Randomised controlled trial of enalapril and beta blockers in non-diabetic chronic renal failure

Association between Acute Declines in eGFR during Renin-Angiotensin System Inhibition and Risk of Adverse Outcomes

Key Points

Renin-angiotensin system inhibition was favorable for risk of kidney failure (compared with 0% decline with use of placebo or other agents) up to declines in eGFR of 13% over a 3-month period. Relation between eGFR decline after renin-angiotensin system inhibitor initiation and risk of outcomes was stronger in the first 2 years of follow-up and waned over time.

Background

Declines in GFR occur commonly when renin-angiotensin system (RAS) inhibitors are started. Our objective was to determine the relation between declines in eGFR during trials of RAS inhibition and kidney outcomes.

Methods

We included participants with CKD (eGFR <60 ml/min per 1.73 m2) from 17 trials of RAS inhibition. The exposure was subacute declines in eGFR expressed as % change between randomization and month 3, and in the subset of trials with data available, we also examined % change in eGFR between randomization and month 1. The primary outcome was kidney failure with replacement therapy. Cox proportional hazards models were used to examine the association between subacute declines in eGFR and risk of kidney failure. We used spline models to identify the threshold of change in eGFR below which RAS inhibition was favorable (conservatively comparing a given decline in eGFR with RAS inhibition to no decline in the comparator).

Results

A total of 11,800 individuals with mean eGFR 43 (SD 11) ml/min per 1.73 m2 and median urine albumin-to-creatinine ratio of 362 mg/g (interquartile range, 50–1367) were included, and 1162 (10%) developed kidney failure. The threshold of decline in eGFR that favored the use of RAS inhibitors for kidney failure was estimated to be up to 13% (95% confidence interval, 8% to 17%) over a 3-month interval and up to 21% (95% confidence interval, 15% to 27%) over a 1-month interval after starting RAS inhibitors.

Conclusions

In patients treated with RAS inhibitors, ≤13% decline in eGFR over a 3-month period or ≤21% decline over a 1-month period was associated with lower risk of kidney failure compared with no decline in those assigned to placebo or other agents.

Clinical Outcomes of Renin-Angiotensin-Aldosterone Blockade in Patients With Advanced Chronic Kidney Disease: A Systematic Review and Meta-analysis

BACKGROUND

The cardiovascular and renal benefits of renin-angiotensin aldosterone system (RAAS) blockade are not well established in patients with advanced chronic kidney disease (CKD). We conducted a systematic review and meta-analysis to identify potential risks and benefits from RAAS blockade in patients with CKD stage 4-5.

METHODS

A Medline search from inception to November 2022 was conducted to identify randomised controlled trials (RCTs) in patients with CKD stage 4-5 (estimated glomerular filtration rate ≤ 30 mL/min/1.73 m2) comparing RAAS blockade vs placebo or alternative antihypertensive therapy. Different intervention strategies were assessed (RAAS use vs nonuse, initiation vs placebo/alternative therapy, or discontinuation vs continuation). The primary outcome was progression to end-stage kidney disease (ESKD). Secondary outcomes were all-cause mortality and major adverse cardiovascular events (MACE). The risk ratio (RR) was estimated with the use of a random-effects model.

RESULTS

Nine RCTs (1150 patients) were included. RAAS blockade was associated with a significant reduction in progression to ESKD: RR 0.84 (95% confidence interval [CI] 0.74-0.96; P = 0.01). There was no benefit from RAAS blockade on all-cause mortality or MACE: RR 1.02 (95% CI 0.63-1.65; P = 0.93) and RR 0.87 (95% CI 0.49-1.57; P = 0.65), respectively.

CONCLUSIONS

RAAS blockade may be considered in selected patients with CKD stage 4-5 to delay progression to ESKD.

Angiotensin-Converting Enzyme Inhibitors or Angiotensin-Receptor Blockers for Advanced Chronic Kidney Disease : A Systematic Review and Retrospective Individual Participant-Level Meta-analysis of Clinical Trials

BACKGROUND

In patients with advanced chronic kidney disease (CKD), the effects of initiating treatment with an angiotensin-converting enzyme inhibitor (ACEi) or angiotensin-receptor blocker (ARB) on the risk for kidney failure with replacement therapy (KFRT) and death remain unclear.

PURPOSE

To examine the association of ACEi or ARB treatment initiation, relative to a non-ACEi or ARB comparator, with rates of KFRT and death.

DATA SOURCES

Ovid Medline and the Chronic Kidney Disease Epidemiology Collaboration Clinical Trials Consortium from 1946 through 31 December 2023.

STUDY SELECTION

Completed randomized controlled trials testing either an ACEi or an ARB versus a comparator (placebo or antihypertensive drugs other than ACEi or ARB) that included patients with a baseline estimated glomerular filtration rate (eGFR) below 30 mL/min/1.73 m2.

DATA EXTRACTION

The primary outcome was KFRT, and the secondary outcome was death before KFRT. Analyses were done using Cox proportional hazards models according to the intention-to-treat principle. Prespecified subgroup analyses were done according to baseline age (<65 vs. ≥65 years), eGFR (<20 vs. ≥20 mL/min/1.73 m2), albuminuria (urine albumin-creatinine ratio <300 vs. ≥300 mg/g), and history of diabetes.

DATA SYNTHESIS

A total of 1739 participants from 18 trials were included, with a mean age of 54.9 years and mean eGFR of 22.2 mL/min/1.73 m2, of whom 624 (35.9%) developed KFRT and 133 (7.6%) died during a median follow-up of 34 months (IQR, 19 to 40 months). Overall, ACEi or ARB treatment initiation led to lower risk for KFRT (adjusted hazard ratio, 0.66 [95% CI, 0.55 to 0.79]) but not death (hazard ratio, 0.86 [CI, 0.58 to 1.28]). There was no statistically significant interaction between ACEi or ARB treatment and age, eGFR, albuminuria, or diabetes (P for interaction > 0.05 for all).

LIMITATION

Individual participant-level data for hyperkalemia or acute kidney injury were not available.

CONCLUSION

Initiation of ACEi or ARB therapy protects against KFRT, but not death, in people with advanced CKD.

PRIMARY FUNDING SOURCE

National Institutes of Health. (PROSPERO: CRD42022307589).

Adapting Clinical Practice Guidelines for Chronic Kidney Disease: Blood Pressure Management and Kidney Replacement Therapy in Adults and Children in the Saudi Arabian Context Using the Grading of Recommendations Assessment, Development, and Evaluation-ADOLOPMENT Methodology

This practice guideline was developed by the chronic kidney disease (CKD) Task Force, which was composed of clinical and methodological experts. The Saudi Arabian Ministry of Health and its health holding company commissioned this guideline project to support the realization of Vision 2030's health-care transformation pillar. The synthesis of these guidelines was guided by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE)- ADOLOPMENT methodology. The final guidelines addressed 12 clinical questions on the management of blood pressure in patients with CKD through a set of recommen-dations and performance measures. The recom-mendations included antihypertensive agents in children; renin- angiotensin system inhibition (RASi) versus non-RASi in adults; intensive versus standard blood pressure targets; early versus late assessment for kidney replacement therapy (KRT); late versus early preparation strategies for KRT; CKD symptoms during assessment for KRT or conservative manage-ment; initiation of KRT in patients with deteriorating CKD; choice of KRT modality or conservative management in certain CKD patient groups; changing or discontinuing KRT modalities; the frequency of reviews for KRT or conservative management; and information, education, and support. These conditional recommendations were based on a low to very low certainty of evidence, which highlights the need for high-quality randomized trials com-paring different antihypertensive agents in patients with CKD.

Role of hypertension in progression of pediatric CKD

Hypertension is frequent in children with chronic kidney disease (CKD). Its prevalence varies according to CKD stage and cause. It is relatively uncommon in children with congenital kidney disease, while acquired kidney disease is associated with a higher prevalence of hypertension. Studies in children with CKD utilizing ambulatory blood pressure monitoring also showed a high prevalence of masked hypertension. Uncontrolled and longstanding hypertension in children is associated with progression of CKD. Aggressive treatment of high blood pressure should be an essential part of care to delay CKD progression in children.

Heart Failure in Patients with Chronic Kidney Disease

The function of the kidney is tightly linked to the function of the heart. Dysfunction/disease of the kidney may initiate, accentuate, or precipitate of the cardiac dysfunction/disease and vice versa, contributing to a negative spiral. Further, the reciprocal association between the heart and the kidney may occur on top of other entities, usually diabetes, hypertension, and atherosclerosis, simultaneously affecting the two organs. Chronic kidney disease (CKD) can influence cardiac function through altered hemodynamics and salt and water retention, leading to venous congestion and therefore, not surprisingly, to heart failure (HF). Management of HF in CKD is challenging due to several factors, including complex interplays between these two conditions, the effect of kidney dysfunction on the metabolism of HF medications, the effect of HF medications on kidney function, and the high risk for anemia and hyperkalemia. As a result, in most HF trials, patients with severe renal impairment (i.e., eGFR 30 mL/min/1.73 m2 or less) are excluded. The present review discusses the epidemiology, pathophysiology, and current medical management in patients with HF developing in the context of CKD.

Effectiveness of nonsteroidal mineralocorticoid receptor antagonists in patients with diabetic kidney disease

Nonsteroidal mineralocorticoid receptor antagonists (MRAs) are a new class of drugs developed to address the medical need for effective and safer treatment to protect the kidney and the heart in patients with diabetic kidney disease (DKD). There are several drugs within this class at varying stages of clinical development. Finerenone is the first nonsteroidal MRA approved in the US for treating patients with chronic kidney disease (CKD) associated with type 2 diabetes (T2D). In clinical studies, finerenone slowed CKD progression without inducing marked antihypertensive effects. Esaxerenone is a nonsteroidal MRA with proven blood pressure-lowering efficacy that is currently licensed in Japan for treating hypertension. There are also three other nonsteroidal MRAs in mid-to-late stages of clinical development. Here we overview evidence addressing pharmacological and clinical differences between the nonsteroidal MRAs and the steroidal MRAs spironolactone and eplerenone. First, we describe a framework that highlights the role of aldosterone-mediated pathological overactivation of the mineralocorticoid receptor and inflammation as important drivers of CKD progression. Second, we discuss the benefits and adverse events profile of steroidal MRAs, the latter of which are often a limiting factor to their use in routine clinical practice. Finally, we show that nonsteroidal MRAs differ from steroidal MRAs based on pharmacology and clinical effects, giving the potential to expand the therapeutic options for patients with DKD. In the recently completed DKD outcome program comprising two randomized clinical trials - FIDELIO-DKD and FIGARO-DKD - and the FIDELITY analysis of both trials evaluating more than 13,000 patients, the nonsteroidal MRA finerenone demonstrated beneficial effects on the kidney and the heart across a broad spectrum of patients with CKD and T2D. The long-term efficacy of finerenone on cardiac and renal morbidity and mortality endpoints, along with the anti-hypertensive efficacy of esaxerenone, widens the scope of available therapies for patients with DKD.

Randomized Controlled Trials on Renin Angiotensin Aldosterone System Inhibitors in Chronic Kidney Disease Stages 3-5: Are They Robust? A Fragility Index Analysis

Inhibition of the renin-angiotensin-aldosterone system (RAAS) is broadly recommended in many nephrological guidelines to prevent chronic kidney disease (CKD) progression. This work aimed to analyze the robustness of randomized controlled trials (RCTs) investigating the renal and cardiovascular outcomes in CKD stages 3-5 patients treated with RAAS inhibitors (RAASi). We searched for RCTs in MEDLINE (PubMed), EMBASE databases, and the Cochrane register. Fragility indexes (FIs) for every primary and secondary outcome were calculated according to Walsh et al., who first described this novel metric, suggesting 8 as the cut-off to consider a study robust. Spearman coefficient was calculated to correlate FI to p value and sample size of statistically significant primary and secondary outcomes. Twenty-two studies met the inclusion criteria, including 80,455 patients. Sample size considerably varied among the studies (median: 1693.5, range: 73-17,276). The median follow-up was 38 months (range 24-58). The overall median of both primary and secondary outcomes was 0 (range 0-117 and range 0-55, respectively). The median of FI for primary and secondary outcomes with a p value lower than 0.05 was 6 (range: 1-117) and 7.5 (range: 1-55), respectively. The medians of the FI for primary outcomes with a p value lower than 0.05 in CKD and no CKD patients were 5.5 (range 1-117) and 22 (range 1-80), respectively. Only a few RCTs have been shown to be robust. Our analysis underlined the need for further research with appropriate sample sizes and study design to explore the real potentialities of RAASi in the progression of CKD.

Diagnosis 101: diabetic kidney disease

Chronic kidney disease (CKD) attributed to diabetes occurs in 20%-40% of patients with diabetes mellitus. Diabetic kidney disease (DKD) is recognized as the most common cause of end-stage kidney disease in the USA and most Western countries. For quite some time, it has been recognized that treatments based on inhibition of the renin-angiotensin system (RAS) can reduce the rates of cardiovascular morbidity and mortality in patients with DKD. Recently however, several novel agents, namely sodium-glucose co-transporter 2 inhibitors, dipeptidyl peptidase 4 inhibitors and glucagon-like peptide-1 receptor agonists, were demonstrated to not only improve glycemic control but also to improve cardiovascular and renal outcomes. Another agent, a nonsteroidal mineralocorticoid antagonist, has also been shown to have cardiorenal benefits in patients with DKD. With such new developments, one would expect that it would eventually translate into further slowing CKD progression in the DKD population, provided that patients are diagnosed appropriately and in a timely manner. In this study, the authors attempt to investigate real-world data, looking at how well providers are establishing the diagnosis of DKD and its potential implications.

Serum Protein Exposure Activates a Core Regulatory Program Driving Human Proximal Tubule Injury

BACKGROUND

The kidneys efficiently filter waste products while retaining serum proteins in the circulation. However, numerous diseases compromise this barrier function, resulting in spillage of serum proteins into the urine (proteinuria). Some studies of glomerular filtration suggest that tubules may be physiologically exposed to nephrotic-range protein levels. Therefore, whether serum components can directly injure the downstream tubular portions of the kidney, which in turn can lead to inflammation and fibrosis, remains controversial.

METHODS

We tested the effects of serum protein exposure in human kidney tubule microphysiologic systems and with orthogonal epigenomic approaches since animal models cannot directly assess the effect of serum components on tubules.

RESULTS

Serum, but not its major protein component albumin, induced tubular injury and secretion of proinflammatory cytokines. Epigenomic comparison of serum-injured tubules and intact kidney tissue revealed canonical stress-inducible regulation of injury-induced genes. Concordant transcriptional changes in microdissected tubulointerstitium were also observed in an independent cohort of patients with proteinuric kidney disease.

CONCLUSIONS

Our results demonstrate a causal role for serum proteins in tubular injury and identify regulatory mechanisms and novel pathways for intervention.

Acute Treatment Effects on GFR in Randomized Clinical Trials of Kidney Disease Progression

BACKGROUND

Acute changes in GFR can occur after initiation of interventions targeting progression of CKD. These acute changes complicate the interpretation of long-term treatment effects.

METHODS

To assess the magnitude and consistency of acute effects in randomized clinical trials and explore factors that might affect them, we performed a meta-analysis of 53 randomized clinical trials for CKD progression, enrolling 56,413 participants with at least one estimated GFR measurement by 6 months after randomization. We defined acute treatment effects as the mean difference in GFR slope from baseline to 3 months between randomized groups. We performed univariable and multivariable metaregression to assess the effect of intervention type, disease state, baseline GFR, and albuminuria on the magnitude of acute effects.

RESULTS

The mean acute effect across all studies was -0.21 ml/min per 1.73 m2 (95% confidence interval, -0.63 to 0.22) over 3 months, with substantial heterogeneity across interventions (95% coverage interval across studies, -2.50 to +2.08 ml/min per 1.73 m2). We observed negative average acute effects in renin angiotensin system blockade, BP lowering, and sodium-glucose cotransporter 2 inhibitor trials, and positive acute effects in trials of immunosuppressive agents. Larger negative acute effects were observed in trials with a higher mean baseline GFR.

CONCLUSION

The magnitude and consistency of acute GFR effects vary across different interventions, and are larger at higher baseline GFR. Understanding the nature and magnitude of acute effects can help inform the optimal design of randomized clinical trials evaluating disease progression in CKD.

Mineralocorticoid receptor antagonists in diabetic kidney disease - mechanistic and therapeutic effects

Chronic kidney disease (CKD) is the leading complication in type 2 diabetes (T2D) and current therapies that limit CKD progression and the development of cardiovascular disease (CVD) include angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and sodium-glucose co-transporter 2 (SGLT2) inhibitors. Despite the introduction of these therapeutics, an important residual risk of CKD progression and cardiovascular death remains in patients with T2D. Mineralocorticoid receptor antagonists (MRAs) are a promising therapeutic option in diabetic kidney disease (DKD) owing to the reported effects of mineralocorticoid receptor activation in inflammatory cells, podocytes, fibroblasts, mesangial cells and vascular cells. In preclinical studies, MRAs consistently reduce albuminuria, CKD progression, and activation of fibrotic and inflammatory pathways. DKD clinical studies have similarly demonstrated that steroidal MRAs lead to albuminuria reduction compared with placebo, although hyperkalaemia is a major secondary effect. Non-steroidal MRAs carry a lower risk of hyperkalaemia than steroidal MRAs, and the large FIDELIO-DKD clinical trial showed that the non-steroidal MRA finerenone also slowed CKD progression and reduced the risk of adverse cardiovascular outcomes compared with placebo in patients with T2D. Encouragingly, other non-steroidal MRAs have anti-albuminuric properties in DKD. Whether or not combining MRAs with other renoprotective drugs such as SGLT2 inhibitors might provide additive protective effects warrants further investigation.

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.

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.

Management of Hypertension in Chronic Kidney Disease

Chronic kidney disease (CKD) is an increasingly prevalent condition globally and is strongly associated with incident cardiovascular disease (CVD). Hypertension is both a cause and effect of CKD and affects the vast majority of CKD patients. Control of hypertension is important in those with CKD as it leads to slowing of disease progression as well as reduced CVD risk. Existing guidelines do not offer a consensus on optimal blood pressure (BP) targets. Therefore, an understanding of the evidence used to create these guidelines is vital when considering how best to manage individual patients. Non-pharmacological interventions are useful in reducing BP in CKD but are rarely sufficient to control BP adequately. Patients with CKD and hypertension will often require a combination of antihypertensive medications to achieve target BP. Certain pharmacological therapies provide additional BP-independent renoprotective and/or cardioprotective action and this must be considered when instituting therapy. Managing hypertension in the context of haemodialysis and following kidney transplantation presents further challenges. Novel therapies may enhance treatment in the near future. Importantly, a personalised and evidence-based management plan remains key to achieving BP targets, reducing CVD risk and slowing progression of CKD.

Renin-angiotensin system inhibitors in hypertensive adults with non-diabetic CKD with or without proteinuria: a systematic review and meta-analysis of randomized trials

The efficacy and safety of renin-angiotensin system inhibitors (RAS-I) in hypertensive adults with non-diabetic chronic kidney disease (CKD) differ depending on the presence or the absence of proteinuria. To estimate the effects of RAS-I in this population, we performed a systematic review and meta-analysis of randomized controlled trials where treatment with angiotensin-converting-enzyme inhibitors or angiotensin II receptor blockers were compared with placebo or active controls in adults with non-diabetic CKD. The treatment effects were separately reviewed in patients with and without proteinuria. Based on a search of Medline and the Cochrane Library up to September 2017, we identified 42 eligible trials (28, proteinuria-positive group; 6, proteinuria-negative group; 2, mixed-proteinuria group; and 6, proteinuria data-unavailable group). RAS-I reduced renal failure events in comparison to placebo or active agents in the proteinuria-positive group (relative risk [RR] 0.63, 95% confidence interval [CI] 0.52-0.75), but showed no significant effects on renal failure risk in the proteinuria-negative group (RR 0.64, 95% CI 0.18-2.30) although it reduced microalbuminuria. For cardiovascular events, RAS-I was not associated with a significantly reduced risk in both the proteinuria-positive and proteinuria-negative group (RR 0.77 and 1.06, 95% CI 0.51-1.16 and 0.85-1.32, respectively). In the mixed-proteinuria group and proteinuria data-unavailable group, RAS-I showed no significant effects on renal and cardiovascular events. Among adverse events, hyperkalemia increased with RAS-I administration in the proteinuria-positive group (RR 2.01, 95% CI 1.07-3.77). Our analysis showed the renoprotective effects of RAS-I treatment in patients with non-diabetic CKD having proteinuria, supporting its use as the first-line antihypertensive therapy in this population.

Angiotensin-converting enzyme inhibitors or angiotensin receptor blocker monotherapy retard deterioration of renal function in Taiwanese chronic kidney disease population

It remains unclear how different uses of angiotensin-converting inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) influence the progression of chronic kidney disease (CKD). This study explored CKD progression in a multicentre, longitudinal cohort study that included 2639 patients with CKD stage 1–5 and hypertension. Patients treated with ACEI or ARB for ≥90 days during a 6-mo period comprised the study group, or no treatment, comprised the control group. The study group was subdivided on the basis of treatment: ACEI monotherapy or ARB monotherapy. Progression of renal deterioration was defined by an average eGFR decline of more than 5 mL/min/1.73 m²/yr or the commencement of dialysis. With at least 1-year follow up, a progression of renal deterioration was demonstrated in 29.70% of the control group and 25.09% of the study group. Patients in the study group had significantly reduced progression of CKD with adjusted odds ratio 0.79 (95% confidence interval: 0.63–0.99). However, when ACEI monotherapy and ARB monotherapy were analyzed separately, none of their associations with CKD progression was statistically significant. In conclusion, ACEI or ARB monotherapy may retard the deterioration of renal function among patients with CKD and hypertension.

Longitudinal association of carotid endothelial shear stress with renal function decline in aging adults with normal renal function: A population-based cohort study

The aim of this study was to investigate the associations between carotid wall shear stress (WSS) and renal function impairment (RFI) and albuminuria in aging adults. A total of 1,447 subjects aged 60 years and older with normal estimated glomerular filtration rate (eGFR ≥ 60 mL·min-1·1.72 m-2) and albumin/creatinine ratio (ACR < 30 mg·g-1) were enrolled between April 2007 and October 2009 in the Shandong area, China. Carotid WSS was assessed at baseline, and eGFR, which is based on serum creatinine and cystatin C, and ACR were assessed at baseline and at the annual follow-up visits. After an average of 62.9 months of follow-up, the reduction in eGFR and the increase in ACR were significantly higher in the Q1+2+3 group than the Q4 group, as classified by either the interquartile of the mean WSS or the interquartile of the peak WSS after adjustment for multi-variabilities, including the average blood pressures at every annual visit and baseline eGFR and ACR. For groups classified by mean WSS, the hazard ratios (95% confidence intervals) were 3.45 (1.36-8.75, p = 0.008) in the incident RFI and 3.24 3.22 (1.37-7.57, p = 0.009) in the incident albuminuria for the Q1+2+3 group compared with the Q4 group. Similar results were observed among groups classified by peak WSS. The Q1+2+3 group was associated with endothelial dysfunction and inflammation with respect to the Q4 group as classified by mean or peak WSS. The results indicate that carotid WSS plays an important role in RFI and albuminuria progression in aging adults. Lower WSS was associated with a higher risk of RFI and albuminuria compared with higher WSS.

Change in Proteinuria or Albuminuria as a Surrogate for Cardiovascular and Other Major Clinical Outcomes: A Systematic Review and Meta-analysis

BACKGROUND

There is ongoing controversy around the surrogacy of proteinuria or albuminuria, particularly for cardiovascular (CV) outcomes, which remain the leading cause of morbidity and mortality among patients with chronic kidney disease. We performed a systematic review and meta-analysis of the literature to assess the surrogacy of changing proteinuria or albuminuria for CV events, end-stage renal disease (ESRD), and all-cause mortality.

METHODS

CENTRAL, EMBASE, and MEDLINE were searched (from inception to October 2017). All randomized controlled trials in adults that reported change in proteinuria or albuminuria and ≥ 10 CV, ESRD, or all-cause mortality events were included. We calculated treatment effect ratios (TERs), defined as the ratio of the treatment effect on a clinical outcome and the effect on the change in the surrogate outcome. TERs close to 1 indicate greater agreement between the clinical outcome and changing proteinuria or albuminuria.

RESULTS

Thirty-six trials were included in the meta-analysis. We observed inconsistent treatment effects for proteinuria and CV events (20 trials; TER 1.11 [95% confidence interval (CI), 1.01-1.22]) with moderate heterogeneity (I² = 51%, P = 0.005). Treatment effects on proteinuria or albuminuria were also inconsistent with the effects on all-cause mortality (21 trials; TER 1.17 [95% CI, 1.07-1.28]; I² = 35%, P for heterogeneity = 0.06), although they were similar with the effects on ESRD (23 trials; TER 0.99 [95% CI, 0.88-1.13]; I² = 9%, P for heterogeneity = 0.337).

CONCLUSIONS

Change in proteinuria or albuminuria might be a suitable surrogate outcome for ESRD. However, overall treatment effects on these potential surrogates are inconsistent and overestimate the treatment effects on CV events and all-cause mortality.

Deleting Death and Dialysis: Conservative Care of Cardio-Vascular Risk and Kidney Function Loss in Chronic Kidney Disease (CKD)

The uremic syndrome, which is the clinical expression of chronic kidney disease (CKD), is a complex amalgam of accelerated aging and organ dysfunctions, whereby cardio-vascular disease plays a capital role. In this narrative review, we offer a summary of the current conservative (medical) treatment options for cardio-vascular and overall morbidity and mortality risk in CKD. Since the progression of CKD is also associated with a higher cardio-vascular risk, we summarize the interventions that may prevent the progression of CKD as well. We pay attention to established therapies, as well as to novel promising options. Approaches that have been considered are not limited to pharmacological approaches but take into account lifestyle measures and diet as well. We took as many randomized controlled hard endpoint outcome trials as possible into account, although observational studies and post hoc analyses were included where appropriate. We also considered health economic aspects. Based on this information, we constructed comprehensive tables summarizing the available therapeutic options and the number and kind of studies (controlled or not, contradictory outcomes or not) with regard to each approach. Our review underscores the scarcity of well-designed large controlled trials in CKD. Nevertheless, based on the controlled and observational data, a therapeutic algorithm can be developed for this complex and multifactorial condition. It is likely that interventions should be aimed at targeting several modifiable factors simultaneously.

Pathophysiological Mechanisms and Correlates of Therapeutic Pharmacological Interventions in Essential Arterial Hypertension

Treating arterial hypertension (HT) remains a hard task. The hypertensive patient is often a subject with several comorbidities and metabolic abnormalities. Clinicians everyday have to choose the right drug for the single patient among the different classes of antihypertensives. Apart from lowering blood pressure, a main therapeutic target should be that of counteracting all the possible pathophysiological mechanisms involved in HT itself and in existing/potential comorbidities. All the ancillary positive and negative effects of the administered drugs should be considered: in particular, since hypertensive patients are often glucose intolerant/diabetic, carrier of serum lipids disorder, have already developed atherosclerotic diseases and endothelial dysfunction, they should not be treated with drugs negatively interfering with these conditions but with molecules that, if possible, improve them. The main pathophysiological mechanisms and correlates of therapeutic pharmacological interventions in essential HT are reviewed here.

Renin-Angiotensin System Inhibitors and Kidney and Cardiovascular Outcomes in Patients With CKD: A Bayesian Network Meta-analysis of Randomized Clinical Trials

BACKGROUND

There is much uncertainty regarding the relative effects of angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) in populations with chronic kidney disease (CKD).

STUDY DESIGN

Systematic review and Bayesian network meta-analysis.

SETTING & POPULATION

Patients with CKD treated with renin-angiotensin system (RAS) inhibitors.

SELECTION CRITERIA FOR STUDIES

Randomized trials in patients with CKD treated with RAS inhibitors.

PREDICTOR

ACE inhibitors and ARBs compared to each other and to placebo and active controls.

OUTCOME

Primary outcome was kidney failure; secondary outcomes were major cardiovascular events, all-cause death.

RESULTS

119 randomized controlled trials (n = 64,768) were included. ACE inhibitors and ARBs reduced the odds of kidney failure by 39% and 30% (ORs of 0.61 [95% credible interval, 0.47-0.79] and 0.70 [95% credible interval, 0.52-0.89]), respectively, compared to placebo, and by 35% and 25% (ORs of 0.65 [95% credible interval, 0.51-0.80] and 0.75 [95% credible interval, 0.54-0.97]), respectively, compared with other active controls, whereas other active controls did not show evidence of a significant effect on kidney failure. Both ACE inhibitors and ARBs produced odds reductions for major cardiovascular events (ORs of 0.82 [95% credible interval, 0.71-0.92] and 0.76 [95% credible interval, 0.62-0.89], respectively) versus placebo. Comparisons did not show significant effects on risk for cardiovascular death. ACE inhibitors but not ARBs significantly reduced the odds of all-cause death versus active controls (OR, 0.72; 95% credible interval, 0.53-0.92). Compared with ARBs, ACE inhibitors were consistently associated with higher probabilities of reducing kidney failure, cardiovascular death, or all-cause death.

LIMITATIONS

Trials with RAS inhibitor therapy were included; trials with direct comparisons of other active controls with placebo were not included.

CONCLUSIONS

Use of ACE inhibitors or ARBs in people with CKD reduces the risk for kidney failure and cardiovascular events. ACE inhibitors also reduced the risk for all-cause mortality and were possibly superior to ARBs for kidney failure, cardiovascular death, and all-cause mortality in patients with CKD, suggesting that they could be the first choice for treatment in this population.

Assessing the Validity of Surrogate Outcomes for ESRD: A Meta-Analysis

Validation of current and promising surrogate outcomes for ESRD in randomized controlled trials (RCTs) has been limited. We conducted a systematic review and meta-analysis of RCTs to further inform the ability of surrogate outcomes for ESRD to predict the efficacy of various interventions on ESRD. MEDLINE, EMBASE, and CENTRAL (from inception through September 2013) were searched. All RCTs in adults with proteinuria, diabetes, or CKD stages 1-4 or renal transplant recipients reporting ≥10 ESRD events and a surrogate outcome (change in proteinuria or doubling of serum creatinine [DSCR]) for ESRD during a ≥1-year follow-up were included. Two reviewers abstracted trial characteristics and outcome data independently. To assess the correlation between the surrogate outcomes and ESRD, we determined the treatment effect ratio (TER), defined as the ratio of the treatment effects on ESRD and the effects on the change in surrogate outcomes. TERs close to 1 indicate greater agreement between ESRD and the surrogate, and these ratios were pooled across interventions. We identified 27 trials (97,458 participants; 4187 participants with ESRD). Seven trials reported the effects on change in proteinuria and showed consistent effects for proteinuria and ESRD (TER, 0.82; 95% confidence interval, 0.59 to 1.16), with minimal heterogeneity. Twenty trials reported on DSCR. Treatment effects on DSCR were consistent with the effects on ESRD (TER, 0.98; 95% confidence interval, 0.85 to 1.14), with moderate heterogeneity. In conclusion, DSCR is generally a good surrogate for ESRD, whereas data on proteinuria were limited. Further assessment of the surrogacy of proteinuria using prospective RCTs is warranted.

GFR decline as an alternative end point to kidney failure in clinical trials: a meta-analysis of treatment effects from 37 randomized trials

BACKGROUND

There is increased interest in using alternative end points for trials of kidney disease progression. The currently established end points of end-stage renal disease and doubling of serum creatinine level, equivalent to a 57% decline in estimated glomerular filtration rate (eGFR), are late events in chronic kidney disease (CKD), requiring large clinical trials with long follow-up. As part of a comprehensive evaluation of lesser declines in eGFR as alternative end points, we describe the consistency of treatment effects of intervention on the alternative and established end points in past trials.

STUDY DESIGN

Diagnostic test study.

SETTING & POPULATION

9,488 participants from 37 randomized controlled trials of CKD progression across 5 intervention types.

INDEX TEST

Alternative end points including percentage change in eGFR from baseline (20%, 30%, 40%, and 57%) throughout study duration and to 12, 18, and 24 months. eGFR change confirmed versus nonconfirmed at the next visit.

REFERENCE TEST

The historically established end point of time to composite of treated kidney failure (end-stage renal disease), untreated kidney failure (GFR<15mL/min/1.73m(2)), or doubling of serum creatinine level throughout study duration.

RESULTS

Over a median of 3.62 years' follow-up, there were 3,070 established end points. Compared to the established end point, the number of alternative end points was greater for smaller versus larger declines in eGFR and longer versus shorter follow-up intervals. There was a general trend toward attenuation of the treatment effect with end points defined by a lesser eGFR decline, with greater attenuation with nonconfirmed end points, except for the low-protein-diet intervention, for which a stronger treatment effect was observed. The ratio (95% credible interval) of the HR for the alternative to established end point for the 5 intervention types ranged from 0.91 (0.64-1.43) to 1.12 (0.89-1.40) for 40% decline and from 0.88 (0.63-1.39) to 1.15 (0.88-1.54) for 30% decline for the overall study duration, indicating consistency of treatment effects.

LIMITATIONS

Limited variety of interventions tested and low statistical power for many CKD clinical trials.

CONCLUSIONS

These results provide some support for the use of lesser eGFR declines as a surrogate end point, with stronger support for the 40% than 30% decline.

Experimental comparison of protective characteristics of enalapril and trimetazidine in diabetic nephropathy

Abstract Hyperglycemia, hypertension, dyslipidemia, and inflammation have been proposed to account for the development of nephropathy in diabetic subjects. The beneficial effects of enalapril on diabetic nephropathy are known. However, the effects of trimetazidine (TMZ) are still unknown. We aimed at comparing the effects of the enalapril and TMZ treatment on fibronectin expression, inducible nitric oxide synthase expression, urine proteinuria, blood glucose and glomerular, and mesangial structures of kidney in rats that take streptozotocin (STZ). In this study, 32 male Sprague-Dawley albino mature rats of 8 weeks, weighing 200-220 g were used. Diabetes was induced by intraperitoneal injection of STZ (60 mg/kg) for 24 rats. We made four groups (Group 1: control, non-diabetic rats (n = 8), Group 2: diabetes, without treatment (n = 8), Group 3: diabetes treatment with enalapril (n = 8), Group 4: diabetes treatment with TMZ (n = 8). The positive effects of renal tissue and tubules in the mesangium immunohistochemical were shown in TMZ receiving rat groups. These positive effects were in parallel with the reduction in fibronectin and I-NOS expression and reduction in the proteinuria. TMZ and enalapril treatment of diabetic rats and renal parenchyma in this study are shown to have positive effects on the different levels.

Early change in proteinuria as a surrogate end point for kidney disease progression: an individual patient meta-analysis

BACKGROUND

It is controversial whether proteinuria is a valid surrogate end point for randomized trials in chronic kidney disease.

STUDY DESIGN

Meta-analysis of individual patient-level data.

SETTING & POPULATION

Individual patient data for 9,008 patients from 32 randomized trials evaluating 5 intervention types.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials of kidney disease progression until 2007 with measurements of proteinuria both at baseline and during the first year of follow-up, with at least 1 further year of follow-up for the clinical outcome.

PREDICTOR

Early change in proteinuria.

OUTCOMES

Doubling of serum creatinine level, end-stage renal disease, or death.

RESULTS

Early decline in proteinuria was associated with lower risk of the clinical outcome (pooled HR, 0.74 per 50% reduction in proteinuria); this association was stronger at higher levels of baseline proteinuria. Pooled estimates for the proportion of treatment effect on the clinical outcome explained by early decline in proteinuria ranged from -7.0% (95%CI, -40.6% to 26.7%) to 43.9% (95%CI, 25.3% to 62.6%) across 5 intervention types. The direction of the pooled treatment effects on early change in proteinuria agreed with the direction of the treatment effect on the clinical outcome for all 5 intervention types, with the magnitudes of the pooled treatment effects on the 2 end points agreeing for 4 of the 5 intervention types. The pooled treatment effects on both end points were simultaneously stronger at higher levels of proteinuria. However, statistical power was insufficient to determine whether differences in treatment effects on the clinical outcome corresponded to differences in treatment effects on proteinuria between individual studies.

LIMITATIONS

Limited variety of interventions tested and low statistical power for many chronic kidney disease clinical trials.

CONCLUSIONS

These results provide new evidence supporting the use of an early reduction in proteinuria as a surrogate end point, but do not provide sufficient evidence to establish its validity in all settings.

Prevention of chronic kidney disease and subsequent effect on mortality: a systematic review and meta-analysis

OBJECTIVES

To perform a systematic review of randomized controlled trials to determine whether prevention or slowing of progression of chronic kidney disease would translate into improved mortality, and if so, the attributable risk due to CKD itself on mortality.

BACKGROUND

CKD is associated with increased mortality. This association is largely based on evidence from the observational studies and evidence from randomized controlled trials is lacking.

METHODS

We searched Ovid, Medline and Embase for RCTs in which an intervention was given to prevent or slow the progression of CKD and mortality was reported as primary, secondary or adverse outcomes were eligible and selected. For the first phase, pooled relative risks for renal endpoints were assessed. For the second phase, we assessed the effect on mortality in trials of interventions that definitively reduced CKD endpoints.

RESULTS

Among 52 studies selected in first phase, only renin-angiotensin-aldosterone-system blockade vs. placebo (n = 18 trials, 32,557 participants) met the efficacy criteria for further analysis in the second phase by reducing renal endpoints 15 to 27% compared to placebo. There was no difference in all-cause mortality (RR 0.99, 95% CI 0.92 to 1.08) or CV death (RR 0.97, 95% CI 0.78 to 1.21) between the treatment and control groups in these trials. There was sufficient statistical power to detect a 9% relative risk reduction in all-cause mortality and a 14% relative risk reduction in cardiovascular mortality.

CONCLUSIONS

Firm evidence is lacking that prevention of CKD translates into reductions in mortality. Larger trials with longer follow-up time are needed to determine the benefit of CKD prevention on survival.

Educational paper: Progression in chronic kidney disease and prevention strategies

Chronic kidney disease (CKD) in children is a rare but devastating condition. Once a critical amount of nephron mass has been lost, progression of CKD is irreversible and results in end-stage renal disease (ESRD) and need of renal replacement therapy. The time course of childhood CKD is highly variable. While in children suffering from congenital anomalies of the kidneys and the urinary tract, progression of CKD in general is slow, in children with acquired glomerulopathies, disease progression can be accelerated resulting in ESRD within months. However, irrespective of the underlying kidney disease, hypertension and proteinuria are independent risk factors for progression. Thus, in order to prevent progression, the primary objective of treatment should always aim for efficient control of blood pressure and reduction of urinary protein excretion. Blockade of the renin-angiotensin-aldosterone system preserves kidney function not only by lowering blood pressure, but also by reducing proteinuria and exerting additional anti-proteinuric, anti-fibrotic, and anti-inflammatory effects. Besides, intensified blood pressure control, aiming for a target blood pressure below the 50th percentile, may exert additive renoprotective effects. Additionally, other modifiable risk factors, such as anemia, metabolic acidosis, dyslipidemia, and altered bone-mineral homeostasis may also contribute to CKD progression. In conclusion, beyond strict blood pressure control and reduction of urinary protein excretion, identification and treatment of both, renal disease-related and conventional risk factors are mandatory in children with CKD in order to prevent deterioration of kidney function.

Loss of renal function in the elderly Italians: a physiologic or pathologic process?

BACKGROUND

Nowadays it seems that chronic kidney disease (CKD) is outbreaking, mostly in the elderly participants. The aim of this study was to assess the progression of CKD in different ages.

METHODS

We conducted a monocentric, retrospective, observational study enrolling 116 patients afferent to our outpatient clinic.

INCLUSION CRITERIA

age >18 years, follow-up ≥5 years, estimated glomerular filtration rate (eGFR) <60mL/min/1.73 m(2), and/or diagnosed renal disease and/or presence of renal damage. Patients were divided into four groups according to their age: 25-55 years (n = 27), 56-65 (25), 66-75 (42), and 76-87 (22). eGFR was calculated using the modification of diet in renal disease and the CKD-epidemiology collaboration formulas.

RESULTS

Younger patients had a significantly longer follow-up and less comorbidities, evaluated by the cumulative illness rating scale score, compared with the other groups. There was no difference between creatinine at baseline and at the end-of-follow-up period among the groups. Even though renal function significantly decreased in all groups, we noticed a slower progression as the age increased, and the difference between basal and end-of-follow-up eGFR was minimal in the group of patients aged 76-87 years. Analyzing the eGFR of every ambulatory control plotted against the year of follow-up, we showed a more rapid loss of filtrate in the younger group. Instead, loss of renal function decreased as the age of patients increased.

CONCLUSIONS

This study demonstrates that, in elderly Italian participants, progression of CKD occurs more slowly than in younger patients. This implies that we may probably face an epidemic of CKD but that most of elderly patients diagnosed with CKD may not evolve to end-stage renal disease and require renal replacement therapy.

Early pancreas graft failure is associated with inferior late clinical outcomes after simultaneous kidney-pancreas transplantation

BACKGROUND

Early pancreas graft failure after simultaneous pancreas and kidney (SPK) transplantation is common. We studied the impact of early pancreas graft failure on long-term kidney and patient survival.

METHODS

We included all primary SPK transplants performed in the United States between January 1, 2000, and December 31, 2007, who had maintained kidney graft function at 90 days posttransplantation. Kaplan-Meier and Cox multivariate analyses were performed. The causes of death between the two cohorts were compared.

RESULTS

A total of 6282 SPK recipients were included in the analyses. Of those, 470 had lost pancreas graft within the first 90 days largely related to pancreas graft thrombosis. Early pancreas graft failure was associated with lower subsequent kidney graft and patient survival (log-rank, P=0.02 and P<0.001, respectively). Multivariate regression analyses demonstrated a 70% higher risk of kidney graft failure after 3 years (adjusted hazard ratio 1.69; 95% CI 1.08, 2.66; P=0.022) and more than doubled the risk for death (adjusted hazard ratio 2.18; 95% CI 1.67, 2.85; P<0.001) among SPK recipients with early pancreas graft failure. The causes of death were similar between the two cohorts.

CONCLUSION

Early pancreas graft failure in SPK transplant recipients is associated with an increased risk for subsequent kidney failure and death. Optimization of therapeutic interventions after early pancreas graft failure is needed.

Effect of combining an ACE inhibitor and a VDR activator on glomerulosclerosis, proteinuria, and renal oxidative stress in uremic rats

Angiotensin-converting enzyme (ACE) inhibitors ameliorate the progression of renal disease. In combination with vitamin D receptor activators, they provide additional benefits. In the present study, uremic (U) rats were treated as follows: U+vehicle (UC), U+enalapril (UE; 25 mg/l in drinking water), U+paricalcitol (UP; 0.8 μg/kg ip, 3 × wk), or U+enalapril+paricalcitol (UEP). Despite hypertension in UP rats, proteinuria decreased by 32% vs. UC rats. Enalapril alone, or in combination with paricalcitol, further decreased proteinuria (≈70%). Glomerulosclerosis and interstitial infiltration increased in UC rats. Paricalcitol and enalapril inhibited this. The increase in cardiac atrial natriuretic peptide (ANP) seen in UC rats was significantly decreased by paricalcitol. Enalapril produced a more dramatic reduction in ANP. Renal oxidative stress plays a critical role in inflammation and progression of sclerosis. The marked increase in p22(phox), a subunit of NADPH oxidase, and decrease in endothelial nitric oxide synthase were inhibited in all treated groups. Cotreatment with both compounds inhibited the uremia-induced increase in proinflammatory inducible nitric oxide synthase (iNOS) and glutathione peroxidase activity better than either compound alone. Glutathione reductase was also increased in UE and UP rats vs. UC. Kidney 4-hydroxynonenal was significantly increased in the UC group compared with the normal group. Combined treatment with both compounds significantly blunted this increase, P < 0.05, while either compound alone had no effect. Additionally, the expression of Mn-SOD was increased and CuZn-SOD decreased by uremia. This was ameliorated in all treatment groups. Cotreatment with enalapril and paricalcitol had an additive effect in increasing CuZn-SOD expression. In conclusion, like enalapril, paricalcitol alone can improve proteinuria, glomerulosclerosis, and interstitial infiltration and reduce renal oxidative stress. The effects of paricalcitol may be amplified when an ACE inhibitor is added since cotreatment with both compounds seems to have an additive effect on ameliorating uremia-induced changes in iNOS and CuZn-SOD expression, peroxidase activity, and renal histomorphometry.

Aging and the kidney

PURPOSE OF REVIEW

Aging in most species is associated with impaired adaptive and homeostatic mechanisms, leading to susceptibility to environmental or internal stresses with increasing rates of disease. A number of different theories of primarily disease-independent renal aging, which can be categorized as evolutionary, molecular, cellular and systemic, have been put forward in the past decades, and recent studies have provided evidence for some of them.

RECENT FINDINGS

This review is focused on the several mechanisms that are considered to underlie the primary aging process and contribute to age-related changes and adaptive responses in the kidney. These mechanisms include genetic modulations, telomere shortening, oxidative stress and mitochondrial dysfunction, all markers of cell senescence. Moreover, we also highlight new advances in understanding functions of angiotensin II type 1 (AT1) receptor that contribute to the renal aging process.

SUMMARY

Here we review recent advances in understanding the role of Klotho, sirtuins, cell senescence through oxidative stress and mitochondrial dysfunction, as well as of the renin-angiotensin system in modulating age-related kidney damage.

Role of angiotensin converting enzyme inhibitors and angiotensin receptor blockers in hypertension of chronic kidney disease and renoprotection. Study results

Chronic kidney disease (CKD) is a global health problem associated with considerable morbidity and mortality and despite advances in the treatment of end stage renal disease (ESRD) mechanisms to prevent and delay its progression are still being sought. The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in many of the pathophysiologic changes that lead to progression of renal disease. Traditionally RAAS was considered as an endocrine system and its principal role was to maintain blood pressure (BP). In recent years local RAAS has been described to operate independently from systemic and local angiotensin II (AngII) in the kidney to contribute in hypertension and kidney damage. The benefits of strict BP control in slowing kidney disease progression have been demonstrated in several clinical trials and the question whether specific agents like angiotensin converting enzyme antagonists (ACEIs) and angiotensin receptor blockers (ARBs) provide renoprotective benefits beyond BP lowering is to be answered. Several studies support these agents reduce proteinuria and protect renal function, whereas the opposite is stated by others. According to guidelines, their use is recommended as first line agents in diabetic renal disease and non diabetic renal disease with albuminuria, whereas there is no data to support the same in non diabetic nonalbuminuric renal disease. Dual blockage of RAAS with the combination of ACEIs and ARBs could offer an alternative in strict RAAS blockade, but studies up to now can not prove its safety and the combination is not recommended until ongoing trials will provide new and unarguable results.

Blood pressure level and kidney disease progression: do we really need to go to 130/80 mm Hg?

Current guidelines recommend a blood pressure goal of less than 130/80 mm Hg in patients with chronic kidney disease. Considerable epidemiologic observational data, post hoc analyses of clinical trials, and meta-analyses support this goal, particularly in patients with proteinuria. Although prospective clinical trials have not shown a clear benefit, recent data indicate that a longer duration of follow-up may be needed to assess the effects of different blood pressure goals. While we await the results of several ongoing and planned studies in this area, the current recommendations of a blood pressure goal less than 130/80 mm Hg appear reasonable.

Early change in proteinuria as a surrogate outcome in kidney disease progression: a systematic review of previous analyses and creation of a patient-level pooled dataset

BACKGROUND

Proteinuria is a candidate surrogate end point for randomized controlled trials (RCTs) in chronic kidney disease (CKD). There is a reasonably sound biological basis for this hypothesis, but only preliminary empirical evidence currently exists.

METHODS

A systematic review and creation of a patient-level dataset of randomized controlled trials (RCTs) in CKD that reported changes in proteinuria and assessed progression of kidney disease as defined by dialysis, transplantation, death, or changes in GFR or creatinine were performed.

RESULTS

Systematic review. Seventy RCTs met the eligibility criteria; 17 eligible RCTs contained analyses of proteinuria as a predictor of outcomes; 15 RCTs concluded that greater proteinuria was associated with adverse outcomes. A majority were studies of diabetic or hypertensive kidney disease and tested renin-angiotensin system blockade. Definitions of predictor and outcome variables were too variable to conduct a meta-analysis of group data. Database creation. Over 4 years was required to create the patient-level dataset. The final dataset included 34 studies and > 9000 patients with a variety of CKD types and interventions.

CONCLUSIONS

There are a relatively small number of RCTs designed to rigorously test therapies for kidney disease progression. Current analyses of change in proteinuria as a predictor of CKD progression are heterogeneous and incomplete, indicating further evaluation in a pooled individual patient-level database is necessary to advance knowledge in this field.

Can we slow the progression of chronic kidney disease?

PURPOSE OF REVIEW

Childhood chronic kidney disease usually progresses towards end-stage renal failure once a critical impairment of renal function has occurred. This process is largely independent of the underlying renal disease. Recent clinical trials have provided evidence that the progressive course of chronic kidney disease can be slowed substantially by pharmacological intervention.

RECENT FINDINGS

Hypertension and proteinuria are the most important independent risk factors for renal disease progression in both adult and pediatric nephropathies. Pharmacological blockade of the renin-angiotensin system provides efficient control of blood pressure and proteinuria, and superior long-term renoprotection compared with other antihypertensive agents. Recent pediatric evidence supports the renoprotective efficacy of tight blood pressure control aiming for the low-normal range. In addition, promising preliminary findings suggest an additional renoprotective potential by correction of metabolic acidosis and hyperuricemia and by administration of antiproliferative and antioxidative drugs.

SUMMARY

Pharmacological renoprotection currently focuses on antihypertensive and antiproteinuric treatment by blockade of the renin-angiotensin system. Intensified blood pressure control can improve 5-year renal survival by 35% in children with chronic kidney disease. Additional complementary strategies under current clinical evaluation bear potential to improve renal survival even further.

Effects of angiotensin II receptor blockers on diabetic nephropathy

Impaired kidney function increases the risk of cardiovascular morbidity and mortality. Coexistence of hypertension and type 2 diabetes increases the risk of kidney damage, hypertension being an independent risk factor for kidney disease progression. Angiotensin II, through its inflammatory, proliferative, and thrombotic effects, adversely affects renal perfusion and increases oxidative stress, thus playing a pivotal role in kidney disease progression. Angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors improve markers of kidney disease and slow kidney disease progression in diabetic and nondiabetic patients; this kidney protection may be in addition to their antihypertensive activity in those with advanced proteinuric nephropathy. Key beneficial effects of ARBs and ACE inhibitors throughout the kidney disease continuum are primarily explained by blood pressure lowering effects and partially by their direct blockade of angiotensin II. Recent studies have shown that telmisartan, an ARB with high lipophilicity and the longest half-life compared with other ARBs, provides benefits on markers of cardiovascular risk, that is, microalbuminuria and slowing of early-stage nephropathy.

The frequency of hyperkalemia and its significance in chronic kidney disease

BACKGROUND

Hyperkalemia is a potential threat to patient safety in chronic kidney disease (CKD). This study determined the incidence of hyperkalemia in CKD and whether it is associated with excess mortality.

METHODS

This retrospective analysis of a national cohort comprised 2 103 422 records from 245 808 veterans with at least 1 hospitalization and at least 1 inpatient or outpatient serum potassium record during the fiscal year 2005. Chronic kidney disease and treatment with angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blockers (blockers of the renin-angiotensin-aldosterone system [RAAS]) were the key predictors of hyperkalemia. Death within 1 day of a hyperkalemic event was the principal outcome.

RESULTS

Of the 66 259 hyperkalemic events (3.2% of records), more occurred as inpatient events (n = 34 937 [52.7%]) than as outpatient events (n = 31 322 [47.3%]). The adjusted rate of hyperkalemia was higher in patients with CKD than in those without CKD among individuals treated with RAAS blockers (7.67 vs 2.30 per 100 patient-months; P < .001) and those without RAAS blocker treatment (8.22 vs 1.77 per 100 patient-months; P < .001). The adjusted odds ratio (OR) of death with a moderate (potassium, >or=5.5 and <6.0 mEq/L [to convert to mmol/L, multiply by 1.0]) and severe (potassium, >or=6.0 mEq/L) hyperkalemic event was highest with no CKD (OR, 10.32 and 31.64, respectively) vs stage 3 (OR, 5.35 and 19.52, respectively), stage 4 (OR, 5.73 and 11.56, respectively), or stage 5 (OR, 2.31 and 8.02, respectively) CKD, with all P < .001 vs normokalemia and no CKD.

CONCLUSIONS

The risk of hyperkalemia is increased with CKD, and its occurrence increases the odds of mortality within 1 day of the event. These findings underscore the importance of this metabolic disturbance as a threat to patient safety in CKD.

Evidence-based guide to slowing the progression of early renal insufficiency

Early renal insufficiency (ERI), defined as a calculated or measured glomerular filtration rate (GFR) between 30 and 60 mL/min per 1.73 m2, is present in more than 10% of the adult Australian population. This pernicious condition is frequently unrecognised, progressive and accompanied by multiple associated comorbidities, including hypertension, renal osteodystrophy, anaemia, sleep apnoea, cardiovascular disease, hyperparathyroidism and malnutrition. Several treatments have been suggested to retard GFR decline in ERI, including blood pressure reduction, angiotensin-converting enzyme inhibition, angiotensin receptor antagonism, calcium channel blockade, cholesterol reduction, smoking cessation, erythropoietin therapy, dietary protein restriction, intensive glycaemic control and early intensive multidisciplinary patient education within a renal unit. In addition, specific interventions have been reported to be renoprotective in atherosclerotic renal artery stenosis, diabetic nephropathy, lupus nephritis and certain forms of primary glomerulonephritis. The present paper reviews the available published randomised controlled clinical trials and meta-analyses supporting (or refuting) a role for each of these therapeutic manoeuvres.

Carvedilol in hypertension treatment

Although β-blockers have been previously shown to effectively reduce blood pressure (BP) and have been used for hypertension treatment for over 40 years, their effect on cardiovascular morbidity and mortality in hypertensive patients remains controversial and its use in uncomplicated hypertension is currently under debate. However, data on the above field derive mainly from studies which were conducted with older agents, such as atenolol and metoprolol, while considerable pharamacokinetic and pharmacodynamic heterogeneity is present within the class of β-blockers. Carvedilol, a vasodilating non-cardioselective β-blocker, is a compound that seems to give the opportunity to the clinician to use a cardioprotective agent without the concerning hemodynamic and metabolic actions of traditional β-blocker therapy. In contrast with conventional β-blockers, carvedilol maintains cardiac output, has a less extended effect on heart rate and reduces BP by decreasing vascular resistance. Further, several studies has shown that carvedilol has a beneficial or at least neutral effect on metabolic parameters, such as glycemic control, insulin sensitivity, and lipid metabolism, suggesting that they could be used in subjects with the metabolic syndrome or diabetes without negative consequences. This article summarizes the distinct pharmacologic, hemodynamic, and metabolic properties of carvedilol in relation to conventional β-blockers, attempting to examine the potential use of this agent for hypertension treatment.