Effect of renin-angiotensin-aldosterone system triple blockade on non-diabetic renal disease: addition of an aldosterone blocker, spironolactone, to combination treatment with an angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker

Mineralocorticoid receptor antagonists for nephroprotection and cardioprotection in patients with diabetes mellitus and chronic kidney disease

Diabetic kidney disease (DKD) develops in ∼40% of patients with diabetes and is the most common cause of chronic kidney disease (CKD) worldwide. Patients with CKD, especially those with diabetes mellitus, are at high risk of both developing kidney failure and cardiovascular (CV) death. The use of renin-angiotensin system (RAS) blockers to reduce the incidence of kidney failure in patients with DKD dates back to studies that are now ≥20 years old. During the last few years, sodium-glucose co-transporter-2 inhibitors (SGLT2is) have shown beneficial renal effects in randomized trials. However, even in response to combined treatment with RAS blockers and SGLT2is, the renal residual risk remains high with kidney failure only deferred, but not avoided. The risk of CV death also remains high even with optimal current treatment. Steroidal mineralocorticoid receptor antagonists (MRAs) reduce albuminuria and surrogate markers of CV disease in patients already on optimal therapy. However, their use has been curtailed by the significant risk of hyperkalaemia. In the FInerenone in reducing kiDnEy faiLure and dIsease prOgression in DKD (FIDELIO-DKD) study comparing the actions of the non-steroidal MRA finerenone with placebo, finerenone reduced the progression of DKD and the incidence of CV events, with a relatively safe adverse event profile. This document presents in detail the available evidence on the cardioprotective and nephroprotective effects of MRAs, analyses the potential mechanisms involved and discusses their potential future place in the treatment of patients with diabetic CKD.

Efficacy and safety of a low-sodium diet and spironolactone in patients with stage 1-3a chronic kidney disease: a pilot study

Background

Excessive salt intake is associated with the deterioration of chronic kidney disease (CKD). Aldosterone is also known as an independent risk factor for kidney injury. Dietary sodium intake acts as a main stimulator in aldosterone-mediated kidney injury. Hence, this study aimed to further investigate the renal protective effects and safety of a low-sodium diet in combination with spironolactone (SPL) in stage 1-3a CKD.

Methods

This single-center, SPL-blinded randomized controlled trial recruited patients with stage 1-3a CKD, randomized into three groups, low-sodium (3 g/d salt) + placebo, medium-sodium (5 g/d salt) + SPL, and low-sodium (3 g/d salt) + SPL. Patients received 12 weeks of intervention. The primary and secondary endpoints were 24-h urine protein and estimated glomerular filtration rate (eGFR) at the end of the intervention, respectively.

Results

A total of 74 patients were analyzed eventually. Significantly decreased 24-h urine protein was found in all three groups, from 0.37 to 0.23 g/d (P = 0.004) in the low-sodium+placebo group, from 0.44 to 0.29 g/d (P = 0.020) in the medium-sodium+SPL group, and from 0.35 to 0.31 g/d (P = 0.013) in the low-sodium +SPL group. There were no significant differences among the three groups in 24-h urine protein amount change after intervention from pre-treatment values (P = 0.760, ITT set). The results of the 24-h urine protein by using PP set analysis was similar to the ITT set. No significant differences in eGFR, nutritional, metabolic, inflammatory, and other biomarkers were observed across all three groups (P > 0.05). No safety signal was observed.

Conclusion

No additional benefit was observed when SPL was prescribed to patients already on a low-sodium diet (3.0 g/d). Still, small doses of SPL may benefit patients with poor sodium restriction. A combination of short-term low-dose SPL and ARB is safe for patients with stage 1-3a CKD, but blood potassium must be regularly monitored.

Trial registration

Name of the registry: Chinese clinical trial registry.

Trial registration number: ChiCTR1900026991.

Date of registration: Retrospectively registered 28 October 2019.

URL of trial registry record: http://www.chictr.org.cn/searchproj.aspx?title=&officialname=&subjectid=&secondaryid=&applier=&studyleader=ðicalcommitteesanction=&spo

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02711-z.

Serum potassium changes due to concomitant ACEI/ARB and spironolactone therapy: A systematic review and meta-analysis

Disclaimer

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

Purpose

To provide evidence of serum potassium changes in individuals taking angiotensin-converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers (ARBs) concomitantly with spironolactone compared to ACEI/ARB therapy alone.

Methods

PubMed, Embase, Scopus, and Web of Science were searched for studies including exposure to both spironolactone and ACEI/ARB therapy compared to ACEI/ARB therapy alone. The primary outcome was serum potassium change over time. Main effects were calculated to estimate average treatment effect using random effects models. Heterogeneity was assessed using Cochran’s Q and I 2. Risk of bias was assessed using the revised Cochrane risk of bias tool.

Results

From the total of 1,225 articles identified, 20 randomized controlled studies were included in the meta-analysis. The spironolactone plus ACEI/ARB group included 570 patients, while the ACEI/ARB group included 547 patients. Treatment with spironolactone and ACEI/ARB combination therapy compared to ACEI/ARB therapy alone increased the mean serum potassium concentration by 0.19 mEq/L (95% CI, 0.12-0.26 mEq/L), with intermediate heterogeneity across studies (Q statistic = 46.5, P = 0.004; I 2 = 59). Sensitivity analyses showed that the direction and magnitude of this outcome did not change with the exclusion of individual studies, indicating a high level of reliability. Reporting risk of bias was low for 16 studies (80%), unclear for 3 studies (15%) and high for 1 study (5%).

Conclusion

Treatment with spironolactone in combination with ACEI/ARB therapy increases the mean serum potassium concentration by less than 0.20 mEq/L compared to ACEI/ARB therapy alone. However, serum potassium and renal function must be monitored in patients starting combination therapy to avoid changes in serum potassium that could lead to hyperkalemia.

Renal haemodynamic and protective effects of renoactive drugs in type 2 diabetes: Interaction with SGLT2 inhibitors

Diabetic kidney disease remains the leading cause of end-stage kidney disease and a major risk factor for cardiovascular disease. Large cardiovascular outcome trials and dedicated kidney trials have shown that sodium-glucose cotransporter (SGLT)2 inhibitors reduce cardiovascular morbidity and mortality and attenuate hard renal outcomes in patients with type 2 diabetes (T2D). Underlying mechanisms explaining these renal benefits may be mediated by decreased glomerular hypertension, possibly by vasodilation of the post-glomerular arteriole. People with T2D often receive several different drugs, some of which could also impact the renal vasculature, and could therefore modify both renal efficacy and safety of SGLT2 inhibition. The most commonly prescribed drugs that could interact with SGLT2 inhibitors on renal haemodynamic function include renin-angiotensin system inhibitors, calcium channel blockers and diuretics. Herein, we review the effects of these drugs on renal haemodynamic function in people with T2D and focus on studies that measured glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) with gold-standard techniques. In addition, we posit, based on these observations, potential interactions with SGLT2 inhibitors with an emphasis on efficacy and safety.

Management of hyperkalemia during treatment with mineralocorticoid receptor blockers: findings from esaxerenone

The nonsteroidal mineralocorticoid receptor (MR) blocker esaxerenone has demonstrated good antihypertensive activity in a variety of patients, including those with uncomplicated grade I-III hypertension, hypertension with moderate renal dysfunction, hypertension with type 2 diabetes mellitus with albuminuria, and hypertension associated with primary aldosteronism. Hyperkalemia has long been recognized as a potential side effect occurring during treatment with MR blockers, but there is a lack of understanding and guidance about the appropriate management of hyperkalemia during antihypertensive therapy with MR blockers, especially in regard to the newer agent esaxerenone. In this article, we first highlight risk factors for hyperkalemia, including advanced chronic kidney disease, diabetes mellitus, cardiovascular disease, age, and use of renin-angiotensin-aldosterone system inhibitors. Next, we examine approaches to prevention and management, including potassium monitoring, diet, and the use of appropriate therapeutic techniques. Finally, we summarize the currently available data for esaxerenone and hyperkalemia. Proper management of serum potassium is required to ensure safe clinical use of MR blockers, including awareness of at-risk patient groups, choosing appropriate dosages for therapy initiation and dosage titration, and monitoring of serum potassium during therapy. It is critical that physicians take such factors into consideration to optimize MR blocker therapy in patients with hypertension.

Eplerenone Attenuates Fibrosis in the Contralateral Kidney of UUO Rats by Preventing Macrophage-to-Myofibroblast Transition

Severe renal fibrosis often occurs in obstructive kidney disease, not only in the obstructed kidney but also in the contralateral kidney, causing renal dysfunction. Although the mechanisms of injury in obstructed kidney have been studied for years, the pathogenesis of fibrosis in the contralateral kidney remains largely unknown. Here, we examined long-term unilateral ureteral obstruction (UUO) model in male Sprague-Dawley rats and found that macrophage-to-myofibroblast transition (MMT) is contributing to renal fibrosis in the contralateral kidney of UUO rats. Interestingly, this process was attenuated by treatment of eplerenone, a specific blocker of the mineralocorticoid receptor (MR). In-vitro, stimulating MR in primary cultured or cell line macrophages enhances MMT, which were also inhibited by MR blockade. Collectively, these findings provide a plausible mechanism for UUO-induced injury in the contralateral kidney, suggesting the benefit of using MR blockage as a part of treatment to UUO to protect the contralateral kidney thereby preserve renal function.

Impact of primary aldosteronism on renal function in patients with type 2 diabetes

AIMS/INTRODUCTION

Renal dysfunction might quickly progress in patients with type 2 diabetes mellitus, when accompanied by hypertension. However, whether primary aldosteronism (PA), which autonomously over-secretes aldosterone, causes additional renal damage in patients with type 2 diabetes mellitus is unclear. We evaluated the impact of PA on renal function in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

A retrospective review of all patients with type 2 diabetes mellitus who visited Yokohama Rosai Hospital's (Yokohama Japan) outpatient department between April 2017 and March 2018 was carried out. Records of patients with PA who underwent PA treatment by adrenalectomy or mineralocorticoid receptor antagonists (PA group) and those without PA (non-PA group) were extracted, and renal function was compared between the two groups. Untreated PA patients were excluded, as their renal function might be overestimated as a result of glomerular hyperfiltration.

RESULTS

There were 83 patients in the PA group and 1,580 patients in the non-PA group. The PA group had significantly lower estimated glomerular filtration rates than the non-PA group (66.3 [52.4-78.2] vs 70.5 [56.0-85.6] mL/min/1.73 m2 , P = 0.047). Multiple regression analysis showed that PA was a factor for decreased estimated glomerular filtration rate, independent of age, sex, glycated hemoglobin, diuretic use and hypertension (P = 0.025). PA induced a 3.7-mL/min/1.73 m2 (95% confidence interval 0.47-6.9) decrease in estimated glomerular filtration rate, equivalent to that induced by 4.4 years of aging.

CONCLUSIONS

Our results show that in patients with type 2 diabetes mellitus, PA is an independent risk factor for renal dysfunction. To prevent the progression of renal failure, PA should not be overlooked.

Aldosterone antagonists in addition to renin angiotensin system antagonists for preventing the progression of chronic kidney disease

BACKGROUND

Treatment with angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) is used to reduce proteinuria and retard the progression of chronic kidney disease (CKD). However, resolution of proteinuria may be incomplete with these therapies and the addition of an aldosterone antagonist may be added to further prevent progression of CKD. This is an update of a Cochrane review first published in 2009 and updated in 2014.

OBJECTIVES

To evaluate the effects of aldosterone antagonists (selective (eplerenone), non-selective (spironolactone or canrenone), or non-steroidal mineralocorticoid antagonists (finerenone)) in adults who have CKD with proteinuria (nephrotic and non-nephrotic range) on: patient-centred endpoints including kidney failure (previously know as end-stage kidney disease (ESKD)), major cardiovascular events, and death (any cause); kidney function (proteinuria, estimated glomerular filtration rate (eGFR), and doubling of serum creatinine); blood pressure; and adverse events (including hyperkalaemia, acute kidney injury, and gynaecomastia).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 January 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared aldosterone antagonists in combination with ACEi or ARB (or both) to other anti-hypertensive strategies or placebo in participants with proteinuric CKD.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Data were summarised using random effects meta-analysis. We expressed summary treatment estimates as a risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, or standardised mean difference (SMD) when different scales were used together with their 95% confidence interval (CI). Risk of bias were assessed using the Cochrane tool. Evidence certainty was evaluated using GRADE.

MAIN RESULTS

Forty-four studies (5745 participants) were included. Risk of bias in the evaluated methodological domains were unclear or high risk in most studies. Adequate random sequence generation was present in 12 studies, allocation concealment in five studies, blinding of participant and investigators in 18 studies, blinding of outcome assessment in 15 studies, and complete outcome reporting in 24 studies. All studies comparing aldosterone antagonists to placebo or standard care were used in addition to an ACEi or ARB (or both). None of the studies were powered to detect differences in patient-level outcomes including kidney failure, major cardiovascular events or death. Aldosterone antagonists had uncertain effects on kidney failure (2 studies, 84 participants: RR 3.00, 95% CI 0.33 to 27.65, I² = 0%; very low certainty evidence), death (3 studies, 421 participants: RR 0.58, 95% CI 0.10 to 3.50, I² = 0%; low certainty evidence), and cardiovascular events (3 studies, 1067 participants: RR 0.95, 95% CI 0.26 to 3.56; I² = 42%; low certainty evidence) compared to placebo or standard care. Aldosterone antagonists may reduce protein excretion (14 studies, 1193 participants: SMD -0.51, 95% CI -0.82 to -0.20, I² = 82%; very low certainty evidence), eGFR (13 studies, 1165 participants, MD -3.00 mL/min/1.73 m², 95% CI -5.51 to -0.49, I² = 0%, low certainty evidence) and systolic blood pressure (14 studies, 911 participants: MD -4.98 mmHg, 95% CI -8.22 to -1.75, I² = 87%; very low certainty evidence) compared to placebo or standard care. Aldosterone antagonists probably increase the risk of hyperkalaemia (17 studies, 3001 participants: RR 2.17, 95% CI 1.47 to 3.22, I² = 0%; moderate certainty evidence), acute kidney injury (5 studies, 1446 participants: RR 2.04, 95% CI 1.05 to 3.97, I² = 0%; moderate certainty evidence), and gynaecomastia (4 studies, 281 participants: RR 5.14, 95% CI 1.14 to 23.23, I² = 0%; moderate certainty evidence) compared to placebo or standard care. Non-selective aldosterone antagonists plus ACEi or ARB had uncertain effects on protein excretion (2 studies, 139 participants: SMD -1.59, 95% CI -3.80 to 0.62, I² = 93%; very low certainty evidence) but may increase serum potassium (2 studies, 121 participants: MD 0.31 mEq/L, 95% CI 0.17 to 0.45, I² = 0%; low certainty evidence) compared to diuretics plus ACEi or ARB. Selective aldosterone antagonists may increase the risk of hyperkalaemia (2 studies, 500 participants: RR 1.62, 95% CI 0.66 to 3.95, I² = 0%; low certainty evidence) compared ACEi or ARB (or both). There were insufficient studies to perform meta-analyses for the comparison between non-selective aldosterone antagonists and calcium channel blockers, selective aldosterone antagonists plus ACEi or ARB (or both) and nitrate plus ACEi or ARB (or both), and non-steroidal mineralocorticoid antagonists and selective aldosterone antagonists.

AUTHORS' CONCLUSIONS

The effects of aldosterone antagonists when added to ACEi or ARB (or both) on the risks of death, major cardiovascular events, and kidney failure in people with proteinuric CKD are uncertain. Aldosterone antagonists may reduce proteinuria, eGFR, and systolic blood pressure in adults who have mild to moderate CKD but may increase the risk of hyperkalaemia, acute kidney injury and gynaecomastia when added to ACEi and/or ARB.

Mineralocorticoid receptor antagonists in patients with chronic kidney disease

Mineralocorticoid receptor antagonists (MRA) can reduce cardiovascular morbidity and mortality in patients with heart failure and ischemic heart disease. In addition, these agents have been used in patients with diabetic nephropathy to control proteinuria and slow down chronic kidney disease (CKD) progression. Current guidelines recommend against the use of MRAs in patients with advanced CKD. However, there is growing interest on their use in this population that has unmet needs (high cardiovascular morbidity and mortality) and unique challenges (risk of acute kidney injury or hyperkalemia). This narrative review discusses the emerging role of MRAs for the management of cardiovascular disease and/or the prevention of CKD progression, highlighting results from randomized controlled trials and presenting real-world data from available registries. Results from recent trials in patients on maintenance dialysis are also discussed.

Effects of mineralocorticoid receptor antagonists in proteinuric kidney disease: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Reductions in albuminuria of more than 30% are considered a strong marker of delay of chronic kidney disease (CKD) progression. Single renin-angiotensin system (RAS) blockade represents the cornerstone of CKD treatment. However, as CKD progression still occurs, other nephroprotective options were explored; mineralocorticoid receptor antagonists (MRA) were tested with generally positive results.

METHODS

We conducted a systematic review and meta-analysis on the effects of MRAs on albuminuria/proteinuria, and adverse events, such as change in renal function and hyperkalemia incidence. A detailed search in electronic databases, clinical trial registries and grey literature was performed to retrieve randomized controlled trials (RCTs) in which administration of an MRA alone or on-top of ACEi/ARB was compared with placebo or active treatment.

RESULTS

Of the 45 initially identified reports, 31, with 2767 participants, were included in analysis of the primary outcome. The use of MRAs (alone or on top of RAS blockade) compared with placebo decreased urine albumin-to-creatinine ratio (UACR) by -24.55% (95% CI -29.57 to -19.53%), urine protein-to-creatinine ratio (UPCR) by -53.93% (95% CI -79% to -28.86%) and 24 h albumin excretion by -32.47% (95% CI -41.1 to -23.85%). MRAs also reduced UACR by -22.48% (95% CI -24.51 to -20.44%) compared with calcium-channel-blockers (CCBs), whereas no differences were found compared with a second ACEi/ARB or nonpotassium-sparing diuretics. Addition of an MRA was associated with change in estimated glomerular filtration rate (eGFR) of -2.38 ml/min per 1.73 m (95% CI -3.51 to -1.25), rise in potassium by 0.22 mEq/l (95% CI 0.16-0.28 mEq/l) and a 2.6-fold increase in hyperkalemia risk (RR 2.63, 95% CI 1.69-4.08) compared with placebo/active control.

CONCLUSION

Use of MRAs alone or on top of RAS blockade confers important antiproteinuric effects in patients with CKD, with a slight increase in mean potassium levels.

Crystal structure of the mineralocorticoid receptor ligand-binding domain in complex with a potent and selective nonsteroidal blocker, esaxerenone (CS-3150)

Activation of the mineralocorticoid receptor (MR) has long been considered a risk factor for cardiovascular diseases. It has been reported that the novel MR blocker esaxerenone shows high potency and selectivity for MR in vitro as well as great antihypertensive and renoprotective effects in salt-sensitive hypertensive rats. Here, we determined the cocrystal structure of the MR ligand-binding domain (MR-LBD) with esaxerenone and found that esaxerenone binds to MR-LBD in a unique manner with large side-chain rearrangements, distinct from those of previously published MR antagonists. This structure also displays an antagonist form that has not been observed for MR previously. Such a unique binding mode of esaxerenone provides great insight into the novelty, potency, and selectivity of this novel antihypertensive drug.

Mineralocorticoid Receptor Antagonists for Nephroprotection: Current Evidence and Future Perspectives

BACKGROUND

The use of single RAS-blockade is currently the recommended first-line treatment for proteinuric diabetic or non-diabetic nephropathy, as these agents were repeatedly shown in studies with hard renal outcomes to retard the progression of renal injury. However, CKD will continue to progress on optimum single RAS-blockade, and other options to ameliorate renal injury were explored. Dual RAS-blockade was associated with an increased risk of adverse-events with no apparent benefits and, therefore, is currently abandoned. Based on the phenomenon of aldosterone escape and the well-documented harmful effects of aldosterone on renal tissue, several randomized trials have studied the effects of a MRA in diabetic and non-diabetic nephropathy.

METHOD

This is a review of the literature in relevance to data evaluating the effect of MRA on renal outcomes.

RESULTS

Studies with spironolactone and eplerenone added to single RAS-blockade showed that these agents are associated with greater reductions in urine albumin or protein excretion compared to either placebo or dual RASblockade. However, studies with these agents on hard renal outcomes are currently missing and the reasonable skepticism of physicians on the real-world incidence of hyperkalemia in CKD patients are limiting their use. A non-steroidal MRA, finerenone, has also great potency in decreasing albuminuria in diabetic nephropathy with possibly lower rates of hyperkalemia. Two multi-center clinical trials examining the effect of finerenone on hard cardiovascular and renal outcomes are currently ongoing.

CONCLUSION

MRAs are able to reduce albuminuria and proteinuria on top of single RAS-blockade in patients with proteinuric CKD. Ongoing clinical trials are expected to clarify whether such an effect is accompanied by delay in CKD progression.

Mineralocorticoid Antagonism and Diabetic Kidney Disease

PURPOSE OF REVIEW

Type 2 diabetes (T2D) is associated with an increased risk of diabetic kidney disease (DKD), cardiovascular disease, and heart failure, in part through activation of the renin-angiotensin-aldosterone system (RAAS). Although recent cardiovascular outcome trials have identified newer therapeutic agents such as sodium-glucose cotransporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 (GLP-1)-receptor agonists that reduce the risk of these complications, patients still exhibit residual cardiorenal morbidity and mortality. Accordingly, the identification of pharmacological agents that attenuate micro- and macrovascular complications related to T2D is a major priority. Our aim was to review evidence for the role of novel mineralocorticoid receptor antagonists (MRAs) that are being developed as adjunctive therapies to reduce the risk of DKD and cardiovascular disease in the setting of T2D.

RECENT FINDINGS

Dual RAAS blockade with angiotensin-converting enzyme (ACE) inhibitor plus angiotensin receptor blockade (ARB) or ARB plus renin inhibition increases serious adverse events such as acute kidney injury and stroke. Due to the potential for these serious side effects, more recent interest has focused on newer, more selective non-steroidal MRAs such as finerenone as cardiorenal protective therapies. Finerenone reduces albuminuria in the setting of DKD in patients with T2D and has a lower risk of hyperkalemia compared to currently available MRAs. Novel MRAs such as finerenone have the potential to reduce the risk of DKD progression in patients with T2D. The impact of finerenone on hard, long-term cardiorenal endpoints is being examined in the FIGARO and FIDELIO trials in patients with DKD.

Role of Aldosterone in Renal Fibrosis

Aldosterone is a mineralocorticoid hormone, as its main renal effect has been considered as electrolyte and water homeostasis in the distal tubule, thus maintaining blood pressure and extracellular fluid homeostasis through the activation of mineralocorticoid receptor (MR) in epithelial cells. However, over the past decade, numerous studies have documented the significant role of aldosterone in the progression of chronic kidney disease (CKD) which has become a subject of interest. It is being studied that aldosterone can affect cardiovascular and renal system, thereby contributing to tissue inflammation, injury, glomerulosclerosis, and interstitial fibrosis. Aldosterone acts on renal vessels, renal cells (glomerular mesangial cells, podocytes, vascular smooth muscle cells, tubular epithelial cells, and interstitial fibroblasts), and infiltrating inflammatory cells, inducing reactive oxygen species (ROS) production, upregulated epithelial growth factor receptor (EGFR), and type 1 angiotensin (AT1) receptor expressions, and activating nuclear factor kappa B (NF-κB), activator protein-1 (AP-1), and EGFR to further promote cell proliferation, apoptosis, and proliferation. Phenotypic transformation of epithelial cells stimulates the expression of transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), osteopontin (OPN), and plasminogen activator inhibitor-1 (PAI-1), eventually leading to renal fibrosis. MR antagonisms are related to inhibition of aldosterone-mediated pro-inflammatory and pro-fibrotic effect. In this review, we will summarize the important role of aldosterone in the pathogenesis of renal injury and fibrosis, emphasizing on its multiple underlying mechanisms and advances in aldosterone research along with the potential therapeutics for targeting MR in a renal fibrosis.

The Role of the Mineralocorticoid Receptor in Inflammation: Focus on Kidney and Vasculature

BACKGROUND

The remarkable success of clinical trials in mineralocorticoid receptor (MR) inhibition in heart failure has driven research on the physiological and pathological role(s) of nonepithelial MR expression. MR is widely expressed in the cardiovascular system and is a major determinant of endothelial function, smooth muscle tone, vascular remodeling, fibrosis, and blood pressure. An important new dimension is the appreciation of the role MR plays in immune cells and target organ damage in the heart, kidney and vasculature, and in the development of insulin resistance.

SUMMARY

The mechanism for MR activation in tissue injury continues to evolve with the evidence to date suggesting that activation of MR results in a complex repertoire of effects involving both macrophages and T cells. MR is an important transcriptional regulator of macrophage phenotype and function. Another important feature of MR activation is that it can occur even with normal or low aldosterone levels in pathological conditions. Tissue-specific conditional models of MR expression in myeloid cells, endothelial cells, smooth muscle cells and cardiomyocytes have been very informative and have firmly demonstrated a critical role of MR as a key pathophysiologic variable in cardiac hypertrophy, transition to heart failure, adipose inflammation, and atherosclerosis. Finally, the central nervous system activation of MR in permeable regions of the blood-brain barrier may play a role in peripheral inflammation. Key Message: Ongoing clinical trials will help clarify the role of MR blockade in conditions, such as atherosclerosis and chronic kidney disease.

Mineralocorticoid Receptor Signaling as a Therapeutic Target for Renal and Cardiac Fibrosis

Activation of the mineralocorticoid receptor (MR) plays important roles in both physiological and pathological events. Blockade of MR signaling with MR antagonists (MRAs) has been used clinically to treat kidney and cardiac disease associated with hypertension and other chronic diseases, resulting in suppression of fibrosis in these organs. However, the current use of steroidal MRAs has been limited by off target effects on other hormone receptors or adverse effects on kidney tubular function. In this review, we summarize recent insights into the profibrotic roles of MR signaling in kidney and cardiovascular disease. We review experimental in vitro data identifying the pathological mechanisms associated with MR signaling in cell types found in the kidney (mesangial cells, podocytes, tubular cells, macrophages, interstitial fibroblasts) and heart (cardiomyocytes, endothelial cells, vascular smooth muscle cells, macrophages). In addition, we demonstrate the in vivo importance of MR signaling in specific kidney and cardiac cell types by reporting the outcomes of cell type selective MR gene deletion in animal models of kidney and cardiac disease and comparing these findings to those obtained with MRAs treatment. This review also includes a discussion of the potential benefits of novel non-steroidal MRAs for targeting kidney and cardiac fibrosis compared to existing steroidal MRAs, as well as the possibility of novel combination therapies and cell selective delivery of MRAs.

Pharmacological profile of CS-3150, a novel, highly potent and selective non-steroidal mineralocorticoid receptor antagonist

The present study was designed to characterize the pharmacological profile of CS-3150, a novel non-steroidal mineralocorticoid receptor antagonist. In the radioligand-binding assay, CS-3150 inhibited (3)H-aldosterone binding to mineralocorticoid receptor with an IC50 value of 9.4nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 36 and 713nM, respectively. CS-3150 also showed at least 1000-fold higher selectivity for mineralocorticoid receptor over other steroid hormone receptors, glucocorticoid receptor, androgen receptor and progesterone receptor. In the reporter gene assay, CS-3150 inhibited aldosterone-induced transcriptional activation of human mineralocorticoid receptor with an IC50 value of 3.7nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 66 and 970nM, respectively. CS-3150 had no agonistic effect on mineralocorticoid receptor and did not show any antagonistic or agonistic effect on glucocorticoid receptor, androgen receptor and progesterone receptor even at the high concentration of 5μM. In adrenalectomized rats, single oral administration of CS-3150 suppressed aldosterone-induced decrease in urinary Na(+)/K(+) ratio, an index of in vivo mineralocorticoid receptor activation, and this suppressive effect was more potent and longer-lasting than that of spironolactone and eplerenone. Chronic treatment with CS-3150 inhibited blood pressure elevation induced by deoxycorticosterone acetate (DOCA)/salt-loading to rats, and this antihypertensive effect was more potent than that of spironolactone and eplerenone. These findings indicate that CS-3150 is a selective and highly potent mineralocorticoid receptor antagonist with long-lasting oral activity. This agent could be useful for the treatment of hypertension, cardiovascular and renal disorders.

Combination antihypertensive therapy in clinical practice. The analysis of 1254 consecutive patients with uncontrolled hypertension

The aim of the study was to analyze the clinical use of different types of combination therapy in a large sample of consecutive patients with uncontrolled hypertension referred to Hypertension Centre. We performed a retrospective analysis of combination antihypertensive therapy in 1254 consecutive patients with uncontrolled hypertension receiving at least triple-combination antihypertensive therapy. Among the most prescribed antihypertensive classes were renin-angiotensin blockers (96.8%), calcium channel blockers (82.5%), diuretics (82.0%), beta-blockers (73.0%), centrally acting drugs (56.0%) and urapidil (24.1%). Least prescribed were spironolactone (22.2%) and alpha-1-blockers (17.1%). Thiazide/thiazide-like diuretics were underdosed in more than two-thirds of patients. Furosemide was prescribed in 14.3% of patients treated with diuretics, while only indicated in 3.9%. Inappropriate combination therapy was found in 40.4% of patients. Controversial dual and higher blockade of renin-angiotensin system occurred in 25.2%. Incorrect use of a combination of two antihypertensive drugs with the similar mechanism of action was found in 28.1%, most commonly a combination of two drugs with central mechanism (13.5%). In conclusion, use of controversial or incorrect combinations of drugs in uncontrolled hypertension is common. Diuretics are frequently underdosed and spironolactone remains neglected in general practice. The improper combination of antihypertensive drugs may contribute to uncontrolled hypertension.

Anti-albuminuric effects of spironolactone in patients with type 2 diabetic nephropathy: a multicenter, randomized clinical trial

BACKGROUND

Several studies have demonstrated that spironolactone has an anti-albuminuric property in diabetic nephropathy. As an adverse event, spironolactone often induces the elevation of creatinine levels with hypotension and hyperkalemia. Therefore, we aimed to evaluate the efficacy and safety of spironolactone in Japanese patients with type 2 diabetes treated with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers.

METHODS

Fifty-two Japanese patients with diabetic nephropathy and albuminuria (100 mg/gCr-2000 mg/gCr) treated with renin-angiotensin system (RAS) blockade were enrolled in a prospective, randomized, open-label study. The patients were subjected to add-on treatment with spironolactone 25 mg once daily and compared with matched controls for 8 weeks. The primary outcome was a reduction in the rate of albuminuria at 8 weeks compared with the baseline value. This study was registered with UMIN Clinical Trials Registry (000008016).

RESULTS

Albuminuria was reduced by 33 % (95 % confidence interval: 22-54; P = 0.0002) at 8 weeks with spironolactone. In the spironolactone group, blood pressure tended to lower and the estimated glomerular filtration rate (eGFR) was significantly decreased compared to those in the control group. When adjusted by systolic blood pressure and eGFR, spironolactone treatment still showed a significant effect on albuminuria reduction in a linear mixed model (coefficient ± standard error; 514.4 ± 137.6 mg/gCr, P < 0.0005). No patient was excluded from the study because of hyperkalemia.

CONCLUSIONS

Spironolactone reduced albuminuria along with conventional RAS inhibitors in patients with diabetic nephropathy. Our study suggests that spironolactone exerts anti-albuminuric effects independent of systemic hemodynamic alterations.

Cardiovascular actions of mineralocorticoid receptor antagonists in patients with chronic kidney disease: A systematic review and meta-analysis of randomized trials

INTRODUCTION

The safety and actions of mineralocorticoid receptor antagonists on surrogate markers of cardiovascular disease as well as major patient level cardiovascular end-points in patients with chronic kidney disease are unclear.

METHODS

MEDLINE, EMBASE, Trip Database, Cochrane Central Register of Controlled Trials, Cochrane Renal Group specialized register, Current Controlled Trials and clinicaltrials.gov were searched for relevant trials.

RESULTS

Twenty-nine trials (1581 patients) were included. Overall, mineralocorticoid receptor antagonists lowered both systolic and diastolic blood pressure (-5.24, 95% confidence interval (CI) -8.65, -1.82 mmHg; p=0.003 and -1.96, 95% CI -3.22, -0.69 mmHg; p=0.002 respectively). There were insufficient data to perform a meta-analysis of other cardiovascular effects. However, a systematic review of the studies included suggested a consistent improvement in surrogate markers of cardiovascular disease. Overall, the use of mineralocorticoid receptor antagonists was associated with an increased serum potassium (0.23, 95% CI 0.13, 0.33 mmol/l; p<0.0001) and higher risk ratio (1.76, 95% CI 1.20, 2.57; p=0.001) of hyperkalemia. Data on long-term cardiovascular outcomes and mortality were not available in any of the trials.

CONCLUSIONS

The long-term effects of mineralocorticoid receptor antagonists on cardiovascular events, mortality and safety need to be established.

Aldosterone blockade in CKD: emphasis on pharmacology

Besides its epithelial effect on sodium retention and potassium excretion in the distal tubule, aldosterone promotes inflammation and fibrosis in the heart, kidneys, and blood vessels. As glomerular filtration rate falls, aldosterone is inappropriately elevated relative to extracellular fluid expansion. In addition, studies in CKD patients on angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and/or direct renin inhibitors have shown that aldosterone levels paradoxically rise in approximately 30% to 40% of patients on these renin-angiotensin system-blocking drugs. Hence, there is interest in using mineralocorticoid receptor blockers that directly target the inflammatory and fibrotic effects of aldosterone in CKD patients. This interest, however, is tempered by a number of unresolved issues, including the safety of using such drugs in advanced CKD and ESRD populations, and the potential for differences in drug efficacy according to race and ethnicity of patient populations. A better understanding of mineralocorticoid receptor blocker pharmacology should help inform future research directions and clinical practice decisions as to how best to use these agents in CKD.

Additive effects of cilnidipine, an L-/N-type calcium channel blocker, and an angiotensin II receptor blocker on reducing cardiorenal damage in Otsuka Long-Evans Tokushima Fatty rats with type 2 diabetes mellitus

Cilnidipine (Cil), which is an L-/N-type calcium channel blocker (CCB), has been known to provide renal protection by decreasing the activity of the sympathetic nervous system (SNS) and the renin–angiotensin system. In this study, we compared the effects of the combination of Cil and amlodipine (Aml), which is an L-type CCB, with an angiotensin (Ang) II receptor blocker on diabetic cardiorenal damage in spontaneously type 2 diabetic rats. Seventeen-week-old Otsuka Long-Evans Tokushima Fatty rats were randomly assigned to receive Cil, Aml, valsartan (Val), Cil + Val, Aml + Val, or a vehicle (eight rats per group) for 22 weeks. Antihypertensive potencies were nearly equal among the CCB monotherapy groups and the combination therapy groups. The lowering of blood pressure by either treatment did not significantly affect the glycemic variables. However, exacerbations of renal and heart failure were significantly suppressed in rats administered Cil or Val, and additional suppression was observed in those administered Cil + Val. Although Val increased the renin–Ang system, Aml + Val treatment resulted in additional increases in these parameters, while Cil + Val did not show such effects. Furthermore, Cil increased the ratio of Ang-(1–7) to Ang-I, despite the fact that Val and Aml + Val decreased the Ang-(1–7) levels. These actions of Cil + Val might be due to their synergistic inhibitory effect on the activity of the SNS, and on aldosterone secretion through N-type calcium channel antagonism and Ang II receptor type 1 antagonism. Thus, Cil may inhibit the progression of cardiorenal disease in type 2 diabetes patients by acting as an N-type CCB and inhibiting the aldosterone secretion and SNS activation when these drugs were administered in combination with an Ang II receptor blocker.

Aldosterone antagonists for preventing the progression of chronic kidney disease

BACKGROUND

Treatment with angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) is increasingly used to reduce proteinuria and retard the progression of chronic kidney disease (CKD). However, resolution of proteinuria may be incomplete with these therapies and the addition of an aldosterone antagonist may be added to further prevent progression of CKD. This is an update of a review first published in 2009.

OBJECTIVES

To evaluate the effect of aldosterone antagonists (both selective (eplerenone) and non-selective (spironolactone)) alone or in combination with ACEi or ARB in adults who have CKD with proteinuria (nephrotic and non-nephrotic range) on: patient-centred endpoints including major cardiovascular events, hospitalisation and all-cause mortality; kidney function (proteinuria, glomerular filtration rate (GFR), serum creatinine, and need for renal replacement therapy; and adverse events (including gynaecomastia and hyperkalaemia).

SEARCH METHODS

For this update, we searched the Cochrane Renal Group's Specialised Register to 30 January 2013 using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared aldosterone antagonists alone or in combination with ACEi or ARB (or both) with other anti-hypertensive strategies or placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Data were summarised using random effects meta-analysis. We tested for heterogeneity in estimated treatment effects using the Cochran Q test and I² statistic. We expressed summary treatment estimates as a risk ratio (RR) for dichotomous outcomes together with their 95% confidence intervals (CI) and mean difference (MD) for continuous outcomes, or standardised mean difference (SMD) when different scales were used.

MAIN RESULTS

We identified 27 studies (1549 participants) that were eligible for inclusion. These studies provided no data relating to aldosterone antagonists in addition to ACEi or ARB (or both) on patient-level outcomes including major cardiovascular events and mortality and progression to end-stage kidney disease (ESKD) requiring dialysis or transplantation.Compared with ACEi or ARB (or both), non-selective aldosterone antagonists (spironolactone) combined with ACEi or ARB (or both) significantly reduced 24-hour protein excretion (11 studies, 596 participants): SMD -0.61, 95% CI -1.08 to -0.13). There was a significant reduction in both systolic and diastolic blood pressure (BP) at the end of treatment with additional non-selective aldosterone antagonist therapy (systolic BP (10 studies, 556 participants): MD -3.44 mm Hg, 95% CI -5.05 to -1.83) (diastolic BP (9 studies, 520 participants): MD -1.73 mm Hg, 95% CI -2.83 to -0.62).However, we found that aldosterone antagonist treatment had imprecise effects at the end of treatment on GFR (9 studies, 528 participants; MD -2.55 mL/min/1.73 m², 95% CI -5.67 to 0.51), doubled the risk of hyperkalaemia (11 studies, 632 patients): RR 2.00, 95% CI 1.25 to 3.20; number needed to treat for an additional harmful outcome (NNTH): 7.2, 95% CI 3.4 to ∞) and increased the risk of gynaecomastia compared to ACEi or ARB (or both) (4 studies, 281 patients): RR 5.14, 95% CI 1.14 to 23.23; NNTH: 14.1, 95% CI 8.7 to 37.3).Most studies enrolled few patients (range 12 to 268) and were powered to observe differences in surrogate end points rather than patient-focused outcomes. Nine studies had a cross-over design and the majority of studies did not adequately report study methods to assess methods and study quality.

AUTHORS' CONCLUSIONS

Aldosterone antagonists reduced proteinuria and blood pressure in adults who had mild to moderate CKD and were treated with ACEi or ARB (or both), but increase hyperkalaemia and gynaecomastia. Whether adding aldosterone antagonists to ACEi or ARB (or both) reduced the risk of major cardiovascular events or ESKD in this population is unknown.

Aldosterone blockade in chronic kidney disease

Although blockade of the renin-angiotensin-aldosterone system with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers has become standard therapy for chronic kidney disease (CKD), renewed interest in the role of aldosterone in mediating the injuries and progressive insults of CKD has highlighted the potential role of treatments targeting the mineralocorticoid receptor (MR). Although salt restriction is an important component of mitigating the profibrotic effects of MR activation, a growing body of literature has shown that MR antagonists, spironolactone and eplerenone, can reduce proteinuria and blood pressure in patients at all stages of CKD. These agents carry a risk of hyperkalemia, but this risk likely can be predicted based on baseline renal function and mitigated using dietary modifications and adjustments of concomitant medications. Data on hard outcomes, such as progression to end-stage renal disease and overall mortality, still are lacking in patients with CKD.

Diuretics: a review and update

Diuretics have been recommended as first-line treatment of hypertension and are also valuable in the management of hypervolemia and electrolyte disorders. This review summarizes the key features of the most commonly used diuretics. We then provide an update of clinical trials for diuretics during the past 5 years. Compared to other classes of medications, thiazide diuretics are at least as effective in reducing cardiovascular events (CVEs) in patients with hypertension and are more effective than β-blockers and angiotensin-converting enzyme inhibitors in reducing stroke. Observational cohort data and a network analysis have shown that CVEs are lowered by one-fifth from chlorthalidone when compared to the commonly used thiazide, hydrochlorothiazide. Relative to placebo, chlorthalidone increases life expectancy. In those aged 80 years and older, the diuretic, indapamide, lowers CVEs relative to placebo. The aldosterone antagonist, eplerenone, lowers total mortality in early congestive heart failure. The benefit of eplerenone following acute myocardial infarction (MI) is limited to administration within 3 to 6 days post-MI. Aldosterone antagonists have been shown to lower the incidence of sudden cardiac death and to reduce proteinuria. In the setting of heart failure, long acting loop diuretics azosemide and torasemide are more effective in improving heart failure outcomes than the far more commonly used short acting furosemide. Evening dosing of diuretics appears to lower CVEs relative to morning dosing. In conclusion, diuretics are a diverse class of drugs that remain extremely important in the management of hypertension and hypervolemic states.

Mineralocorticoid receptor blockade-a novel approach to fight hyperkalaemia in chronic kidney disease

Hyperkalaemia continues to be a major hazard of mineralocorticoid receptor blockade in an effort to retard the progression of chronic kidney disease (CKD). In cardiac patients on mineralocorticoid receptor blockade, RLY-5016 which captures K⁺ in the colon has been effective in reducing the risk of hyperkalaemia. This compound might be useful in CKD as well.

Alport syndrome: the effects of spironolactone on proteinuria and urinary TGF-β1

BACKGROUND

Alport syndrome (AS) is a progressive hereditary glomerular disease. Recent data indicate that aldosterone promotes fibrosis mediated by the transforming growth factor-β1 (TGF-β1) pathway, which may worsen proteinuria. Spironolactone (SP) antagonizes aldosterone and this study aimed to evaluate the efficacy of SP in reducing proteinuria and urinary TGF-β1 excretion in proteinuric AS patients.

METHODS

The study involved ten children with AS, normal renal function, and persistent proteinuria (>6 months; uPr/uCr ratio >1). SP 25 mg once a day for 6 months was added to existing ACE inhibitor treatment with or without angiotensin-II receptor blockade. Urine and blood samples were examined monthly. Urinary TGF-β1 levels were measured twice before and three times during SP treatment. Plasma renin activity (PRA) and serum aldosterone levels were also measured. In eight patients, uProt/uCreat was also assessed after 9 months and 12 months of SP treatment.

RESULTS

After beginning SP therapy, all patients showed significant decrease in mean uProt/uCreat ratio (1.77 ± 0.8 to 0.86 ± 0.6; p < 0.001) and mean urinary TGF-β1 levels (104 ± 54 to 41 ± 20 pg/mgCreatinine; p < 0.01), beginning after 30 days of treatment and remaining stable throughout SP administration. PRA remain unchanged, and mean serum aldosterone increased from 105 ± 72 pg/ml to 303 ± 156 pg/ml (p < 0.001). The only side effect was gynecomastia in an obese boy. After 1 year of therapy, mean uProt/uCreat remains low (0.82 ± 0.48).

CONCLUSIONS

Addition of SP to ACE-I treatment with or without angiotensin II receptor blokers (ARB) significantly reduced proteinuria. This was mediated by decreased urinary TGF-β1 levels and not associated with major side effects.

Spironolactone, eplerenone and the new aldosterone blockers in endocrine and primary hypertension

Mineralocorticoid receptor antagonists (MRAs) are commonly used to reduce blood pressure, left-ventricular hypertrophy, and urinary albumin excretion in patients with essential hypertension or primary aldosteronism. Effects of MRAs on hypertensive organ damage seem to occur beyond what is expected from the mere reduction of blood pressure. This suggests that activation of the mineralocorticoid receptor plays a central role in the development of cardiac and renal abnormalities in hypertensive patients. However, broad use of classic MRAs such as spironolactone has been limited by significant incidence of gynecomastia and other sex-related adverse effects. To overcome these problems, new aldosterone blockers have been developed with different strategies that include use of nonsteroidal MRAs and inhibition of aldosterone synthesis. Both strategies have been designed to avoid the steroid receptor cross-reactivity of classic MRAs that accounts for most adverse effects. Moreover, inhibition of aldosterone synthesis could have an additional benefit due to blockade of the mineralocorticoid receptor-independent pathways that might account for some of the untoward effects of aldosterone. The new aldosterone blockers are currently having extensive preclinical evaluation, and one of these compounds has passed phase 2 trials showing promising results in patients with primary hypertension and primary aldosteronism. This narrative review summarizes the knowledge on the use of classic MRAs in hypertension and covers the evidence currently available on new aldosterone blockers.

Aldosterone receptor antagonists: current perspectives and therapies

Aldosterone is a downstream effector of angiotensin II in the renin-angiotensin-aldosterone system and binds to the mineralocorticoid receptor. The classical view of aldosterone primarily acting at the level of the kidneys to regulate plasma potassium and intravascular volume status is being supplemented by evidence of new "off-target" effects of aldosterone in other organ systems. The genomic effects of aldosterone are well known, but there is also evidence for non-genomic effects and these recently identified effects of aldosterone have required a revision in the traditional view of aldosterone's role in human health and disease. The aim of this article is to review the biological action of aldosterone and the mineralocorticoid receptor leading to subsequent physiologic and pathophysiologic effects involving the vasculature, central nervous system, heart, and kidneys. Furthermore, we outline current evidence evaluating the use of mineralocorticoid receptor antagonists in the treatment of primary aldosteronism, primary hypertension, resistant hypertension, obstructive sleep apnea, heart failure, and chronic kidney disease.

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.

Renoprotective effects of mineralocorticoid receptor blockers in patients with proteinuric kidney diseases

BACKGROUND

Several studies have demonstrated a short-term antiproteinuric effect of mineralocorticoid receptor blockers (MRB) on proteinuric kidney diseases, but no information is available about the long-term persistence (>1 year) of such reduction in proteinuria and the long-term effects of MRB on renal function.

METHODS

We prospectively studied the effects of adding spironolactone (25 mg/day) to 87 patients who maintained proteinuria higher than 1 g/day in spite of renin-angiotensin system blockade. The mean follow-up was 25 ± 15 (1-84) months.

RESULTS

Estimated glomerular filtration rate (eGFR) showed an acute fall in the first month of treatment (5.1 ± 9.4 mL/min/1.73 m(2)), but it remained stable thereafter (+0.04 ± 0.7 mL/min/1.73 m(2)/month), with a significant difference with respect to the eGFR slope during the 12-month pre-treatment period. The initial eGFR fall predicted a more stable course of renal function, the higher the eGFR initial fall, the better the long-term evolution of eGFR. Proteinuria showed an important and sustained reduction since the first month of treatment. At the end of follow-up, it had decreased by 61% (43-77%) with respect to baseline values. The antiproteinuric and renoprotective influence of spironolactone was also observed in diabetic patients and in patients with renal function impairment, although tolerance was poorer among the latter.

CONCLUSIONS

Spironolactone induces an initial acute fall in eGFR that predicts a later favourable influence on the course of renal function and a remarkable and sustained reduction in proteinuria.

High-circulating leptin levels are associated with increased blood pressure in uncontrolled resistant hypertension

Leptin and aldosterone have been associated with the pathophysiological mechanisms of hypertension. However, despite studies showing the association of leptin with intima-media thickness, arterial distensibility and sympathetic nerve activation, the relationship between leptin and blood pressure (BP) in resistant hypertension (RHTN) is unknown. We aimed to assess the correlation of plasma leptin and aldosterone levels with BP in uncontrolled controlled RHTN (UCRHTN) and CRHTN patients. Plasma leptin and aldosterone levels, office BP, ambulatory BP monitoring and heart rate were measured in 41 UCRHTN, 39 CRHTN and 31 well-controlled HTN patients. No differences were observed between the three groups regarding gender, body mass index and age. The UCRHTN group had increased leptin when compared with CRHTN and well-controlled HTN patients (38.2±21.4, 19.6±8.7 and 20.94±13.9 ng ml(-1), respectively; P<0.05). Aldosterone levels values were also statistically different when comparing RHTN, CRHTN and well-controlled HTN patients (9.6±3.8, 8.1±5.0 and 8.0±4.7 ng dl(-1), respectively; P<0.05). As expected, UCRHTN patients had higher heart rate values compared with CRHTN and well-controlled HTN patients (86.2±7.2, 83.5±6.7 and 83.4±8.5, respectively; P<0.05). Plasma leptin positively correlated with systolic (SBP) and diastolic BP (DBP), and aldosterone (r=0.43, 0.35 and 0.47, respectively; all P<0.05) in UCRHTN, but neither in the CRHTN nor in the HTN group. Simple linear regression showed that SBP, DBP and aldosterone may be predicted by leptin (r(2)=0.16, 0.15 and 0.19, respectively; all P<0.05) only in the UCRHTN subgroup. In conclusion, UCRHTN patients have higher circulating leptin levels associated with increased plasma aldosterone and BP levels when compared with CRHTN and HTN subjects.

Aldosterone blockade and the mineralocorticoid receptor in the management of chronic kidney disease: current concepts and emerging treatment paradigms

The past two decades have witnessed a striking paradigm shift with respect to our understanding of the widespread effects of aldosterone. There is substantive evidence that mineralocorticoid receptor (MR) activation promotes myriad 'off target' effects on the heart, the vasculature, and importantly the kidney. In the present review, we summarize the expanding role of MR activation in promoting both vascular and renal injury. We review the recent clinical studies that investigated the efficacy of MR antagonism (MRA) in reducing proteinuria and attenuating progressive renal disease. We also review in-depth both the utility and safety of MRA in the end-stage renal disease (ESRD) patient undergoing dialysis. Because the feasibility of add-on MRA is critically dependent on our ability to minimize or avoid hyperkalemia, and because controversy centers on the incidence of hyperkalemia, we critically review the risk of hyperkalemia with add-on MRA. Our present analysis suggests that hyperkalemia supervening in MRA-treated patients is overstated. Furthermore, recent studies demonstrating the efficacy of new non-absorbed, orally administered, potassium [K+]-binding polymers suggest that a multi-pronged approach encompassing adequate surveillance, moderate or low-dose MRA, and K-binding polymers may adequately control serum K in both chronic kidney disease and ESRD patients.

Moderate antiproteinuric effect of add-on aldosterone blockade with eplerenone in non-diabetic chronic kidney disease. A randomized cross-over study

Background

Reduction of proteinuria and blood pressure (BP) with blockers of the renin-angiotensin system (RAS) impairs the progression of chronic kidney disease (CKD). The aldosterone antagonist spironolactone has an antiproteinuric effect, but its use is limited by side effects. The present study evaluated the short-term antiproteinuric effect and safety of the selective aldosterone antagonist eplerenone in non-diabetic CKD.

Study Design

Open randomized cross-over trial.

Setting and Participants

Forty patients with non-diabetic CKD and urinary albumin excretion greater than 300 mg/24 hours.

Intervention

Eight weeks of once-daily administration of add-on 25–50 mg eplerenone to stable standard antihypertensive treatment including RAS-blockade.

Outcomes & Measurements

24 hour urinary albumin excretion, BP, p-potassium, and creatinine clearance.

Results

The mean urinary albumin excretion was 22% [CI: 14,28], P<0.001, lower during treatment with eplerenone. Mean systolic BP was 4 mmHg [CI: 2,6], P = 0.002, diastolic BP was 2 mmHg [CI: 0,4], P = 0.02, creatinine clearance was 5% [CI: 2,8], P = 0.005, lower during eplerenone treatment. After correction for BP and creatinine clearance differences between the study periods, the mean urinary albumin excretion was 14% [CI: 4,24], P = 0.008 lower during treatment. Mean p-potassium was 0.1 mEq/L [CI: 0.1,0.2] higher during eplerenone treatment, P<0.001. Eplerenone was thus well tolerated and no patients were withdrawn due to hyperkalaemia.

Limitations

Open label, no wash-out period and a moderate sample size.

Conclusions

In non-diabetic CKD patients, the addition of eplerenone to standard antihypertensive treatment including RAS-blockade caused a moderate BP independent fall in albuminuria, a minor fall in creatinine clearance and a 0.1 mEq/L increase in p-potassium.

Trial Registration

Clinicaltrials.gov NCT00430924

Changes in the perceived epidemiology of primary hyperaldosteronism

Primary aldosteronism has been considered a rare disease in the past years, affecting 1% of the hypertensive population. Subsequently, growing evidence of its higher prevalence is present in literature, although the estimates of disease range from 5 up to 20%, as in type 2 diabetes and resistant hypertension. The main reasons for these variations are associated with the selection of patients and diagnostic procedures. If we consider that hypertension is present in about 20% of the adult population, primary aldosteronism can no longer be considered a rare disease. Patients with primary aldosteronism have a high incidence of cardiovascular, cerebrovascular and kidney complications. The identification of these patients has therefore a practical value on therapy, and to control morbidities derived from vascular damage. The ability to identify the prevalence of a disease depends on the number of subjects studied and the methods of investigation. Epidemiological studies are affected by these two problems: there is not consensus on patients who need to be investigated, although testing is recommended in subjects with resistant hypertension and diabetes. The question of how to determine aldosterone and renin levels is open, particularly if pharmacological wash-out is difficult to perform because of inadequate blood pressure control.

Effects of an N-type calcium antagonist on angiotensin II-renin feedback

BACKGROUND

Interrupting the renin-angiotensin system (RAS) with an angiotensin II receptor blocker (ARB) has been found to induce RAS overactivation. In this study, we investigated the effect of 2 calcium channel blockers (CCBs), cilnidipine (L-/N-type CCB) and amlodipine (L-type CCB), on the RAS activation induced by an ARB in a strain of spontaneously hypertensive rats (SHR/Izm, 10 weeks of age).

METHODS

Rats intravenously catheterized for blood collection were randomly divided into groups that were administered the vehicle, the ARB valsartan or valsartan combined with one of the 2 CCBs. Their blood and kidneys were collected 270 min after administration.

RESULTS

Valsartan increased the plasma angiotensin II (Ang II) level in a dose-dependent manner. Cilnidipine suppressed the increase in plasma renin activity and plasma Ang II levels induced by valsartan, but amlodipine did not. Combined administration of cilnidipine, but not amlodipine, and valsartan significantly reduced the noradrenaline content in the renal cortex.

CONCLUSIONS

The results of this study suggest that the suppressive effect of cilnidipine on the valsartan-induced increase in RAS activity can be partly explained by its sympatholytic action mediated by N-type calcium channel blockade, and that combined administration of cilnidipine and valsartan might provide a synergistic therapeutic effect.

Resistant hypertension in the high-risk metabolic patient

The metabolic syndrome is a constellation of metabolic and vascular abnormalities that include insulin resistance with compensatory hyperinsulinemia, central or visceral obesity, hypertension, dyslipidemia, microalbuminuria, and oxidative stress as well as prothrombotic and inflammatory abnormalities that contribute to a hypercoagulable state and systemic endothelial dysfunction. Visceral adipose tissue is now known to secrete into the circulation a number of protein and nonprotein factors that regulate glucose metabolism in traditional insulin-sensitive tissue as well as nontraditional insulin-sensitive tissue including cardiovascular tissue. Collectively, this constellation of factors that lead to metabolic dysregulation contributes to a substantial risk for adverse cardiovascular and renal outcomes. The development of a particularly resistant form of hypertension in these individuals can be attributed to a number of factors including vasoconstriction from increased sympathetic activation, proinflammatory cytokines, and inappropriate activation of the renin-angiotensin-aldosterone system. The management of hypertension in such patients can be challenging and generally requires nonpharmacologic as well as pharmacologic interventions.

Diabetic microvascular complications: possible targets for improved macrovascular outcomes

The results of recent outcome trials challenge hypotheses that tight control of both glycohemoglobin and blood pressure diminishes macrovascular events and survival among type 2 diabetic patients. Relevant questions exist regarding the adequacy of glycohemoglobin alone as a measure of diabetes control. Are we ignoring mechanisms of vasculotoxicity (profibrosis, altered angiogenesis, hypertrophy, hyperplasia, and endothelial injury) inherent in current antihyperglycemic medications? Is the polypharmacy for lowering cholesterol, triglyceride, glucose, and systolic blood pressure producing drug interactions that are too complex to be clinically identified? We review angiotensin-aldosterone mechanisms of tissue injury that magnify microvascular damage caused by hyperglycemia and hypertension. Many studies describe interruption of these mechanisms, without hemodynamic consequence, in the preservation of function in type 1 diabetes. Possible interactions between the renin-angiotensin-aldosterone system and physiologic glycemic control (through pulsatile insulin release) suggest opportunities for further clinical investigation.

[Aldosterone and kidney diseases: an emergent paradigm with important clinical implications]

Slowing the progression of chronic kidney diseases needs new efficient treatments. Aldosterone classically acts on the distal nephron: it allows sodium reabsorption, potassium secretion and participates to blood volume control. Recently, new targets of aldosterone have been described including the heart and the vasculature but also non-epithelial kidney cells such as mesangial cells, podocytes and renal fibroblasts. The pathophysiological implication of aldosterone and its receptor, the mineralocorticoid receptor has been demonstrated ex vivo in cell culture and in vivo in experimental animal models with kidney damages such as diabetic and hypertensive kidney nephropathies, chronic kidney disease and glomerulopathies. The beneficial effects of the pharmacological antagonists of the mineralocorticoid receptor are independent of the hypertensive effect of aldosterone, indicating that blocking the activation of the mineralocorticoid receptor in these non-classical renal targets may be of clinical importance. Several clinical studies now report benefit and safety when using spironolactone or eplerenone, the currently available mineralocorticoid receptor antagonists, in patients with kidney diseases. In this review, we discuss the recent results reported in experimental and clinical research in this domain.

Time to achieve blood pressure goal with a combination versus a conventional monotherapy approach in hypertensive patients with metabolic syndrome

The time to achieve a blood pressure (BP) goal < or =130/85 mmHg with a combination versus a conventional monotherapy approach was evaluated in 308 hypertensive patients with metabolic syndrome. They were randomized to valsartan (V) 8 mg/amlodipine (A) 5 mg combination or to V 160 mg monotherapy for 12 weeks and every 2 weeks, there was a titration in nonresponder patients: in the combination group V/A was progressively increased to V 160/A 5 mg; V160/A 7.5 mg; V160/A 10 mg; V 240/A 10 mg, and V 320/A 10 mg. In the monotherapy group, the regimen was progressively modified as following: V 240 mg; V 320 mg; V 320/A 5 mg; V 320/A 7.5 mg, and V 320/A 10 mg. The mean time to achieve the BP goal was shorter in patients randomized to combination therapy compared to those randomized to conventional monotherapy (4.7 +/- 2.7 weeks vs. 7.1 +/- 3.9 weeks, respectively, p < 0.001). The percentage of patients who achieved target BP in the combination approach group statistically exceeded that of the monotherapy treated one already after 2 weeks of treatment (30.5 vs. 14.9%, p < 0.01) and again after 4, 6, 8, and 10 weeks of treatment. Only at 12 weeks the percentage of normalized patients was similar in the two treatment groups (78.8% vs. 75.3%, ns). These results suggest that initial therapy with a V/A combination approach may be more quickly effective than a conventional sequential monotherapy approach in achieving target BP in hypertensive patients with metabolic syndrome.

New approaches to blockade of the renin-angiotensin-aldosterone system: mineralocorticoid-receptor blockers exert antihypertensive and renoprotective effects independently of the renin-angiotensin system

The role of angiotensin II in mediating hypertension and renal diseases is well documented, and inhibition of the renin-angiotensin-aldosterone system elicits antihypertensive and renoprotective effects. There is increasing evidence implicating aldosterone, in addition to angiotensin II, in the pathogenesis of hypertension and renal diseases. Beneficial effects of mineralocorticoid receptor (MR) blockers against these diseases have been reported and are independent of the effects exerted by renin-angiotensin system (RAS) inhibitors. MR blockers are increasingly being used, not only for primary aldosteronism but also for other resistant hypertensive patients whose blood pressure is insufficiently controlled by RAS inhibitors. In these settings, MR blockers have shown impressive results. In addition, anti-proteinuric effects of MR blockers have been observed in hypertensive patients treated with RAS inhibitors, but without significant effects on blood pressure. Interestingly, these effects of MR blockers are not always dependent on plasma aldosterone levels. These data suggest that MR blockers provide a potential therapeutic approach for patients with hypertension and renal impairment who are being treated with RAS inhibitors.