Long-term effects of addition of mineralocorticoid receptor antagonist to angiotensin II receptor blocker in patients with diabetic nephropathy: a randomized clinical trial

Decoding the role of aldosterone in glycation-induced diabetic complications

Diabetes-mediated development of micro and macro-vascular complications is a global concern. One of the factors is hyperglycemia induced the non-enzymatic formation of advanced glycation end products (AGEs). Accumulated AGEs bind with receptor of AGEs (RAGE) causing inflammation, oxidative stress and extracellular matrix proteins (ECM) modifications responsible for fibrosis, cell damage and tissue remodeling. Moreover, during hyperglycemia, aldosterone (Aldo) secretion increases, and its interaction with mineralocorticoid receptor (MR) through genomic and non-genomic pathways leads to inflammation and fibrosis. Extensive research on individual involvement of AGEs-RAGE and Aldo-MR pathways in the development of diabetic nephropathy (DN), cardiovascular diseases (CVDs), and impaired immune system has led to the discovery of therapeutic drugs. Despite mutual repercussions, the cross-talk between AGEs-RAGE and Aldo-MR pathways remains unresolved. Hence, this review focuses on the possible interaction of Aldo and glycation in DN and CVDs, considering the clinical significance of mutual molecular targets.

Strategies to address diabetic kidney disease burden in Mexico: a narrative review by the Mexican College of Nephrologists

Chronic kidney disease (CKD) is a growing global public health challenge worldwide. In Mexico, CKD prevalence is alarmingly high and remains a leading cause of morbidity and mortality. Diabetic kidney disease (DKD), a severe complication of diabetes, is a leading determinant of CKD. The escalating diabetes prevalence and the complex regional landscape in Mexico underscore the pressing need for tailored strategies to reduce the burden of CKD. This narrative review, endorsed by the Mexican College of Nephrologists, aims to provide a brief overview and specific strategies for healthcare providers regarding preventing, screening, and treating CKD in patients living with diabetes in all care settings. The key topics covered in this review include the main cardiometabolic contributors of DKD (overweight/obesity, hyperglycemia, arterial hypertension, and dyslipidemia), the identification of kidney-related damage markers, and the benefit of novel pharmacological approaches based on Sodium-Glucose Co-Transporter-2 Inhibitors (SGLT2i) and Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RA). We also address the potential use of novel therapies based on Mineralocorticoid Receptor Antagonists (MRAs) and their future implications. Emphasizing the importance of multidisciplinary treatment, this narrative review aims to promote strategies that may be useful to alleviate the burden of DKD and its associated complications. It underscores the critical role of healthcare providers and advocates for collaborative efforts to enhance the quality of life for millions of patients affected by DKD.

Epigenetic modification in diabetic kidney disease

Diabetic kidney disease (DKD) is a common microangiopathy in diabetic patients and the main cause of death in diabetic patients. The main manifestations of DKD are proteinuria and decreased renal filtration capacity. The glomerular filtration rate and urinary albumin level are two of the most important hallmarks of the progression of DKD. The classical treatment of DKD is controlling blood glucose and blood pressure. However, the commonly used clinical therapeutic strategies and the existing biomarkers only partially slow the progression of DKD and roughly predict disease progression. Therefore, novel therapeutic methods, targets and biomarkers are urgently needed to meet clinical requirements. In recent years, increasing attention has been given to the role of epigenetic modification in the pathogenesis of DKD. Epigenetic variation mainly includes DNA methylation, histone modification and changes in the noncoding RNA expression profile, which are deeply involved in DKD-related inflammation, oxidative stress, hemodynamics, and the activation of abnormal signaling pathways. Since DKD is reversible at certain disease stages, it is valuable to identify abnormal epigenetic modifications as early diagnosis and treatment targets to prevent the progression of end-stage renal disease (ESRD). Because the current understanding of the epigenetic mechanism of DKD is not comprehensive, the purpose of this review is to summarize the role of epigenetic modification in the occurrence and development of DKD and evaluate the value of epigenetic therapies in DKD.

Mineralocorticoid interaction with glycated albumin downregulates NRF - 2 signaling pathway in renal cells: Insights into diabetic nephropathy

In diabetic nephropathy, hyperglycemia elevates albumin glycation and also results in increased plasma aldosterone. Both glycation and aldosterone are reported to cause oxidative stress by downregulating the NRF-2 pathway and thereby resulting in reduced levels of antioxidants and glycation detoxifying enzymes. We hypothesize that an interaction between aldosterone and glycated albumin may be responsible for amplified oxidative stress and concomitant renal cell damage. Hence, human serum albumin was glycated by methylglyoxal (MGO) in presence of aldosterone. Different structural modifications of albumin, functional modifications and aldosterone binding were analyzed. HEK-293 T cells were treated with aldosterone+glycated albumin along with inhibitors of receptors for mineralocorticoid (MR) and advanced glycation endproducts (RAGE). Cellular MGO content, antioxidant markers (nitric oxide, glutathione, catalase, superoxide dismutase, glutathione peroxidase), detoxification enzymes (aldose reductase, Glyoxalase I, II), their expression along with NRF-2 and Keap-1 were measured. Aldosterone binds to albumin with high affinity which is static and spontaneous. Cell treatment by aldosterone+glycated albumin increased intracellular MGO, MR and RAGE expression; hampered antioxidant, detoxification enzyme activities and reduced NRF-2, Keap-1 expression. Thus, the glycated albumin-aldosterone interaction and its adverse effect on renal cells were confirmed. The results will help in developing better pharmacotherapeutic strategies for diabetic nephropathy.

Mineralocorticoid Receptor Antagonists in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a major cause of end-stage kidney disease (ESKD) worldwide. Mineralocorticoid receptor (MR) plays an important role in the development of DKD. A series of preclinical studies revealed that MR is overactivated under diabetic conditions, resulting in promoting inflammatory and fibrotic process in the kidney. Clinical studies demonstrated the usefulness of MR antagonists (MRAs), such as spironolactone and eplerenone, on DKD. However, concerns regarding their selectivity for MR and hyperkalemia have remained for these steroidal MRAs. Recently, nonsteroidal MRAs, including finerenone, have been developed. These agents are highly selective and have potent anti-inflammatory and anti-fibrotic properties with a low risk of hyperkalemia. We herein review the current knowledge and future perspectives of MRAs in DKD treatment.

Mineralocorticoid Receptor Antagonists-Use in Chronic Kidney Disease

Mineralocorticoid receptor antagonists (MRA) are drugs with a potentially broad spectrum of action. They have been reported to have healing effects in many diseases, such as chronic heart failure, hypertension, or nephrotic syndrome. Numerous studies suggest that mineralocorticoid receptor activation is pathogenic and a progression factor of chronic kidney disease (CKD); however, results of studies on the use of MRA in the treatment of CKD are inconclusive. Current guidelines recommend against the use of MRA in patients with advanced CKD. Although, there is growing interest on their use in this population due to treatment benefits. In this review, we summarize studies which were purposed to evaluate the impact of MRA therapy on CKD patients. Despite many benefits of this treatment e.g., reducing cardiovascular mortality or alleviating proteinuria, steroidal MRA (such as spironolactone or eplerenone) have a low safety profile. They often lead to hyperkalemia complications which are dangerous in patients with CKD, and diabetic nephropathy, especially in hemodialysis patients. Studies on recently developed nonsteroidal MRA showed that they have fewer side effects. In our review, we discuss steroidal and nonsteroidal MRA treatment effects on the estimated glomerular filtration rate (eGFR), proteinuria, the cardiovascular system, and hyperkalemia in CKD patients. We present new content and recent publications in this field.

The Forgotten Antiproteinuric Properties of Diuretics

BACKGROUND

Although diuretics are one of the most widely used drugs by nephrologists, their antiproteinuric properties are not generally taken into consideration.

SUMMARY

Thiazide diuretics have been shown to reduce proteinuria by >35% in several prospective controlled studies, and these values are markedly increased when combined with a low-salt diet. Thiazide-like diuretics (indapamide and chlorthalidone) have shown similar effectiveness. The antiproteinuric effect of mineralocorticoid receptor antagonists (spironolactone, eplerenone, and finerenone) has been clearly established through prospective and controlled studies, and treatment with finerenone reduces the risk of chronic kidney disease progression in type-2 diabetic patients. The efficacy of other diuretics such as amiloride, triamterene, acetazolamide, or loop diuretics has been less explored, but different investigations suggest that they might share the same antiproteinuric properties of other diuretics that should be evaluated through controlled studies. Although the inclusion of sodium-glucose cotransporter-2 inhibitors (SGLT2i) among diuretics is a controversial issue, their renoprotective and cardioprotective properties, confirmed in various landmark trials, constitute a true revolution in the treatment of patients with kidney disease. Recent subanalyses of these trials have shown that the early antiproteinuric effect induced by SGLT2i predicts long-term preservation of kidney function. Key Message: Whether the early reduction in proteinuria induced by diuretics other than finerenone and SGLT2i, as summarized in this review, also translates into long-term renoprotection requires further prospective and observational studies. In any case, it is important for the clinician to be aware of the antiproteinuric properties of drugs so often used in daily clinical practice.

Mineralocorticoid Receptor Antagonists in Diabetic Kidney Disease

Diabetes mellitus is a global health issue and main cause of chronic kidney disease. Both diseases are also linked through high cardiovascular morbidity and mortality. Diabetic kidney disease (DKD) is present in up to 40% of diabetic patients; therefore, prevention and treatment of DKD are of utmost importance. Much research has been dedicated to the optimization of DKD treatment. In the last few years, mineralocorticoid receptor antagonists (MRA) have experienced a renaissance in this field with the development of non-steroidal MRA. Steroidal MRA have known cardiorenal benefits, but their use is limited by side effects, especially hyperkalemia. Non-steroidal MRA still block the damaging effects of mineralocorticoid receptor overactivation (extracellular fluid volume expansion, inflammation, fibrosis), but with fewer side effects (hormonal, hyperkalemia) than steroidal MRA. This review article summarizes the current knowledge and newer research conducted on MRA in DKD.

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

Disclaimer

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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.

Role of mineralocorticoid receptor antagonists in kidney diseases

Mineralocorticoid receptor (MR) antagonists, for example, spironolactone and eplerenone, are in clinical use to treat hypertension. Increasing evidence suggests that mineralocorticoid receptor activation causes the pathogenesis and progression of chronic kidney disease. Aldosterone-induced MR activation increases inflammation, fibrosis, and oxidative stress in the kidney. MR antagonists (MRAs) have demonstrated therapeutic actions in chronic kidney disease (CKD), diabetic nephropathy (DN), renal fibrosis, and drug-induced renal injury in preclinical and clinical studies. We have summarized and discussed these studies in this review. The nonsteroidal MRA, esaxerenone, recently received approval for the treatment of hypertension. It has also shown a positive therapeutic effect in phase 3 clinical trials in patients with DN. Other nonsteroidal MRA such as apararenone, finerenone, AZD9977, and LY2623091 are in different clinical trials in patients with hypertension suffering from renal or hepatic fibrotic diseases. Hyperkalemia associated with MRA therapy has frequently led to the discontinuation of the treatment. The new generation nonsteroidal MRAs like esaxerenone are less likely to cause hyperkalemia at therapeutic doses. It appears that the nonsteroidal MRAs can provide optimum therapeutic benefit for patients suffering from kidney diseases.

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.

The Ascent of Mineralocorticoid Receptor Antagonists in Diabetic Nephropathy

Diabetic nephropathy is defined as a decline in the renal function and an increase in the amount of albuminuria (>300 mg/day). The interruption of the renin-angiotensin-aldosterone system (RAAS) by well-established therapies such as angiotensin-converting enzyme inhibitor, angiotensin receptor blockers, calcium channel blockers or diuretics has been beneficial in reducing the progression of renal diseases; however, there is an increase in the levels of aldosterone due to the aldosterone escape phenomenon. Newer and novel approaches to counteract this aldosterone breakthrough while accentuating the anti-hypertensive and anti-proteinuric effects of these agents would be ideal and mineralocorticoid receptor antagonists fit in this slot perfectly. This review attempted to evaluate the safety and efficacy of and mineralocorticoid receptor antagonists for diabetic nephropathy. Presently mineralocorticoid receptor antagonists such as spironolactone, eplerenone and finerenone are being investigated as both monotherapies and as additional therapies. Clinical studies have shown that these drugs have been effective in the reduction of blood pressure, urinary-albumin-excretion and estimated glomerular filtration rate. The commonly observed adverse effects are hyperkalemia, gynaecomastia and vaginal bleeding, that are bothersome with spironolactone seems to be avoidable if these patients are switched to non-steroidal and mineralocorticoid receptor antagonists such as finerenone and eplerenone. Most of the studies have only evaluated the short-term effects of mineralocorticoid receptor antagonists on diabetic nephropathy. Hard outcomes such as cardiovascular events, creatinine doubling, progression to end-stage renal disease, mortality and the need for temporary or permanent dialysis need to be studied with these molecules.

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.

Aldosterone and the mineralocorticoid receptor in renal injury: A potential therapeutic target in feline chronic kidney disease

There is a growing body of experimental and clinical evidence supporting mineralocorticoid receptor (MR) activation as a powerful mediator of renal damage in laboratory animals and humans. Multiple pathophysiological mechanisms are proposed, with the strongest evidence supporting aldosterone-induced vasculopathy, exacerbation of oxidative stress and inflammation, and increased growth factor signalling promoting fibroblast proliferation and deranged extracellular matrix homeostasis. Further involvement of the MR is supported by extensive animal model experiments where MR antagonists (such as spironolactone and eplerenone) abrogate renal injury, including ischaemia-induced damage. Additionally, clinical trials have shown MR antagonists to be beneficial in human chronic kidney disease (CKD) in terms of reducing proteinuria and cardiovascular events, though current studies have not evaluated primary end points which allow conclusions to made about whether MR antagonists reduce mortality or slow CKD progression. Although differences between human and feline CKD exist, feline CKD shares many characteristics with human disease including tubulointerstitial fibrosis. This review evaluates the evidence for the role of the MR in renal injury and summarizes the literature concerning aldosterone in feline CKD. MR antagonists may represent a promising therapeutic strategy in feline CKD.

A Prospective Single-Blind Randomized Trial of Ramipril, Eplerenone and Their Combination in Type 2 Diabetic Nephropathy

<b><i>Introduction:</i></b> Angiotensin-converting enzyme inhibitors (ACEI) combined with mineralocorticoid receptor antagonists were found to have a beneficial effect on patients with chronic kidney disease. <b><i>Objective:</i></b> The aim of our clinical trial was to compare the antialbuminuric effect of ramipril monotherapy, eplerenone monotherapy and eplerenone/ramipril combination therapy in patients with stage 1 hypertension and type 2 diabetes mellitus. <b><i>Methods:</i></b> In a single-blind, randomized clinical trial, 75 hypertensive patients (stage 1 hypertension) with type 2 diabetes mellitus and microalbuminuria were randomized in a 1:1:1 ratio to 1 of 3 groups: ramipril 10 mg monotherapy (25 patients), eplerenone 50 mg monotherapy (25 patients) and combination therapy of eplerenone/ramipril 50/10 mg (25 patients) through a randomized clinical trial. Blood pressure, urinary albumin/creatinine ratio (UACR), serum creatinine, estimated glomerular filtration rate (eGFR) and serum K level were measured before randomization and after 24 weeks. <b><i>Results:</i></b> Ramipril and eplerenone monotherapy showed a significant lowering of UACR compared with baseline levels (<i>p</i> ≤ 0.0001). The eplerenone/ramipril combination group showed a more significant reduction of UACR compared with the ramipril and eplerenone monotherapy groups (<i>p</i> = 0.0001). There was a more significant lowering of systolic blood pressure in the combination group (<i>p</i> &#x3c; 0.0001). A nonsignificant change of serum potassium level, serum creatinine and eGFR was found among the 3 groups. <b><i>Conclusion:</i></b> Addition of eplerenone to ACEI shows an added antialbuminuric effect without significant change of the serum K level compared with eplerenone or ACEI.

Should ACE inhibitors and ARBs be used in combination in children?

The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in a host of renal and cardiovascular functions. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), drugs that disrupt RAAS function, are effective in treating hypertension and offer other renoprotective effects independent of blood pressure (BP) reduction. As our understanding of RAAS physiology and the feedback mechanisms of ACE inhibition and angiotensin receptor blockade have improved, questions have been raised as to whether combination ACEI/ARB therapy is warranted in certain patients with incomplete angiotensin blockade on one agent. In this review, we discuss the rationale for combination ACEI/ARB therapy and summarize the results of key adult studies and the limited pediatric literature that have investigated this therapeutic approach. We additionally review novel therapies that have been developed over the past decade as alternative approaches to combination ACEI/ARB therapy, or that may be potentially used in combination with ACEIs or ARBs, in which further adult and pediatric studies are needed.

Efficacy and safety of mineralocorticoid receptor antagonists with ACEI/ARB treatment for diabetic nephropathy: A meta-analysis

BACKGROUND

To explore the efficacy and safety of adding mineralocorticoid receptor antagonists (MRAs) to the treatment in diabetic nephropathy (DN) with ACEI/ARB.

METHODS

We systematically searched the PubMed, Embase and Cochrane Library databases for randomised controlled trials up to November 1st 2018 that evaluated the effects of MRAs with ACEI/ARB treatment.

RESULTS

The combination treatment of MRAs and ACEI/ARB further reduced urinary protein/albumin excretion compared with ACEI/ARB monotherapy (mean difference [MD], -44.17 [95% CIs, -61.73 to -26.61], P < .00001). Although no statistically significant changes in glomerular filtration rate were observed, the combination group significantly increased serum/plasma creatinine (MD, 7.40 [95% CIs, 4.69-10.11], P < .00001). Subgroup analysis based on generations of MRAs suggested a lower relative risk of hyperkalaemia with finerenone (relative risk, 2.22 [95% CIs, 0.13-38.13], P = .58) than eplerenone (relative risk, 2.81 [95% CIs, 1.03-7.69], P = .04) or spironolactone (relative risk, 4.58 [95% CIs, 2.60-8.08], P < .00001).

CONCLUSION

MRAs can significantly reduce proteinuria and increase blood creatinine in DN patients under blockade of the renin-angiotensin system. The combination treatment of finerenone and ACEI/ARB runs a lower risk of hyperkalaemia than eplerenone or spironolactone.

Boosting the Limited Use of Mineralocorticoid Receptor Antagonists Through New Agents for Hyperkalemia

Background:

Hyperkalemia is an important clinical problem that is associated with significant lifethreatening complications. Several conditions are associated with increased risk for hyperkalemia such as chronic kidney disease, diabetes mellitus, heart failure, and the use of renin-angiotensin-aldosterone system (RAAS) inhibitors.

Objective:

The purpose of this review is to present and critically discuss treatment options for the management of hyperkalemia.

Method:

A comprehensive review of the literature was performed to identify studies assessing the drug-induced management of hyperkalemia.

Results:

The management of chronic hyperkalemia seems to be challenging and includes a variety of traditional interventions, such as restriction in the intake of the dietary potassium, loop diuretics or sodium polystyrene sulfonate. In the last few years, several new agents have emerged as promising options to reduce potassium levels in hyperkalemic patients. Patiromer and sodium zirconium cyclosilicate 9 (ZS-9) have been examined in hyperkalemic patients and were found to be efficient and safe. Importantly, the efficacy of these novel drugs might allow the continuation of the use of RAAS inhibitors, morbidity- and mortality-wise beneficial class of drugs in the setting of chronic kidney disease and heart failure.

Conclusion:

Data support that the recently emerged patiromer and ZS-9 offer significant hyperkalemia-related benefits. Larger trials are needed to unveil the impact of these drugs in other patients’ subpopulations, as well.

Mineralocorticoid receptor antagonists and kidney diseases: pathophysiological basis

Chronic kidney disease (CKD) represents a global health concern, and its prevalence is increasing. The ultimate therapeutic option for CKD is kidney transplantation. However, the use of drugs that target specific pathways to delay or halt CKD progression, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and sodium-glucose co-transporter-2 (SGLT-2) inhibitors is limited in clinical practice. Mineralocorticoid receptor activation in nonclassical tissues, such as the endothelium, smooth muscle cells, inflammatory cells, podocytes, and fibroblasts may have deleterious effects on kidney structure and function. Several preclinical studies have shown that mineralocorticoid receptor antagonists (MRAs) ameliorate or cure kidney injury and dysfunction in different models of kidney disease. In this review, we present the preclinical evidence showing a benefit of MRAs in acute kidney injury, the transition from acute kidney injury to CKD, hypertensive and diabetic nephropathy, glomerulonephritis, and kidney toxicity induced by calcineurin inhibitors. We also discuss the molecular mechanisms responsible for renoprotection related to MRAs that lead to reduced oxidative stress, inflammation, fibrosis, and hemodynamic alterations. The available clinical data support a benefit of MRA in reducing proteinuria in diabetic kidney disease and improving cardiovascular outcomes in CKD patients. Moreover, a benefit of MRAs in kidney transplantation has also been observed. The past and present clinical trials describing the effect of MRAs on kidney injury are presented, and the risk of hyperkalemia and use of other options, such as potassium binding agents or nonsteroidal MRAs, are also addressed. Altogether, the available preclinical and clinical data support a benefit of using MRAs in CKD, an approach that should be further explored in future clinical trials.

The endogenous cardiotonic steroid Marinobufagenin and decline in estimated glomerular filtration rate at follow-up in patients with arterial hypertension

BACKGROUND

Marinobufagenin (MBG) is an endogenous cardiotonic steroid (CTS) that inhibits the Na+/K+-ATPase. Human MBG is significantly increased in end-stage renal disease and immunization against MBG attenuates cardiovascular fibrosis in a rat model of uremic cardiomyopathy. Mineralocorticoid antagonists (MRA) block MBG binding sites and decrease proteinuria in chronic kidney disease (CKD) patients. We therefore aimed to investigate the association of MBG and albuminuria, as a marker of renal damage, as well as MBG and decline of glomerular filtration rate (GFR).

METHODS

The Graz endocrine causes of hypertension (GECOH) study is a single center study of adults routinely referred for screening of endocrine hypertension. Plasma MBG was measured by an enzyme-linked immunoassay, and in a post-hoc analysis, follow-up creatinine levels were obtained. Patients with proteinuria >3.5g/day at baseline were excluded from further evaluation.

RESULTS

We measured MBG concentrations in 40 hypertensive subjects and excluded one patient due to pre-existing proteinuria. Plasma MBG was significantly correlated with albuminuria (Spearman ρ = .357; p = .028) and proteinuria (ρ = .336; p = .039). In linear regression analysis, the association remained significant after adjustment for age, sex, and BMI (β = .306; p = .036), and for mean systolic blood pressure (β = .352; p = .034). In follow-up analyses (N = 30), MBG was significantly associated with decline in GFR after adjustment for time-to-follow-up (β = -.374; p = .042).

CONCLUSION

The findings suggest that MBG plasma concentrations were associated with albuminuria as well as decline in kidney function. Whether MBG predicts hard renal endpoints warrants further investigations.

The renin-angiotensin-aldosterone system and its suppression

Chronic activation of the renin-angiotensin-aldosterone system (RAAS) promotes and perpetuates the syndromes of congestive heart failure, systemic hypertension, and chronic kidney disease. Excessive circulating and tissue angiotensin II (AngII) and aldosterone levels lead to a pro-fibrotic, -inflammatory, and -hypertrophic milieu that causes remodeling and dysfunction in cardiovascular and renal tissues. Understanding of the role of the RAAS in this abnormal pathologic remodeling has grown over the past few decades and numerous medical therapies aimed at suppressing the RAAS have been developed. Despite this, morbidity from these diseases remains high. Continued investigation into the complexities of the RAAS should help clinicians modulate (suppress or enhance) components of this system and improve quality of life and survival. This review focuses on updates in our understanding of the RAAS and the pathophysiology of AngII and aldosterone excess, reviewing what is known about its suppression in cardiovascular and renal diseases, especially in the cat and dog.

Angiotensin-Converting Enzyme Inhibitors vs. Angiotensin Receptor Blockers for the Treatment of Hypertension in Adults With Type 2 Diabetes: Why We Favour Angiotensin Receptor Blockers

Cardiovascular disease is the principal cause of morbidity and mortality in patients with diabetes mellitus. The incidence or progression of kidney disease is also common in these patients. Several clinical trials have established the efficacy of angiotensin receptor blockers for the prevention of adverse cardiovascular and renal outcomes in this population and are summarized in this review article. Head-to-head comparison of angiotensin receptor blockers with angiotensin-converting enzyme inhibitors has shown similar cardioprotective and renoprotective properties of both medication classes. However, angiotensin receptor blockers have an improved safety profile with fewer episodes of cough and angioedema and may be the agent of choice in patients with diabetes and hypertension. Novel therapeutic strategies, such as those that include a mineralocorticoid receptor blocker or a selective sodium-glucose cotransporter type 2 inhibitor, may further protect patients with diabetes from cardiovascular and renal complications.

Identification of Morpholino-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-ones as Nonsteroidal Mineralocorticoid Antagonists

A novel series of morpholine-based nonsteroidal mineralocorticoid receptor antagonists is reported. Starting from a pyrrolidine HTS hit 9 that possessed modest potency but excellect selectivity versus related nuclear hormone receptors, a series of libraries led to identification of morpholine lead 10. After further optimization, cis disubstituted morpholine 22 was discovered, which showed a 45-fold boost in binding affinity and corresponding functional potency compared to 13. While 22 had high clearance in rat, it provided sufficient exposure at high doses to favorably assess in vivo efficacy (increased urinary Na⁺/K⁺ ratio) and safety. In contrast to rat, the dog and human MetID and PK profiles of 22 were adequate, suggesting that it could be suitable as a potential clinical asset.

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.

Effects of mineralocorticoid receptor antagonists on the progression of diabetic nephropathy

Aims/Introduction

We aimed to evaluate the potential benefits and adverse effects of adding a mineralocorticoid receptor antagonist (MRA) to angiotensin‐converting enzyme inhibitors (ACEI) and/or angiotensin receptor blockers (ARB), as standard treatment in patients with diabetic nephropathy.

Materials and Methods

We scanned the Embase, PubMed and Cochrane Central Register of Controlled Trials databases for human clinical trials published in English until June 2016, evaluating renal outcomes in patients with diabetic nephropathy.

Results

A total of 18 randomized controlled trials involving 1,786 patients were included. Compared with ACEI/ARB alone, co‐administration of MRA and ACEI/ARB significantly reduced urinary albumin excretion and the urinary albumin–creatinine ratio (mean difference −69.38, 95% confidence intervals −103.53 to −35.22, P < 0.0001; mean difference −215.74, 95% confidence intervals −409.22 to −22.26, P = 0.03, respectively). A decrease of blood pressure was also found in the co‐administration of MRA and ACEI/ARB groups. However, we did not observe any improvement in the glomerular filtration rate. There was a significant increase in the risk of hyperkalemia on the addition of MRA to ACEI/ARB treatment (relative risk 3.74, 95% confidence intervals 2.30–6.09, P < 0.00001).

Conclusions

These findings suggest that co‐administration of MRA and ACEI/ARB has beneficial effects on renal outcomes with increasing the incidence of hyperkalemia.

The next generation of therapeutics for chronic kidney disease

Chronic kidney disease (CKD) represents a leading cause of death in the United States. There is no cure for this disease, with current treatment strategies relying on blood pressure control through blockade of the renin-angiotensin system. Such approaches only delay the development of end-stage kidney disease and can be associated with serious side effects. Recent identification of several novel mechanisms contributing to CKD development - including vascular changes, loss of podocytes and renal epithelial cells, matrix deposition, inflammation and metabolic dysregulation - has revealed new potential therapeutic approaches for CKD. This Review assesses emerging strategies and agents for CKD treatment, highlighting the associated challenges in their clinical development.

Mineralocorticoid receptor antagonists-pharmacodynamics and pharmacokinetic differences

Mineralocorticoid receptor antagonists (MRAs) are best known as potassium-sparing diuretics due to their blockade of aldosterone action in renal epithelial tissues. They are also beneficial for the treatment of heart failure, primarily due to effects in non-epithelial tissues. Currently there are only two steroidal MRAs that have been approved for use; spironolactone (and its active metabolite canrenone) and eplerenone. However, the search is on for novel generations of MRAs with increased potency and tissue selectivity. A number of novel non-steroidal compounds are in preclinical and early development, with one agent moving to phase III trials. The development of these agents and the mechanisms for their pharmacologic superiority compared to earlier generations of MRAs will be discussed in this review.

Effects of mineralocorticoid receptor antagonists in patients with hypertension and diabetes mellitus: a systematic review and meta-analysis

Blood pressure (BP) control is important to ameliorate cardiovascular events in patients with diabetes mellitus (DM). However, achieving the target BP with a single drug is often difficult. The objective of this study was to evaluate the antihypertensive effects of mineralocorticoid receptor antagonists (MRAs) as add-on therapy to renin–angiotensin system (RAS) inhibitor(s) in patients with hypertension and DM. Studies were searched through October 2014 in MEDLINE, Embase and the Cochrane Central Register of Controlled Trials. Randomized, controlled trials or prospective, observational studies regarding concomitant administration of MRA and RAS inhibitor(s) in patients with DM were included. Articles were excluded if the mean systolic BP (SBP) was <130 mm Hg before randomization for interventional studies or at baseline for prospective cohort studies. We identified nine eligible studies (486 patients): five randomized placebo-controlled trials; three randomized active drug-controlled trials; and one single-arm observational study. The mean differences in office SBP and diastolic BP (DBP) between the MRA and placebo groups were −9.4 (95% confidence interval (CI) −12.9 to −5.9) and −3.8 (95% CI, −5.5 to −2.2) mm Hg, respectively. Subgroup analysis results for study type, age, baseline office SBP and follow-up duration were similar to those of the main analysis. MRA mildly increased serum potassium (0.4 mEq l⁻¹; 95% CI, 0.3–0.5 mEq l⁻¹). A consistent reduction of albuminuria across these studies was also demonstrated. MRA further reduced SBP and DBP in patients with hypertension and DM already taking RAS inhibitors. Serum potassium levels should be monitored to prevent hyperkalemia.

Improvements in the Management of Diabetic Nephropathy

The burden of diabetes mellitus is relentlessly increasing. Diabetic nephropathy is the most common cause of end-stage renal disease (ESRD) worldwide and a major cause of morbidity and mortality in patients with diabetes. The current standard therapy of diabetic nephropathy involves intensive treatment of hyperglycemia and strict blood pressure control, mainly via blockade of the renin-angiotensin system (RAS). Attention has been drawn to additional beneficial effects of oral hypoglycemic drugs and fibrates on other aspects of diabetic nephropathy. On the other hand, antiproteinuric effects of RAS combination therapy do not seem to enhance the prevention of renal disease progression, and it has been associated with an increased rate of serious adverse events. Novel agents, such as bardoxolone methyl, pentoxifylline, inhibitors of protein kinase C (PKC), sulodexide, pirfenidone, endothelin receptor antagonists, vitamin D supplements, and phosphate binders have been associated with controversial outcomes or significant side effects. Although new insights into the pathogenetic mechanisms have opened new horizons towards novel interventions, there is still a long way to go in the field of DN research. The aim of this review is to highlight the recent progress made in the field of diabetes management based on the existing evidence. The article also discusses novel targets of therapy, with a special focus on the major pathophysiologic mechanisms implicated in the initiation and progression of diabetic nephropathy.

Spironolactone Add-on for Preventing or Slowing the Progression of Diabetic Nephropathy: A Meta-analysis

PURPOSE

The aim of this meta-analysis was to evaluate the benefits and potential adverse effects of adding spironolactone to standard antidiabetic/renoprotective/antihypertensive (AD/RP/AHT) treatment in patients with diabetic nephropathy (DN).

METHODS

PubMed/MEDLINE and Web of Knowledge were searched for relevant randomized, controlled studies (RCTs) or quasi-RCTs of the effects of adding spironolactone to standard AD/RP/AHT treatment in patients with DN. Results were summarized with a random-effects model or a fixed-effects model.

FINDINGS

According to the outcomes measured (benefits and risks of adding spironolactone to standard AD/RP/AHT treatment), compared with controls, the addition of spironolactone significantly decreased end-of-treatment (EOT) 24-hour urinary albumin/protein excretion and significantly increased percentage reduction from baseline in urinary albumin/creatinine ratio (UACR), although it did not significantly affect EOT UACR. The addition of spironolactone further led to a significantly greater reduction from baseline in glomerular filtration rate (GFR)/estimated (e) GFR, although it did not significantly affect EOT GFR/eGFR. Further, the addition of spironolactone significantly reduced EOT in-office, 24-hour, and daytime systolic and diastolic blood pressure (SBP and DBP, respectively) and led to significantly greater reductions from baseline in in-office SBP and DBP, although it did not significantly affect nighttime SBP or DBP. Finally, the addition of spironolactone significantly increased mean serum/plasma potassium levels and the risk for hyperkalemia.

IMPLICATIONS

Spironolactone could be added to preexisting AD/RP/AHT therapy in patients with DN to prevent or slow DN progression by reducing proteinuria. The addition of spironolactone would likely provide even more beneficial effect in patients with DN and hypertension due to the BP reduction associated with spironolactone use. However, the beneficial effects of spironolactone add-on should be weighed against its potential risks, especially hyperkalemia. The long-term effects of spironolactone add-on on renal outcomes and mortality need to be studied.

Finerenone : third-generation mineralocorticoid receptor antagonist for the treatment of heart failure and diabetic kidney disease

INTRODUCTION

The mineralocorticoid receptor antagonists (MRAs) spironolactone and eplerenone reduce the risk of hospitalizations and mortality in patients with heart failure (HF) with reduced ejection fraction (HFrEF), and attenuate progression of diabetic kidney disease. However, their use is limited by the fear of inducing hyperkalemia, especially in patients with renal dysfunction. Finerenone is a novel nonsteroidal MRA, with higher selectivity toward the mineralocorticoid receptor (MR) compared to spironolactone and stronger MR-binding affinity than eplerenone.

AREAS COVERED

This paper discusses the chemistry, pharmacokinetics, clinical efficacy and safety of finerenone.

EXPERT OPINION

The selectivity and greater binding affinity of finerenone to the MR may reduce the risk of hyperkalemia and renal dysfunction and thereby overcome the reluctance to start and uptitrate MRAs in patients with HF and diabetic kidney disease. Studies conducted in patients with HFrEF and moderate chronic kidney disease and diabetic kidney disease, showed promising results. Phase III trials will have to show whether finerenone might become the third-generation MRA for the treatment of HF and diabetic kidney disease.

Polymorphisms in VEGFA gene affect the antihypertensive responses to enalapril

PURPOSE

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that affects blood pressure by promoting vasodilation mediated by nitric oxide. Angiotensin-converting enzyme inhibitors (ACEi) up-regulate the VEGF expression; thus, genetic polymorphisms in the VEGFA gene could affect the antihypertensive responses to these drugs.

METHODS

Hypertensive patients (n = 102) were prospectively treated only with the ACEi enalapril for 60 days. We compared the effect of VEGFA polymorphisms on changes in blood pressure after enalapril treatment. In addition, multiple linear regression analysis was carried out to assess the effect of covariates on blood pressure. Genotypes for g.-2578C>A (rs699947), g.-1154G>A (rs1570360), and g.-634G>C (rs2010963) VEGFA polymorphisms were determined, and haplotype frequencies were estimated.

RESULTS

Individuals carrying the CA and AA genotypes for the g.-2578C>A polymorphism and the AGG haplotype showed more intense decrease in blood pressure in response to enalapril 20 mg/day. A multiple linear regression analysis showed that the AA genotype for the g.-2578C>A polymorphism and the AGG haplotype are associated with more intense decrease in blood pressure in response to enalapril 20 mg/day, while the CC genotype for the g.-2578C>A polymorphism and the CGG haplotype are associated with the opposite effect.

CONCLUSIONS

These findings suggest that polymorphisms in VEGFA gene may affect the antihypertensive responses to enalapril.

Present and future in the treatment of diabetic kidney disease

Diabetic kidney disease is the leading cause of end-stage renal disease. Albuminuria is recognized as the most important prognostic factor for chronic kidney disease progression. For this reason, blockade of renin-angiotensin system remains the main recommended strategy, with either angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. However, other antiproteinuric treatments have begun to be studied, such as direct renin inhibitors or aldosterone blockers. Beyond antiproteinuric treatments, other drugs such as pentoxifylline or bardoxolone have yielded conflicting results. Finally, alternative pathogenic pathways are being explored, and emerging therapies including antifibrotic agents, endothelin receptor antagonists, or transcription factors show promising results. The aim of this review is to explain the advances in newer agents to treat diabetic kidney disease, along with the background of the renin-angiotensin system blockade.

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.

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.