Clinical validation for the aldosterone-to-renin ratio and aldosterone suppression testing using simultaneous fully automated chemiluminescence immunoassays

Diagnostic Accuracy of Aldosterone and Renin Measurement by Chemiluminescence for Screening of Patients with Primary Aldosteronism

Primary aldosteronism (PA) is the most common cause of endocrine arterial hypertension, and the suggested screening test for case detection is the aldosterone-to-renin ratio (ARR) or aldosterone-to-direct renin ratio (ADRR) based on radio-immunoassay (RIA) and chemiluminescence assay (CLIA), respectively. The objective of our study was to evaluate the reliability of CLIA for aldosterone and renin measurement and the diagnostic performance of ADRR. A prospective cohort of 1110 patients referred to a single laboratory medicine center underwent measurement of aldosterone and direct renin concentration (DRC) by CLIA and measurement of aldosterone and plasma renin activity (PRA) by RIA. Of 1110 patients, 640 obtained a final diagnosis of hypertension, and 90 of these patients were diagnosed with PA. Overall, between-method correlation was highly significant for aldosterone concentrations (R = 0.945, p < 0.001) and less strong but significant for DRC/PRA (R = 0.422, p < 0.001). Among hypertensive patients, in PA cases, the areas under the receiver operator characteristics (ROC) curves were 0.928 (95% confidence interval 0.904-0.954) for ADRR and 0.943 (95% confidence interval 0.920-0.966) for ARR and were comparable and not significantly different. The highest accuracy was obtained with an ADRR cut-off of 25 (ng/L)/(mIU/L), displaying a sensitivity of 91% and a specificity of 85%. The chemiluminescence assay for aldosterone and DRC is a reliable method for PA diagnosis compared to the classical RIA method.

Screening for Primary Aldosteronism by Mass Spectrometry Versus Immunoassay Measurements of Aldosterone: A Prospective Within-Patient Study

BACKGROUND

Measurements of aldosterone by mass spectrometry are more accurate and less prone to interferences than immunoassay measurements, and may produce a more accurate aldosterone:renin ratio (ARR) when screening for primary aldosteronism (PA).

METHODS

Differences in diagnostic performance of the ARR using mass spectrometry vs immunoassay measurements of aldosterone were examined in 710 patients screened for PA. PA was confirmed in 153 patients and excluded in 451 others. Disease classifications were not achieved in 106 patients. Areas under receiver-operating characteristic curves (AUROC) and other measures were used to compare diagnostic performance.

RESULTS

Mass spectrometry-based measurements yielded lower plasma aldosterone concentrations than immunoassay measurements. For the ARR based on immunoassay measurements of aldosterone, AUROCs were slightly lower (P = 0.018) than those using mass spectrometry measurements (0.895 vs 0.906). The cutoff for the ARR to reach a sensitivity of 95% was 30 and 21.5 pmol/mU by respective immunoassay and mass spectrometry-based measurements, which corresponded to specificities of 57% for both. With data restricted to patients with unilateral PA, diagnostic sensitivities of 94% with specificities >81% could be achieved at cutoffs of 68 and 52 pmol/mU for respective immunoassay and mass spectrometry measurements.

CONCLUSIONS

Mass spectrometry-based measurements of aldosterone for the ARR provide no clear diagnostic advantage over immunoassay-based measurements. Both approaches offer limited diagnostic accuracy for the ARR as a screening test. One solution is to employ the higher cutoffs to triage patients likely to have unilateral PA for further tests and possible adrenalectomy, while using the lower cutoffs to identify others for targeted medical therapy.German Clinical Trials Register ID: DRKS00017084.

Comparison between screening for primary aldosteronism with and without drug adjustment

OBJECTIVE

Few studies have evaluated the performance of non-drug-adjusted primary aldosteronism (PA) screening. Therefore, we aimed to examine the consistency between PA screening results with and without drug adjustment and to explore the effectiveness of screening without drug adjustment.

METHODS

This prospective study included 650 consecutive patients with a high risk of incidence PA. Patients who initially screened positive underwent rescreening with drug adjustments and confirmatory tests. Regarding the remaining patients, one of every three consecutive patients underwent rescreening with drug adjustments and confirmatory tests. The changes in aldosterone and renin concentrations were compared between patients with essential hypertension (EH) and those with PA before and after drug adjustment. Sensitivity and specificity were used to assess the diagnostic performance of screening without drug adjustment, using the confirmatory test results as the reference.

RESULTS

We screened 650 patients with hypertension for PA. Forty-nine patients were diagnosed with PA and 195 with EH. Regarding drugs, 519 patients were taking angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), calcium channel blockers (CCBs), or diuretics alone or in combination. Forty-one patients were taking beta-blockers. Ninety patients were taking beta-blockers in combination with other drugs. In patients treated with ACEIs, ARBs, CCBs, or diuretics alone, or in combination, or beta-blockers alone, PA positivity was determined using the criteria, aldosterone-to-renin ratio (ARR) >38 pg/mL/pg/mL and plasma aldosterone concentration (PAC) >100 pg/mL, and negativity, using the criteria, ARR <9 pg/mL/pg/mL; the sensitivity and specificity were 94.7% and 94.5%, respectively. After drug adjustment, the sensitivity and specificity of screening were 92.1% and 89%, respectively.

CONCLUSIONS

In patients not treated with beta-blockers combined with others, when ARR >38 pg/mL/pg/mL and plasma aldosterone concentration (PAC) >100 pg/mL, or, ARR <9 pg/mL/pg/mL, non-drug-adjusted screening results were identical to with drug adjustment. Non-drug-adjusted screening could reduce the chance of medication adjustment, enable patients to continue their treatments and avoiding adverse effects, is of clinical importance.

Unilateral Primary Aldosteronism: Long-Term Disease Recurrence After Adrenalectomy

BACKGROUND

Primary aldosteronism (PA) is frequently caused by a unilateral aldosterone-producing adenoma with a PA-driver mutation. Unilateral adrenalectomy has a high probability of short-term biochemical remission, but long-term postsurgical outcomes are relatively undefined. Our objective was to investigate the incidence of long-term recurrence of PA in individuals with postsurgical short-term biochemical remission.

METHODS

Adrenalectomized patients for unilateral PA were included from a single referral center. Histopathology and outcomes were assessed according to international histopathology of unilateral primary aldosteronism and PASO (Primary Aldosteronism Surgical Outcome) consensuses. Genotyping was performed using CYP11B2 (aldosterone synthase)-guided sequencing.

RESULTS

Classical adrenal histopathology, exemplified by a solitary aldosterone-producing adenoma, was observed in 78% of 90 adrenals, compared with 22% with nonclassical histopathology. The classical group displayed higher aldosterone-to-renin ratios (P=0.013) and lower contralateral ratios (P=0.008). Outcome assessments at both short (12 months [7; 12]) and long (89 months [48; 124]) terms were available for 57 patients. At short-term assessment, 53 (93%) displayed complete biochemical success (43 classical and 10 nonclassical), but long-term assessment demonstrated biochemical PA recurrence in 12 (23%) with an overrepresentation of the nonclassical histopathology (6 [60%] of 10 nonclassical histopathology versus 6 [14%] of 43 classical histopathology; P=0.005). PA-driver mutations were identified in 97% of 64 aldosterone-producing adenomas; there was no association of the aldosterone-producing adenoma genotype with PA recurrence.

CONCLUSIONS

A substantial proportion of individuals display postsurgical biochemical recurrence of PA, which is related to the histopathology of the resected adrenal gland. These findings emphasize the role of histopathology and the requirement for continued outcome assessment in the management of surgically treated patients for PA.

Aldosterone Immunoassay-Specific Cutoff Value for Seated Saline Suppression Test for Diagnosing Primary Aldosteronism

A seated saline loading test (SLT) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) is one of the most accepted confirmatory tests of primary aldosteronism. However, LC-MS/MS is time-consuming and is not widely available in diagnostic laboratories compared to immunoassay. With immunoassay, it is unknown whether SLT in the seated position is more accurate than that of the supine position, and a cutoff value of post-seated SLT plasma aldosterone concentration (PAC) must be established in the Korean population. Ninety-eight patients underwent SLT in both positions, and post-SLT PAC was measured by LC-MS/MS and radioimmunoassay. We confirmed primary aldosteronism if post-seated SLT PAC by LC-MS/MS exceeded 5.8 ng/dL. The area under the receiver operating characteristic curve was greater for seated than supine SLT (0.928 vs. 0.834, P=0.003). The optimal cutoff value of post-seated SLT by radioimmunoassay was 6.6 ng/dL (sensitivity 83.3%, specificity 92.2%).

Approach to the Patient on Antihypertensive Therapy: Screen for Primary Aldosteronism

Primary aldosteronism (PA) is a condition that is still largely overlooked, resulting in a considerable burden of mortality and morbidity. This is despite decades of clinical and translational research on the deleterious effects of aldosterone on the cardiovascular system and the publication of several guidelines and consensuses on its diagnosis and treatment. One of the main reasons for the low rate of testing is the difficulty of screening patients on antihypertensive therapy that potentially interferes with aldosterone and renin levels and thus confound the interpretation of the aldosterone to renin ratio, the accepted and conventionally used screening test. To avoid interference, usually the therapies that affect the renin-angiotensin aldosterone system are withdrawn and substituted with noninterfering medications. However, in many cases the screening test can be confidently interpreted even when such therapies are not discontinued. In this review, we will evaluate the effects of antihypertensive therapies on the screening test for PA and suggest a practical approach for its interpretation.

Analytical evaluation and bioclinical validation of new aldosterone and renin immunoassays

OBJECTIVES

Aldosterone and renin determinations play an important role in the etiological diagnosis of secondary hypertension. The analytical performances of new aldosterone and renin immunoassays on the Lumipulse G600II^® system (Fujierbio) were investigated and compared with those of the iSYS^® system (IDS) on patients concerned by medical investigations in a context of suspected or proven Primary aldosteronism.

METHODS

By using the Lumipulse^® G Aldosterone and Renin assays we performed imprecision study, linearity and method comparison (n=107). Accuracy of this new renin assay was tested using the International Standard (WHO IS 68/356). We also assessed the equivalence of the different samples types (n=29).

RESULTS

The imprecision evaluation showed all CVs <3% and <6% for Lumipulse^® G Aldosterone and Renin assays respectively. The linearity was excellent over the clinical range and the comparison with the iSYS^® assays (n=79) showed a strong correlation (R²=1) despite a slight tendency to underestimation (bias of -17.53 pg/mL or 48.56 pmol/L for aldosterone and -15.395 pg/mL for renin). Moreover, the contingency studies based on diagnostic criteria showed that Lumipulse^® G results lead to the same clinical diagnosis that iSYS^® results. A clear correlation was obtained between EDTA and heparin plasma as well as with the serum for all range of measures.

CONCLUSIONS

The Lumipulse^® G Aldosterone and Renin assays present performances compatible with a routine use in medical laboratories. The precise quantification in the low range can be of interest in some clinical contexts especially standing/laying tests. However, the standardisation against the WHO International Standard Renin would be advisable.

Novel chemiluminescent immunoassay to measure plasma aldosterone and plasma active renin concentrations for the diagnosis of primary aldosteronism

Determination of plasma aldosterone concentrations (PAC) and plasma active renin concentrations (ARC) is essential for the diagnosis of primary aldosteronism (PA). In Japan, although PAC and ARC are measured by radioimmunoassay and immunoradiometric assay, respectively, non-radioisotopic methods with better detection sensitivity, measurement accuracy, and technical simplicity are needed. We developed two-site sandwich chemiluminescent enzyme immunoassays (CLEIAs) to measure both PAC and ARC using monoclonal antibodies immobilized onto ferrite particles. The results of both assays are obtained simultaneously from a single plasma sample within 30 min using a fully automated system. The novel CLEIAs were validated using plasma samples from patients with PA (n = 52) and essential hypertension (n = 23). The PAC determined by the CLEIA was significantly correlated with that measured by liquid chromatography/mass spectrometry or conventional radioimmunoassay. The ARC determined by the CLEIA was significantly correlated with that measured by immunoradiometric assay. The limits of detection of the CLEIAs for PAC and ARC were 0.1 ng/dl and 0.04 pg/ml, respectively, which were better than those of conventional methods (PAC: 2.5 ng/dl; ARC: 5 pg/ml). The PAC and PAC/ARC ratio (ARR) were significantly higher, and the ARC significantly lower, in patients with PA than in those with essential hypertension. An ARR cut-off of 1.31 ng/dl per pg/ml showed a sensitivity of 96.2% and specificity of 78.3% for PA screening. The newly developed CLEIAs for measuring PAC and ARC could provide a clinically powerful alternative to conventional methods used for hypertension screening in clinical practice.

Aldosterone-potassium ratio predicts primary aldosteronism subtype

OBJECTIVE

Prediction models have been developed to predict either unilateral or bilateral primary aldosteronism, and these have not been validated externally. We aimed to develop a simplified score to predict both subtypes and validate this externally.

METHODS

Our development cohort was taken from 165 patients who underwent adrenal vein sampling (AVS) in two Asian tertiary centres. Unilateral disease was determined using both AVS and postoperative outcome. Multivariable analysis was used to construct prediction models. We validated our tool in a European cohort of 97 patients enrolled in the SPARTACUS trial who underwent AVS. Previously published prediction models were also tested in our cohorts.

RESULTS

Backward stepwise logistic regression analysis yielded a final tool using baseline aldosterone-to-lowest-potassium ratio (APR, ng/dl/mmol/l), with an area under receiver-operating characteristic curve of 0.80 (95% CI 0.70-0.89). In the Asian development cohort, probability of bilateral disease was 90.0% (with APR <5) and probability of unilateral disease was 91.4% (with APR >15). Similar results were seen in the European validation cohort. Combining both cohorts, probability of bilateral disease was 76.7% (with APR <5), and probability for unilateral was 91.7% (with APR >15). Other models had similar predictive ability but required more variables, and were less sensitive for identifying bilateral PA.

CONCLUSION

The novel aldosterone-to-lowest-potassium ratio is a convenient score to guide clinicians and patients of various ethnicities on the probability of primary aldosteronism subtype. Using APR to identify patients more likely to benefit from AVS may be a cost-effective strategy to manage this common condition.

Urinary sodium-to-potassium ratio and plasma renin and aldosterone concentrations in normotensive children: implications for the interpretation of results

OBJECTIVES

To identify associations among the plasma renin concentration (PRC), plasma aldosterone and urinary sodium (Na)/potassium (K) ratio, and to integrate these variables into a nomogram with the aim of estimating the expected versus observed aldosterone concentration.

METHODS

We studied 40 healthy normotensive children (5-8 years old, 57.5% girls) who were born at term and were adequate for their gestational age. Following overnight fasting, the PRC and plasma aldosterone in blood samples were measured, and the Na/K ratio was calculated from a simultaneously obtained urinary spot sample. A mathematical function was defined with these three variables, and a nomogram was built that would return the expected aldosterone concentration from the obtained plasma renin and urinary Na/K ratio values.

RESULTS

The PRC (B =  5.9, P < 0.001) and urinary Na/K ratio (B = -98.1, P = 0.003) were significant independent predictors of plasma aldosterone. The correlation between the observed plasma aldosterone and the expected plasma aldosterone, as obtained from the nomogram, was r = 0.88, P < 0.001. The average difference between the observed and expected plasma aldosterone was -0.89, with a standard deviation of ±30%.

CONCLUSION

The strong correlation between the urinary Na/K ratio, from urine samples taken at the same as the blood samples, and plasma renin and aldosterone concentrations allowed us to build a nomogram to predict aldosterone levels. This approach may be useful for evaluating the renin-angiotensin-aldosterone system (RAAS) in pediatric patients with hypertension and RAAS dysfunction.

Confirmatory testing of primary aldosteronism with saline infusion test and LC-MS/MS

OBJECTIVE

Saline infusion testing (SIT) for confirmation of primary aldosteronism (PA) is based on impaired aldosterone suppression in PA compared to essential hypertension (EH). In the past, aldosterone was quantified using immunoassays (IA). Liquid chromatography tandem mass spectrometry (LC-MS/MS) is increasingly used in clinical routine. We aimed at a method-specific aldosterone threshold for the diagnosis of PA during SIT and explored the diagnostic utility of steroid panel analysis.

DESIGN

Retrospective cohort study of 187 paired SIT samples (2009-2018). Diagnosis of PA (n = 103) and EH (n = 84) was established based on clinical routine workup without using LC-MS/MS values.

SETTING

Tertiary care center.

METHODS

LC-MS/MS using a commercial steroid panel. Receiver operator characteristics analysis was used to determine method-specific cut-offs using a positive predictive value (PPV) of 90% as criterion.

RESULTS

Aldosterone measured by IA was on average 31 ng/L higher than with LC-MS/MS. The cut-offs for PA confirmation were 54 ng/L for IA (sensitivity: 95%, 95% CI: 89.0-98.4; specificity: 87%, 95% CI: 77.8-93.3; area under the curve (AUC): 0.955, 95% CI: 0.924-0.986; PPV: 90%, 95% CI: 83.7-93.9) and 69 ng/L for LC-MS/MS (79%, 95% CI: 69.5-86.1; 89%, 95% CI: 80.6-95.0; 0.902, 95% CI: 0.857-0.947; 90%, 95% CI: 82.8-94.4). Other steroids did not improve SIT.

CONCLUSIONS

Aldosterone quantification with LC-MS/MS and IA yields comparable SIT-cut-offs. Lower AUC for LC-MS/MS is likely due to the spectrum of disease in PA and previous decision making based on IA results. Until data of a prospective trial with clinical endpoints are available, the suggested cut-off can be used in clinical routine.

Confounders of the aldosterone-to-renin ratio when used as a screening test in hypertensive patients: A critical analysis of the literature

The aldosterone‐to‐renin ratio (ARR) is a common screening test for primary aldosteronism in hypertensives. However, there are many factors which could confound the ARR test result and reduce the accuracy of this test. The present review's objective is to identify these factors and to describe to what extent they affect the ARR. Our analysis revealed that sex, age, posture, and sodium‐intake influence the ARR, whereas assay techniques do not. Race and body mass index have an uncertain effect on the ARR. We conclude that several factors can affect the ARR. Not taking these factors into account could lead to misinterpretation of the ARR.

Genetics, prevalence, screening and confirmation of primary aldosteronism: a position statement and consensus of the Working Group on Endocrine Hypertension of The European Society of Hypertension

: Autonomous aldosterone overproduction represents the underlying condition of 5-10% of patients with arterial hypertension and carries a significant burden of mortality and morbidity. The diagnostic algorithm for primary aldosteronism is sequentially based on hormonal tests (screening and confirmation tests), followed by lateralization studies (adrenal CT scanning and adrenal venous sampling) to distinguish between unilateral and bilateral disease. Despite the recommendations of the Endocrine Society guideline, primary aldosteronism is largely underdiagnosed and undertreated with high between-centre heterogeneity. Experts from the European Society of Hypertension have critically reviewed the available literature and prepared a consensus document constituting two articles to summarize current knowledge on the epidemiology, diagnosis, treatment, and complications of primary aldosteronism.

High Efficiency and Problems of Chemiluminescence Assay-Detected Aldosterone-To-Renin Ratio in Practical Primary Aldosteronism Screening

Primary aldosteronism is a main cause of secondary hypertension which can be effectively treated. The screening test for primary aldosteronism is benefit for minimizing damage to the patient. In the previous retrospective study, we obtained the optimal cutoff value of aldosterone-to-renin ratio detected by chemiluminescence assay, a newly developing method, and prompted its high efficiency in primary aldosteronism screening in upright position. In this study, we want to evaluate its efficiency in practical work. We used this ratio to continuously screen 238 patients, and 58 patients were finally diagnosed with primary aldosteronism. We found it had 86.13% accuracy rate in the upright position compared with the final clinical diagnosis. False negative and positive rates were 13.79% and 13.89%. Diagnostic sensitivity and specificity were 86.21% and 86.11%, which are slightly different from results in our previous study. False negative rate can be improved by combining the aldosterone-to-renin ratio with aldosterone concentration. We also found impaired glucose tolerance may be a reason for high false positive rate. Besides, chemiluminescence assay may be interfered in aldosterone detection. Although it has some shortcomings, chemiluminescence assay-detected aldosterone-to-renin ratio is a highly effective index for screening primary aldosteronism in practice.

Plasma Renin Concentration is Associated With Hemodynamic Deficiency and Adverse Renal Outcome in Septic Shock

BACKGROUND

In septic shock, both systemic vasodilatation and glomerular arteriole dilatation are responsible for the drop in glomerular filtration observed in early acute kidney injury. Angiotensin II has been shown to act on both mechanisms. Our objective was to evaluate the impact of renin angiotensin system activation, on hemodynamic deficiency and renal outcome in patient with septic shock and to assess whether urinary sodium could be a reliable test for high plasma renin concentration screening.

METHODS

This was a prospective and observational study. Inclusion criteria were early septic shock (first episode), dose of norepinephrine ≥ 0.25 μg/kg/min, before the start of substitutive corticosteroids. Plasma renin concentration, plasma aldosterone concentration, and urinary sodium were measured at inclusion. Renal outcome, organ deficiency, and 28-day survival were followed.

RESULTS

Plasma renin concentration was associated with worse hemodynamic deficiency and adverse renal outcome. Natriuresis was associated with shock severity but was not associated with renal outcome. Low natriuresis (< 20 mM) was associated with higher renin concentration. Those two variables were only weakly correlated.

CONCLUSION

Plasma renin concentration is associated with adverse renal outcome, probably through shock severity and insufficient glomerular efferent arterioles vasoconstriction. An association was observed between low natriuresis and high plasma renin concentration.

Mass spectrometry reveals misdiagnosis of primary aldosteronism with scheduling for adrenalectomy due to immunoassay interference

BACKGROUND

Diagnosis of primary aldosteronism (PA) involves a multistep process reliant on the accuracy of aldosterone measurements at each step. We report on immunoassay interference leading to a wrongful diagnosis and indication for surgical intervention.

CASE

A 38-year old hypertensive male with a 1.4 cm left adrenal mass was diagnosed with PA based on an elevated aldosterone:renin ratio and a positive saline infusion test. Adrenal venous sampling (AVS) indicated left-sided aldosterone hypersecretion, supporting a decision to remove the left adrenal. The patient was also enrolled in a study to evaluate mass spectrometry-based steroid profiling, which indicated plasma aldosterone concentrations measured in five different peripheral samples averaging only 11% those of the immunoassay. Mass spectrometric measurements did not support left-sided adrenal aldosterone hypersecretion. Two independent laboratories confirmed differences in measurements by immunoassay and mass spectrometry. Lowered concentrations measured by the immunoassay that matched those by mass spectrometry were achieved after sample purification to remove macromolecules, confirming immunoassay interference.

CONCLUSIONS

Although our patient may represent an isolated case of immunoassay interference leading to misdiagnosis of PA, unnecessary AVS and potentially wrongful removal of an adrenal, it is also possible that such inaccuracies may impact the diagnostic process and treatment for other patients.

The 2020 Italian Society of Arterial Hypertension (SIIA) practical guidelines for the management of primary aldosteronism

Background and aim

Considering the amount of novel knowledge generated in the last five years, a team of experienced hypertensionlogists was assembled to furnish updated clinical practice guidelines for the management of primary aldosteronism.

Methods

To identify the most relevant studies, the authors utilized a systematic literature review in international databases by applying the PICO strategy, and then they were required to make use of only those meeting predefined quality criteria. For studies of diagnostic tests, only those that fulfilled the Standards for Reporting of Diagnostic Accuracy recommendations were considered.

Results

Each section was jointly prepared by at least two co-authors, who provided Class of Recommendation and Level of Evidence following the American Heart Association methodology. The guidelines were sponsored by the Italian Society of Arterial Hypertension and underwent two rounds of revision, eventually reexamined by an External Committee. They were presented and thoroughly discussed in two face-to-face meetings with all co-authors and then presented on occasion of the 36th Italian Society of Arterial Hypertension meeting in order to gather further feedbacks by all members. The text amended according to these feedbacks was subjected to a further peer review.

Conclusions

After this process, substantial updated information was generated, which could simplify the diagnosis of primary aldosteronism and assist practicing physicians in optimizing treatment and follow-up of patients with one of the most common curable causes of arterial hypertension.

Diagnosis of Primary Aldosteronism by Seated Saline Suppression Test-Variability Between Immunoassay and HPLC-MS/MS

BACKGROUND

In primary aldosteronism (PA), excessive, autonomous secretion of aldosterone is not suppressed by salt loading or fludrocortisone. For seated saline suppression testing (SSST), the recommended diagnostic cutoff 4-hour plasma aldosterone concentration (PAC) measured by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS is 162 pmol/L. Most diagnostic laboratories, however, use immunoassays to measure PAC. The cutoff for SSST using immunoassay is not known. We hypothesized that the cutoff is different between the assays.

METHODS

We analyzed 80 of the 87 SSST tests that were performed during our recent study defining the HPLC-MS/MS cutoff. PA was confirmed in 65 by positive fludrocortisone suppression testing (FST) and/or lateralization on adrenal venous sampling and excluded in 15 by negative FST. PAC was measured by a chemiluminescence immunoassay (PACIA) in the SSST samples using the DiaSorin Liaison XL analyzer, and receiver operating characteristics (ROC) analysis was performed to identify the PACIA cutoff.

RESULTS

ROC revealed good performance (area under the curve = 0.893; P < .001) of 4-hour postsaline PACIA for diagnosis of PA and an optimal diagnostic cutoff of 171 pmol/L, with sensitivity and specificity of 95.4% and 80.0%, respectively. A higher cutoff of 217 pmol/L improved specificity (86.7%) with lower sensitivity (86.2%). PACIA measurements strongly correlated with PAC measured by HPLC-MS (r = 0.94, P < .001).

CONCLUSIONS

A higher diagnostic cutoff for SSST should be employed when PAC is measured by immunoassay rather than HPLC-MS/MS. The results suggest that (i) PA can be excluded if 4-hour PACIA is less than 171 pmol/L, and (ii) PA is highly likely if the PACIA is greater than 217 pmol/L by chemiluminescence immunoassay. A gray zone exists between the cutoffs of 171 and 217 pmol/L, likely reflecting a lower specificity of immunoassay.

Hypertensive Crisis in Pediatric Patients: An Overview

Hypertensive crisis can be a source of morbidity and mortality in the pediatric population. While the epidemiology has been difficult to pinpoint, it is well-known that secondary causes of pediatric hypertension contribute to a greater incidence of hypertensive crisis in pediatrics. Hypertensive crisis may manifest with non-specific symptoms as well as distinct and acute symptoms in the presence of end-organ damage. Hypertensive emergency, the form of hypertensive crisis with end-organ damage, may present with more severe symptoms and lead to permanent organ damage. Thus, it is crucial to evaluate any pediatric patient suspected of hypertensive emergency with a thorough workup while acutely treating the elevated blood pressure in a gradual manner. Management of hypertensive crisis is chosen based on the presence of end-organ damage and can range from fast-acting intravenous medication to oral medication for less severe cases. Treatment of such demands a careful balance between decreasing blood pressure in a gradual manner while preventing damage end-organ damage. In special situations, protocols have been established for treatment of hypertensive crisis, such as in the presence of endocrinologic neoplasms, monogenic causes of hypertension, renal diseases, and cardiac disease. With the advent of telehealth, clinicians are further able to extend their reach of care to emergency settings and aid emergency medical service (EMS) providers in real time. In addition, further updates on the evolving topic of hypertension in the pediatric population and novel drug development continues to improve outcomes and efficiency in diagnosis and management of hypertension and consequent hypertensive crisis.

Österreichischer Blutdruckkonsens 2019

Erhöhter Blutdruck bleibt eine Hauptursache von kardiovaskulären Erkrankungen, Behinderung und frühzeitiger Sterblichkeit in Österreich, wobei die Raten an Diagnose, Behandlung und Kontrolle auch in rezenten Studien suboptimal sind. Das Management von Bluthochdruck ist eine häufige Herausforderung für Ärztinnen und Ärzte vieler Fachrichtungen. In einem Versuch, diagnostische und therapeutische Strategien zu standardisieren und letztendlich die Rate an gut kontrollierten Hypertoniker/innen zu erhöhen und dadurch kardiovaskuläre Erkrankungen zu verhindern, haben 13 österreichische medizinische Fachgesellschaften die vorhandene Evidenz zur Prävention, Diagnose, Abklärung, Therapie und Konsequenzen erhöhten Blutdrucks gesichtet. Das hier vorgestellte Ergebnis ist der erste Österreichische Blutdruckkonsens. Die Autoren und die beteiligten Fachgesellschaften sind davon überzeugt, daß es einer gemeinsamen nationalen Anstrengung bedarf, die Blutdruck-assoziierte Morbidität und Mortalität in unserem Land zu verringern.

Diagnostic Accuracy of the Aldosterone-to-Active Renin Ratio for Detecting Primary Aldosteronism

Context

The aldosterone-to-active renin ratio (AARR) is the recommended screening test for primary aldosteronism (PA), but prospective study data on its sensitivity and specificity are sparse.

Objective

To investigate the diagnostic accuracy of the AARR for detecting PA.

Design

Prospective diagnostic accuracy study.

Setting

This study was conducted from February 2009 to August 2015 at the outpatient clinic of the Department of Endocrinology and Diabetology of the Medical University of Graz, Austria.

Participants

Four hundred patients with arterial hypertension who were referred to a tertiary care center for screening for endocrine hypertension.

Intervention

Participants had a determination of the AARR (index test) and a second AARR determination followed by a saline infusion test (SIT) after 2 to 6 weeks. PA was diagnosed in individuals with any AARR ≥3.7 ng/dL/µU/mL [including a plasma aldosterone concentration (PAC) of ≥9 ng/dL] who had a PAC ≥10 ng/dL after the SIT. We did not substantially alter antihypertensive drug intake.

Main Outcome Measures

Primary outcome was the receiver-operating characteristic (ROC) curve of the AARR in diagnosing PA.

Results

A total of 382 participants were eligible for analyses; PA was diagnosed in 18 (4.7%) patients. The area under the ROC curve of the AARR in detecting PA was 0.973 (95% CI, 0.956 to 0.990). Sensitivity and specificity for a positive AARR in diagnosing PA were 100% (95% CI, 81.5% to 100.0%) and 89.6% (95% CI, 86.0% to 92.5%), respectively.

Conclusions

The AARR has good diagnostic accuracy for detecting 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.

[Adrenal incidentaloma : Diagnostic and therapeutic concept from an endocrinological perspective]

An adrenal incidentaloma is an adrenal mass detected on imaging that was not performed for suspected adrenal disease. The prevalence is approximately 3% and increases up to 10% in older people. The risk of malignancy and a hormone excess have to be evaluated. Approximately 15% of incidentalomas harbor an overproduction of hormones, in particular primary aldosteronism (Conn's syndrome), hypercortisolism (Cushing's syndrome) and pheochromocytoma. Primary aldosteronism is the main cause of endocrine hypertension. It is characterized by an overproduction of aldosterone usually due to a unilateral adenoma or an idiopathic, often bilateral hyperplasia. The aldosterone to renin ratio is an established screening parameter for the diagnosis. If the ratio is elevated a confirmatory test, e. g. saline infusion test, should follow. Usually an adrenal venous catheter has to be used to discriminate between unilateral and bilateral aldosterone overproduction. In the case of unilateral overproduction an adrenalectomy is recommended, otherwise treatment is carried out with an aldosterone antagonist. For the diagnosis of an adrenal Cushing's syndrome a dexamethasone suppression test and a suppressed or in the lower limit of normal ACTH is required. The rare pheochromocytoma is a catecholamine-producing tumor. The diagnosis is carried out by determination of metanephrines in plasma or in 24 h urine samples. Unilateral adrenal tumors leading to clinically significant hormone excess or tumors with suspicion of malignancy should be surgically removed. A minimally invasive adrenalectomy is normally the method of choice in patients with a unilateral adrenal tumor <6 cm and without local tumor invasion. In unilateral, clearly benign, non-functioning, small adrenal tumors (<4 cm) surgery is not required.

Diagnostic approach to low-renin hypertension

Renin-angiotensin-aldosterone system (RAAS) plays a crucial role in maintaining water and electrolytes homoeostasis, and its deregulation contributes to the development of arterial hypertension. Since the historical description of the "classical" RAAS, a dramatic increase in our understanding of the molecular mechanisms underlying the development of both essential and secondary hypertension has occurred. Approximatively 25% of the patients affected by arterial hypertension display low-renin levels, a definition that is largely arbitrary and depends on the investigated population and the specific characteristics of the assay. Most often, low-renin levels are expression of a physiological response to sodium-volume overload, but also a significant number of secondary hereditary or acquired conditions falls within this category. In a context of suppressed renin status, the concomitant examination of plasma aldosterone levels (which can be inappropriately elevated, within the normal range or suppressed) and plasma potassium are essential to formulate a differential diagnosis. To distinguish between the different forms of low-renin hypertension is of fundamental importance to address the patient to the proper clinical management, as each subtype requires a specific and targeted therapy. The present review will discuss the differential diagnosis of the most common medical conditions manifesting with a clinical phenotype of low-renin hypertension, enlightening the novelties in genetics of the familial forms.

High efficiency of the aldosterone-to-renin ratio in precisely detecting primary aldosteronism

The aldosterone-to-renin ratio (ARR) is extensively used for primary aldosteronism detection. Chemiluminescence immune assay (CLIA) is newly applied in aldosterone and renin detection for calculating the aldosterone-to-renin ratio. The performance of new ARR in aldosteronism detection is poorly evaluated. We aim to estimate the diagnostic value of this new aldosterone-to-renin ratio by highly standardized and clinically based protocol. Four hundred and forty-two patients were enrolled in our retrospective study. They went to the first affiliated hospital of Sun Yat-sen University with difficult-to-control hypertension. Primary aldosteronism diagnosis was based on clinical criteria, including a saline infusion test and other necessary inspections. ARR was calculated from plasma aldosterone and renin measured by CLIA. The cutoff value was determined and the diagnostic value was evaluated. The cutoff value of ARR for primary aldosteronism diagnosis was 28.3, with a sensitivity of 87.6%, specificity of 100%, negative-predictive value of 96.4%, and positive-predictive value of 100%. Then, we found that Age was weakly correlated with ARR. The cutoff values of ARR for primary aldosteronism diagnosis in 26-45-, 46-65-, and 66-85-year-old patients were, respectively, 29.45, 27.95, and 28.4, with sensitivities of 87.5%, 87.7%, and 87.5%, specificities of 100% for all, negative-predictive values of 97.7%, 94.3%, and 96.3%, and positive-predictive values of 100% for all. ARR generated by CLIA is a good diagnostic test for primary aldosteronism without making a false-positive diagnosis. Although ARR is correlated with age, ARR cutoff values for different ages are not more efficient than that for total sample in primary aldosteronism diagnosis.

MANAGEMENT OF ENDOCRINE DISEASE: Diagnosis and management of primary aldosteronism: the Endocrine Society guideline 2016 revisited

The syndrome of primary aldosteronism (PA) is characterized by hypertension with excessive, autonomous aldosterone production and is usually caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia. The diagnostic workup of PA is a sequence of three phases comprising screening tests, confirmatory tests and the differentiation of unilateral from bilateral forms. The latter step is necessary to determine the optimal treatment approach of unilateral laparoscopic adrenalectomy (for patients with unilateral PA) or medical treatment with a mineralocorticoid receptor antagonist (for patients with bilateral PA). Since the publication of the revised Endocrine Society guideline 2016, a number of key studies have been published. They challenge the recommendations of the guideline in some areas and confirm current practice in others. Herein, we present the recent developments and current approaches to the medical management of PA.

Progress in the Management of Primary Aldosteronism

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

Histopathological and genetic characterization of aldosterone-producing adenomas with concurrent subclinical cortisol hypersecretion: a case series

PURPOSE

Aldosterone-producing adenomas with concurrent subclinical cortisol hypersecretion are reported in an increasing number of patients. Five aldosterone-producing adenomas from patients with primary aldosteronism and subclinical hypercortisolism were examined.

THE AIMS OF OUR STUDY WERE

(1) to analyze pathological features and immunohistochemical expression of CYP11B1 (11β-hydroxylase) and CYP11B2 (aldosterone synthase) in these tumors; (2) to investigate somatic mutations involved in adrenal steroid hypersecretion and/or tumor growth.

METHODS

Archival micro-dissected paraffin-embedded slides from tumor specimens were used for histological and molecular studies. Immunohistochemistry was performed using monoclonal anti-CYP11B1 and anti-CYP11B2 antibodies. Cellular composition was determined by examining for known features of zona fasciculata and zona glomerulosa, and immunoreactivity for CYP11B1 and CYP11B2 by McCarty H-score. Spot regions for mutations in KCNJ5, ATP1A1, ATP2B3, CACNA1D, PRKACA, and CTNNB1 gene sequences were evaluated.

RESULTS

Four APAs showed a predominant (≥50%) zona fasciculata-like cell pattern: one tumor had CYP11B1 H-score = 150, no detectable CYP11B2 expression, and harbored a PRKACA p.Leu206Arg mutation (that we have reported previously elsewhere), one had no CYP11B1 expression, CYP11B2 H-score = 40, and no mutations; the remaining two adenomas had high CYP11B1 H-score (160 and 240, respectively) and low CYP11B2 H-score (30 and 15, respectively), with the latter harboring a CTNNB1 p.Ser45Phe activating mutation. One of five aldosterone-producing adenomas had a predominant zona glomerulosa-like pattern, CYP11B1 H-score = 15, CYP11B2 H-score = 180, and no mutations.

CONCLUSIONS

The majority of aldosterone-producing adenomas with concurrent subclinical cortisol hypersecretion were composed mainly of zona fasciculata-like cells, while CYP11B1 and CYP11B2 immunostaining demonstrated clear heterogeneity. In a subset of cases, different somatic mutations may be involved in hormone excess and tumor formation.

Update in diagnosis and management of primary aldosteronism

Primary aldosteronism (PA) is a group of disorders in which aldosterone is excessively produced. These disorders can lead to hypertension, hypokalemia, hypervolemia and metabolic alkalosis. The prevalence of PA ranges from 5% to 12% around the globe, and the most common causes are adrenal adenoma and adrenal hyperplasia. The importance of PA recognition arises from the fact that it can have a remarkably adverse cardiovascular and renal impact, which can even result in death. The aldosterone-to-renin ratio (ARR) is the election test for screening PA, and one of the confirmatory tests, such as oral sodium loading (OSL) or saline infusion test (SIT), is in general necessary to confirm the diagnosis. The distinction between adrenal hyperplasia (AH) or aldosterone-producing adenoma (APA) is essential to select the appropriate treatment. Therefore, in order to identify the subtype of PA, imaging exams such as computed tomography or magnetic ressonance imaging, and/or invasive investigation such as adrenal catheterization must be performed. According to the subtype of PA, optimal treatment – surgical for APA or pharmacological for AH, with drugs like spironolactone and amiloride – must be offered.

Rapid Screening of Primary Aldosteronism by a Novel Chemiluminescent Immunoassay

Measurement of plasma aldosterone and renin concentration, or activity, is useful for selecting antihypertensive agents and detecting hyperaldosteronism in hypertensive patients. However, it takes several days to get results when measured by radioimmunoassay and development of more rapid assays has been long expected. We have developed chemiluminescent enzyme immunoassays enabling the simultaneous measurement of both aldosterone and renin concentrations in 10 minutes by a fully automated assay using antibody-immobilized magnetic particles with quick aggregation and dispersion. We performed clinical validation of diagnostic ability of this newly developed assay-based screening of 125 patients with primary aldosteronism from 97 patients with essential hypertension. Results of this novel assay significantly correlated with the results of radioimmunoassay (aldosterone, active renin concentration, and renin activity) and liquid chromatography-tandem mass spectrometry (aldosterone). The analytic sensitivity of this particularly novel active renin assay was 0.1 pg/mL, which was better than that of radioimmunoassay (2.0 pg/mL). The ratio of aldosterone-to-renin concentrations of 6.0 (ng/dL per pg/mL) provided 92.0% sensitivity and 76.3% specificity as a cutoff for differentiating primary aldosteronism from essential hypertension. This novel measurement is expected to be a clinically reliable alternative for conventional radioimmunoassay and to provide better throughput and cost effectiveness in diagnosis of hyperaldosteronism from larger numbers of hypertensive patients in clinical settings.

Screening for primary aldosteronism using the newly developed IDS-iSYS® automated assay system

BACKGROUND

The recommended approach to screening for primary aldosteronism (PA) in at-risk populations is to determine the ratio of aldosterone concentration (serum (SAC)/plasma (PAC)) to renin measured in plasma as activity (PRA) or concentration (DRC). However, lack of assay standardisation mandates the need for method-specific decision thresholds and clinical validation in the local population.

AIM

The study objective was to establish method-specific aldosterone: renin ratio (ARR) cut-offs for PA in men and women using the IDS-iSYS® assay system (IDS plc).

METHODS

A prospective cohort study design was used. PAC and DRC were measured immunochemically in ethylenediamine-tetraacetic acid (EDTA) plasma on the IDS-iSYS® instrument.

RESULTS

A total of 437 subjects (218 men, 219 women) were recruited including: healthy normotensive volunteers (n=266) and women taking the oral contraceptive pill (OCP; n=15); patients with essential hypertension (EH; n=128); confirmed PA (n=16); adrenal cortical carcinoma (ACC; n=3); Addison's disease (AD; n=4) and phaeochromocytoma/paraganglioma (PPGL; n=5). In this population, an ARR cut-off at >37.4 pmol/mIU provided 100% diagnostic sensitivity, 96% specificity and positive likelihood ratio for PA of 23:1. When the ARR decision threshold was stratified according to gender, a cut-off of >26.1 pmol/mIU in men and >113.6 pmol/mIU in women resulted in diagnostic sensitivity and specificity of 100%.

CONCLUSION

This study demonstrates that decision thresholds for PA should not only be method-specific but also gender-specific. However, given the small number of PA patients (n=16), particularly women (n=4), further validation through a prospective study with a larger PA cohort is required before the thresholds presented here could be recommended for routine clinical use.

Prospective validation of an automated chemiluminescence-based assay of renin and aldosterone for the work-up of arterial hypertension

BACKGROUND

The availability of simple and accurate assays of plasma active renin (DRC) and aldosterone concentration (PAC) can improve the detection of secondary forms of arterial hypertension. Thus, we investigated the performance of an automated chemiluminescent assay for DRC and PAC in referred hypertensive patients.

METHODS

We prospectively recruited 260 consecutive hypertensive patients referred to an ESH Center for Hypertension. After exclusion of six protocol violations, 254 patients were analyzed: 67.3% had primary hypertension, 17.3% an aldosterone producing adenoma (APA), 11.4% idiopathic hyperaldosteronism (IHA), 2.4% renovascular hypertension (RVH), 0.8% familial hyperaldosteronism type 1 (FH-1), 0.4% apparent mineralocorticoid excess (AME), 0.4% a renin-producing tumor, and 3.9% were adrenalectomized APA patients. Bland-Altman plots and Deming regression were used to analyze results. The diagnostic accuracy (area under the curve, AUC of the ROC) of the DRC-based aldosterone-renin ratio (ARRCL) was compared with that of the PRA-based ARR (ARRRIA) using as reference the conclusive diagnosis of APA.

RESULTS

At Bland-Altman plot, the DRC and PAC assay showed no bias as compared to the PRA and PAC assay. A tight relation was found between the DRC and the PRA values (concordance correlation coefficient=0.92, p<0.0001) and the PAC values measured with radioimmunoassay and chemiluminescence (concordance correlation coefficient=0.93, p<0.001). For APA identification the AUC of the ARRCL was higher than that of the ARRRIA [0.974 (95% CI 0.940-0.991) vs. 0.894 (95% CI 0.841-0.933), p=0.02].

CONCLUSIONS

This rapid automated chemiluminescent DRC/PAC assay performed better than validated PRA/PAC radioimmunoassays for the identification of APA in referred hypertensive patients.

Acute administration of acyl, but not desacyl ghrelin, decreases blood pressure in healthy humans

OBJECTIVE

To compare the effects of acyl ghrelin (AG) and desacyl ghrelin (DAG) on blood pressure (BP), heart rate (HR) and other autonomic parameters in healthy humans and to elucidate the hormonal mechanisms through which AG could exert its cardiovascular effects.

DESIGN

Seventeen healthy participants underwent frequent monitoring of systolic (sBP) and diastolic blood pressure (dBP), HR, respiratory rate (RR) and body surface temperature (Temp) during continuous infusion of AG, DAG, combined AG + DAG or saline control before and during an IV glucose tolerance test on 4 separate days. Plasma catecholamines, renin and aldosterone levels were also measured. Differences in outcome measures between treatment groups were assessed using mixed-model analysis.

RESULTS

Compared to the saline control, AG and combined AG + DAG infusions decreased sBP, dBP, mean arterial blood pressure (MAP), HR and Temp. In contrast, DAG infusion did not alter BP, RR or Temp, but did decrease HR. The AG and AG + DAG infusions also raised plasma aldosterone levels compared to saline (P < 0.001) without affecting renin or catecholamine levels.

CONCLUSIONS

The decrease in BP, HR, RR and Temp with AG infusion suggests mediation through the autonomic nervous system. The lack of response to DAG suggests that these autonomic effects require activation of the ghrelin receptor.

Endocrine Hypertension: A Practical Approach

Elevated blood pressure resulting from few endocrine disorders (endocrine hypertension) accounts for a high proportion of cases of secondary hypertension. Although some features may be suggestive, many cases of endocrine hypertension remain silent until worked up for the disease. A majority of cases result from primary aldosteronism. Other conditions that can cause endocrine hypertension are: congenital adrenal hyperplasia, Liddle syndrome, pheochromocytomas, Cushing's syndrome, acromegaly, thyroid diseases, primary hyperparathyroidism and iatrogenic hormone manipulation. Early identification and treatment of the cause of endocrine hypertension may help to reduce morbidity and mortality related to these disorders. This article gives a comprehensive and practical approach to the diagnosis and management of endocrine hypertension.

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.

Worsening of lipid metabolism after successful treatment of primary aldosteronism

Primary aldosteronism (PA) describes the most frequent cause of secondary arterial hypertension. Recently, deterioration of lipid metabolism after adrenalectomy (ADX) for aldosterone-producing adenoma (APA) has been described. We analysed longitudinal changes in lipid profiles in a large prospective cohort of PA patients. Data of 215 consecutive PA patients with APA (n = 144) or bilateral idiopathic adrenal hyperplasia (IHA, n = 71) were extracted from the database of the German Conn's Registry. Patients were investigated before and 1 year after successful treatment by ADX or by mineralocorticoid receptor antagonists (MRA). Glomerular filtration rate (GFR), fasting plasma glucose and components of lipid metabolism including triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined at 8.00 after a 12-h fasting period. One year after initiation of treatment mean serum potassium levels and blood pressure normalized in the patients. HDL-C and TG developed inversely with decreasing HDL-C levels in patients with APA (p = .046) and IHA (p = .004) and increasing TG levels (APA p = .000; IHA p = .020). BMI remained unchanged and fasting plasma glucose improved in patients with APA (p = .004). Furthermore, there was a significant decrease of GFR in both subgroups at follow-up (p = .000). Changes in HDL-C and TG correlated with decrease in GFR in multivariate analysis (p = .024). Treatment of PA is associated with a deterioration of lipid parameters despite stable BMI and improved fasting plasma glucose and blood pressure. This effect can be explained by renal dysfunction following ADX or MRA therapy.

Hyperaldosteronism: How to Discriminate Among Different Disease Forms?

Primary aldosteronism (PA), characterized by the inappropriate and abnormal adrenal secretion of aldosterone, is the most common cause of secondary hypertension. PA has been shown to increase cardiovasular and cerebrovascular risks in comparison with essential hypertension. PA is a multi-faceted disease, which comprises unilateral forms, benefitting from surgical treatment, and bilateral forms, which are the best managed medically. PA is more frequently sporadic, but in some cases, it displays a familial transmission pattern. For these reasons, it is important to diagnose PA early on and correctly distinguish and manage its different forms. In this review, we analyze the different forms of PA, with attention on the diagnostic pathway and the genetics of the disease.