Elevated prevalence of abnormal glucose metabolism in patients with primary aldosteronism: a meta-analysis

Prevalence and impact of diabetes and prediabetes on presentation and complications of primary hyperaldosteronism at diagnosis

BACKGROUND

Primary hyperaldosteronism (PH) is considered to contribute to increased risk of developing type 2 diabetes mellitus (T2DM) and prediabetes. Both PH and DM are associated with increased risk for hypertension, cardiovascular diseases, and chronic kidney diseases. However, data on prevalence of T2DM and prediabetes in PH, and impact of T2DM and prediabetes on presentation and cardio renal complications in PH at presentation is sparse.

AIM

To determine the prevalence of T2DM and prediabetes in PH at diagnosis and impact on presentation and complications of PH.

METHODS

A retrospective cohort study was conducted in tertiary care settings in individuals with confirmed diagnosis of PH at presentation. Demographic variables, clinical presentations, duration and degree of hypertension, complications, laboratory parameters including sodium, potassium levels, plasma aldosterone concentration (PAC), plasma renin activity (PRA), and aldosterone to renin ratio (ARR) and cardio-renal parameters were collected. Comparison was done between three groups: PH with no DM (Group A) or with pre-diabetes (Group B) or with T2DM (Group C). P < 0.05 was statistically significant.

RESULTS

Among 78 individuals with confirmed PH, 62% had pre-diabetes or diabetes; with 37% having DM. Mean duration of T2DM was 5.97 ± 4.7 years. The mean levels of glycaemic parameters among the group A vs B vs C individuals were fasting plasma glucose (mg/dL): 87.9 ± 6.5, 105.4 ± 9.02, 130.6 ± 21.1; post prandial plasma glucose (mg/dL): 122.7 ± 9.8, 154.9 ± 14, 196.7 ± 38.0; glycated haemoglobin (%) (5.3 ± 0.2, 5.9 ± 0.2, 7.5 ± 0.6, P < 0.05), respectively. There was no significant difference in the biochemical parameters (PAC, PRA, ARR, sodium, potassium levels), presentation and complications between the groups. Cardio renal parameters or degree and duration of hypertension were comparable between the groups.

CONCLUSION

Significant prevalence of T2DM and prediabetes in PH at diagnosis does not impact its presentation or complications. Early screening for undetected PH in T2DM and prediabetes subjects with hypertension may prevent complications.

Characterization of a Biochemical Mouse Model of Primary Aldosteronism for Thermal Therapies

Introduction

Aldosterone-producing adenoma (APA) is the most common cause of endocrine-related hypertension but surgery is not always feasible. Current medical interventions are associated with significant side effects and poor patient compliance. New APA animal models that replicate basic characteristics of APA and give physical and biochemical feedback are needed to test new non-surgical treatment methods, such as image-guided thermal ablation.

Methods

A model of APA was developed in nude mice using HAC15 cells, a human adrenal carcinoma cell line. Tumor growth, aldosterone production, and sensitivity to angiotensin II were characterized in the model. The utility of the model was validated via treatment with microwave ablation and characterization of the resulting physical and biochemical changes in the tumor.

Results

The APA model showed rapid and relatively homogeneous growth. The tumors produced aldosterone and steroid precursors in response to angiotensin II challenge, and plasma aldosterone levels were significantly higher in tumor bearing mice two hours after challenge verses non-tumor bearing mice. The model was useful for testing microwave ablation therapy, reducing aldosterone production by 80% in treated mice.

Conclusion

The HAC15 model is a useful tumor model to study and develop localized treatment methods for APA.

Follow-up care and assessment of comorbidities and complications in patients with primary aldosteronism: The clinical practice guideline of the Taiwan Society of aldosteronism

Primary aldosteronism (PA) is the most common form of endocrine hypertension, characterized by excess aldosterone production that leads to an increased risk of cardiovascular events and target organ damage. Both adrenalectomy and medical treatment have shown efficacy in improving clinical outcomes and comorbidities associated with PA, including a specific subtype of PA with autonomous cortisol secretion (ACS). Understanding the comorbidities of PA and establishing appropriate follow-up protocols after treatment are crucial for physicians to enhance morbidity and mortality outcomes in patients with PA. Additionally, the screening for hypercortisolism prior to surgery is essential, as the prognosis of patients with coexisting PA and ACS differs from those with PA alone. In this review, we comprehensively summarize the comorbidities of PA, encompassing cardiovascular, renal, and metabolic complications. We also discuss various post-treatment outcomes and provide insights into the strategy for glucocorticoid replacement in patients with overt or subclinical hypercortisolism. This clinical practice guideline aims to equip medical professionals with up-to-date information on managing concurrent hypercortisolism, assessing treatment outcomes, and addressing comorbidities in patients with PA, thereby improving follow-up care.

Prevalence, risk factors and evolution of diabetes mellitus after treatment in primary aldosteronism. Results from the SPAIN-ALDO registry

PURPOSE

To evaluate the prevalence, risk factors and evolution of diabetes mellitus (DM) after targeted treatment in patients with primary aldosteronism (PA).

METHODS

A retrospective multicenter study of PA patients in follow-up at 27 Spanish tertiary hospitals (SPAIN-ALDO Register).

RESULTS

Overall, 646 patients with PA were included. At diagnosis, 21.2% (n = 137) had DM and 67% of them had HbA1c levels < 7%. In multivariate analysis, family history of DM (OR 4.00 [1.68-9.53]), the coexistence of dyslipidemia (OR 3.57 [1.51-8.43]) and advanced age (OR 1.04 per year of increase [1.00-1.09]) were identified as independent predictive factors of DM. Diabetic patients were on beta blockers (46.7% (n = 64) vs. 27.5% (n = 140), P < 0.001) and diuretics (51.1% (n = 70) vs. 33.2% (n = 169), p < 0.001) more frequently than non-diabetics. After a median follow-up of 22 months [IQR 7.5-63.0], 6.9% of patients developed DM, with no difference between those undergoing adrenalectomy and those treated medically (HR 1.07 [0.49-2.36], p = 0.866). There was also no significant difference in the evolution of glycemic control between DM patients who underwent surgery and those medically treated (p > 0.05).

CONCLUSION

DM affects about one quarter of patients with PA and the risk factors for its development are common to those of the general population. Medical and surgical treatment provides similar benefit in glycemic control in patients with PA and DM.

Findings from the Indonesian family life survey on patterns and factors associated with multimorbidity

The prevalence of multimorbidity tends to increase with age, but it is now also reported in the middle-aged population, which has a negative impact on healthcare systems and health outcomes. This study aims to analyze the patterns and factors associated with multimorbidity in Indonesia. This national cross-sectional population-based survey used publicly available data from the Indonesian Family Life Survey (IFLS-5) for 2014 among middle-aged (40-59 years old) and elderly (≥ 60 years old) respondents. Information on all chronic diseases was assessed using a self-reported questionnaire. Sociodemographic and health-related behavioral factors were obtained from self-reported data. Binary logistic regression analysis was used to identify the factors associated with multimorbidity. Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were reported. The study recruited 11,867 respondents. The prevalence of multimorbidity was 18.6% (95% CI 17.9-19.3) with which 15.6% among middle age (95% CI 14.95-16.25) and 24.9% among the elderly (95% CI 24.12-25.68). Hypertension was the most commonly reported disease (23.2%) in all combinations of multimorbidity and among all age groups. Socio-demographic factors: elderly (AOR: 1.66; 95% CI 1.46-1.89), female (AOR: 1.42; 95% CI 1.20-1.69), living in the urban area (AOR: 1.22; 95% CI 1.09-1.38), higher educational level (AOR: 2.49; 95% CI 1.91-3.26), unemployed (AOR: 1.63; 95% CI 1.44-1.84), and higher economic level (AOR: 1.41; 95% CI 1.18-1.68) were associated with multimorbidity. Poor health behavior factors: being former smokers (AOR: 2.03; 95% CI 1.65-2.51) and obesity (AOR: 1.53; 95% CI 1.35-1.75) were also associated with multimorbidity. The prevalence of multimorbidity in the middle-aged and elderly population in Indonesia is relatively high, particularly in populations with poor health behaviors. Therefore, healthcare professionals should integrate more patient-specific factors when designing and implementing tailored interventions to manage multimorbidity in Indonesia.

Links between Metabolic Syndrome and Hypertension: The Relationship with the Current Antidiabetic Drugs

Hypertension poses a significant burden in the general population, being responsible for increasing cardiovascular morbidity and mortality, leading to adverse outcomes. Moreover, the association of hypertension with dyslipidaemia, obesity, and insulin resistance, also known as metabolic syndrome, further increases the overall cardiovascular risk of an individual. The complex pathophysiological overlap between the components of the metabolic syndrome may in part explain how novel antidiabetic drugs express pleiotropic effects. Taking into consideration that a significant proportion of patients do not achieve target blood pressure values or glucose levels, more efforts need to be undertaken to increase awareness among patients and physicians. Novel drugs, such as incretin-based therapies and renal glucose reuptake inhibitors, show promising results in decreasing cardiovascular events in patients with metabolic syndrome. The effects of sodium-glucose co-transporter-2 inhibitors are expressed at different levels, including renoprotection through glucosuria, natriuresis and decreased intraglomerular pressure, metabolic effects such as enhanced insulin sensitivity, cardiac protection through decreased myocardial oxidative stress and, to a lesser extent, decreased blood pressure values. These pleiotropic effects are also observed after treatment with glucagon-like peptide-1 receptor agonists, positively influencing the cardiovascular outcomes of patients with metabolic syndrome. The initial combination of the two classes may be the best choice in patients with type 2 diabetes mellitus and multiple cardiovascular risk factors because of their complementary mechanisms of action. In addition, the novel mineralocorticoid receptor antagonists show significant cardio-renal benefits, as well as anti-inflammatory and anti-fibrotic effects. Overall, the key to better control of hypertension in patients with metabolic syndrome is to consider targeting multiple pathogenic mechanisms, using a combination of the different therapeutic agents, as well as drastic lifestyle changes. This article will briefly summarize the association of hypertension with metabolic syndrome, as well as take into account the influence of antidiabetic drugs on blood pressure control.

Secondary diabetes mellitus due to primary aldosteronism

Primary aldosteronism (PA) and diabetes mellitus (DM) are clinical conditions that increase cardiovascular risk. Approximately one in five patients with PA have DM. Nevertheless, the pathophysiology linking these two entities is not entirely understood. In addition, the majority of patients with PA have glucocorticoid co-secretion, which is associated with increased risk of impaired glucose homeostasis. In the present review, we aim to comprehensively discuss all the available research data concerning the interplay between mineralocorticoid excess and glucose metabolism, with separate analysis of the sequalae in muscle, adipose tissue, liver and pancreas. Aldosterone binds both mineralocorticoid and glucocorticoid receptors and amplifies tissue glucocorticoid activity, via 11-β-hydroxysteroid dehydrogenase type 1 stimulation. A clear classification of the molecular events as per specific receptor in insulin-sensitive tissues is impossible, while their synergistic interaction is plausible. Furthermore, aldosterone induces oxidative stress and inflammation, perturbs adipokine expression, thermogenesis and lipogenesis in adipose tissue, and increases hepatic steatosis. In pancreas, enhanced oxidative stress and inflammation of beta cells, predominantly upon glucocorticoid receptor activation, impair insulin secretion. No causality between hypokalemia and impaired insulin response is yet proven; in contrast, hypokalemia appears to be implicated with insulin resistance and hepatic steatosis. The superior efficacy of adrenalectomy in ameliorating glucose metabolism vs. mineralocorticoid receptor antagonists in clinical studies highlights the contribution of non-mineralocorticoid receptor-mediated mechanisms in the pathophysiologic process. The exact role of hypokalemia, the mechanisms linking mineralocorticoid excess with hepatic steatosis, and possible disease-modifying role of pioglitazone warrant further studies.

Primary Aldosteronism: State-of-the-Art Review

We are witnessing a revolution in our understanding of primary aldosteronism (PA). In the past 2 decades, we have learned that PA is a highly prevalent syndrome that is largely attributable to pathogenic somatic mutations, that contributes to cardiovascular, metabolic, and kidney disease, and that when recognized, can be adequately treated with widely available mineralocorticoid receptor antagonists and/or surgical adrenalectomy. Unfortunately, PA is rarely diagnosed, or adequately treated, mainly because of a lack of awareness and education. Most clinicians still possess an outdated understanding of PA; from primary care physicians to hypertension specialists, there is an urgent need to redefine and reintroduce PA to clinicians with a modern and practical approach. In this state-of-the-art review, we provide readers with the most updated knowledge on the pathogenesis, prevalence, diagnosis, and treatment of PA. In particular, we underscore the public health importance of promptly recognizing and treating PA and provide pragmatic solutions to modify clinical practices to achieve this.

Primary aldosteronism - a multidimensional syndrome

Primary aldosteronism is a common cause of hypertension and is a risk factor for cardiovascular and renal morbidity and mortality, via mechanisms mediated by both hypertension and direct insults to target organs. Despite its high prevalence and associated complications, primary aldosteronism remains largely under-recognized, with less than 2% of people in at-risk populations ever tested. Fundamental progress made over the past decade has transformed our understanding of the pathogenesis of primary aldosteronism and of its clinical phenotypes. The dichotomous paradigm of primary aldosteronism diagnosis and subtyping is being redefined into a multidimensional spectrum of disease, which spans subclinical stages to florid primary aldosteronism, and from single-focal or multifocal to diffuse aldosterone-producing areas, which can affect one or both adrenal glands. This Review discusses how redefining the primary aldosteronism syndrome as a multidimensional spectrum will affect the approach to the diagnosis and subtyping of primary aldosteronism.

Association of a novel electrolyte index, SUSPPUP, based on the measurement of fasting serum and spot urinary sodium and potassium, with prediabetes and diabetes in Chinese population

BACKGROUND

SUSPPUP, calculated as serum sodium [Na+] to urinary Na+ divided by (serum potassium [K+]) 2 to urinary K+, is a composite electrolyte index that reflects renal Na+ retention and K+ excretion. It remains unclear whether SUSPPUP and its components including serum or urinary Na+ or K+, are associated with glucose metabolism. This study aimed to address their associations.

METHODS

We conducted a cross-sectional study enrolling 5,581 Chinese adults (1,269 with prediabetes, 1,044 with diabetes, and 3,268 with normoglycemia). Fasting serum and morning spot urine were used to measure electrolytes that included Na+ and K+.

RESULTS

SUSPPUP was higher in prediabetes and diabetes than normoglycemia. The odds of prediabetes and diabetes were increased by 21% and 39% for every 1-standard deviation increment of SUSPPUP after multivariable-adjustment. Multiple linear regression analysis showed that SUSPPUP correlated positively with fasting plasma glucose, 2 h plasma glucose after OGTT, and glycated hemoglobin A1c. Higher spot urinary Na+ was associated with lower odds of prediabetes and diabetes, while spot urinary K+ showed the opposite.

CONCLUSION

Increases in Na+ retention and K+ excretion in the kidney, as reflected by an elevated SUSPPUP, are associated with increased prevalence of prediabetes and diabetes in Chinese community-dwellers.

Prevalence of primary aldosteronism in type 2 diabetes mellitus and hypertension: A prospective study from Western India

OBJECTIVE

Type 2 diabetes mellitus (T2DM) and hypertension commonly coexist; however, underlying primary aldosteronism (PA) can lead to worsening of hypertension, glycemia and cardiovascular risk. We aim to screen patients with T2DM and hypertension for PA by conducting a prospective monocentric study from Western India, which included adults with T2DM and hypertension from the outpatient diabetes clinic.

DESIGN

Prospective study.

PATIENTS AND MEASUREMENTS

Patients with an aldosterone renin ratio of ≥1.6 ng/dl/µIU/ml with plasma aldosterone concentration (PAC) ≥ 10 ng/dl were considered to be positive on a screening test. A PAC ≥ 6 ng/dl on seated saline suppression test (SST) was used to confirm the diagnosis of PA.

RESULTS

Four hundred and eighty-six patients were included in this study. Seventy-six (15.6%, 95% confidence interval [CI]: 12.7%-19.1%) patients had a positive screening test with positive confirmatory test in 20 of the 36 (55.5%, 95% CI: 39.3%-71.7%) screen-positive patients who underwent SST. Patients with positive screening test had a higher proportion of females (65.8% vs. 50%; p = .011), frequent history of hypertensive crises (21.1% vs. 8%; p = .001), uncontrolled blood pressure (51.3% vs. 34.6%; p = .006), diagnosis of hypertension before diabetes (32.9% vs. 21.7%; p = .035) and higher systolic (137.6 ± 6.9 vs. 131.2 ± 17.8 mmHg; p = .004) and diastolic (85.3 ± 11.1 vs. 81.7 ± 10.7 mmHg; p = .007) blood pressures. Patients with positive confirmatory test had longer duration of diabetes (108 [60-162] vs. 42 [24-87] months; p = .012), hypertension (84 [42-153] vs. 36 [15-81] months; p = .038) and higher creatinine (1.16 [1.02-1.42] vs. 0.95 [0.84-1.12] mg/dl; p = .021).

CONCLUSIONS

PA is prevalent (at least 4.1%) in Asian Indian patients with T2DM and hypertension. Further studies are needed to assess the cost-effectiveness of routine screening.

Differences in Glycemic Abnormalities Between Primary Aldosteronism and Essential Hypertension: A Systematic Review and Meta-Analysis

Background

The relationship of glycemic abnormalities between primary aldosteronism (PA) patients and essential hypertension (EH) patients is still debatable. This meta-analysis aimed to explore differences in the prevalence of glycemic abnormalities and levels of abnormal glucose metabolism in PA and EH patients.

Methods

A search was performed using PubMed, Scopus, Cochrane and Web of Science databases from their inception through January 2022. Inclusion criteria for this study were 1) observational studies which contained specific data of interest, 2) studies including data which compared adult PA and EH patients and 3) studies which used appropriate methods to diagnose PA. Risk ratio (RR) or standardized mean difference (SMD) with a 95% confidence interval (95% CI) was calculated.

Results

Twenty-six studies involving 53,186 patients were included in the meta-analysis. Patients with PA demonstrated significantly higher overall incidence of glycemic abnormalities than patients with EH [RR 1.54; 95% CI (1.20,1.98)]. Risk of diabetes mellitus (DM) and impaired glucose tolerance (IGT) in PA patients were higher than in EH patients [RR 1.27; 95%CI (1.08, 1.49) and RR 2.99; 95%CI (1.74, 5.16), respectively]. There was no statistically significant difference of risk between these groups for impaired fasting glucose (IFG) [RR 1.70; 95%CI (0.55, 5.26)]. Moderate heterogeneity was observed in overall glycemic abnormalities outcomes. A high level of heterogeneity was observed for IFG, while the level was low for DM and IGT.

Conclusions

PA patients have a higher risk of glycemic abnormalities than in EH patients. Further study should be conducted to investigate underlying mechanisms of glycemic abnormalities in PA.

Systematic Review Registration

www.inplasy.com, INPLASY, identifier 202220004.

Cerebro-Cardiovascular Risk, Target Organ Damage, and Treatment Outcomes in Primary Aldosteronism

Primary aldosteronism (PA) is the most common type of endocrine hypertension, and numerous experimental and clinical evidence have verified that prolonged exposure to excess aldosterone is responsible for an increased risk of cerebro-cardiovascular events and target organ damage (TOD) in patients with PA. Therefore, focusing on restoring the toxic effects of excess aldosterone on the target organs is very important to reduce cerebro-cardiovascular events. Current evidence convincingly demonstrates that both surgical and medical treatment strategies would benefit cerebro-cardiovascular outcomes and mortality in the long term. Understanding cerebro-cardiovascular risk in PA would help clinical doctors to achieve both early diagnosis and treatment. Therefore, in this review, we will summarize the cerebro-cardiovascular risk in PA, focusing on the TOD of aldosterone, including brain, heart, vascular system, renal, adipose tissues, diabetes, and obstructive sleep apnea (OSA). Furthermore, the various treatment outcomes of adrenalectomy and medical treatment for patients with PA will also be discussed. We hope this knowledge will help improve cerebro-cardiovascular prognosis and reduce the incidence and mortality of cerebro-cardiovascular events in patients with PA.

Benefits of Surgical Over Medical Treatment for Unilateral Primary Aldosteronism

Primary aldosteronism is the most common and modifiable form of secondary hypertension. Left untreated, primary aldosteronism leads high rates of cardiovascular, metabolic, and kidney disease. Therefore, early diagnosis and targeted therapy are crucial to improve long-term patient outcomes. In the case of unilateral primary aldosteronism, surgical adrenalectomy is the guideline-recommended treatment of choice as compared to alternative medical therapies such as mineralocorticoid receptor antagonist medications. Surgical adrenalectomy is not only highly successful in reversing the biochemical abnormalities inherent to primary aldosteronism, but also in mitigating the long-term risks associated with this disease. Indeed, as opposed to medical treatment alone, surgical adrenalectomy offers the potential for disease cure. Within this review article, we review the existing evidence highlighting the benefits of surgical over medical treatment for unilateral primary aldosteronism.

The Relationship Between Renal Stones and Primary Aldosteronism

INTRODUCTION

The association between primary aldosteronism (PA) and nephrolithiasis is still unclear. The hypercalciuria and hypocitraturia of PA patients might be the reason leading to recurrent calcium nephrolithiasis. This study aimed to evaluate the relationship between PA and renal stones, including stone size and density.

MATERIALS AND METHODS

From February 2010 to March 2021, we retrospectively collected 610 patients who presented to our medical center with hypertension history, and all these patients, suspicious of PA, had PA data survey. In total, 147 patients had kidney stone and were divided into 44 patients with essential hypertension as group 1 and 103 patients with PA as group 2. Pearson χ² test and independent Student's t-test were performed to examine the differences among variables.

RESULTS

The mean age was 54.4 ± 12.0 years in group 1 and 53.0 ± 11.1 years in group 2. The incidence rate of renal stones in the PA group was around 24%. No significant differences between the two groups were found for gender, systolic/diastolic blood pressure, duration of hypertension, diabetes mellitus history, and laterality of kidney stone; however, mean stone size was 4.0 ± 3.3 mm in group 1 and 6.5 ± 7.2 mm in group 2, with a significantly larger renal stone size noted in the PA group than that in the essential hypertension group (p = 0.004). Hounsfield unit (HU) density was higher in the PA group vis-à-vis the essential hypertension cohort, although this did not reach a significant difference (p = 0.204).

CONCLUSIONS

Our study revealed that PA patients had a higher incidence rate of renal stones compared to that of the general population. Besides, the PA-related renal stones also presented as larger and harder than those of the essential hypertension group. Further investigation concerning the association between PA and renal stones is warranted.

Metabolic risk factors for non-communicable diseases in Ethiopia: a systematic review and meta-analysis

OBJECTIVES

Non-communicable diseases (NCDs) are causing a new and yetsignificant health challenge in low-income countries. In Ethiopia, although 39% of deaths are NCD related, the health system remains underprepared, highlighting the clear need for evidence on risk factor distributions to inform resource planning and the health response. Therefore, this review investigates prevalence distributions and sex and age variations of metabolic risk factors among Ethiopian adults.

RESEARCH DESIGN AND METHODS

This systematic review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies published until 6 January 2021 were searched from PubMed, Scopus, ProQuest and Web of Science databases, reference lists of selected studies and grey literature. Studies reporting prevalence of metabolic risk factors: overweight/obesity, hypertension, impaired glucose homoeostasis and metabolic syndrome among Ethiopian adults were eligible for this systematic review and meta-analysis. Two authors independently extracted data and used the Joanna Briggs Institute tool for quality appraisal. The random effects model was used to conduct meta-analysis using Stata V.16. Subgroup analyses examined prevalence differences by region, study year, sample size and settings.

RESULTS

From 6087 records, 74 studies including 104 382 participants were included. Most showed high prevalence of metabolic risk factors. Meta-analysis revealed pooled prevalence of metabolic risk factors from 12% to 24% with the highest prevalence observed for overweight/obesity (23.9%, 95% CI 19.9% to 28.0%) and hypertension (21.1%, 95% CI 18.7% to 23.5%), followed by metabolic syndrome (14.7%, 95% CI 9.8% to 19.6%) and impaired glucose tolerance (12.4%, 95% CI 8.7% to 16.1%). The prevalence of overweight/obesity was higher in women. All metabolic risk factors were higher among people aged above 45 years.

CONCLUSIONS

A signficant proportion of Ethiopian adults have at least one metabolic risk factor for NCDs. Despite heterogeneity of studies limiting the certainty of evidence, the result suggests the need for coordinated effort among policymakers, healthcare providers, non-governmental stakeholders and the community to implement appropriate preventive measures to reduce these factors.

Development and validation of a novel diagnostic nomogram model to predict primary aldosteronism in patients with hypertension

PURPOSE

Primary aldosteronism (PA) remains, to a large extent, an under-diagnosed disease. We aimed to develop and validate a novel clinical nomogram to predict PA based on routine biochemical variables including new ones, calcium-phosphorus product.

METHODS

Records from 806 patients with hypertension were randomly divided into 70% (n = 564) as the training set and the remaining 30% (n = 242) as the validation set. Predictors for PA were extracted to construct a nomogram model based on regression analysis of the training set. An internal validation was performed to assess the nomogram model's discrimination and consistency using the area under the curve for receiver operating characteristic curves and calibration plots. The diagnostic accuracy was compared between nomogram and other known prediction models, using receiver operating characteristics (ROC) and decision curve analyses (DCA).

RESULTS

Female gender, serum potassium, serum calcium-phosphorus product, and urine pH were adopted as predictors in the nomogram. The nomogram resulted in an area under the curve of 0.73 (95% confidence interval: 0.68-0.78) in the training set and an area under the curve of 0.68 (0.59-0.75) in the validation set. Predicted probability and actual probability matched well in the nomogram (p > 0.05). Based on ROC and DCA, 21-70% threshold to predict PA in the nomogram model was clinically useful.

CONCLUSIONS

We have developed a novel nomogram to predict PA in hypertensive individuals based on routine biochemical variables. External validation is needed to further demonstrate its predictive ability in primary care settings.

Prevalence of Primary Aldosteronism Across the Stages of Hypertension Based on a New Combined Overnight Test

Primary aldosteronism (PA) is the most common endocrine cause of arterial hypertension. Despite the increasing incidence of hypertension worldwide, the true prevalence of PA in hypertension was only recently recognized. The objective of the work was to estimate the prevalence of PA in patients at different stages of hypertension based on a newly developed screening-diagnostic overnight test. This is a prospective study with hypertensive patients (n=265) at stage I (n=100), II (n=88), and III (n=77) of hypertension. A group of 103 patients with essential hypertension without PA was used as controls. PA diagnosis was based on a combined screening-diagnostic overnight test, the Dexamethasone-Captopril-Valsartan Test (DCVT) that evaluates aldosterone secretion after pharmaceutical blockade of angiotensin-II and adrenocorticotropic hormone. DCVT was performed in all participants independently of the basal aldosterone to renin ratio (ARR). The calculated upper normal limits for post-DCVT aldosterone levels [3 ng/dl (85 pmol/l)] and post-DCVT ARR [0.32 ng/dl/μU/ml (9 pmol/IU)] from controls, were applied together to establish PA diagnosis. Using these criteria PA was confirmed in 80 of 265 (30%) hypertensives. The prevalence of PA was: 21% (21/100) in stage I, 33% (29/88) in stage II, and 39% (30/77) in stage III. Serum K⁺ levels were negatively correlated and urinary K⁺ was positively correlated in PA patients with post-DCVT ARR (r=-0.349, p <0.01, and r=0.27, p <0.05 respectively). In conclusion, DCVT revealed that PA is a highly prevalent cause of hypertension. DCVT could be employed as a diagnostic tool in all subjects with arterial hypertension of unknown cause.

Insulin sensitivity and pancreatic β-cell function in patients with primary aldosteronism

BACKGROUND

Primary aldosteronism (PA) is associated with an increased risk for dysglycemia. However, the effects of hyperaldosteronism on insulin sensitivity and β-cell function are unclear.

METHODS

Using a cross-sectional study design, we assessed insulin sensitivity and pancreatic β-cell function from an oral glucose tolerance test (OGTT) in patients from two cohorts: subjects with PA (n = 21) and essential hypertension control (EHC) subjects (n = 22). Age, sex, BMI, and mean arterial pressure adjusted measures of insulin sensitivity and β-cell function were compared between the groups.

RESULTS

PA individuals were less insulin sensitive compared to EHC subjects (Quantitative insulin sensitivity check index [QUICKI]: 0.340 ± 0.006 vs. 0.374 ± 0.013, p < 0.001; Matsuda index: 4.14 ± 0.49 vs. 7.87 ± 1.42, p < 0.001; S_I: 11.45 ± 4.85 vs. 21.23 ± 6.11 dL/kg/min per μU/mL, p = 0.02). The hepatic insulin resistance index (HIRI) was higher in PA subjects (PA: 5.61 ± 1.01 vs. EHC: 4.13 ± 0.61, p = 0.002). The insulinogenic index (IGI), an index of β-cell function was higher in the PA cohort (PA: 1.49 ± 0.27 vs. 1.11 ± 0.21 μU/mL/mg/dL, p = 0.03). However, the oral disposition index (DI) was similar between the groups (PA: 4.77 ± 0.73 vs. EHC: 5.46 ± 0.85, p = 0.42), which likely accounts for the similar glucose tolerance between the two cohorts, despite lower sensitivity.

CONCLUSIONS

In summary, insulin sensitivity is significantly lower in PA with an appropriately compensated β-cell function. These results suggest that excess aldosterone and/or other steroids in the context of PA may negatively affect insulin action without adversely impacting β-cell function.

How common is primary aldosteronism?

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Changes in Glucose Metabolism after Adrenalectomy or Treatment with a Mineralocorticoid Receptor Antagonist for Primary Aldosteronism

BACKGROUND

Data on the effects of excess aldosterone on glucose metabolism are inconsistent. This study compared the changes in glucose metabolism in patients with primary aldosteronism (PA) after adrenalectomy or treatment with a mineralocorticoid receptor antagonist (MRA).

METHODS

Overall, 241 patients were enrolled; 153 underwent adrenalectomy and 88 received an MRA. Fasting glucose, homeostatic model assessment of insulin resistance (HOMA-IR), and homeostatic model assessment of β-cell function (HOMA-β) were compared between the treatment groups after 1 year. Plasma aldosterone concentration (PAC) and factors determining HOMA-IR and PAC were evaluated.

RESULTS

No baseline differences were observed between the groups. Fasting insulin, HOMA-IR, and HOMA-β increased in both groups and there were no significant differences in fasting glucose following treatment. Multiple regression analysis showed associations between PAC and HOMA-IR (β=0.172, P=0.017) after treatment. Treatment with spironolactone was the only risk factor associated with PAC >30 ng/dL (odds ratio, 5.2; 95% confidence interval [CI], 2.7 to 10; P<0.001) and conferred a 2.48-fold risk of insulin resistance after 1 year compared with surgery (95% CI, 1.3 to 4.8; P=0.007).

CONCLUSION

Spironolactone treatment might increase insulin resistance in patients with PA. This strengthened the current recommendation that adrenalectomy is the preferred strategy for patient with positive lateralization test. Achieving a post-treatment PAC of <30 ng/dL for improved insulin sensitivity may be appropriate.

MANAGEMENT OF ENDOCRINE DISEASE: The role of surgical adrenalectomy in primary aldosteronism

Primary aldosteronism is common and contributes to adverse cardiovascular, kidney, and metabolic outcomes. When instituted early and effectively, targeted therapies can mitigate these adverse outcomes. Surgical adrenalectomy is among the most effective treatments because it has the potential to cure, or attenuate the severity of, pathologic aldosterone excess, resulting in a host of biochemical and clinical changes that improve health outcomes. Herein, we review the role of surgical adrenalectomy in primary aldosteronism while emphasizing the physiologic ramifications of surgical intervention, and compare these to other targeted medical therapies for primary aldosteronism. We specifically review the role of curative adrenalectomy for unilateral primary aldosteronism, the role of non-curative adrenalectomy for bilateral primary aldosteronism, and how these interventions influence biochemical and clinical outcomes in relation to medical therapies for primary aldosteronism.

Determining the Prevalence of Primary Aldosteronism in Patients With New-Onset Type 2 Diabetes and Hypertension

CONTEXT

Despite a high prevalence of hypertension in diabetes and close relationship between primary aldosteronism (PA) and glucose metabolism, few study concerns the prevalence of PA in diabetes with hypertension.

OBJECTIVE

This study aimed to detect the prevalence of PA in patients with new-onset type 2 diabetes (T2D) and hypertension and to explore the association between PA and diabetes.

METHODS

A total of 256 outpatients with new-onset T2D and hypertension were screened for PA. Plasma aldosterone concentration (PAC), plasma renin activity (PRA) were measured. Patients with an aldosterone renin activity ratio (ARR) ≥ 30 ng/dL/ng/mL/h and PAC ≥ 15 ng/dL underwent confirmatory captopril challenge test (CCT) for PA. The diagnostic criteria for PA were, after CCT, (1) PAC decreased < 30%, (2) ARR maintained ≥ 30 ng/dL/ng/mL/h, and (3) PAC was ≥ 11 ng/dL.

RESULTS

Of 256 consecutive patients, 99 (39%) were positive for the screening test, and 49 (19%) were diagnosed with PA. Compared with those in groups A (screening test -) and B (screening test +, CCT -), patients in group C (diagnosed with PA) had a higher percentage of systolic blood pressure of ≥ 160 mmHg, less family history of hypertension, and lower serum potassium. Patients in group B and C had higher PAC and ARR levels, but lower PRA than those in group A. Homeostatic model assessment for insulin resistance (HOMA-IR) was positively associated with PAC level among the diabetic patients.

CONCLUSION

The prevalence of PA in new-onset T2D patients with hypertension is at least 19%. Higher aldosterone may be related with insulin resistance in patients with diabetes.

Primary Aldosteronism Diagnosis and Management: A Clinical Approach

Primary aldosteronism used to be considered a rare cause of secondary hypertension. However, accruing evidence indicates that primary aldosteronism is more common than previously recognized. The implications of this increased prevalence are important to public health because autonomous aldosterone production contributes to cardiovascular disease and can be treated in a targeted manner. This article focuses on clinical approaches for diagnosing primary aldosteronism more frequently and earlier in its course, as well as practical treatment objectives to reduce the risk for incident cardiovascular disease.

Insulin secretion and sensitivity before and after surgical treatment for aldosterone-producing adenoma

AIM

Primary aldosteronism, which is usually caused by an aldosterone-producing tumour, affects glucose metabolism. The effects of this condition on insulin secretion and insulin sensitivity have remained unclear, however. To gain insight into the influence of primary aldosteronism on glucose tolerance, various parameters related to insulin secretion or insulin sensitivity in patients with an aldosterone-producing tumour were comprehensively analyzed.

METHODS

To assess 14 patients with an aldosterone-producing tumour, hyperglycaemic and hyperinsulinaemic-euglycaemic clamp tests as well as oral glucose tolerance tests (OGTTs) were performed before and after tumour excision. Time between presurgical analysis and surgery was 27-559 (194±132) days, and 14-142 (51±38) days between surgery and postsurgical analysis. Various parameters related to insulin secretion or sensitivity as determined by OGTT as well as hyperglycaemic and hyperinsulinaemic-euglycaemic clamp analyses were evaluated.

RESULTS

Surgical treatment of tumours ameliorated hypokalaemia and reduced plasma aldosterone levels. First and second phases of insulin secretion during the hyperglycaemic clamp, as well as the insulinogenic index and total insulin secretion measured during OGTT, were also improved after surgery. In addition, the insulin sensitivity index determined during the hyperinsulinaemic-euglycaemic clamp was reduced after surgery.

CONCLUSION

Primary aldosteronism impairs insulin secretion.

Primary Aldosteronism: Cardiovascular Outcomes Pre- and Post-treatment

PURPOSE OF REVIEW

Primary aldosteronism (PA) is a common form of hypertension characterized by autonomous aldosterone secretion from one or both adrenal glands. The purpose of this review is to synthesize recent research findings regarding cardiovascular disease risk in PA both pre- and post-targeted therapy.

RECENT FINDINGS

Previously considered a rare disease, recent prevalence studies demonstrate that PA is actually a very common, yet vastly under-diagnosed, etiology of hypertension. Prior to targeted therapy, PA is associated with substantially higher rates of cardiovascular disease compared with essential hypertension. Surgical adrenalectomy is highly effective in curing or improving hypertension as well as mitigating cardiovascular disease risk in patients with unilateral PA. For the remainder of PA patients, MR antagonists are recommended; however, several recent studies have brought into question their effectiveness in improving cardiovascular outcomes. PA is a common cause of hypertension that leads to disproportionately high rates of cardiovascular disease. Future studies are needed to enhance the clinical approach to both identification and treatment of patients with PA to optimize long-term cardiovascular outcomes.

Endocrine Diseases and the Liver: An Update

The endocrine system is a complex interconnected system of organs that control corporeal processes and function. Primary endocrine organs are involved in hormonal production and secretion but rely on a bevy of signals from the hypothalamic-pituitary axis and secondary endocrine organs, such as the liver. In turn, proper hepatic function is maintained through hormonal signaling. Thus, the endocrine system and liver are codependent, and diseases affecting either organs can lead to alterations in function within their counterparts. This article explores the hepato-endocrine relationship, including the effects on endocrine diseases on the liver.

How Hypertension Affects Heart Metabolism

Hypertension is one of the most frequently observed cardiovascular diseases, which precedes heart failure in 75% of its cases. It is well-established that hypertensive patients have whole body metabolic complications such as hyperlipidemia, hyperglycemia, decreased insulin sensitivity or diabetes mellitus. Since myocardial metabolism is strictly dependent on hormonal status as well as substrate milieu, the above mentioned disturbances may affect energy generation status in the heart. Interestingly, it was found that hypertension induces a shift in substrate preference toward increased glucose utilization in cardiac muscle, prior to structural changes development. The present work reports advances in the aspect of heart metabolism under high blood pressure conditions, including human and the most common animal models of hypertension.

Aldosterone stimulation mediates cardiac metabolism remodeling via Sirt1/AMPK signaling in canine model

Aldosterone (Aldo), a pivotal hormone that is ubiquitously expressed in systemic tissues of mammals, is a crucial factor in the pathogenesis of cardiac disease. Accumulating evidence suggests that disturbances in cell energy metabolism are involved in increasing aldosterone levels. However, the precise mechanism underlying the impact of cardiac metabolic remodeling underlying aldosterone stimulation remains limited. In this work, we evaluated the underlying effect of aldosterone on regulating cardiac metabolism remodeling in a canine model. Fifteen beagle dogs were divided into a control group (n = 5), Aldo group (n = 5), and a group treated with spironolactone (SP), a mineralocorticoid receptor antagonist (n = 5), for 4 weeks. Blood pressure, electrocardiogram and respiratory parameters, H&E, Masson staining, ultrastructural changes, the adenosine triphosphate (ATP) and free fatty acid (FFA) levels of ventricular tissues, the level of mRNA, and the protein expression of key metabolic factors and regulators were assessed. The Sirt1/AMPK signaling pathway was significantly inhibited in the canine model of aldosterone stimulation, resulting in a reduction of the key downstream metabolic factors involved in glucose and fatty acid oxidation. The dysregulation of expression of key factors in glycogen metabolism led to glycogen deposition, an increase in FFA levels, a reduction in ATP levels, apoptosis, inflammatory cell infiltration, and mitochondrial damage in the ventricular myocardium. These effects were significantly restored by spironolactone. Aldosterone stimulation induced cardiac metabolic remodeling in ventricular cardiomyocytes possibly through the Sirt1/AMPK signaling pathway, implying that this pathway may provide a novel therapeutic target for cardiac metabolic remodeling.

The Expanding Spectrum of Primary Aldosteronism: Implications for Diagnosis, Pathogenesis, and Treatment

Primary aldosteronism is characterized by aldosterone secretion that is independent of renin and angiotensin II and sodium status. The deleterious effects of primary aldosteronism are mediated by excessive activation of the mineralocorticoid receptor that results in the well-known consequences of volume expansion, hypertension, hypokalemia, and metabolic alkalosis, but it also increases the risk for cardiovascular and kidney disease, as well as death. For decades, the approaches to defining, diagnosing, and treating primary aldosteronism have been relatively constant and generally focused on detecting and treating the more severe presentations of the disease. However, emerging evidence suggests that the prevalence of primary aldosteronism is much greater than previously recognized, and that milder and nonclassical forms of renin-independent aldosterone secretion that impart heightened cardiovascular risk may be common. Public health efforts to prevent aldosterone-mediated end-organ disease will require improved capabilities to diagnose all forms of primary aldosteronism while optimizing the treatment approaches such that the excess risk for cardiovascular and kidney disease is adequately mitigated. In this review, we present a physiologic approach to considering the diagnosis, pathogenesis, and treatment of primary aldosteronism. We review evidence suggesting that primary aldosteronism manifests across a wide spectrum of severity, ranging from mild to overt, that correlates with cardiovascular risk. Furthermore, we review emerging evidence from genetic studies that begin to provide a theoretical explanation for the pathogenesis of primary aldosteronism and a link to its phenotypic severity spectrum and prevalence. Finally, we review human studies that provide insights into the optimal approach toward the treatment of primary aldosteronism.

Predictors of confirmatory test results for the diagnosis of primary hyperaldosteronism in hypertensive patients with an aldosterone-to-renin ratio greater than 20. The SHRIMP study

It remains unknown which surrogate markers can predict diagnostic test results for primary hyperaldosteronism (PA). The Secondary Hypertension Registry Investigation in Mie Prefecture (SHRIMP) study has sequentially and prospectively recruited 128 patients with hypertension with an aldosterone-to-renin ratio (ARR) greater than 20, evaluated the differences among essential hypertension (EHT), idiopathic hyperaldosteronism (IHA), and aldosterone-producing adenoma (APA), and analyzed the predictors for the confirmatory tests. The patients underwent saline-loading, captopril-challenge, and upright furosemide-loading tests. Carotid, renovascular, and cardiac echography, brachial ankle pulse wave velocity (baPWV), endothelial function, nocturnal blood pressure decline, and the apnea hypopnea index were evaluated. Multivariate regression analyses showed that the plasma aldosterone concentration (PAC) at screening was a strong predictor of the saline and captopril test results. The plasma renin activity (PRA) at screening, urine β2-microglobulin, and left ventricular mass index (LVMI) were independent predictors for the captopril test. The estimated saline PAC and captopril 60 and 90 min ARRs predicted by the equations were highly correlated with the real values. The ROC curve analysis showed PAC at screening among each of predictors for the diagnostic tests and PAC after the saline-loading test had the highest diagnostic abilities of APA. Patients with IHA were older and had glucose intolerance and increased U-Alb/gCre and resistive indices. In patients with APA, the levels of U-Alb/gCre and urine β2-microglobulin were increased, and levels of insulin and the HOMA-IR were decreased. In conclusion, our proposed equations may be useful for estimating saline PAC and captopril ARR. Diagnostic predictors may differ for each confirmatory test.

Higher Screening Aldosterone to Renin Ratio in Primary Aldosteronism Patients with Diabetes Mellitus

Accumulated evidence has shown that low renin hypertension is common in patients with diabetic nephropathy. However, the performance of aldosterone to renin ratio (ARR) in primary aldosteronism (PA) patients with diabetes has not been well validated. Here, we report the performance of screening ARR in PA patients with diabetes. The study enrolled consecutive patients and they underwent ARR testing at screening. Then the diagnosis of PA was confirmed from the Taiwan Primary Aldosteronism Investigation registration dataset. Generalized additive model smoothing plot was used to validate the performance of screening ARR in PA patients with or without diabetes. During this study period, 844 PA patients were confirmed and 136 (16.0%) among them had diabetes. Other 816 patients were diagnosed with essential hypertension and used as the control group and 89 (10.9%) among them had diabetes. PA patients with diabetes were older and had a longer duration of hypertensive latency, higher systolic blood pressure and lower glomerular filtration rate than those PA patients without diabetes. The cut-off value of ARR in the generalized additive model predicting PA was 65 ng/dL per ng/mL/h in diabetic patients, while 45 ng/dL per ng/mL/h in non-diabetic patients. There was a considerable prevalence of diabetes among PA patients, which might be capable of interfering with the conventional screening test. The best cut-off value of ARR, more than 65 ng/dL per ng/mL/h in PA patients with diabetes, was higher than those without diabetes.

Surgical outcomes of patients with primary aldosteronism lateralized with I-131-6 β-iodomethyl-norcholesterol single photon emission/computed tomography without discontinuation or modification of antihypertensive medications

OBJECTIVES

Adrenocortical scintigraphy for patients with primary aldosteronism (PA) without discontinuation or modification of antihypertensive medications is of concern because of drug interference with the renin-angiotensin-aldosterone system. We report the surgical outcomes of patients with PA lateralized with adrenocortical scintigraphy without drug discontinuation or modification.

MATERIALS AND METHODS

We retrospectively reviewed 34 patients with PA with computed tomography (CT)-documented adrenal tumors who had undergoing subsequent I-131-6 β-iodomethyl-norcholesterol (NP-59) single photon emission CT (SPECT)/CT followed by unilateral adrenalectomy according to the results of NP-59 uptake between May 2005 and December 2014. All enrolled patients underwent standard confirmatory tests and lateralization with NP-59 SPECT/CT without discontinuation of existing antihypertensive medications, including spironolactone. The pathological findings, hypertension outcomes, and biochemical changes were reported. The accuracy of NP-59 SPECT/CT without drug discontinuation or modification was also evaluated.

RESULTS

None of the 34 enrolled patients (M:F = 16:18) had complications such as a hypertensive crisis, life-threatening hypokalemic event, or cardiac arrhythmia. Pathology disclosed 31 (91%) adenomas and three cases of hyperplasia. Hypertension cure and improvement were observed in 12 (35%) and 18 (53%) patients, respectively. All of the 30 patients (100%) without postoperative use of beta-blockers and with an available postoperative aldosterone/renin ratio achieved a biochemical cure. The positive predictive values of NP-59 SPECT/CT were 91%, 88%, and 100% for the pathological findings, hypertension outcomes, and biochemical changes, respectively.

CONCLUSION

Noninvasive NP-59 SPECT/CT without discontinuation or modification of antihypertensive medications not only provided accurate lateralization and safety but also resulted in a high improvement rate for PA-associated hypertension.

Cardiovascular events and target organ damage in primary aldosteronism compared with essential hypertension: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence, relying on heterogeneous studies, as to whether aldosterone excess is responsible for an increased risk of cardiovascular and cerebrovascular complications in patients with primary aldosteronism. We aimed to assess the association between primary aldosteronism and adverse cardiac and cerebrovascular events, target organ damage, diabetes, and metabolic syndrome, compared with the association of essential hypertension and these cardiovascular and end organ events, by integrating results of previous studies.

METHODS

We did a meta-analysis of prospective and retrospective observational studies that compared patients with primary aldosteronism and essential hypertension, to analyse the association between primary aldosteronism and stroke, coronary artery disease (as co-primary endpoints), atrial fibrillation and heart failure, target organ damage, metabolic syndrome, and diabetes (as secondary endpoints). We searched MEDLINE and Cochrane Library for articles published up to Feb 28, 2017, with no start date restriction. Eligible studies compared patients with primary aldosteronism with patients with essential hypertension (as a control group) and reported on the clinical events or endpoints of interest. We also compared primary aldosteronism subtypes, aldosterone-producing adenoma, and bilateral adrenal hyperplasia.

FINDINGS

We identified 31 studies including 3838 patients with primary aldosteronism and 9284 patients with essential hypertension. After a median of 8·8 years (IQR 6·2-10·7) from the diagnosis of hypertension, compared with patients with essential hypertension, patients with primary aldosteronism had an increased risk of stroke (odds ratio [OR] 2·58, 95% CI 1·93-3·45), coronary artery disease (1·77, 1·10-2·83), atrial fibrillation (3·52, 2·06-5·99), and heart failure (2·05, 1·11-3·78). These results were consistent for patients with aldosterone-producing adenoma and bilateral adrenal hyperplasia, with no difference between these subgroups. Similarly, primary aldosteronism increased the risk of diabetes (OR 1·33, 95% CI 1·01-1·74), metabolic syndrome (1·53, 1·22-1·91), and left ventricular hypertrophy (2·29, 1·65-3·17).

INTERPRETATION

Diagnosing primary aldosteronism in the early stages of disease, with early initiation of specific treatment, is important because affected patients display an increased cardiovascular risk compared with patients with essential hypertension.

FUNDING

None.

Diagnosis and management of primary aldosteronism

Primary aldosteronism (PA) is the most common form of secondary hypertension (HTN), with an estimated prevalence of 4% of hypertensive patients in primary care and around 10% of referred patients. Patients with PA have higher cardiovascular morbidity and mortality than age- and sex-matched patients with essential HTN and the same degree of blood pressure elevation. PA is characterized by an autonomous aldosterone production causing sodium retention, plasma renin supression, HTN, cardiovascular damage, and increased potassium excretion, leading to variable degrees of hypokalemia. Aldosterone-producing adenomas (APAs) account for around 40% and idiopathic hyperaldosteronism for around 60% of PA cases. The aldosterone-to-renin ratio is the most sensitive screening test for PA. There are several confirmatory tests and the current literature does not identify a "gold standard" confirmatory test for PA. In our institution, we recommend starting case confirmation with the furosemide test. After case confirmation, all patients with PA should undergo adrenal CT as the initial study in subtype testing to exclude adrenocortical carcinoma. Bilateral adrenal vein sampling (AVS) is the gold standard method to define the PA subtype, but it is not indicated in all cases. An experienced radiologist must perform AVS. Unilateral laparoscopic adrenalectomy is the preferential treatment for patients with APAs, and bilateral hyperplasia should be treated with mineralocorticoid antagonist (spironolactone or eplerenone). Cardiovascular morbidity caused by aldosterone excess can be decreased by either unilateral adrenalectomy or mineralocorticoid antagonist. In this review, we address the most relevant issues regarding PA screening, case confirmation, subtype classification, and treatment.

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.

Aldosterone and type 2 diabetes mellitus

Primary hyperaldosteronism (PA) has recently been demonstrated to be strictly associated to metabolic syndrome as compared with essential hypertension (EH). Besides, the characteristics of metabolic syndrome are different in PA compared to EH, as high fasting glucose is more frequent in the former condition. The adverse effect of excess aldosterone on insulin metabolic signaling has generated increasing interest in the role of hyperaldosteronism in the pathogenesis of insulin resistance and resistant hypertension. Moreover, aldosterone receptor antagonist therapy in diabetic and cardiopathic patients improved coronary flow. The aim of this review is to present recent knowledge about the relationship between aldosterone, insulin resistance and diabetes.

Aldosterone and the Mineralocorticoid Receptor: Risk Factors for Cardiometabolic Disorders

Preclinical studies have convincingly demonstrated a role for the mineralocorticoid receptor (MR) in adipose tissue physiology. These studies show that increased MR activation causes adipocyte dysfunction leading to decreased production of insulin-sensitizing products and increased production of inflammatory factors, creating an environment conducive to metabolic and cardiovascular disease. Accumulating data also suggest that MR activation may be an important link between obesity and metabolic syndrome. Moreover, MR activation may mediate the pathogenic consequences of metabolic syndrome. Recent attempts at reversing cardiometabolic damage in patients with type 2 diabetes using MR antagonists have shown promising results. MR antagonists are already used to treat heart failure where their use decreases mortality and morbidity over and above the use of traditional therapies alone. However, more data are needed to establish the benefits of MR antagonists in diabetes, obesity, and metabolic syndrome.