Comorbidities in primary aldosteronism

Expression Patterns of MOTS-c in Adrenal Tumors: Results from a Preliminary Study

Adrenal tumors, such as adrenocortical carcinoma (ACC), adrenocortical adenoma (ACA), and pheochromocytoma (PCC) are complex diseases with unclear causes and treatments. Mitochondria and mitochondrial-derived peptides (MDPs) are crucial for cancer cell survival. The primary aim of this study was to analyze samples from different adrenal diseases, adrenocortical carcinoma, adrenocortical adenoma, and pheochromocytoma, and compare them with normal adrenal tissue to determine whether the expression levels of the mitochondrial open reading frame of the 12S rRNA type-c (MOTS-c) gene and protein vary between different types of adrenal tumors compared to healthy controls using qPCR, ELISA, and IHC methods. Results showed decreased MOTS-c mRNA expression in all adrenal tumors compared to controls, while serum MOTS-c protein levels increased in ACA and PCC but not in ACC. The local distribution of MOTS-c protein in adrenal tissue was reduced in all tumors. Notably, MOTS-c protein expression declined with ACC progression (stages III and IV) but was unrelated to patient age or sex. Tumor size and testosterone levels positively correlated with MOTS-c mRNA but negatively with serum MOTS-c protein. Additionally, serum MOTS-c protein correlated positively with glucose, total cholesterol, HDL, LDL, and SHGB levels. These findings suggest disrupted expression of MOTS-c in the spectrum of adrenal diseases, which might be caused by mechanisms involving increased mitochondrial dysfunction and structural changes in the tissue associated with disease progression. This study provides a detailed examination of MOTS-c mRNA and protein in adrenal tumors, indicating the potential role of MDPs in tumor biology and progression.

The influence of cortisol co-secretion on clinical characteristics and postoperative outcomes in unilateral primary aldosteronism

Context

The prevalence of unilateral primary aldosteronism (UPA) with cortisol co-secretion varies geographically.

Objective

To investigate the prevalence and clinical characteristics of UPA with cortisol co-secretion in a Chinese population.

Design

Retrospective cohort study.

Methods

We recruited 580 patients with UPA who underwent cosyntropin stimulation test (CST) after the 1-mg dexamethasone suppression test (DST) and retrospectively analyzed the clinical characteristics and postoperative outcomes of UPA with and without cortisol co-secretion.

Results

UPA with cortisol co-secretion (1 mg DST>1.8 ug/dL) was identified in 65 of 580 (11.2%) patients. These patients were characterized by older age, longer duration of hypertension, higher concentration of plasma aldosterone and midnight cortisol, lower adrenocorticotropic hormone (ACTH) and dehydroepiandrosterone sulfate (DHEAS), larger tumor diameter, and more history of diabetes mellitus. Cortisol and aldosterone levels were higher and DHEAS level was lower in UPA with cortisol co-secretion at 0-120 min after CST. Among 342 UPA patients with KCNJ5 gene sequencing and follow-up results, the complete clinical success rate was lower in UPA with cortisol co-secretion (33.3% vs. 56.4%, P<0.05); the complete biochemical success rate and KCNJ5 mutation did not differ between the two groups. Age, tumor size, and ACTH were independent predictors of UPA with cortisol co-secretion. Sex, BMI, duration of hypertension, KCNJ5 mutation, and cortisol co-secretion were independent predictors for complete clinical success in UPA after surgery.

Conclusions

UPA with cortisol co-secretion is not uncommon in China, but the clinical features were distinctly different from those without co-secretion. Cortisol co-secretion is an independent risk factor for incomplete clinical success after surgery in UPA.

Who needs to be screened for primary aldosteronism?

The prevalence of patients with primary aldosteronism (PA) is about 5%-15% in hypertensive patients, and it is common cause of secondary hypertension in clinical practice. Two major causes of PA are noted, namely bilateral adrenal hyperplasia and aldosterone-producing adenoma, and the general diagnosis is based on three steps: (1) screening, (2) confirmatory testing, and (3) subtype differentiation (Figure 1). The recommendation for screening patients is at an increased risk of PA, here we focus on which patients should be screened for PA, not only according to well-established guidelines but for potential patients with PA. We recommend screening for 1) patients with resistant or persistent hypertension, 2) hypertensive patients with hypokalemia (spontaneous or drug-induced), 3) young hypertensive patients (age <40 years), and 4) all hypertensive patients with a history of PA in first-degree relatives. Moreover, we suggest screening for 1) hypertensive patients themselves or first-degree relatives with early target organ damage, such as stroke and other diseases, 2) all hypertensive patients with a concurrent adrenal incidentaloma, 3) hypertensive patients with obstructive sleep apnea, 4) hypertensive patients with atrial fibrillation unexplained by structural heart defects and/or other conditions resulting in the arrhythmia, 5) hypertensive patients with anxiety and other psychosomatic symptoms, and 6) hypertensive patients without other comorbidities to maintain cost-effectiveness.

Treating Primary Aldosteronism-Induced Hypertension: Novel Approaches and Future Outlooks

Primary aldosteronism (PA) is the most common cause of secondary hypertension and is associated with increased morbidity and mortality when compared with blood pressure-matched cases of primary hypertension. Current limitations in patient care stem from delayed recognition of the condition, limited access to key diagnostic procedures, and lack of a definitive therapy option for nonsurgical candidates. However, several recent advances have the potential to address these barriers to optimal care. From a diagnostic perspective, machine-learning algorithms have shown promise in the prediction of PA subtypes, while the development of noninvasive alternatives to adrenal vein sampling (including molecular positron emission tomography imaging) has made accurate localization of functioning adrenal nodules possible. In parallel, more selective approaches to targeting the causative aldosterone-producing adrenal adenoma/nodule (APA/APN) have emerged with the advent of partial adrenalectomy or precision ablation. Additionally, the development of novel pharmacological agents may help to mitigate off-target effects of aldosterone and improve clinical efficacy and outcomes. Here, we consider how each of these innovations might change our approach to the patient with PA, to allow more tailored investigation and treatment plans, with corresponding improvement in clinical outcomes and resource utilization, for this highly prevalent disorder.

Effects of a low-sodium diet in patients with idiopathic hyperaldosteronism: a randomized controlled trial

Background

Idiopathic hyperaldosteronism (IHA) is one of the most common types of primary aldosteronism (PA), an important cause of hypertension. Although high dietary sodium is a major risk factor for hypertension, there is no consensus on the recommended dietary sodium intake for IHA.

Objective

This study investigated the effect of a low-sodium diet on hemodynamic variables and relevant disease biomarkers in IHA patients, with the aim of providing a useful reference for clinical treatment.

Methods

Fifty IHA patients were evenly randomized into two groups and provided, after a 7-day run-in period (100 mmol/d sodium), either a low-sodium diet (50 mmol/d sodium) or a normal sodium diet (100 mmol/d sodium) for an additional 7 days. After the 14-day intervention (conducted without potassium supplementation), changes in blood pressure (BP) and serum potassium were evaluated in both groups.

Results

After the dietary intervention, the low sodium group exhibited, compared to the normal sodium group, decreased BP (SBP: 121.8 ± 12.8 vs. 129.9 ± 12.1 mmHg, p < 0.05; DBP: 82.6 ± 7.6 vs. 86.4 ± 8.2 mmHg, p < 0.05; MAP: 95.7 ± 8.8 vs. 100.9 ± 8.4 mmHg, p < 0.05) and increased serum potassium levels (3.38 ± 0.33 vs. 3.07 ± 0.27 mmol/L, p < 0.001). The low sodium group showed also better control of both BP and serum potassium: BP <140/90 mmHg in 70.0% of total patients (76.0% vs. 64.0%, in the low and normal sodium groups, respectively; p > 0.05), BP <130/85 mmHg in 38.0% of total patients (56.0% vs. 20.0%, p < 0.05), BP <120/80 mmHg in 28.0% of total patients (44.0% vs. 12.0%, p < 0.05); serum potassium ≥3.5 mmol/L in 22.0% of total patients (32.0% vs. 12.0% in the low and normal sodium groups, respectively; p = 0.088). There were differences between the controlled BP group (<120/80 mmHg) and the non-controlled BP group (≥120/80 mmHg) in gender, BP at baseline, and type of diet (low vs. normal sodium). Female gender and low-sodium diet were protective factors for BP control.

Conclusions

A low-sodium diet is effective in lowering BP and elevating serum potassium in IHA patients. Female patients on a low-sodium diet are more likely to achieve BP control (<120/80 mmHg). We advocate a dietary sodium intake of 50 mmol/d for IHA patients.

Clinical trial registration

https://clinicaltrials.gov, Identifier NCT05649631.

Influence of cortisol cosecretion on non-ACTH-stimulated adrenal venous sampling in primary aldosteronism: a retrospective cohort study

OBJECTIVE

Cortisol measurements are essential for the interpretation of adrenal venous samplings (AVS) in primary aldosteronism (PA). Cortisol cosecretion may influence AVS indices. We aimed to investigate whether cortisol cosecretion affects non-adrenocorticotrophic hormone (ACTH)-stimulated AVS results.

DESIGN

Retrospective cohort study at a tertiary referral center.

METHODS

We analyzed 278 PA patients who underwent non-ACTH-stimulated AVS and had undergone at least a 1-mg dexamethasone suppression test (DST). Subsets underwent additional late-night salivary cortisol (LSC) and/or 24-h urinary free cortisol (UFC) measurements. Patients were studied from 2013 to 2020 with follow-up data of 6 months following adrenalectomy or mineralocorticoid antagonist therapy initiation. We analyzed AVS parameters including adrenal vein aldosterone/cortisol ratios, selectivity, lateralization (LI) and contralateral suppression indices and post-operative ACTH-stimulation. We classified outcomes according to the primary aldosteronism surgical outcome (PASO) criteria.

RESULTS

Among the patients, 18.9% had a pathological DST result (1.9-5 µg/dL: n = 44 (15.8%); >5 µg/dL: n = 8 (2.9%)). Comparison of AVS results stratified according to the 1-mg DST (≤1.8 vs >1.8 µg/dL: P = 0.499; ≤1.8 vs 1.8 ≤ 5 vs >5 µg/dL: P = 0.811) showed no difference. Lateralized cases with post DST serum cortisol values > 5 µg/dL had lower LI (≤1.8 µg/dL: 11.11 (5.36; 26.76) vs 1.9-5 µg/dL: 11.76 (4.9; 31.88) vs >5 µg/dL: 2.58 (1.67; 3.3); P = 0.008). PASO outcome was not different according to cortisol cosecretion.

CONCLUSIONS

Marked cortisol cosecretion has the potential to influence non-ACTH-stimulated AVS results. While this could result in falsely classified lateralized cases as bilateral, further analysis of substitutes for cortisol are required to unmask effects on clinical outcome.

Who should be screened for primary aldosteronism? A comprehensive review of current evidence

Arterial hypertension is a major risk factor for cardiovascular disease. The prevalence of primary aldosteronism (PA) ranges from 5% to 10% in the general hypertensive population and is regarded as one of the most common causes of secondary hypertension. There are two major causes of PA: bilateral adrenal hyperplasia and aldosterone-producing adenoma. The diagnosis of PA comprises screening, confirmatory testing, and subtype differentiation. The Endocrine Society Practice Guidelines for the diagnosis and treatment of PA recommends screening of patients at an increased risk of PA. These categories include patients with stage 2 and 3 hypertension, drug-resistant hypertension, hypertensive with spontaneous or diuretic-induced hypokalemia, hypertension with adrenal incidentaloma, hypertensive with a family history of early onset hypertension or cerebrovascular accident at a young age, and all hypertensive first-degree relatives of patients with PA. Recently, several studies have linked PA with obstructive sleep apnea and atrial fibrillation unexplained by structural heart defects and/or other conditions known to cause the arrhythmia, which may be partly responsible for the higher rates of cardiovascular and cerebrovascular accidents in patients with PA. The aim of this review is to discuss which patients should be screened for PA, focusing not only on well-established guidelines but also on additional groups of patients with a potentially higher prevalence of PA, as has been reported in recent research.

Proanthocyanidins Maintain Cardiac Ionic Homeostasis in Aldosterone-Induced Hypertension and Heart Failure

Excess aldosterone promotes pathological remodeling of the heart and imbalance in cardiac ion homeostasis of sodium, potassium and calcium. Novel treatment with proanthocyanidins in aldosterone-treated rats has resulted in downregulation of cardiac SGK1, the main genomic aldosterone-induced intracellular mediator of ion handling. It therefore follows that proanthocyanidins could be modulating cardiac ion homeostasis in aldosterone-treated rats. Male Wistar rats received aldosterone (1 mg kg⁻¹ day⁻¹) +1% NaCl for three weeks. Half of the animals in each group were simultaneously treated with the proanthocyanidins-rich extract (80% w/w) (PRO80, 5 mg kg⁻¹ day⁻¹). PRO80 prevented cardiac hypertrophy and decreased calcium content. Expression of ion channels (ROMK, NHE1, NKA and NCX1) and calcium transient mediators (CAV1.2, pCaMKII and oxCaMKII) were reduced by PRO80 treatment in aldosterone-treated rats. To conclude, our data indicate that PRO80 may offer an alternative treatment to conventional MR-blockade in the prevention of aldosterone-induced cardiac pathology.

Measurement of Equilibrium Angiotensin II in the Diagnosis of Primary Aldosteronism

BACKGROUND

Many medications (including most antihypertensives) and physiological factors affect the aldosterone/renin ratio (ARR) when screening for primary aldosteronism (PA). We sought to validate a novel equilibrium angiotensin II (eqAngII) assay and compare correlations between the aldosterone/angiotensin II ratio (AA2R) and the current ARR under conditions affecting the renin-angiotensin system.

METHODS

Among 78 patients recruited, PA was excluded in 22 and confirmed in 56 by fludrocortisone suppression testing (FST). Peripheral levels of eqAngII, plasma renin activity (PRA) and direct renin concentration (DRC) were measured.

RESULTS

EqAngII showed good consistency with DRC and PRA independent of PA diagnosis, posture, and fludrocortisone administration. EqAngII showed close (P < 0.01) correlations with DRC (r = 0.691) and PRA (r = 0.754) during FST. DRC and PRA were below their assays' functional sensitivity in 43.9% and 15.1%, respectively, of the total 312 samples compared with only 7.4% for eqAngII (P < 0.01). Bland-Altman analysis revealed an overestimation of PRA and DRC compared with eqAngII in a subset of samples with low renin levels. The AA2R showed not only consistent changes with the ARR but also close (P < 0.01) correlations with the ARR, whether renin was measured by DRC (r = 0.878) or PRA (r = 0.880).

CONCLUSIONS

Dynamic changes of eqAngII and the AA2R show good consistency and close correlations with renin and the ARR. The eqAngII assay shows better sensitivity than DRC and PRA assays, especially at low concentrations. Whether the AA2R can reduce the impact of some factors that influence the diagnostic power of the ARR warrants further study.

The Impact of Glucocorticoid Co-Secretion in Primary Aldosteronism on Thyroid Autoantibody Titers During the Course of Disease

Excess aldosterone is associated with the increased risk of cardio-/cerebrovascular events as well as metabolic comorbidities not only due to its hypertensive effect but also due to its proinflammatory action. Autonomous cortisol secretion (ACS) in the setting of primary aldosteronism (PA) is known to worsen cardiovascular outcome and potentially exhibit immunosuppressive effects. The aim of this study was to determine the impact of ACS status in patients with PA on kinetics of thyroid autoantibodies (anti-TPO, anti-TG) pre and post therapy initiation. Ninety-seven PA patients (43 unilateral, 54 with bilateral PA) from the database of the German Conn's Registry were included. Anti-TPO and anti-TG levels were measured pre and 6-12 months post therapeutic intervention. Patients were assessed for ACS according to their 24- hour urinary cortisol excretion, late night salivary cortisol and low-dose dexamethasone suppression test. Abnormal test results in line with ACS were identified in 74.2% of patients with PA. Following adrenalectomy, significant increases in anti-TPO levels were observed in patients with at least one abnormal test (p = 0.049), adrenalectomized patients with at least two pathological ACS tests (p = 0.015) and adrenalectomized patients with pathologic dexamethasone suppression tests (p = 0.018). No antibody increases were observed in unilateral PA patients without ACS and in patients with bilateral PA receiving mineralocorticoid antagonist therapy (MRA). Our data are in line with an immunosuppressive effect of mild glucocorticoid excess in PA on thyroid autoantibody titers. This effect is uncovered by adrenalectomy, but not by MRA treatment.

Impaired Glucose Metabolism in Primary Aldosteronism Is Associated With Cortisol Cosecretion

CONTEXT

Primary aldosteronism (PA) is associated with higher cardiovascular morbidity and metabolic risks. Recent studies report glucocorticoid cosecretion as a relevant phenotype of PA, which could contribute to associated risks, including type 2 diabetes mellitus (T2DM). The relationship between autonomous cortisol secretion (ACS) and glucose metabolism in PA has not been investigated.

OBJECTIVE

To evaluate the prevalence of impaired glucose homeostasis in patients with PA according to cortisol cosecretion.

DESIGN

We performed oral glucose tolerance tests (OGTTs) and complete testing for hypercortisolism [1-mg dexamethasone suppression test (DST), late-night salivary cortisol, 24-hour urinary free cortisol] in 161 newly diagnosed patients with PA of the German Conn Registry. Seventy-six of 161 patients were reevaluated at follow-up. We compared our results to a population-based sample from the Cooperative Health Research in the Region of Augsburg (KORA)-F4 study matched to the participants with PA (3:1) by sex, age, and body mass index.

RESULTS

At the time of diagnosis, 125 patients (77.6%) had a pathological response in at least one of the Cushing screening tests; T2DM was diagnosed in 6.4% of these 125 cases. Patients with a pathological DST exhibited significantly higher 2-hour plasma glucose in OGTTs and were significantly more often diagnosed with T2DM than were patients with a normal DST (20% vs 0.8%, P < 0.0001) and matched controls from the KORA study (20.6% vs 5.9%, P = 0.022). Patients with PA without ACS tended to have higher homeostatic model assessment of insulin resistance levels than did KORA control subjects (P = 0.05).

CONCLUSION

ACS appears frequently in patients with PA and is associated with impaired glucose metabolism, which could increase the risk of T2DM. PA itself seems to enhance insulin resistance.

Treatment of Primary Aldosteronism Reduces the Probability of Obstructive Sleep Apnea

BACKGROUND

Aldosterone excess is hypothesized to worsen obstructive sleep apnea (OSA) symptoms by promoting peripharyngeal edema. However, the extent to which primary aldosteronism (PA), hypertension, and body mass index (BMI) influence OSA pathogenesis remains unclear.

METHODS

We conducted a cross-sectional study of PA patients from our endocrine database to retrospectively evaluate OSA probability before and after adrenalectomy or medical management of PA. A control group of patients undergoing adrenalectomy for nonfunctioning benign adrenal masses was also evaluated. We categorized patients as high or low OSA probability after evaluation with the Berlin Questionnaire, a validated 10-question survey that explores sleep, fatigue, hypertension, and BMI.

RESULTS

We interviewed 91 patients (83 PA patients and eight control patients). Median follow-up time was 2.6 y. The proportion of high OSA probability in all PA patients decreased from 64% to 35% after treatment for PA (mean Berlin score 1.64 versus 1.35, P < 0.001). This decline correlated with improvements in hypertension (P < 0.001) and fatigue symptoms (P = 0.03). Both surgical (n = 48; 1.69 versus 1.33, P < 0.001) and medical (n = 35; 1.57 versus 1.37, P = 0.03) treatment groups demonstrated reduced OSA probability. BMI remained unchanged after PA treatment (29.1 versus 28.6, P = nonsignificant), and the impact of treatment on OSA probability was independent of BMI. The control surgical group showed no change in OSA probability after adrenalectomy (1.25 versus 1.25, P = nonsignificant).

CONCLUSIONS

Both surgical and medical treatments of PA reduce sleep apnea probability independent of BMI and are associated with improvements in hypertension and fatigue. Improved screening for PA could reduce OSA burden.

Migration from RIA to LC-MS/MS for aldosterone determination: Implications for clinical practice and determination of plasma and urine reference range intervals in a cohort of healthy Belgian subjects

Background

Aldosterone measurement is critical for diagnosis of primary aldosteronism and disorders of the renin-angiotensin system. We developed an LC-MS/MS method for plasma and urinary aldosterone and compared it to our RIA method. We present a reference interval study for a Belgian population.

Methods

68 plasma and 23 urine samples were assayed for as part of a method comparison. For the reference interval study, we enrolled 282 healthy Caucasian volunteers (114 Male: mean age 35 ± 11 y and 168 Female: mean age 42 ± 13 y). A subset of 139 healthy volunteers agreed to a 24-h urine collection. For the method validation, 5 plasma and 8 urine pools were run in triplicate and quadruplicate, respectively, on 3 different days.

Results

Between-run imprecision (CV) was 2.8-5.1% for plasma and 4.5-8.6% for urine, except at the low urine concentration of 2.99 nmol/L where a CV of 15.4% was observed. The limit of quantitation was 0.04 nmol/L for plasma and 6.65 nmol/L for urine. Recoveries, based on spiking experiments into natural matrix, did not differ significantly from 100%. Regression comparisons showed that, on average, RIA generated results were 59% and 11% higher than LC-MS/MS for plasma and urine, respectively. The MS reference interval we propose for plasma aldosterone is 0.07 nmol/L-0.73 nmol/L for women and 0.04 nmol/L-0.41 nmol/L for men. No gender difference was observed for urine aldosterone. The reference interval was determined to be <60.94 nmol/day.

Conclusions

The LC-MS/MS method was validated and reference intervals for plasma and urine were established. A significant bias between RIA and LC-MS/MS was noted.

Physiological Aldosterone Concentrations Are Associated with Alterations of Lipid Metabolism: Observations from the General Population

OBJECTIVE

Aldosterone and high-density lipoprotein cholesterol (HDL-C) are involved in many pathophysiological processes that contribute to the development of cardiovascular diseases. Previously, associations between the concentrations of aldosterone and certain components of the lipid metabolism in the peripheral circulation were suggested, but data from the general population is sparse. We therefore aimed to assess the associations between aldosterone and HDL-C, low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, or non-HDL-C in the general adult population.

METHODS

Data from 793 men and 938 women aged 25-85 years who participated in the first follow-up of the Study of Health in Pomerania were obtained. The associations of aldosterone with serum lipid concentrations were assessed in multivariable linear regression models adjusted for sex, age, body mass index (BMI), estimated glomerular filtration rate (eGFR), and HbA1c.

RESULTS

The linear regression models showed statistically significant positive associations of aldosterone with LDL-C (β-coefficient = 0.022, standard error = 0.010, p = 0.03) and non-HDL-C (β-coefficient = 0.023, standard error = 0.009, p = 0.01) as well as an inverse association of aldosterone with HDL-C (β-coefficient = -0.022, standard error = 0.011, p = 0.04).

CONCLUSIONS

The present data show that plasma aldosterone is positively associated with LDL-C and non-HDL-C and inversely associated with HDL-C in the general population. Our data thus suggests that aldosterone concentrations within the physiological range may be related to alterations of lipid metabolism.

Associations of aldosterone and renin concentrations with inflammation-the Study of Health in Pomerania and the German Conn's Registry

PURPOSE

Chronic inflammation is an age-independent and body mass index-independent contributor to the development of multi-morbidity. Alterations of the renin-angiotensin-aldosterone system are observed within the context of proinflammatory states. We assessed circulating aldosterone, renin, and inflammatory biomarker concentrations in healthy, normotensive subjects and patients with primary aldosteronism.

METHODS

We included 1177 normotensive individuals from the population-based Study of Health in Pomerania (first follow-up, Study of Health in Pomerania-1) and 103 primary aldosteronism patients from the German Conn's Registry. A 1:1 matching for sex, age, body mass index, smoking status, diabetes mellitus, and the estimated glomerular filtration rate was performed to determine whether primary aldosteronism patients exhibit higher inflammatory biomarker concentrations than normotensive controls. The associations of plasma aldosterone concentration or plasma renin concentration with circulating fibrinogen concentrations, white blood cell count, and high sensitive C-reactive protein concentrations in the normotensive sample were determined with multivariable linear and logistic regression analyses.

RESULTS

1:1 matched primary aldosteronism patients demonstrated significantly (p < 0.01) higher plasma aldosterone concentration (198 vs. 47 ng/l), lower plasma renin concentration (3.1 vs. 7.7 ng/l) and higher high sensitive C-reactive protein concentrations (1.5 vs. 1.0 mg/l) than normotensive controls. Within the normotensive cohort, plasma renin concentration but not plasma aldosterone concentration was positively associated with fibrinogen concentrations and white blood cell count. Further, a J-shaped association between plasma renin concentration and high sensitive C-reactive protein concentrations was detected.

CONCLUSIONS

High plasma aldosterone concentration in a primary aldosteronism cohort and high plasma renin concentration in normotensive subjects are associated with increased concentrations of inflammatory biomarkers. This suggests a link between the renin-angiotensin-aldosterone system and inflammatory processes in patients with primary aldosteronism and even in normotensive subjects.

Hyperaldosteronism and cardiovascular risk in patients with autosomal dominant polycystic kidney disease

Hypertension is commonly associated with autosomal dominant polycystic kidney disease (ADPKD), often discovered before the onset of renal failure, albeit the pathogenetic mechanisms are not well elucidated. Hyperaldosteronism in ADPKD may contribute to the development of insulin resistance and endothelial dysfunction, and progression of cardiorenal disease. The aim of study was to evaluate the prevalence of primary aldosteronism (PA) in ADPKD patients and identify some surrogate biomarkers of cardiovascular risk.We have enrolled 27 hypertensive ADPKD patients with estimated glomerular filtration rate (eGFR) ≥ 60 mL/min, evaluating the renin-angiotensin-aldosterone system (RAAS), inflammatory indexes, nutritional status, homocysteine (Hcy), homeostasis model assessment-insulin resistance (HOMA-IR), mineral metabolism, microalbuminuria, and surrogate markers of atherosclerosis [carotid intima media thickness (cIMT), ankle/brachial index (ABI), flow mediated dilation (FMD), renal resistive index (RRI) and left ventricular mass index (LVMI)]. Furthermore, we have carried out the morpho-functional magnetic resonance imaging (MRI) with high-field 3 T Magnetom Avanto.We have divided patients into group A, with normal plasma aldosterone concentration (PAC) and group B with PA, present in 9 (33%) of overall ADPKD patients. Respect to group A, group B showed a significant higher mean value of LVMI, HOMA-IR and Hcy (P = 0.001, P = 0.004, P = 0.018; respectively), and a lower value of FMD and 25-hydroxyvitamin D (25-OH-VitD) (P = 0.037, P = 0.019; respectively) with a higher prevalence of non-dipper pattern at Ambulatory Blood Pressure Monitoring (ABPM) (65% vs 40%, P < 0.05) at an early stage of the disease.In this study, we showed a high prevalence of PA in ADPKD patients, associated to higher LVMI, HOMA-IR, Hcy, lower FMD, and 25-OH-VitD, considered as surrogate markers of atherosclerosis, compared to ADPKD patients with normal PAC values. Our results indicate a higher overall cardiovascular risk in ADPKD patients with inappropriate aldosterone secretion, and a screening for PA in all patients with ADPKD is recommended.

Prevalence of Malignancies in Patients With Primary Aldosteronism

CONTEXT

Primary aldosteronism (PA) is the most common cause of secondary hypertension. Aldosterone excess can cause DNA damage in vitro and in vivo. Single case reports have indicated a coincidence of PA with renal cell carcinoma and other tumors. However, the prevalence of benign and malignant neoplasms in patients with PA has not yet been studied.

PATIENTS AND DESIGN

In the multicenter MEPHISTO study, the prevalence of benign and malignant tumors was investigated in 335 patients with confirmed PA. Matched hypertensive subjects from the population-based Study of Health in Pomerania cohort served as controls.

RESULTS

Of the 335 PA patients, 119 (35.5%) had been diagnosed with a tumor at any time, and 30 had two or more neoplasms. Lifetime malignancy occurrence was reported in 9.6% of PA patients compared to 6.0% of hypertensive controls (P = .08). PA patients with a history of malignancy had higher baseline aldosterone levels at diagnosis of PA (P = .009), and a strong association between aldosterone levels and the prevalence of malignancies was observed (P = .03). In total, 157 neoplasms were identified in the PA patients; they were benign in 61% and malignant in 25% of the cases (14% of unknown dignity). Renal cell carcinoma was diagnosed in five patients (13% of all malignancies) and was not reported in controls

CONCLUSION

Compared to hypertensive controls, the prevalence of malignancies was positively correlated with aldosterone levels, tended to be higher in PA patients, but did not differ significantly.

Glucose Metabolism in Primary Aldosteronism

In recent years, an increasing number of studies have revealed deleterious effects of aldosterone via the mineralocorticoid receptor (MR). Especially in patients with primary aldosteronism (PA) a significant higher estimated risk of developing cardiovascular comorbidities and comortalities compared to essential hypertensives was reported. As diabetes mellitus and the metabolic syndrome are one of the major contributors to cardiovascular morbidity and mortality their connection to aldosterone excess became a focus of research in PA patients. Several studies assessed the effect of PA on glucose metabolism, the prevalence of diabetes mellitus, and the effect of PA treatment on both revealing different results. Therefore, we performed an extensive literature research. This review focuses on the current knowledge of the connection between aldosterone excess, glucose homeostasis, and diabetes mellitus in patients with PA. We have highlighted this topic from a pro and contra perspective followed by a summarizing concluding remark. Additionally, we have briefly reviewed the data on possible underlying mechanisms and indicated future considerations on the possible impact of cortisol co-secretion in PA.

Post-saline infusion test aldosterone levels indicate severity and outcome in primary aldosteronism

OBJECTIVE

The saline infusion test (SIT) is widely used as a confirmatory test for primary aldosteronism (PA). SIT results are judged as follows: post-test aldosterone levels <50 ng/l exclude PA, whereas levels >50 ng/l confirm PA. We hypothesized that post-SIT aldosterone concentrations indicate the severity of PA and might predict outcome.

DESIGN

The study includes 256 PA patients of the German Conn's Registry who prospectively underwent SIT. The data of 126 patients with complete follow-up of 1.2±0.3 years after diagnosis were analyzed. The patients were divided into two groups with post-SIT aldosterone levels of 50-100 ng/l (group 1; n=38) and of >100 ng/l (group 2; n=88).

RESULTS

Patients in group 2 had a significantly shorter duration of hypertension (7.5 vs 11.7 years (median), P=0.014), higher systolic blood pressure (BP; 151±16 vs 143±17 mmHg, P=0.036), lower serum potassium (3.3±0.6 vs 3.5±0.4 mmol/l, P=0.006), higher 24-h urine protein excretion (7.4 vs 5.4 mg/dl (median), P=0.012), and were more often female (P=0.038). They showed more often unilateral disease (P<0.005) with larger tumors (14±10 vs 7±10 mm, P=0.021), underwent more often adrenalectomy (75% vs 37%, P<0.005), required a lower number of antihypertensive drugs after adrenalectomy (1.2±1.2 vs 2.5±1.4, P=0.001), had a faster normalization of urinary protein excretion (with medical treatment P=0.049; with Adx P<0.005) at follow-up, and more frequently underlying well-characterized mutation (P=0.047).

CONCLUSIONS

PA patients with post-SIT aldosterone levels of >100 ng/l have a more rapid development of PA caused more frequently by unilateral disease with larger aldosterone-producing adenomas. However, this group of patients may have a significantly better outcome following specific treatment.

Risk of ischemic stroke in primary aldosteronism patients

BACKGROUND

High aldosterone concentrations are associated with the risk of stroke that is independent of blood pressure levels. We investigated the risk of ischemic stroke in primary aldosteronism (PA) patients.

METHODS

This retrospective case-control study was based on the Taiwan Primary Aldosteronism Investigation (TAIPAI) database from 2004 to 2010. The study group comprised the patients who developed ischemic stroke after the diagnosis of PA. The PA patients who did not develop stroke were matched according to age and sex as the control group. A multivariate logistic regression model was performed to determine the risk factors of ischemic stroke.

RESULTS

Of 339 patients diagnosed with PA, 22 patients (6.5%) developed de novo ischemic stroke. The PA patients with stroke suffered from a longer hypertensive period (11.0±6.5 vs 7.8±8.3, P=.007) and a higher prevalence of proteinuria than those who did not develop stroke (40.9% vs 12.9%, P=.002). A multivariate logistic regression model showed that PA patients with proteinuria (HR 3.58, P=.02), preexisting coronary artery disease (HR 11.12, P<.001) or left ventricular hypertrophy (HR 3.09, P=.047) were associated with an increased risk of ischemic stroke.

CONCLUSIONS

Proteinuria, a medical history of coronary artery disease or left ventricular hypertrophy, was associated with an increased risk of ischemic stroke in PA patients. Our results suggest that a public health initiative is necessary to enhance the follow-up of proteinuria and to manage subsequent stroke among patients with aldosteronism.

Computational analysis of functional single nucleotide polymorphisms associated with the CYP11B2 gene

Single nucleotide polymorphisms (SNPs) are the most common type of genetic variations in humans and play a major role in the genetics of human phenotype variation and the genetic basis of human complex diseases. Recently, there is considerable interest in understanding the possible role of the CYP11B2 gene with corticosterone methyl oxidase deficiency, primary aldosteronism, and cardio-cerebro-vascular diseases. Hence, the elucidation of the function and molecular dynamic behavior of CYP11B2 mutations is crucial in current genomics. In this study, we investigated the pathogenic effect of 51 nsSNPs and 26 UTR SNPs in the CYP11B2 gene through computational platforms. Using a combination of SIFT, PolyPhen, I-Mutant Suite, and ConSurf server, four nsSNPs (F487V, V129M, T498A, and V403E) were identified to potentially affect the structure, function, and activity of the CYP11B2 protein. Furthermore, molecular dynamics simulation and structure analyses also confirmed the impact of these nsSNPs on the stability and secondary properties of the CYP11B2 protein. Additionally, utilizing the UTRscan, MirSNP, PolymiRTS and miRNASNP, three SNPs in the 3'UTR region were predicted to exhibit a pattern change in the upstream open reading frames (uORF), and eight microRNA binding sites were found to be highly affected due to 3'UTR SNPs. This cataloguing of deleterious SNPs is essential for narrowing down the number of CYP11B2 mutations to be screened in genetic association studies and for a better understanding of the functional and structural aspects of the CYP11B2 protein.

Aldosterone and glomerular filtration--observations in the general population

Background

Increasing evidence suggests that aldosterone promotes renal damage. Since data on the association between aldosterone and renal function in the general population are sparse, we chose to address this issue. We investigated the associations between the plasma aldosterone concentration (PAC) or the aldosterone-to-renin ratio (ARR) and the estimated glomerular filtration rate (eGFR) in a sample of adult men and women from Northeast Germany.

Methods

A study population of 1921 adult men and women who participated in the first follow-up of the Study of Health in Pomerania was selected. None of the subjects used drugs that alter PAC or ARR. The eGFR was calculated according to the four-variable Modification of Diet in Renal Disease formula. Chronic kidney disease (CKD) was defined as an eGFR <60 ml/min/1.73 m².

Results

Linear regression models, adjusted for sex, age, waist circumference, diabetes mellitus, smoking status, systolic and diastolic blood pressures, serum triglyceride concentrations and time of blood sampling revealed inverse associations of PAC or ARR with eGFR (ß-coefficient for log-transformed PAC −3.12, p < 0.001; ß-coefficient for log-transformed ARR −3.36, p < 0.001). Logistic regression models revealed increased odds for CKD with increasing PAC (odds ratio for a one standard deviation increase in PAC: 1.35, 95% confidence interval: 1.06-1.71). There was no statistically significant association between ARR and CKD.

Conclusion

Our study demonstrates that PAC and ARR are inversely associated with the glomerular filtration rate in the general population.

Sleep quality in patients with primary aldosteronism

OBJECTIVE

In subjects at high risk for sleep apnea (SA), aldosterone concentrations correlate with severity of SA and primary aldosteronism (PA) is very often diagnosed. Patients with PA show a high prevalence of SA. Treatment of PA either by adrenalectomy (ADX) or mineralocorticoid receptor (MR) blockade is thought to abolish the increased comorbidities. However, no data are available regarding effectiveness of different PA treatments on quality of sleep.

DESIGN

This prospective multi-center study included 15 patients with newly diagnosed PA evaluated before and 0.7 ± 0.2 years after treatment initiation, and a second cohort including 81 patients who were evaluated 5.3 and 6.8 years after treatment initiation. Biochemical parameters, 24h blood pressure and three validated self-assessment questionnaires (Giessen Complaint List (GBB-24), Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality-Index (PSQI)) were analyzed.

RESULTS

Z-scores of exhaustion tendency of GBB significantly improved in newly diagnosed PA patients after treatment initiation (1.8 ± 1.4 vs. 1.0 ± 1.2, p=0.034). In the second cohort no differences were found in GBB-24, ESS and PSQI. No differences were found in all three questionnaires independently of type of PA therapy. However, female patients scored significantly higher than males in the PSQI (8.7 ± 3.6 vs 5.7 ± 4.2, p<0.005), indicating lower sleep quality, independently of the type of therapy.

CONCLUSIONS

For the first time, we analyzed quality of sleep in patients with PA, demonstrating that therapy initiation improves exhaustion tendency. Surprisingly, female PA patients showed significantly more sleep disturbances than male PA patients several years after treatment initiation.

Cardiovascular complications associated with primary aldosteronism: a controlled cross-sectional study

A higher risk of cardiovascular events has been reported in patients with primary aldosteronism (PA) than in otherwise similar patients with essential hypertension (EH). However, the evidence is limited by small sample size and potential confounding factors. We, therefore, compared the prevalence of cardiovascular events in 459 patients with PA diagnosed in our hypertension unit from 2001 to 2006 and 1290 controls with EH. PA cases and EH controls were individually matched for sex, age (± 2 years), and office systolic blood pressure (± 10 mm Hg). Patients with PA and EH differed significantly in duration of hypertension, serum potassium, plasma aldosterone and plasma renin concentrations, aldosterone-to-renin ratio, and urinary aldosterone concentration (P<0.001 for all comparisons). The prevalence of electrocardiographic and echocardiographic left ventricular hypertrophy was about twice higher in patients with PA even after adjustment for hypertension duration. PA patients also had a significantly higher prevalence of coronary artery disease (adjusted odds ratio, 1.9), nonfatal myocardial infarction (adjusted odds ratio, 2.6), heart failure (adjusted odds ratio, 2.9), and atrial fibrillation (adjusted odds ratio, 5.0). The risks associated with PA were similar across levels of serum potassium and plasma aldosterone. To conclude, patients with PA are more likely to have had a cardiovascular complication at diagnosis than otherwise similar patients with EH. Target organ damage and complications disproportionate to blood pressure should be considered as an additional argument for suspecting PA in a given individual and possibly for broadening the scope of screening at the population level.

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

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

Effectiveness of eplerenone or spironolactone treatment in preserving renal function in primary aldosteronism

OBJECTIVE

Primary aldosteronism (PA) has deleterious effects on kidney function independent of blood pressure levels. Up to now, data on effectiveness of different PA therapies regarding renal function are scarce.

DESIGN AND METHODS

This prospective multi-center study included 29 patients with newly diagnosed PA evaluated before and 1 year after treatment initiation, and a second cohort including 119 patients who were evaluated 5.3 and 6.8 years after treatment initiation. Glomerular filtration rate (GFR), spot urine albumin excretion/urinary creatinine (UAE/Ucrea) ratio, biochemical parameters, and 24-h blood pressure were measured. In a larger cross-sectional cohort, renal function was evaluated depending on the type of treatment (adrenalectomy (ADX; n=86); spironolactone (n=65); and eplerenone (n=18)).

RESULTS

GFR and UAE/Ucrea ratio significantly decreased in newly diagnosed PA patients after treatment initiation. In the second cohort, GFR and UAE/Ucrea ratio did not change during study period, and blood pressure was well controlled. In the larger cross-sectional cohort, no differences were seen in GFR and UAE/Ucrea ratio between PA patients on different treatment regimens. However, eplerenone treatment showed lower potassium levels and higher number of required antihypertensive medications.

CONCLUSIONS

Renal dysfunction with elevated albuminuria was seen in PA patients and was reversible after treatment initiation. Medical therapies with spironolactone or eplerenone seem to be as effective as ADX regarding renal function and blood pressure; however, sufficient daily doses need to be given.

Association of CYP11B2 polymorphisms with susceptibility to primary aldosteronism: a meta-analysis

The association of CYP11B2 gene polymorphisms with the risk of primary aldosteronism (PA) was controversial in previous studies. Here we selected two commonly studied CYP11B2 alleles: T-344C, A2718G to explore their associations with PA risk by meta-analyses of published case-control studies. Six electronic databases were searched for relevant studies up to November 2012. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random or fixed effects model. Seven studies (621 cases and 1027 controls) on T-344C polymorphism, three studies (327 cases and 336 controls) on A2718G polymorphism were finally included. Then significant association was observed between T-344C polymorphism and idiopathic hyperaldosteronism (IHA) under three genetic models (CC vs. TT, OR=0.544, 95% CI=0.324~0.914; CT vs. TT, OR=0.554, 95% CI=0.406~0.757; CC+CT vs. TT, OR=0.542, 95% CI=0.402~0.731). But patients with aldosterone-producing adenoma had no significant association with T-344C polymorphism under all genetic models except CT vs. TT model. Concerning A2718G polymorphism, a decreased PA risk was observed only under GG+GA vs AA model. But this association disappeared after removing the studies not in Hardy-Weinberg equilibrium. The evidence accumulated suggested that -344C allele may be associated with decreased risk of IHA and there was still no enough evidence to indicate the association of A2718G polymorphism with PA risk.

Screening for primary aldosteronism in hypertensive subjects: results from two German epidemiological studies

OBJECTIVE

The prevalence of primary aldosteronism in unselected hypertensive patients is currently unknown. We investigated the frequency of positive screening results for primary aldosteronism based on the aldosterone-to-renin ratio (ARR) in hypertensive subjects aged 30-79 years from two German epidemiological studies. We further examined the frequency of positive screening results in subjects with resistant hypertension or stage III hypertension and assessed possible disparities between untreated and treated hypertensive subjects.

METHODS

Data were obtained from the first follow-ups of the population-based study of health in Pomerania (SHIP; n=1392) and the cooperative health research in the region of Augsburg (KORA; n=1052). Study-specific reference ranges for plasma aldosterone concentration (PAC), plasma renin concentration (PRC) and the ARR were applied. Confirmation tests for primary aldosteronism were not performed in these epidemiological studies.Three definitions for a positive screening for primary aldosteronism were applied: A) increased ARR; B) increased ARR and decreased PRC; and C) increased ARR and increased PAC and decreased PRC.

RESULTS

The frequency of positive screening results was 7.0, 3.8 and 0.2% according to definitions A-C respectively. In the subgroups of subjects with resistant hypertension (11.9, 5.5 and 0.9%) or stage III hypertension (18.3, 14.0 and 1.1%), these frequencies were markedly higher than those in the general hypertensive population. There was no difference in the frequency of positive screening results between the treated and untreated hypertensive subjects.

CONCLUSIONS

A maximum of 7.0% of the hypertensive population in Germany shows a positive screening result for primary aldosteronism. Thus, primary aldosteronism may be less frequent than previously expected based on data from referred hypertensive patients.

Endocrine hypertension: then and now

OBJECTIVE

To review the first reported cases of successfully treated pheochromocytoma and primary aldosteronism and to document the diagnostic and therapeutic advances that have occurred since the initial descriptions.

METHODS

The original case descriptions and the subsequent pertinent literature were reviewed.

RESULTS

The successful management of the initial cases of pheochromocytoma in 1926 and primary aldosteronism in 1954 was highlighted by keen clinical observation, clinical intuition, and application of scientific principles. Since those prismatic case descriptions, the technological advances in laboratory-based diagnosis, radiology-based tumor localization, and surgical approaches to the adrenal glands have been truly remarkable.

CONCLUSIONS

The evolution in the diagnosis and treatment of pheochromocytoma will continue to progress as we identify more genetic causes, develop biochemical markers for "preclinical" pheochromocytoma, identify better markers for malignant disease, and develop more effective treatment options for malignant pheochromocytoma. Over the next decade, we hope to determine the pathophysiology for bilateral idiopathic hyperaldosteronism, develop less invasive and less technically demanding tests to distinguish between unilateral aldosterone-producing adenoma and bilateral idiopathic hyperaldosteronism, determine where low renin hypertension stops and primary aldosteronism starts, and determine the impact of genetic and environmental factors on aldosterone secretion in patients with and without primary aldosteronism.