for three additional weeks) of atenolol.

RESULTS

Compared with baseline, levels of aldosterone, DRC, and PRA were lower (P < 0.001) after both 1 and 4 wk [median (25-75th percentiles): baseline, 189 (138-357) pmol/liter, 40 (30-46) mU/liter, and 4.6 (2.7-5.8) ng/ml x h; 1 wk, 166 (112-310) pmol/liter, 34 (30-40) mU/liter, and 2.6 (2.0-3.1) ng/ml x h; 4 wk, 136 (97-269) pmol/liter, 16 (13-23) mU/liter, and 2.1(1.7-2.6) ng/ml x h, respectively]. ARR was significantly higher after 1 wk compared with baseline when calculated using PRA [61 (30-73) vs. 65 (44-130), P < 0.01] but not DRC [5 (4-7) vs. 5 (4-8)]. At 4 wk, ARR calculated by both PRA [78 (49-125)] and DRC [8 (6-14)] were significantly higher (P < 0.001) compared with baseline, and cortisol levels were significantly lower [92 (68-100) vs. 66 (48-91) ng/ml, P < 0.01]. There were no changes in plasma sodium, potassium, creatinine, or any urinary measurements.

CONCLUSION

beta-Blockers can significantly raise the ARR and thereby increase the risk of false positives during screening for PAL.

Primary aldosteronism and its impact on the generation of arterial hypertension, endothelial injury and oxidative stress

Aldosterone plays an important role in blood pressure homeostasis, the regulation of circulating volume, and the maintenance of the sodium-potassium balance by binding to the mineralocorticoid receptor (MR). Primary aldosteronism (PA) states are associated with an increased cardiovascular risk, mediated not only by hypertension but also by the action of aldosterone in the modulation of vasodilation/vasoconstriction and oxidative stress. In this review, we discuss some of the cardiovascular actions of aldosterone and the most frequent causes of PA.

Plasma aldosterone to renin ratio predicts treatment response in primary aldosteronism: Is volume loading needed?

Volume loading is considered the golden standard of the confirmatory tests in the diagnostics of primary aldosteronism (PA). However, it is time-consuming, and it is unclear to what extent it improves the diagnostics of PA in comparison to simple screening tests. To study this question, the diagnostics with and without oral sodium loading (OSL) were evaluated by receiver operating characteristic curves analyses in 77 consecutive OSL patients. The final diagnosis was essential hypertension in 39 cases and PA in 38 cases, determined by review of the patient records, biochemical tests, imaging findings, and the response to therapy with spironolactone and/or operation. Plasma aldosterone-to-renin-activity ratio (ARR) and daily urinary aldosterone had a good diagnostic ability that did not significantly improve by accomplishing OSL. Cut-off values with optimal sensitivity and specificity were >or=1050 pmol/l per ng/ml/h for upright ARR, and >or=45 nmol/day for daily urinary aldosterone. To conclude, carefully conducted outpatient tests are sufficient for the diagnostics of PA, when the diagnosis is justified by the positive response to treatment. However, volume loading serves as an additional diagnostic tool in the most problematic cases, improving slightly the discriminative ability of urinary aldosterone determination.

The prevalence of a raised aldosterone–renin ratio (ARR) among new referrals to a hypertension clinic

The wider application of the plasma aldosterone to renin activity ratio (ARR) test has led independent groups to report a 10-fold or higher prevalence in the detection and prevalence of primary aldosteronism than previously suggested, although such figures have been contested. We determined the prevalence of a raised ARR in an unselected group of patients who were referred to the hypertension clinic at Aberdeen Royal Infirmary. Over a 4-month period, all newly referred patients had an ARR, urea and electrolytes, and 24-h ambulatory blood pressure monitoring (ABPM) performed in addition to a detailed clinical examination. One hundred and twenty-two patients (mean age 51 +/- 16 years) were examined over the study period; 57 (47%) were receiving no anti-hypertensive medication, 32(26% of total) had a normal 24-h ABPM of which 15 patients were receiving antihypertensive medication ("controlled" hypertensives) and 17(14%) were receiving no anti-hypertensive medication ("white-coat hypertensives). Twenty patients (mean age 58 +/- 11 years) were found to have a raised ARR (> 750), of which 10 patients were receiving beta-blocker therapy as part of their anti-hypertensive regimen. Patients with a raised ARR were more likely (odds ratio 3.6, 95% confidence interval 1.2-13.2, p < 0.05) to be classified as a "non-dipper" compared with those whose blood pressure fell at night. The proportion of newly referred hypertensive patients with a raised ARR is still significant and confirms that of previous studies The ratio appears to be significantly driven by a suppressed renin value and further investigation is required to clarify the status of those patients receiving anti-hypertensive medications, particularly beta-blockers.

Role of unilateral adrenalectomy in bilateral primary aldosteronism: a 22-year single center experience

OBJECTIVE

The aim of the study was to examine blood pressure and biochemical responses to unilateral adrenalectomy in patients with bilateral primary aldosteronism (PA) and identify predictive parameters.

CONTEXT

PA considered due to bilateral autonomous production of aldosterone is usually treated medically. Unilateral adrenalectomy has been considered ineffective. Because quality outcome data are lacking and medical treatment may cause adverse effects or fail to control hypertension, defining the role for unilateral adrenalectomy in bilateral PA is an important clinical issue.

DESIGN AND SETTING

Between 1984 and 2004, 51 of 684 patients diagnosed with bilateral PA underwent unilateral adrenalectomy. This report is based on the records of the 40 considered suitable for inclusion, who were followed for at least 12 (median, 56.4) months.

RESULTS

Hypertension was cured in 15% of patients and improved in 20%, usually within 1 yr of unilateral adrenalectomy. The proportion with controlled hypertension was significantly (P < 0.001) higher after adrenalectomy (65%) than before (25%). Mean systolic (P < 0.001) and diastolic (P < 0.001) blood pressure, left ventricular mass index (P < 0.05), plasma upright aldosterone (P < 0.05), and aldosterone/renin ratio (P < 0.001) fell. Serum creatinine independently predicted hypertension cure.

CONCLUSION

Although this retrospective analysis of patients from a single center does not permit prediction of response rates among patients diagnosed elsewhere, it suggests that unilateral adrenalectomy can be beneficial in some patients with apparent bilateral PA and should not be dismissed as a treatment option.

Curable hypertension

Hypertension due to a reninoma (suspected on the basis of biochemical and clinical features, and exquisite sensitivity of hypertension to angiotensin-converting enzyme [ACE] inhibition, but not visible on imaging) was cured by laparoscopic nephrectomy. Treatment was followed by an uneventful pregnancy.

Clinical Use of Laboratory Tests for the Identification of Secondary Forms of Arterial Hypertension

The prevalence of secondary hypertension can be underestimated if appropriate tests are not performed. The importance of selecting patients with a high pre-test probability of secondary forms of hypertension is first discussed. The laboratory tests currently used for seeking a cause of hypertension are critically reviewed, with emphasis on their operative features and limitations. Strategies to identify primary aldosteronism, the most frequent form of secondary hypertension, and to determine its unilateral or bilateral causes are described. Treatment entails adrenalectomy in unilateral forms, and mineralocorticoid receptor blockade in bilateral forms. Renovascular hypertension is also a common, curable form of hypertension, that should be identified as early as possible to avoid the onset of cardiovascular target organ damage. The tests for its confirmation or exclusion are discussed. The various tests available for the diagnosis of pheochromocytoma, which is much rarer than the above but extremely important to identify, are also described, with emphasis on recent developments in genetic testing. Finally, the tests for diagnosing some rarer monogenic forms and other renal and endocrine causes of arterial hypertension are explored.

Case detection, diagnosis, and treatment of patients with primary aldosteronism: an endocrine society clinical practice guideline

OBJECTIVE

Our objective was to develop clinical practice guidelines for the diagnosis and treatment of patients with primary aldosteronism.

PARTICIPANTS

The Task Force comprised a chair, selected by the Clinical Guidelines Subcommittee (CGS) of The Endocrine Society, six additional experts, one methodologist, and a medical writer. The Task Force received no corporate funding or remuneration.

EVIDENCE

Systematic reviews of available evidence were used to formulate the key treatment and prevention recommendations. We used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) 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

Consensus was guided by systematic reviews of evidence and discussions during one group meeting, several conference calls, and multiple e-mail communications. The drafts prepared by the task force with the help of a medical writer were reviewed successively by The Endocrine Society's CGS, Clinical Affairs Core Committee (CACC), and Council. The version approved by the CGS and CACC was placed on The Endocrine Society's Web site for comments by members. At each stage of review, the Task Force received written comments and incorporated needed changes.

CONCLUSIONS

We recommend case detection of primary aldosteronism be sought in higher risk groups of hypertensive patients and those with hypokalemia by determining the aldosterone-renin ratio under standard conditions and that the condition be confirmed/excluded by one of four commonly used confirmatory tests. 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 the presence of a unilateral form of primary aldosteronism should be established/excluded by bilateral adrenal venous sampling by an experienced radiologist and, where present, optimally treated by laparoscopic adrenalectomy. We recommend that patients with bilateral adrenal hyperplasia, or those unsuitable for surgery, optimally be treated medically by mineralocorticoid receptor antagonists.

Primary aldosteronism, a major form of low renin hypertension: from screening to diagnosis

There is general consensus on the use of (but not cut-off values for) the aldosterone/plasma renin activity ratio as a screening test for primary aldosteronism. There is also agreement on the need for subsequent confirmatory testing, but not on the protocols to be chosen. The four most common confirmatory tests in clinical practice are oral sodium loading, intravenous saline infusion, captopril challenge and fludrocortisone administration plus sodium loading. The choice of test reflects multiple variables: patient factors (including accessibility, compliance and safety), established practice and cost. Finally, subtype forms and lateralization of aldosterone production should be established by bilateral adrenal venous sampling, despite its technical difficulty and varying criteria for success.

Screening and diagnosis of primary aldosteronism

Primary aldosteronism (PA) is the most common cause of mineralocorticoid hypertension. Different studies using the plasma aldosterone concentration (PAC)-plasma renin activity ratio (ARR ratio) for the screening of patients with hypertension, have shown a marked increase in the detection rate of PA. PA is commonly caused by an adrenal adenoma (APA) or idiopathic bilateral adrenal hyperplasia of the adrenal zona glomerulosa (IHA) and, in rare cases, by the inherited condition of glucocorticoid-remediable aldosteronism (GRA). The early diagnosis of PA is important, not only because the forms caused by adrenal adenoma are surgically curable, but also because correlation between the duration of PA and the development of cardiovascular complications has been reported. Patients with resistant and/or severe hypertension, patients with hypokalemia, those with a family history of hypertension and stroke at an early age, or patients with an adrenal incidentaloma should be screened for PA using the ARR ratio. Suspicion of PA owing to a pathological ratio requires confirmatory testing, including fludrocortisone suppression test, saline infusion and captopril challenge. Adrenal gland imaging is important in subtype differentiation (APA vs IHA), but adrenal venous sampling is the gold standard and should be used when other tests prove inconclusive. Genetic testing has facilitated detection of GRA.