Effect of spironolactone on K(+) homeostasis and ENaC expression in lymphocytes from chronic hemodialysis patients

Research Progress on the Efficacy and Safety of Spironolactone in Reversing Left Ventricular Hypertrophy in Hemodialysis Patients

The mineralocorticoid receptor antagonist spironolactone has been shown to improve cardiac function and reverse left ventricular hypertrophy in heart failure patients, but there are no consistent findings on the efficacy and safety in hemodialysis patients. Abnormal aldosterone secretion plays a critical role in the formation of left ventricular hypertrophy. Because of the existence of "aldosterone escape", the routine use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers does not completely inhibit aldosterone secretion. Low-dose spironolactone (25 mg/d) has been found in small-sample clinical studies to have a significant positive impact with respect to decreasing left ventricular mass index, increasing left ventricular ejection fraction, reversing left ventricular hypertrophy, and improving cardiovascular function while still being safe. More prospective multicenter clinical trials with large sample sizes are needed, however, to provide convincing evidence.

Association of Mineralocorticoid Receptor Antagonists With the Mortality and Cardiovascular Effects in Dialysis Patients: A Meta-analysis

Whether Mineralocorticoid receptor antagonists (MRA) reduce mortality and cardiovascular effects of dialysis patients remains unclear. A meta-analysis was designed to investigate whether MRA reduce mortality and cardiovascular effects of dialysis patients, with a registration in INPLASY (INPLASY2020120143). The meta-analysis revealed that MRA significantly reduced all-cause mortality (ACM) and cardiovascular mortality (CVM). Patients receiving MRA presented improved left ventricular mass index (LVMI) and left ventricular ejection fraction (LVEF), decreased systolic blood pressure (SBP) and diastolic blood pressure (DBP). There was no significant difference in the serum potassium level between the MRA group and the placebo group. MRA vs. control exerts definite survival and cardiovascular benefits in dialysis patients, including reducing all-cause mortality and cardiovascular mortality, LVMI, and arterial blood pressure, and improving LVEF. In terms of safety, MRA did not increase serum potassium levels for dialysis patients with safety. Systematic Review Registration: (https://inplasy.com/inplasy-protocol-1239-2/), identifier (INPLASY2020120143).

Mineralocorticoid Receptor Antagonist Use in Heart Failure With Reduced Ejection Fraction and End-Stage Renal Disease Patients on Dialysis: A Literature Review

Mineralocorticoid receptor antagonists (MRAs) are known to have a proven mortality benefit in heart failure with reduced ejection fraction (HFrEF) without kidney disease. As patients with end-stage renal disease (ESRD) requiring either peritoneal dialysis or hemodialysis were excluded in clinical trials of HFrEF, the data are scant on the appropriate use of MRAs in this population. The unknown efficacy, along with concerns of adverse effects such as hyperkalemia, has limited the willingness of clinicians to consider using MRAs in these patients. However, it is unclear whether the risk of hyperkalemia is present if a patient is oliguric or anuric. Current guidelines recommend against the use of MRAs in patients with chronic kidney disease, but do not address the use of MRAs in patients requiring dialysis. This article will review the epidemiology of heart failure in ESRD, the pathophysiological derangements of the renin-angiotensin-aldosterone system in patients with kidney disease, and the results from case series and trials of the use of MRAs in ESRD with HFrEF. Although limited to several small trials using MRAs in peritoneal and hemodialysis patients with or without HFrEF, the current literature appears to show the potential for clinical benefits with little risk.

A systematic review and meta-analysis of the impact of mineralocorticoid receptor antagonists on glucose homeostasis

BACKGROUND

Spironolactone, a nonselective mineralocorticoid receptor antagonist (MRA), may have a deleterious effect on glycemia. The objective of this review was to assess current knowledge on MRAs' influence (spironolactone, eplerenone, and canrenone) on glucose homeostasis and the risk of diabetes.

METHOD

A systematic review was conducted using the Medline database on articles published from 1946 to January 2017 that studied the effects of MRAs on any glucose-related endpoints, without any restrictions regarding the participants' characteristics.Study design, patient population, dose and duration of intervention, and the quantitative results on glycemic markers were extracted, interpreted for result synthesis, and evaluated for sources of bias. From the articles included in the qualitative analysis, a select number were used in a meta-analysis on studies having measured glycated hemoglobin (HbA1c) or risk of diabetes.

RESULTS

Seventy-two articles were selected from the Medline database and references of articles. Results on spironolactone were heterogeneous, but seemed to be disease-specific. A potential negative effect on glucose regulation was mainly observed in heart failure and diabetes trials, while a neutral or positive effect was detected in diseases characterized by hyperandrogenism, and inconclusive for hypertension. Interpretation of data from heart failure trials was limited by the small number of studies. From a meta-analysis of 12 randomized controlled studies evaluating spironolactone's impact on HbA1c in diabetic patients, spironolactone had a nonsignificant effect in parallel-group studies (mean difference 0.03 [-0.20;0.26]), but significantly increased HbA1c in crossover studies (mean difference 0.24 [0.18;0.31]). Finally, eplerenone did not seem to influence glycemia, while limited data indicated that canrenone may exert a neutral or beneficial effect.The studies had important limitations regarding study design, sample size, duration of follow-up, and choice of glycemic markers.

CONCLUSION

Spironolactone may induce disease-specific and modest alterations on glycemia. It is uncertain whether these effects are transient or not. Data from the most extensively studied population, individuals with diabetes, do not support a long-term glycemic impact in these patients. Further prospective studies are necessary to establish spironolactone's true biological effects and their clinical implications.

Long-Term Effects of Low-Dose Spironolactone on Chronic Dialysis Patients: A Randomized Placebo-Controlled Study

The purpose of this 2-year multicentric, randomized, placebo-controlled study was to evaluate the long-term effects and adverse effects of spironolactone on chronic dialysis patients. A total of 253 non-heart failure dialysis patients with end-stage renal disease were randomly assigned to 2-year treatment with spironolactone (25 mg once daily, n=125) or a matching placebo (n=128) as add-on therapy. The primary outcome was a composite of death from cardiocerebrovascular (CCV) events, aborted cardiac arrest, and sudden cardiac death, and the secondary outcome was death from all causes. Other CCV-related indexes such as left ventricular mass index, left ventricular ejection fraction, heart rate variability, vascular endothelial function, and blood pressure-lowering effect were analyzed for patients who completed the whole 2-year follow-up study. Sociodemographic, clinical, and relevant laboratory data were also collected. During the 2-year follow-up, the primary outcome occurred less frequently in the spironolactone group vs the control group (7.2% vs 18.0%; adjusted hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.26-0.78). Death from CCV events occurred in 4.0% of patients in the spironolactone group and in 11.7% of patients in the control group. Neither aborted cardiac arrest nor sudden cardiac death was significantly reduced by spironolactone treatment. The secondary outcome occurred less frequently in the spironolactone group vs the control group (9.6% vs 19.5%; adjusted HR, 0.52; 95% CI, 0.29-0.94). Other CCV-related indexes except for heart rate variability were significantly improved. This study demonstrates that use of low-dose spironolactone in non-heart failure dialysis patients can effectively reduce the risks of both CCV morbidity and mortality with few side effects. Moreover, the beneficial effect was mediated through improving the endothelial function or reducing left ventricular size independent of blood pressure changes, rather than mediation through changes in salt or potassium handling in the kidney.

Management of cardiovascular disease in patients with kidney disease

The burden of cardiovascular disease is high in patients with chronic kidney disease or end-stage renal disease. The presence of kidney dysfunction affects the cardiovascular system in multiple ways, including accelerated progression of atherosclerosis and valvular disease, the exacerbation of congestive heart failure, and the development of pericardial disease. This comorbidity results not only from the concordance of shared risk factors, but also from other issues specific to this population, such as systemic inflammation and vascular calcification. Furthermore, both the sensitivity and specificity of noninvasive testing modalities, and the efficacy of several pharmacotherapeutic strategies, are diminished in this population. The exclusion of patients with severe kidney disease from many clinical trials of cardiac interventions raises various therapeutic uncertainties, and kidney disease itself is likely to alter the underlying cardiovascular physiology. In this Review, we discuss aspects of the epidemiology, pathophysiology, and diagnosis of cardiovascular disease in patients with kidney disease, and propose specific, evidence-based recommendations for pharmacological and surgical treatment.

A physiological concept unmasking vascular salt sensitivity in man

About one third of the population worldwide is supposed to be salt sensitive which is a major cause for arterial hypertension later in life. For preventive actions it is thus desirable to identify salt-sensitive individuals before the appearance of clinical symptoms. Recent observations suggest that the vascular endothelium consists of two salt-sensitive barriers in series, the glycocalyx that buffers sodium and the endothelial cell membrane that contains sodium channels. Glycocalyx sodium buffer capacity and sodium channel activity are conversely related to each other. For proof of concept, a so-called salt provocation test (SPT) was developed that should unmask vascular salt sensitivity in humans at virtually any age. Nineteen healthy subjects, ranging from 25 to 63 years of age, underwent two series of 1-h blood pressure measurements after acute ingestion of a salt cocktail with or without addition of a sodium channel blocker effective in vascular endothelium. Differential analysis of the changes in diastolic blood pressure (net ∆DP) identified 12 individuals (63 %) as being salt resistant (net ∆DP = −0.05 ± 0.62 mmHg) and seven individuals (37 %) as being salt sensitive (net ∆DP = +6.98 ± 0.75 mmHg). Vascular salt sensitivity was not related to the age of the study participants. It is concluded that the SPT could be useful for identifying vascular salt sensitivity in humans already early in life.

Safety of mineralocorticoid receptor antagonists in patients receiving hemodialysis

OBJECTIVE

To evaluate the literature supporting the safe use of mineralocorticoid antagonists (MRAs) in patients with end-stage renal disease who are receiving hemodialysis.

DATA SOURCES

A review of the literature was performed using MEDLINE (1950 through week 2 of February 2012) using the key words and MeSH terms mineralocorticoid antagonists, aldosterone antagonists, spironolactone, or eplerenone combined with dialysis, renal disease, or kidney disease.

STUDY SELECTION AND DATA EXTRACTION

Studies eligible for inclusion evaluated the impact of MRAs on serum potassium levels in patients with end-stage renal disease receiving hemodialysis. Data related to the patient populations and outcomes of interest were extracted from each publication.

DATA SYNTHESIS

Ten studies were included in this review (spironolactone, 9; eplerenone, 1) and reported on the impact of MRAs on potassium levels in this population. In aggregate, the studies, with spironolactone doses ranging from 25 mg 3 times/week after dialysis to 300 mg/day and eplerenone doses of 25 mg twice daily, have shown little increases in serum potassium, particularly with the lower doses. The overall incidence of severe hyperkalemia was low. The literature base is limited by significant methodologic weaknesses of the studies, including low patient numbers, short follow-up periods, and lack of a blinded control group.

CONCLUSIONS

The current literature suggests that MRAs may be used safely in patients with end-stage renal disease receiving hemodialysis, although additional large controlled trials are needed before definitive treatment recommendations can be made.

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.

[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.

Spironolactone use in heart failure patients with end-stage renal disease on hemodialysis: is it safe?

BACKGROUND

Spironolactone is used in the treatment of cardiovascular disease, but is contraindicated in renal dysfunction due to the risk of hyperkalemia. It is not known if patients with end-stage renal disease (ESRD) on hemodialysis are at the same risk for hyperkalemia. The objective of this study was to systematically review the evidence evaluating the incidence of hyperkalemia with spironolactone use in ESRD patients on hemodialysis.

HYPOTHESIS

Spironolactone use in ESRD patients on hemodialysis may not lead to greater incidence of hyperkalemia.

METHODS

We searched the MEDLINE, Embase, CINAHL, Cochrane, and PubMed databases up to January 2010 for English-language, human-subject clinical trials that evaluated the rate of hyperkalemia with spironolactone use in ESRD patients on hemodialysis. Search terms included were "spironolactone," "eplerenone," "aldosterone antagonist," "heart failure," "kidney failure," "hemodialysis," "dialysis," and "renal replacement therapy."

RESULTS

Six prospective trials demonstrated that spironolactone use was safe in ESRD patients on hemodialysis. The incidence of hyperkalemia with spironolactone treatment in these studies was similar to control groups. The studies involved a small population of compliant subjects who were at low risk for hyperkalemia.

CONCLUSIONS

Small pilot studies demonstrated that spironolactone treatment in ESRD patients on hemodialysis did not result in higher hyperkalemia rates. Larger studies are needed to confirm these preliminary results before spironolactone is routinely considered in hemodialysis patients.

A randomized, double-blind, placebo-controlled trial of spironolactone on carotid intima-media thickness in nondiabetic hemodialysis patients

BACKGROUND AND OBJECTIVES

Hemodialysis patients (HD) display high rates of cardiac diseases and mortality. In chronic kidney disease, vascular injury leads to coronary artery disease, heart failure, and stroke. Carotid intima-media thickness (CIMT) measurements are currently widely used in randomized controlled trials (RCTs) to study the efficacy of interventions. An RCT was designed for the assessment of the safety and effectiveness of spironolactone to inhibit the progression of CIMT in HD patients as a primary outcome. Secondary outcomes included measurements of plasma potassium.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

HD patients were randomly assigned to receive 50 mg spironolactone or placebo thrice weekly after dialysis. In between dialysis sessions, plasma potassium concentrations were measured every month. Ultrasonographic measurements of CIMT were done at the beginning of the study and after 2 years.

RESULTS

Fifty-three age- and sex-adjusted patients (30 with drug and 23 with placebo) successfully completed the trial. There were no significant differences between the two groups in all profiles studied at baseline. Measurements of CIMT after 2 years showed a progression in the placebo group, whereas in the spironolactone group a significant decrease or even reversed CIMT was observed. Progression rates (mm/yr) were: common carotid, placebo: 0.06 +/- 0.07, spironolactone: 0.01 +/- 0.04; carotid bifurcation, placebo: 0.15 +/- 0.27, spironolactone: 0.0001 +/- 0.01; internal carotid, placebo: 0.10 +/- 0.12, spironolactone: -0.10 +/- 0.15. No episodes of hyperkalemia were observed, but a slight increase in plasma potassium was found in the spironolactone group.

CONCLUSIONS

Fifty milligrams of spironolactone thrice weekly significantly reduced the progression of CIMT in HD patients.

Role of aldosterone in the progression of chronic kidney disease and potential use of aldosterone blockade in children

Much focus has been placed on the role of the renin-angiotensin system as a mediator of the progression of chronic kidney disease. Novel therapeutic strategies to inhibit the negative impact of renin-angiotensin activation, including dual therapy with an angiotensin-converting enzyme inhibitor and an angiotensin-receptor blocker, have been suggested to achieve more complete disruption of the renin-angiotensin system. The role played by aldosterone, a target of angiotensin II, in the progression of chronic kidney disease has become a subject of significant interest over the past decade. Experimental studies in animals have shown that persistently elevated aldosterone levels lead to pathohistological changes in the kidney, along with renal and cardiac fibrosis. Incomplete suppression of aldosterone may, therefore, contribute to the deleterious effects of the renin-angiotensin system in the setting of chronic kidney disease. Clinical trials in adults have shown a potential role for mineralocorticoid receptor blockers to delay further the development of end-stage renal disease by completing renin-angiotensin blockade. In adults, mineralocorticoid receptor blockade produces a significant anti-proteinuric effect and has minimal risk of causing hyperkalemia if the condition of the patients is closely monitored. Further studies will need to be conducted to determine whether mineralocorticoid receptor blockers are equally effective and safe for the treatment of chronic kidney disease in children.

Mineralocorticoid receptor antagonism attenuates cardiac hypertrophy and prevents oxidative stress in uremic rats

Chronic renal failure causes left ventricular hypertrophy, but the molecular mechanisms involved remain unknown. We, therefore, investigated whether the mineralocorticoid receptor is implicated in the cardiac hypertrophy observed in uremic rats and whether mineralocorticoid receptor blockade could be protective in chronic renal failure. Experimental groups were: control rats, uremic rats (NPX) with 5/6 nephrectomy (5 weeks), and NPX rats fed with spironolactone for 5 weeks. Systolic blood pressure was increased in both NPX rats and NPX rats fed with spironolactone for 5 weeks. Echocardiography revealed concentric left ventricular hypertrophy in uremia, which was attenuated by spironolactone. Enlarged cardiomyocyte size was observed in both left and right ventricles of NPX rats, an effect that was prevented by spironolactone. Mineralocorticoid receptor antagonism attenuated the increase of ventricular brain natriuretic peptide mRNA levels induced by nephrectomy. Left ventricular gene expressions of aldosterone synthase, mineralocorticoid receptor, and hydroxysteroid dehydrogenase type 2 were the same in the 3 groups, whereas gene expression of the glucocorticoid receptor was significantly diminished in chronic renal failure rats. No significant differences in cardiac aldosterone were observed between control rats and NPX rats, although NPX rats fed with spironolactone for 5 weeks showed increased plasma aldosterone levels. However, a significant increase in serum and glucocorticoid-inducible kinase-1 mRNA expression and protein was present in the NPX group; spironolactone treatment significantly reduced serum and glucocorticoid-inducible kinase-1 mRNA and protein in the left ventricle. Uremic rats exhibited a significant increase of superoxide production and reduced nicotinamide-adenine dinucleotide phosphate oxidase subunits expression (NOX-2, NOX-4, and p47(phox)) in the left ventricle, which was prevented by the mineralocorticoid receptor antagonist. Our findings provide evidence of the beneficial effects of spironolactone in cardiac hypertrophy and cardiac oxidative stress in chronic renal failure.

Role of aldosterone in left ventricular hypertrophy among African-American patients with end-stage renal disease on hemodialysis

AIMS

Recently, serum aldosterone levels have been reported to play a significant role in cardiac hypertrophy. One study of Japanese patients correlated aldosterone levels with the degree of left ventricular hypertrophy (LVH) in those undergoing hemodialysis. However, the role of aldosterone in LVH in non-Japanese patients with end-stage renal disease (ESRD) has not been established.

MATERIALS AND METHODS

Researchers evaluated 42 [29 African-Americans (69%), 11 Caucasians (26%), and 2 other (5%)] male ESRD patients on dialysis for more than 6 months. Pre- and postdialysis, blood pressures and aldosterone and renin concentrations were measured. Transthoracic echocardiography was performed and left ventricular mass (LVM) index was calculated using the Devereaux formula. Medications were reviewed.

RESULTS

There were no differences noted in medications prescribed for African-Americans and for Caucasians. Additionally, data from diabetic patients showed no statistically significant correlation between LVM index and any of the variables, including pre- and postdialysis blood pressure, serum potassium, renin, and aldosterone levels, for African-Americans compared to Caucasians. Data from nondiabetic patients showed a positive correlation between LVM and plasma aldosterone concentration in African-Americans (n = 10). Data from nondiabetic Caucasians were disregarded because only one was studied.

CONCLUSION

LVM and aldosterone correlate in African-American males with ESRD on hemodialysis without diabetes. This has important implications for the etiology of, and therapy for LVH in this population. Larger studies are needed to determine whether the same associations exist in females and Caucasians.

Effect of spironolactone on blood pressure and the renin-angiotensin-aldosterone system in oligo-anuric hemodialysis patients

BACKGROUND

Through its actions on nonepithelial tissues, including brain, blood vessels, and heart, aldosterone may mediate hypertension, cardiac hypertrophy, and fibrosis. Whether aldosterone has a direct pathogenic role in the development of cardiovascular complications in patients with end-stage renal disease is unknown. Oligo-anuric dialysis patients provide a clinical setting to study the effects of the mineralocorticoid receptor blocker spironolactone that are independent of the diuretic properties of the drug. We performed a randomized, double-blinded, placebo-controlled, crossover study to assess the effect of spironolactone on blood pressure and the renin-angiotensin-aldosterone system in oligo-anuric hemodialysis patients.

METHODS

Eight hemodialysis patients were administered either spironolactone, 50 mg, or placebo orally twice daily for 2 weeks, followed by a 3-week washout period, after which patients crossed over in their treatment arms for 2 more weeks.

RESULTS

Administration of spironolactone for 2 weeks decreased predialysis systolic blood pressure from 142.0 +/- 19.6 to 131.4 +/- 18.2 mm Hg (P < 0.05). Compared with placebo, a 2-week course of spironolactone had no effect on predialysis and postdialysis plasma potassium or aldosterone concentrations or renin activity.

CONCLUSION

When administered for 2 weeks, spironolactone, 50 mg twice daily, reduced predialysis systolic blood pressure, but did not produce hyperkalemia in oligo-anuric hemodialysis patients.