Imaging Concordance With Vein Sampling for Primary Aldosteronism: A Cohort Study and Literature Review.

INTRODUCTION: Adrenal venous sampling (AVS) is used to distinguish unilateral from bilateral aldosterone hypersecretion as a cause of primary aldosteronism (PA). Unilateral disease is treated with adrenalectomy and bilateral hypersecretion managed medically. METHODS: We performed a single institution retrospective cohort study of adult patients undergoing adrenalectomy for PA from July 2013 to June 2022. Concordance of imaging findings with AVS was evaluated. Statistical analysis was performed with Mann-Whitney U and chi-squared Fisher's exact. Literature review performed via triple method search strategy. RESULTS: Twenty-one patients underwent AVS and adrenalectomy for PA. Two patients did not have imaging findings and 19 were localized with an adenoma. For patients with image localization, AVS was concordant in nine, discordant in four, and nondiagnostic in six. For patients with discordant findings, age range was 35.8 to 72.4 y compared with concordant patient age range of 49.8 to 71.7 y. Overall discordance between imaging results and AVS was 40%. The aldosterone level was associated with concordance with a median of 52 ng/dL compared with 26 ng/dL if discordant (P = 0.002). There was a significant reduction in antihypertensive medications for the entire cohort from a median of three medications (interquartile range 2-4) to 1 medication (interquartile range 1-2), P < 0.001. CONCLUSIONS: In this cohort, 40% of patients with selective AVS had discordant imaging and AVS results. Aldosterone level was associated with concordance. Hypertension was significantly improved with a median decrease of two antihypertensives. Our results support performance of AVS on all candidates for adrenalectomy for PA.

Conn´s syndrome after kidney transplantation.

Conn's syndrome, defined as unilateral aldosterone-producing adenoma, accounts for 35-40% of cases of primary hyperaldosteronism. Primary hyperaldosteronism typically occurs in younger patients with poorly controlled arterial hypertension due to extracellular fluid retention, in whom at least a triple combination of antihypertensives, including a diuretic, is needed to maintain normotension. The clinical picture of arterial hypertension may be complemented by symptoms associated with hypokalaemia, such as weakness, fatigue, palpitations, convulsions, polydipsia, or polyuria. In addition to arterial hypertension and hypokalaemia, the diagnosis of Conn's syndrome relies on examination of serum renin and aldosterone concentrations, plasma renin activity, exercise or furosemide stimulation tests, and imaging studies, preferably computed tomography. The method of treatment of Conn's syndrome is adrenalectomy. In patients with primary hyperaldosteronism with underlying bilateral adrenal cortical hyperplasia or patients contraindicated for surgery, mineralocorticoid receptor antagonists are administered in combination with antihypertensives targeted for optimal blood pressure control.In the group of patients after kidney transplantation, the exact incidence of primary hyperaldosteronism is unknown. Based on a cross-sectional study performed in 2020, it is estimated to be approximately 15% in the group of patients with unsatisfactorily compensated arterial hypertension; in the cohort of normotensive recipients, the incidence of primary hyperaldosteronism is not documented. Diagnosis of Conn's syndrome in patients in the early period after kidney transplantation is problematic, as the prevalence of arterial hypertension in transplanted patients is high (70-90%) according to the literature. Mineral abnormalities, including hypokalaemia, are also common in the early post-transplant period, mainly due to factors such as duration of cold ischaemia, onset of graft function, donor parameters, post-transplant tubulopathy, and diuretics, the effects of immunosuppressive drugs (especially calcineurin inhibitors and corticosteroids), and possibly potassium-restricted dietary habits that the patient brings from the pre-transplant period, which may mask the effect of hyperaldosteronism on potassium.We present the case of a patient who was diagnosed with Conn's syndrome 7 months after primary kidney transplantation from a deceased donor based on persistent hypokalaemia unresponsive to replacement therapy. At the time of the first manifestation of severe hypokalaemia, the patient was treated with a dual combination of antihypertensives (amlodipine at a daily dose of 5 mg and carvedilol at a daily dose of 50 mg), without the need for a diuretics.We consider the case interesting because the spectrum of mineral and acid-base abnormalities in advanced renal failure and in the early post-transplant period, as well as acid-base and mineral imbalances, including hypokalaemia, and the high prevalence of arterial hypertension in the post-transplant period, may mask the picture of Conn's syndrome (Fig. 3, Ref. 19). Text in PDF www.elis.sk Keywords: kidney transplantation, primary hyperaldosteronism, hypokalaemia, metabolic alkalosis, secondary arterial hypertension.

The outcomes of transcatheter adrenal ablation in patients with primary aldosteronism: a systematic review and meta-analysis.

BACKGROUND: The use of transcatheter adrenal ablation as an alternative treatment for primary aldosteronism (PA) patients remains a subject of debate, with outcomes varying widely across existing studies. This meta-analysis aims to evaluate the results of adrenal ablation and estimate the effectiveness and safety of this therapeutic approach. METHODS: A comprehensive search was conducted across PubMed, Embase, and Cochrane Library databases for studies published up to October 2022. Outcomes analyzed included the combined clinical success rate, biochemical success rate, and complication rate, which were assessed using a random-effects model. RESULTS: Five studies, comprising 234 PA patients, were included in the analysis. The combined clinical success rate was 74% (95% CI: 69%-79%), and the biochemical success rate was 74% (95% CI: 53%-95%). Subgroup analysis revealed that the combined clinical success rate from Unilateral PA (72%, 95% CI: 46%-98%) was similar to the rate from Unilateral + Bilateral (73%, 95% CI: 52.0%-94.0%), while the clinical success rate of the PASO subgroup (78%, 95% CI: 66.0%-89.0%) was higher than the rate of other criteria (51%, 95% CI: 40.0%-63.0%). The combined complication rates were as follows: mild fever, 23% (95% CI: 12%-33%); back pain, 84% (95% CI: 77%-91%); and pleural effusion, 9% (95% CI: 0%-18%). All complications resolved within one week following the procedure. No late complications or ablation-related deaths were reported. CONCLUSIONS: Transcatheter adrenal ablation for PA patients is safe and demonstrates a relatively high clinical success rate. Presently, this approach is suitable for PA patients who are unwilling to undergo surgery or receive long-term mineralocorticoid receptor antagonist (MRA) treatment. SYSTEMATIC REVIEW REGISTRATION: INPLASY, identifier 2022110076.

Discordant imaging: adrenal vein sampling in almost half of patients with primary aldosteronism and a unilateral adrenal adenoma.

BACKGROUND: Primary hyperaldosteronism (PHA) is an underdiagnosed cause of secondary hypertension, with an increased risk of cardiovascular and renal complications compared with those with essential hypertension alone. Distinguishing between unilateral and bilateral aldosterone secretion is important as management differs. Adrenal vein sampling (AVS) is the gold standard for determining lateralisation. Current international guidelines suggest AVS may be omitted in those aged <35 years with PHA and a unilateral adrenal adenoma on imaging. AIM: To characterise all patients referred for AVS at Waitemata District Health Board (WDHB), review the success rate of AVS and compare concordance of AVS with imaging. METHODS: All patients who underwent AVS in WDHB from January 2015 to September 2020 were retrospectively assessed. Clinical records, laboratory data and radiological findings were reviewed. RESULTS: Ninety-six patients underwent AVS, with four excluded as private records were unable to be obtained. Of the 92 patients included, age ranged from 22 to 79 years. AVS was successful on first attempt in 89 (96.7%) patients. AVS and imaging findings were concordant in 62.2% of patients. One (14.3%) of seven aged <35 years had discordant results, and 16 (47%) of 34 patients with a unilateral adenoma on imaging had discordant results to AVS. CONCLUSIONS: AVS at WDHB is successful on first attempt in most patients. AVS is essential in the management of PHA for those deemed to be surgical candidates, regardless of age.

Unilateral adrenalectomy in bilateral adrenal hyperplasia with primary aldosteronism.

PURPOSE: Mineralocorticoid receptor antagonists are the first-line treatment for bilateral adrenal hyperplasia (BAH) with primary aldosteronism (PA), while unilateral adrenalectomy is the standard treatment for aldosterone-producing adenoma (APA). In this study, we investigated the outcomes of patients with BAH after unilateral adrenalectomy and compared them with those of patients with APA. METHODS: From January 2010 to November 2018, 102 patients with a diagnosis of PA confirmed by adrenal vein sampling (AVS) and available NP-59 scans were enrolled. All patients underwent unilateral adrenalectomy based on the lateralization test results. We prospectively collected the clinical parameters over 12 months and compared the outcomes of BAH and APA. RESULTS: A total of 102 patients were enrolled in this study: 20 (19.6%) had BAH and 82 (80.4%) had APA. Significant improvements in serum aldosterone-renin ratio (ARR), potassium level, and reduction of antihypertensive drugs were observed in both groups at 12 months after surgery (all p < 0.05). Patients with APA showed a significant decrease in blood pressure after surgery (p < 0.001) than those with BAH. Additionally, multivariate logistic regression analysis indicated that APA was associated with biochemical success (odds ratio: 4.32, p = 0.024) compared to BAH. CONCLUSION: Patients with BAH had a higher failure rate in clinical outcomes, and APA was associated with biochemical success after unilateral adrenalectomy. However, significant improvements in ARR, hypokalemia, and a decreased use of antihypertensive drugs were noted in patients with BAH after surgery. Unilateral adrenalectomy is feasible and beneficial in selected patients, and could potentially serve as a treatment option.

Tako-Tsubo Syndrome Following Pulmonary Vein Isolation for Atrial Fibrillation in a Patient with Primary Aldosteronism.

Tako-tsubo syndrome (TTS) can be triggered by emotional or physical stress and is characterized by transient left ventricular dysfunction with apical ballooning. Some neurologic disorders and pheochromocytoma serve as triggers for TTS, however, its association with primary aldosteronism (PA) is not well known. Pulmonary vein isolation (PVI) with catheter ablation for atrial fibrillation (AF) has been performed worldwide, and TTS following PVI has been reported as a rare complication. Sympathetic stimulation can play an important role in TTS development, however, its mechanism and risk factors are not yet understood.We describe a 72-year-old woman with PA who developed TTS after PVI with radiofrequency catheter ablation (RFCA) for symptomatic paroxysmal AF. Complete isolation of the pulmonary vein was carried out without any complications, however, she complained of epigastric discomfort 7 hours after the procedure. An electrocardiogram showed recurrent AF with a new negative-T wave and prolonged QT interval. Transthoracic echocardiography revealed apical ballooning and basal hypercontraction, characteristic of TTS, and coronary angiography showed no significant stenosis. She was diagnosed with TTS following RFCA for AF and managed well with conservative therapy.The present case suggests that TTS should be recognized as a complication associated with AF ablation. Moreover, PA may be involved in TTS development by increasing sympathetic activity. Further studies on the mechanism and characteristics of TTS are required.

Testing for Primary Aldosteronism and Mineralocorticoid Receptor Antagonist Use Among U.S. Veterans : A Retrospective Cohort Study.

BACKGROUND: Primary aldosteronism is a common cause of treatment-resistant hypertension. However, evidence from local health systems suggests low rates of testing for primary aldosteronism. OBJECTIVE: To evaluate testing rates for primary aldosteronism and evidence-based hypertension management in patients with treatment-resistant hypertension. DESIGN: Retrospective cohort study. SETTING: U.S. Veterans Health Administration. PARTICIPANTS: Veterans with apparent treatment-resistant hypertension (n = 269 010) from 2000 to 2017, defined as either 2 blood pressures (BPs) of at least 140 mm Hg (systolic) or 90 mm Hg (diastolic) at least 1 month apart during use of 3 antihypertensive agents (including a diuretic), or hypertension requiring 4 antihypertensive classes. MEASUREMENTS: Rates of primary aldosteronism testing (plasma aldosterone-renin) and the association of testing with evidence-based treatment using a mineralocorticoid receptor antagonist (MRA) and with longitudinal systolic BP. RESULTS: 4277 (1.6%) patients who were tested for primary aldosteronism were identified. An index visit with a nephrologist (hazard ratio [HR], 2.05 [95% CI, 1.66 to 2.52]) or an endocrinologist (HR, 2.48 [CI, 1.69 to 3.63]) was associated with a higher likelihood of testing compared with primary care. Testing was associated with a 4-fold higher likelihood of initiating MRA therapy (HR, 4.10 [CI, 3.68 to 4.55]) and with better BP control over time. LIMITATIONS: Predominantly male cohort, retrospective design, susceptibility of office BPs to misclassification, and lack of confirmatory testing for primary aldosteronism. CONCLUSION: In a nationally distributed cohort of veterans with apparent treatment-resistant hypertension, testing for primary aldosteronism was rare and was associated with higher rates of evidence-based treatment with MRAs and better longitudinal BP control. The findings reinforce prior observations of low adherence to guideline-recommended practices in smaller health systems and underscore the urgent need for improved management of patients with treatment-resistant hypertension. PRIMARY FUNDING SOURCE: National Institutes of Health.

Clinical Translationality of KCNJ5 Mutation in Aldosterone Producing Adenoma.

Hypertension due to primary aldosteronism poses a risk of severe cardiovascular complications compared to essential hypertension. The discovery of the KCNJ5 somatic mutation in aldosteroene producing adenoma (APA) in 2011 and the development of specific CYP11B2 antibodies in 2012 have greatly advanced our understanding of the pathophysiology of primary aldosteronism. In particular, the presence of CYP11B2-positive aldosterone-producing micronodules (APMs) in the adrenal glands of normotensive individuals and the presence of renin-independent aldosterone excess in normotensive subjects demonstrated the continuum of the pathogenesis of PA. Furthermore, among the aldosterone driver mutations which incur excessive aldosterone secretion, KCNJ5 was a major somatic mutation in APA, while CACNA1D is a leading somatic mutation in APMs and idiopathic hyperaldosteronism (IHA), suggesting a distinctive pathogenesis between APA and IHA. Although the functional detail of APMs has not been still uncovered, its impact on the pathogenesis of PA is gradually being revealed. In this review, we summarize the integrated findings regarding APA, APM or diffuse hyperplasia defined by novel CYP11B2, and aldosterone driver mutations. Following this, we discuss the clinical implications of KCNJ5 mutations to support better cardiovascular outcomes of primary aldosteronism.

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

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

A life-threatening case of pseudo-aldosteronism secondary to excessive liquorice ingestion.

BACKGROUND: Liquorice is found in many food products, soft drinks, and herbal medicines. Liquorice ingestion is an uncommon cause of apparent mineralocorticoid excess or pseudo-aldosteronism. The mechanism involves the inhibition of 11-beta-hydroxysteroid dehydrogenase type-2 by the active ingredient called glycyrrhizin. This leads to the uninhibited activation of mineralocorticoid receptors by cortisol. Confectionary products that contain liquorice are readily available in many countries around the world. CASE PRESENTATION: We report a case of severe refractory hypokalaemia with hypertensive crisis and acute pulmonary oedema due to excessive liquorice consumption. A 79-year-old female presented to the emergency department following a road traffic accident. She described feeling weak and dizzy while driving before the collision. She attended her general practitioner (GP) several weeks earlier for fatigue and was being managed for hypokalaemia on oral potassium supplements. Investigations revealed hypertension (BP 180/69 mmHg), severe hypokalaemia (K 2.2 mmol/l), normal renal function, normal serum magnesium with metabolic alkalosis. Spot urinary potassium was 22 mmol/l. The patient denied taking medications including over-the-counter or herbal medication that can cause hypokalaemia. Hypokalaemia persisted despite aggressive intravenous (i.v.) and oral potassium replacement. She later developed a hypertensive crisis (BP 239/114 mmHg) with pulmonary oedema. She required admission to the intensive care unit and was managed with intravenous furosemide infusion and isosorbide dinitrate infusion. On further discussion, our patient admitted to struggling with nicotine cravings since quitting smoking two months earlier. She began eating an excessive amount of liquorice sweets to manage her cravings. Suppression of plasma renin and aldosterone supported the diagnosis of apparent mineralocorticoid excess secondary to excessive liquorice consumption. Her symptoms and hypokalaemia resolved after stopping liquorice intake. CONCLUSIONS: This case highlights the life-threatening and refractory nature of hypokalaemia secondary to excessive liquorice consumption. This case also emphasizes the importance of comprehensive history taking including dietary habits. Increased awareness among the public is required regarding the potential health hazards of excessive liquorice consumption.

Determination of adrenal hypersecretion in primary Aldosteronism without aldosterone-production adenomas.

BACKGROUND: Primary aldosteronism (PA) is highly prevalent in hypertensive population. Adrenal vein sampling (AVS) is the only procedure to assess adrenal aldosterone hypersecretion in PA. PA patients without aldosterone-producing adenomas (APA) frequently have unilateral aldosterone hypersecretion (UAH). These patients could bear inappropriate adrenalectomy without AVS. This study aims to identify which clinical characteristics should be recommended to perform AVS in these PA patients. METHODS: This study was performed from January 2018 to July 2019 at a center for hypertension and metabolic diseases. Adrenal computed tomography (CT) scan, biochemical evaluation, and AVS were performed. RESULTS: Total 141 patients were included in this study. Aldosterone to renin ratio (ARR) after confirmatory test is highly associated with adrenal laterality. The specificity of ARR > 10 (ng/dL)/(mU/L) after confirmatory test is 100%. After confirmatory test, patients with ARR > 10 (ng/dL)/(mU/L) had higher plasma aldosterone concentration and incidences of ischemic heart diseases and renal damage(p < 0.05). CONCLUSIONS: After confirmatory tests, ARR > 10 (ng/dL)/(mU/L) indicates adrenal laterality, with increasingly cardiorenal damage in PA patients without APA. Thus, AVS should be recommended in these patients before surgery. TRIAL REGISTRATION: NCT03398785 , Date of Registration: December 24, 2017.

A case of primary aldosteronism with a negative aldosterone-to-renin ratio.

BACKGROUND: Primary aldosteronism (PA), as a cause of secondary hypertension, can cause more serious cardiovascular damage than essential hypertension. The aldosterone-to-renin ratio (ARR) is recommended as the most reliable screening method for PA, but ARR screening is often influenced by many factors. PA cannot be easily excluded when negative ARR. CASE PRESENTATION: We report the case of a 45-year-old Chinese man with resistant hypertension. Three years ago, he underwent a comprehensive screening for secondary hypertension, including the ARR, and the result was negative. After that, the patient's blood pressure was still poorly controlled with four kinds of antihypertensive drugs, the target organ damage of hypertension progressed, and hypokalaemia was difficult to correct. When the patient was hospitalized again for comprehensive examination, we found that aldosterone levels had significantly increased, although the ARR was negative. An inhibitory test with saline was further carried out, and the results suggested that aldosterone was not inhibited; therefore, PA was diagnosed. We performed a unilateral adenoma resection for this patient, and spironolactone was continued to control blood pressure. After the operation, blood pressure is well controlled, and hypokalaemia is corrected. CONCLUSION: When the ARR is negative, PA cannot be easily excluded. Comprehensive analysis and diagnosis should be based on the medication and clinical conditions of patients.

[Chronic kidney disease after adrenalectomy in a patient with primary aldosteronism].

We report one case of estimated glomerular filtration rate (eGFR) decline after taking unilateral adrenalectomy due to aldosterone adenoma. A 60-year-old male with 23-year history of hypertension was reported to the endocrinologist due to hypokalemia (serum potassium 3.01 mmol/L). Urine microalbumin/creatinine (ALB/CR) was 70.15 mg/g, serum creatinine was 82 µmol/L and eGFR was 89.79 mL/(min·1.73 m2). Random serum aldosterone was 172.2-203.5 ng/L, and random plasma rennin activity was 0-0.17 µg/(L·h). His captopril challenge test suggested that his aldosterone le-vels were suppressed by 8% (< 30%) and the adrenal enhanced computed tomography scan revealed a left adrenal tumor. The patient was diagnosed with primary hyperaldosteronism (PA), aldosterone adenoma and underwent left laparoscopic adrenalectomy. Histological examination confirmed adrenal cortical adenoma. One week after the operation, his serum creatinine was increased to 127 µmol/L compared with preoperative level; eGFR was 32.34 mL/(min·1.73 m2). His systolic blood pressure (SBP) was 110 mmHg and diastolic blood pressure (DBP) was 60 mmHg (hypotensive drugs discontinued), and serum potassium level was 5.22 mmol/L. At the end of the 2-year follow up, the serum creatinine of this patient remained at 109-158 µmol/L and eGFR fluctuated from 63.28-40.12 mL/(min·1.73 m2). PA is one of the most common causes of secondary hypertension. Several studies have reported renal function deterioration of PA patients after unilateral adrenalectomy, like the patient in this article. Age, preoperative plasma aldosterone concentration, albuminuria and preoperative potassium level might be significant predictors of a decrease in the eGFR. Growing evidence suggests that aldosterone could contribute to structural kidney damage, arterial injury and hemodynamic disorder. At the same time, patients with PA exhibit glomerular hyperfiltration and glomerular vascular hypertension, leading to the misinterpretation of renal function in PA patients as subtle kidney damage may be masked by the glomerular hyperfiltration before treatment. After a unilateral adrenalectomy, glomerular hyperfiltration by aldosterone excess is resolved and renal damage can be unmasked. In conclusion, kidney function deterioration after adrenalectomy can be detected in some patients with PA. Thus, accurate evaluation of kidney function in patients with PA may be essential, especially for those with preoperative risk factors for postoperative renal impairment. After unilateral adrenalectomy, close monitoring of renal function and adequate management are required for PA patients.

Primary Aldosteronism: Where Are We Now? Where to from Here?

The past nine years have seen major advances in establishing the etiology of unilateral primary aldosteronism, and very possibly that of bilateral hyperaldosteronism, in response to somatic mutations in aldosterone synthase expressing cells. Though there have been important advances in the management of primary aldosteronism, in small but convincing studies, they represent minor changes to current guidelines. What has been totally absent is consideration of the public health issue that primary aldosterone represents, and the public policy issues that would be involved in addressing the disorder. In his introduction to PiPA 6, Martin Reincke calculated that only one in a thousand patients in Germany with primary aldosteronism were treated appropriately, an astounding figure for any disease in the 21st century. Towards remedying this totally unacceptable public health issue, the author proposes a radical simplification and streamlining of screening for primary aldosteronism, and the management of most patients by general practitioners. The second bottle-neck in current management is that of mandatory adrenal venous sampling for all but 1-2% of patients, a costly procedure requiring rare expertise. Ideally, it should be reserved - on the basis of likelihood, enhanced imaging, or peripheral steroid profiles - for a small minority of patients with clear evidence for unilateral disease. Only when costs are minimized and roadblocks removed will primary aldosteronism be properly treated as the public health issue that it is.

Developments in Primary Aldosteronism Subtyping Using Steroid Profiling.

Adrenal venous sampling is the standard of care for identifying patients with unilateral primary aldosteronism, which is often caused by an aldosterone producing adenoma and can be cured with surgery. The numerous limitations of adrenal venous sampling, including its high cost, scarce availability, technical challenges, and lack of standardized protocols, have driven efforts to develop alternative, non-invasive tools for the diagnosis of aldosterone producing adenomas. Seminal discoveries regarding the pathogenesis of aldosterone producing adenomas made over the past decade have leveraged hypotheses-driven research of steroid phenotypes characteristic of various aldosterone producing adenomas. In parallel, the expanding availability of mass spectrometry has enabled the simultaneous quantitation of many steroids in single assays from small volume biosamples. Steroid profiling has contributed to our evolving understanding about the pathophysiology of primary aldosteronism and its subtypes. Herein, we review the current state of knowledge regarding the application of multi-steroid panels in assisting with primary aldosteronism subtyping.

Angiotensin II Type 1 Receptor Autoantibodies in Primary Aldosteronism.

Primary aldosteronism (PA) is the most common form of endocrine hypertension. Agonistic autoantibodies against the angiotensin II type 1 receptor (AT1R-Abs) have been described in transplantation medicine and women with pre-eclampsia and more recently in patients with PA. Any functional role of AT1R-Abs in either of the two main subtypes of PA (aldosterone-producing adenoma or bilateral adrenal hyperplasia) requires clarification. In this review, we discuss the studies performed to date on AT1R-Abs in PA.

Hypokalemia and the Prevalence of Primary Aldosteronism.

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

Loss of sodium chloride co-transporter impairs the outgrowth of the renal distal convoluted tubule during renal development.

BACKGROUND: Loss-of-function mutations in the sodium chloride (NaCl) co-transporter (NCC) of the renal distal convoluted tubule (DCT) cause Gitelman syndrome with hypokalemic alkalosis, hypomagnesemia and hypocalciuria. Since Gitelman patients are usually diagnosed around adolescence, we tested the idea that a progressive regression of the DCT explains the late clinical onset of the syndrome. METHODS: NCC wild-type and knockout (ko) mice were studied at Days 1, 4 and 10 and 6 weeks after birth using blood plasma analysis and morphological and biochemical methods. RESULTS: Plasma aldosterone levels and renal renin messenger RNA expression were elevated in NCC ko mice during the first days of life. In contrast, plasma ion levels did not differ between genotypes at age 10 days, but a significant hypomagnesemia was observed in NCC ko mice at 6 weeks. Immunofluorescent detection of parvalbumin (an early DCT marker) revealed that the fractional cortical volume of the early DCT is similar for mice of both genotypes at Day 4, but is significantly lower at Day 10 and is almost zero at 6 weeks in NCC ko mice. The DCT atrophy correlates with a marked reduction in the abundance of the DCT-specific Mg2+ channel TRPM6 (transient receptor potential cation channel subfamily M member 6) and an increased proteolytic activation of the epithelial Na+ channel (ENaC). CONCLUSION: After an initial outgrowth, DCT development lags behind in NCC ko mice. The impaired DCT development associates at Day 1 and Day 10 with elevated renal renin and plasma aldosterone levels and activation of ENaC, respectively, suggesting that Gitelman syndrome might be present much earlier in life than is usually expected. Despite an early downregulation of TRPM6, hypomagnesemia is a rather late symptom.

Prevalence of primary aldosteronism in hypertensive kidney transplant recipients: A cross-sectional study.

Due to high prevalence of primary aldosteronism (PA) in the general hypertensive population, and its association with worse cardiovascular and renal outcomes, the 2016 Endocrine Society Guidelines explicitly recognize PA as a major public health issue requiring urgent attention. Its prevalence in hypertensive kidney transplant recipients (KTRs) is unknown. In this cross-sectional study, we screened KTRs with hypertension who were on ≥4 antihypertensive medications, on 3 antihypertensive medications with BP ≥ 140/90, and on potassium supplements, or were hypokalemic. 172 of 280 eligible patients successfully completed the testing. A positive screen for PA defined by an aldosterone-to-renin ratio of ≥20 and a plasma aldosterone concentration of >15 ng/dL yielded a prevalence of 15.7%. Potassium supplement requirement (52% vs 27%, P = .01) and hypokalemia (25.9% vs 4.8%, P < .01) were more common in patients who screened positive compared with those who screened negative. 67% of patients who screened positive were on potassium supplements and/or were hypokalemic. Our study is the first to systematically explore the prevalence of PA among the hypertensive KTR population, which has inherently high cardiovascular risk. Further studies are needed to determine the cardiovascular and renal risk attributable to PA, and define optimal therapy for KTRs with PA.

A clinical prediction score using age at diagnosis and saline infusion test parameters can predict aldosterone-producing adenoma from idiopathic adrenal hyperplasia.

PURPOSE: Accurate subtyping of the primary aldosteronism into aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IAH) is important to direct for specific treatment modalities. The objective of the study was to compare the clinical and biochemical parameters of APA and IAH patients to derive a Clinical Prediction Score reliably predicting APA from IAH. METHODS: This was a retrospective multi-centre study recruiting 38 APA patients and 42 IAH patients from four major hospitals in Hong Kong using database from Surgical Outcomes Monitoring and Improvement Programme and Clinical Data Analysis and Reporting System. Their clinical and biochemical parameters were evaluated. RESULTS: Patients in APA group were younger than IAH group (mean age 48.6 ± 9.2 vs. 57.1 ± 7.3 years old, p < 0.001), had more suppressed renin before saline infusion in saline infusion test (SIT) (median 0.19 [IQR 0.15-0.37] vs. 0.39 [IQR 0.19-0.69] ng/mL/h, p = 0.01), and higher aldosterone level after saline infusion in SIT (median 674 [IQR 498-1000] vs. 327 [IQR 242-483] pmol/L, p < 0.001). A clinical prediction score using three parameters was devised, comprising age at diagnosis < 50 years, PRA before saline infusion in SIT ≤ 0.26 ng/mL/h, and aldosterone level after saline infusion in SIT ≥ 424 pmol/L. A score of 2 would predict APA with a sensitivity of 84.2% and specificity of 88.1%, and a score of 3 would predict APA with a sensitivity of 31.6% and specificity of 100%. CONCLUSIONS: Clinical Prediction Score based on the combination of age at diagnosis, PRA, and aldosterone level in the saline infusion tests could reliably predict APA from IAH.