Long-term comparison between captopril and nifedipine in the progression of renal insufficiency

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).

Secular Trend in GFR Decline in Non-Dialysis CKD Based on Observational Data From Standard of Care Arms of Trials

RATIONALE & OBJECTIVE

The standard of care (SoC) group of randomized controlled trials (RCTs) is a useful setting to explore the secular trends in kidney disease progression because implementation of best clinical practices is pursued for all patients enrolled in trials. This meta-analysis evaluated the secular trend in the change of glomerular filtration rate (GFR) decline in the SoC arm of RCTs in chronic kidney disease (CKD) published in the last 30 years.

STUDY DESIGN

Systematic review and meta-analysis of the SoC arms of RCTs analyzed as an observational study.

SETTING & STUDY POPULATIONS

Adult patients with CKD enrolled in the SoC arm of RCTs.

SELECTION CRITERIA FOR STUDIES

Phase 3 RCTs evaluating GFR decline as an outcome in SoC arms.

DATA EXTRACTION

Two independent reviewers evaluated RCTs for eligibility and extracted relevant data.

ANALYTICAL APPROACH

The mean of GFR declines extracted in the SoC arm of selected RCTs were pooled by using a random effects model. Meta-regression analyses were performed to identify factors that may explain heterogeneity.

RESULTS

The SoC arms from 92 RCTs were included in the meta-analysis with a total of 32,202 patients. The overall mean GFR decline was-4.00 (95% CI, -4.55 to-3.44) mL/min/1.73m2 per year in the SoC arms with a high level of heterogeneity (I2, 98.4% [95% CI, 98.2-98.5], P<0.001). Meta-regression analysis showed an association between publication year (β estimate, 0.09 [95% CI, 0.032-0.148], P=0.003) and reduction in GFR over time. When evaluating publication decade categorically, GFR decline was-5.44 (95% CI, -7.15 to-3.73), -3.92 (95% CI, -4.82 to-3.02), and -3.20 (95% CI, -3.75 to -2.64) mL/min/1.73m2 per year during 1991-2000, 2001-2010, and 2011-2023, respectively. Using meta-regression, the heterogeneity of GFR decline was mainly explained by age and proteinuria.

LIMITATIONS

Different methods assessing GFR in selected trials and observational design of the study.

CONCLUSIONS

In the last 3 decades, GFR decline has decreased over time in patients enrolled in RCTs who received the standard of care.

TRIAL REGISTRATION

Registered at PROSPERO with record number CRD42022357704.

PLAIN-LANGUAGE SUMMARY

This study evaluated the secular trend in the change in glomerular filtration rate (GFR) decline in the placebo arms of randomized controlled trials (RCTs) that were studying approaches to protect the kidneys in the setting of chronic kidney disease. The placebo groups of RCTs are useful for examining whether the rate of progression of kidney disease has changed over time. We found an improvement in the slope of change in GFR over time. These findings suggest that adherence to standards of kidney care as implemented in clinical trials may be associated with improved clinical outcomes, and these data may inform the design of future RCTs in nephrology.

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.

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.

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.

Treatments for Chronic Kidney Disease: A Systematic Literature Review of Randomized Controlled Trials

Delaying disease progression and reducing the risk of mortality are key goals in the treatment of chronic kidney disease (CKD). New drug classes to augment renin-angiotensin-aldosterone system (RAAS) inhibitors as the standard of care have scarcely met their primary endpoints until recently. This systematic literature review explored treatments evaluated in patients with CKD since 1990 to understand what contemporary data add to the treatment landscape. Eighty-nine clinical trials were identified that had enrolled patients with estimated glomerular filtration rate 13.9-102.8 mL/min/1.73 m2 and urinary albumin-to-creatinine ratio (UACR) 29.9-2911.0 mg/g, with (75.5%) and without (20.6%) type 2 diabetes (T2D). Clinically objective outcomes of kidney failure and all-cause mortality (ACM) were reported in 32 and 64 trials, respectively. Significant reductions (P < 0.05) in the risk of kidney failure were observed in seven trials: five small trials published before 2008 had evaluated the RAAS inhibitors losartan, benazepril, or ramipril in patients with (n = 751) or without (n = 84-436) T2D; two larger trials (n = 2152-2202) published onwards of 2019 had evaluated the sodium-glucose co-transporter 2 (SGLT2) inhibitors canagliflozin (in patients with T2D and UACR > 300-5000 mg/g) and dapagliflozin (in patients with or without T2D and UACR 200-5000 mg/g) added to a background of RAAS inhibition. Significant reductions in ACM were observed with dapagliflozin in the DAPA-CKD trial. Contemporary data therefore suggest that augmenting RAAS inhibitors with new drug classes has the potential to improve clinical outcomes in a broad range of patients with CKD.

Approach and Management of Hypertension After Kidney Transplantation

Hypertension is one of the most common cardiovascular co-morbidities after successful kidney transplantation. It commonly occurs in patients with other metabolic diseases, such as diabetes mellitus, hyperlipidemia, and obesity. The pathogenesis of post-transplant hypertension is complex and is a result of the interplay between immunological and non-immunological factors. Post-transplant hypertension can be divided into immediate, early, and late post-transplant periods. This classification can help clinicians determine the etiology and provide the appropriate management for these complex patients. Volume overload from intravenous fluid administration is common during the immediate post-transplant period and commonly contributes to hypertension seen early after transplantation. Immunosuppressive medications and donor kidneys are associated with post-transplant hypertension occurring at any time point after transplantation. Transplant renal artery stenosis (TRAS) and obstructive sleep apnea (OSA) are recognized but common and treatable causes of resistant hypertension post-transplantation. During late post-transplant period, chronic renal allograft dysfunction becomes an additional cause of hypertension. As these patients develop more substantial chronic kidney disease affecting their allografts, fibroblast growth factor 23 (FGF23) increases and is associated with increased cardiovascular and all-cause mortality in kidney transplant recipients. The exact relationship between increased FGF23 and post-transplant hypertension remains poorly understood. Blood pressure (BP) targets and management involve both non-pharmacologic and pharmacologic treatment and should be individualized. Until strong evidence in the kidney transplant population exists, a BP of <130/80 mmHg is a reasonable target. Similar to complete renal denervation in non-transplant patients, bilateral native nephrectomy is another treatment option for resistant post-transplant hypertension. Native renal denervation offers promising outcomes for controlling resistant hypertension with no significant procedure-related complications. This review addresses the epidemiology, pathogenesis, and specific etiologies of post-transplant hypertension including TRAS, calcineurin inhibitor effects, OSA, and failed native kidney. The cardiovascular and survival outcomes related to post-transplant hypertension and the utility of 24-h blood pressure monitoring will be briefly discussed. Antihypertensive medications and their mechanism of actions relevant to kidney transplantation will be highlighted. A summary of guidelines from different professional societies for BP targets and antihypertensive medications as well as non-pharmacological interventions, including bilateral native nephrectomy and native renal denervation, will be reviewed.

Hypertension control among euvolemic hypertensive hemodialysis patients in Malaysia: a prospective follow-up study

Objectives

Existing literature does not provide enough information on evaluation of factors associated with pre-dialysis controlled hypertension among euvolemic hemodialysis (HD) patients. We conducted a study to evaluate the rate and factors influencing pre-dialysis controlled hypertension among euvolemic HD patients.

Design

A multicenter prospective follow-up study.

Setting

Tertiary care teaching hospital and its associated private dialysis centers.

Participants

This study included 145 euvolemic eligible hypertensive patients. Various sociodemographic, clinical factors and drugs were investigated and analyzed by using appropriate statistical methods to determine the factors influencing hypertension control among the study participants.

Results

On baseline visit, the mean pre-dialysis systolic and diastolic BP (mmHg) of study participants was 161.2 ± 24. and 79.21 ± 11.8 retrospectively, and 30 (20.6%) patients were on pre-dialysis goal BP. At the end of the 6-months follow-up, the mean pre-dialysis systolic BP and diastolic BP (mmHg) of the patients was 154.6 ± 18.3 and 79.2 ± 11.8 respectively, and 42 (28.9%) were on pre-dialysis goal BP. In multivariate analysis, the use of calcium channel blockers (CCBs) was the only variable which had statistically significant association with pre-dialysis controlled hypertension at baseline (OR = 7.530, p-value = 0.001) and final (OR = 8.988, p-value < 0.001) visits.

Conclusions

In present study, the positive association observed between CCBs and controlled hypertension suggests that CCBs are effective antihypertensive drugs in the management of hypertension among euvolemic HD patients.

Strengths and limitations of this study

This study involved a group of patients from tertiary-level teaching hospital and its associated private dialysis centers of Malaysia.To the best of the authors' knowledge, this is the first study to assess the factors influencing pre-dialysis controlled hypertension in a cohort of 145 euvolemic HD patients in a Malaysian setting.For determining the factors influencing hypertenion control multivariate analysis was conducted.Being a prospective follow-up study, the findings of the present study need to be interpreted with caution since it is limited to only 6 months follow up.Nevertheless, a multicenter study with a large sample size and longer follow up time is needed to confirm the findings of the current study.

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.

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.

Effects of calcium channel blockers comparing to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in patients with hypertension and chronic kidney disease stage 3 to 5 and dialysis: A systematic review and meta-analysis

Background

Calcium channel blocker (CCB) or two renin angiotensin aldosterone system blockades (RAAS), angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are major potent and prevalently used as initial antihypertensive agents for mild to moderate hypertension, but no uniform agreement as to which antihypertensive drugs should be given for initial therapy, especially among chronic kidney disease (CKD) patients.

Design

A systematic review and meta-analysis comparing CCBs and the two RAAS blockades for hypertensive patients with CKD stage 3 to 5D. The inclusion criteria for this systematic review was RCT that compared the effects of CCBs and the two RAAS blockades in patients with hypertension and CKD. The exclusion criteria were (1) renal transplantation, (2) CKD stage 1 or 2, (3) combined therapy (data cannot be extracted separately). Outcomes were blood pressure change, mortality, heart failure, stroke or cerebrovascular events, and renal outcomes.

Results

21 randomized controlled trials randomized 9,492 patients with hypertensive and CKD into CCBs and the two RAAS blockades treatments. The evidence showed no significant differences in blood presser change, mortality, heart failure, stroke or cerebrovascular events, and renal outcomes between CCBs group and the two RAAS blockades group. The publication bias of pooled mean blood presser change that was detected by Egger’s test was non-significant.

Conclusions

CCBs has similar effects on long term blood pressure, mortality, heart failure, stroke or cerebrovascular events, and renal function to RAAS blockades in patients CKD stage 3 to 5D and hypertension.

Effects of Vitamin D Receptor Activation and Dietary Sodium Restriction on Residual Albuminuria in CKD: The ViRTUE-CKD Trial

Reduction of residual albuminuria during single-agent renin-angiotensin-aldosterone blockade is accompanied by improved cardiorenal outcomes in CKD. We studied the individual and combined effects of the vitamin D receptor activator paricalcitol (PARI) and dietary sodium restriction on residual albuminuria in CKD. In a multicenter, randomized, placebo (PLAC)-controlled, crossover trial, 45 patients with nondiabetic CKD stages 1-3 and albuminuria >300 mg/24 h despite ramipril at 10 mg/d and BP<140/90 mmHg were treated for four 8-week periods with PARI (2 μg/d) or PLAC, each combined with a low-sodium (LS) or regular sodium (RS) diet. We analyzed the treatment effect by linear mixed effect models for repeated measurements. In the intention-to-treat analysis, albuminuria (geometric mean) was 1060 (95% confidence interval, 778 to 1443) mg/24 h during RS + PLAC and 990 (95% confidence interval, 755 to 1299) mg/24 h during RS + PARI (P=0.20 versus RS + PLAC). LS + PLAC reduced albuminuria to 717 (95% confidence interval, 512 to 1005) mg/24 h (P<0.001 versus RS + PLAC), and LS + PARI reduced albuminuria to 683 (95% confidence interval, 502 to 929) mg/24 h (P<0.001 versus RS + PLAC). The reduction by PARI beyond the effect of LS was nonsignificant (P=0.60). In the per-protocol analysis restricted to participants with ≥95% compliance with study medication, PARI did provide further albuminuria reduction (P=0.04 LS + PARI versus LS + PLAC). Dietary adherence was good as reflected by urinary excretion of 174±64 mmol Na⁺ per day in the combined RS groups and 108±61 mmol Na⁺ per day in the LS groups (P<0.001). In conclusion, moderate dietary sodium restriction substantially reduced residual albuminuria during fixed dose angiotensin-converting enzyme inhibition. The additional effect of PARI was small and nonsignificant.

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.

Clinical pharmacology = disease progression + drug action

Clinical pharmacology is concerned with understanding how to use medicines to treat disease. Pharmacokinetics and pharmacodynamics have provided powerful methodologies for describing the time course of concentration and effect in individuals and in populations. This population approach may also be applied to describing the progression of disease and the action of drugs to change disease progress. Quantitative models for symptomatic and disease-modifying effects of drugs are valuable not only for describing drugs and diseases but also for identifying criteria to distinguish between types of drug actions, with implications for regulatory decisions and long-term patient care.

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.

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.

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.

Antiproteinuric Effect of an N-Type Calcium Channel Blocker, Cilnidipine

The objective of the present study was to determine anti-proteinuric effect of an N-type calcium channel blocker-cilnidipine. Subjects were 43 essential or renal hypertensive subjects who had been taking calcium channel blockers other than cilnidipine for at least 6 months. All patients had proteinuria greater than 0.2 g/day in spite of fair blood pressure control (<150/90 mmHg). Calcium channel blockers in 25 patients (62+/-3 years) were switched to cilnidipine (cilnidipine group), whereas other 18 patients (58+/-3 years) continued to take originally prescribed calcium channel blockers (control group). The 24-hr urine collections were done at baseline and after 6 months of the follow-up period. Baseline characteristics including age, blood pressure levels, body mass index and creatinine clearance were similar between cilnidipine and control groups. Urinary protein excretion also was comparable between cilnidipine (0.61+/-0.10 g/day) and control (0.86+/-0.17 g/day) groups. Urinary protein significantly decreased after 6 months in cilnidipine group (- 0.21+/- 0.11 g/day, - 36%, p< 0.01), whereas it did not change in control group (+ 0.01+/- 0.15 g/day, 0.4%, ns). There were no significant changes in blood pressure, serum creatinine, creatinine clearance, estimated protein intake, and urinary salt excretion during the follow-up period in either group. The reduction of urinary protein by cilnidipine was evident in essential hypertensives (- 54+/-9%, n=18, p<0.01) but not in renal hypertensives (+10+/-35%, n=7, ns). Results suggest that cilnidipine has an anti-proteinuric effect especially in patients with essential hypertension.

Therapeutic strategies to slow chronic kidney disease progression

Childhood chronic kidney disease commonly progresses toward end-stage renal failure, largely independent of the underlying disorder, once a critical impairment of renal function has occurred. Hypertension and proteinuria are the most important independent risk factors for renal disease progression. Therefore, current therapeutic strategies to prevent progression aim at controlling blood pressure and reducing urinary protein excretion. Renin-angiotensin-system (RAS) antagonists preserve kidney function not only by lowering blood pressure but also by their antiproteinuric, antifibrotic, and anti-inflammatory properties. Intensified blood pressure control, probably aiming for a target blood pressure below the 75th percentile, may exert additional renoprotective effects. Other factors contributing in a multifactorial manner to renal disease progression include dyslipidemia, anemia, and disorders of mineral metabolism. Measures to preserve renal function should therefore also comprise the maintenance of hemoglobin, serum lipid, and calcium-phosphorus ion product levels in the normal range.

Renin angiotensin system blockade and cardiovascular outcomes in patients with chronic kidney disease and proteinuria: a meta-analysis

OBJECTIVE

The role of renin angiotensin system (RAS) blockade in controlling hypertension and the positive impact on cardiovascular (CV) outcomes is well known. However, the role of RAS blockade in improving CV outcomes in patients with chronic kidney disease (CKD) is still unclear.

METHODS

Randomized controlled trials that analyzed CV outcomes in patients with CKD/proteinuria treated with RAS blockade (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers) were included in our study. The relative risk across all study groups was computed using Mantel-Hanszel random effects model. Results were calculated with 95% CI and was considered statistically significant if 2-sided alpha error was <.05. Renin angiotensin system blockade-based therapy was compared with placebo and control (beta-blocker, calcium-channel blockers and other antihypertensive-based therapy) therapy in the study.

RESULTS

Twenty-five trials (N = 45758) were used for analysis. Renin angiotensin system blockade decreased the risk for heart failure in patients with diabetic nephropathy when compared with placebo 0.78 (95% CI 0.66-0.92, P = .003) and control therapy (0.63, 95% CI 0.47-0.86, P = .003). The risk for CV outcomes was decreased with RAS blockade (0.56, 95% CI 0.47-0.67, P < .001) in nondiabetic nephropathy patients with CKD when compared with control therapy. There was also a significant reduction of CV outcomes (0.84, 95% CI 0.78-0.91, P < .0001), myocardial infarction (0.78, 95% CI 0.65-0.97, P = .03), and heart failure (0.74, 95% CI 0.58-0.95, P = .02) when we pooled all the patients with CKD and compared RAS blockade to placebo.

CONCLUSIONS

A pooled analysis of all causes of CKD revealed a reduction in the risk for myocardial infarction, heart failure, and total CV outcomes when RAS blockade was compared with placebo. RAS blockade decreases the risk for CV outcomes and heart failure when compared with control therapy in patients with proteinuria. There were also benefits with RAS blockade in reducing the risk of CV outcomes and heart failure in patients with diabetic nephropathy when compared with placebo.

Impact of the preintervention rate of renal function decline on outcome of renoprotective intervention

BACKGROUND AND OBJECTIVES

Randomized clinical trials on progression of renal diseases usually include patients according to criteria for BP, renal function, and proteinuria. There are no data showing that this provides groups with similar baseline rates of renal function loss. Accordingly, the impact of preintervention rate of renal function loss (slope) on outcome of studies has not been established.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Preintervention slope was established in 60 of 89 renal patients without diabetes in whom a 4-yr prospective, randomized intervention had been performed (enalapril versus atenolol), and whether (1) preintervention slope was distributed equally over the groups; (2) treatment benefit, defined as slope improvement, corresponded to study outcome; and (3) preintervention slope was a determinant of intervention slope were analyzed.

RESULTS

The preintervention slope was different in the groups: -3.7 +/- 3.2 in the group to receive enalapril versus -2.2 +/- 3.3 ml/min per yr in the group to receive atenolol. The intervention slopes were similar: -1.9 +/- 0.8 enalapril and -1.8 +/- 0.7 ml/min per yr atenolol. Accordingly, slope improved during enalapril only. When analyzed by angiotensin-converting enzyme (I/D) genotype, slope improvement was found only in DD genotype. On multivariate analysis, the preintervention slope was a main predictor of the intervention slope.

CONCLUSIONS

Differences in preintervention slope are relevant to outcome of trials and can induce bias. For future studies, allocation according to preintervention slope, although time-consuming, may be useful to allow conduction of more valid studies in a smaller number of patients.

Combination therapy with an angiotensin-converting enzyme inhibitor and a vitamin D analog suppresses the progression of renal insufficiency in uremic rats

Monotherapy with angiotensin-converting enzyme inhibitors has been shown to be beneficial in suppressing the progression of experimentally induced kidney diseases. Whether such therapy provides additional benefits when combined with vitamin D or an analog of vitamin D has not been established. Rats were made uremic by 5/6 nephrectomy and treated as follows: Uremic + vehicle (UC), uremic + enalapril (30 mg/L in drinking water; E), uremic + paricalcitol (19-nor; 0.8 microg/kg, three times a week), and uremic + enalapril + paricalcitol (E + 19-nor). A group of normal rats served as control (NC). BP was significantly elevated in the UC and 19-nor groups compared with the NC group but was indistinguishable from normal in the E and E + 19-nor groups. The decrease in creatinine clearance and the increase in the excretion of urinary protein that were observed in the UC group were ameliorated by the use of E alone or by E + 19-nor (P < 0.05 versus UC). The glomerulosclerotic index was significantly decreased in both the 19-nor (P < 0.01) and E + 19-nor groups (P < 0.01) compared with the UC group. Tubulointerstitial volume was significantly decreased in both the E (P < 0.05) and E + 19-nor groups (P < 0.01) compared with the UC group. Both macrophage infiltration (ED-1-positive cells) and production of the chemokine monocyte chemoattractant protein-1 were significantly blunted in E + 19-nor compared with E group. TGF-beta1 mRNA and protein expression were increased in the UC group (mRNA: 23.7-fold; protein: 29.1-fold versus NC). These increases were significantly blunted in the 19-nor group (mRNA: 7.1-fold; protein: 8.0-fold versus NC) and virtually normalized in the E + 19-nor group (protein: 0.8-fold versus NC). Phosphorylation of Smad2 was also elevated in the UC group (7.6-fold versus NC) but less so in the 19-nor-treated rats (5.5-fold versus NC). When rats were treated with E + 19-nor, the phosphorylation of Smad2 was normal (1.1-fold versus NC). Thus, 19-nor can suppress the progression of renal insufficiency via mediation of the TGF-beta signaling pathway, and this effect is amplified when BP is controlled via renin-angiotensin system blockade.

Progression risk, urinary protein excretion, and treatment effects of angiotensin-converting enzyme inhibitors in nondiabetic kidney disease

It is unclear whether patients with nondiabetic kidney disease benefit from angiotensin-converting enzyme inhibitor (ACEI) therapy when they are at low risk for disease progression or when they have low urinary protein excretion. With the use of a combined database from 11 randomized, clinical trials (n = 1860), a Cox proportional hazards model, based on known predictors of risk and the composite outcome kidney failure or creatinine doubling, was developed and used to stratify patients into equal-sized quartiles of risk. Outcome risk and treatment effect were examined across various risk strata. Use of this risk model for targeting ACEI therapy was also compared with a strategy based on urinary protein excretion alone. Control patients in the highest quartile of predicted risk had an annualized outcome rate of 28.7%, whereas control patients in the lowest quartile of predicted risk had an annualized outcome rate of 0.4%. Despite the extreme variation in risk, there was no variation in the degree of benefit of ACEI therapy (P = 0.93 for the treatment x risk interaction). Significant interaction was detected between baseline urine protein and ACEI therapy (P = 0.003). When patients were stratified according to their baseline urinary protein excretion, among the subgroup of patients with proteinuria > or =500 mg/d, significant treatment effect was seen across all patients with a measurable outcome risk, including those at relatively low risk (1.7% annualized risk for progression). However, there was no benefit of ACEI therapy among patients with proteinuria <500 mg/d, even among higher risk patients (control outcome rate 19.7%). Patients with nondiabetic kidney disease vary considerably in their risk for disease progression, but the treatment effect of ACEI does not vary across risk strata. Patients with proteinuria <500 mg/d do not seem to benefit, even when at relatively high risk for progression.

Hypertension and the kidney

The kidney could be the cause of essential hypertension which can also cause renal disease. High blood pressure is also very common in chronic kidney disease, and is moreover a well-known risk factor for a faster progression of kidney failure. Hypertension and kidneys are thus closely linked. Hypertension must be aggressively treated in patients suffering from chronic kidney disease, with a blood pressure goal of less than 130/80 mmHg, even lower than 125/75 mmHg when proteinuria is over 1g/day, using optimal and effective antihypertensive drugs. Among them, the blockers of the renin-angiotensin axis offer nephroprotective but also cardioprotective properties beyond their effect on blood pressure.

Modified-release nifedipine: a review of the use of modified-release formulations in the treatment of hypertension and angina pectoris

Nifedipine is a dihydropyridine calcium channel antagonist with predominantly vasodilatory activity. Modified-release formulations of nifedipine are effective antihypertensive and antianginal therapies and are generally well tolerated. Among the available formulations, those that produce a gradual increase in plasma nifedipine concentration, which is then sustained over a 24-hour period, are preferred, as they cause a gradual onset of vasodilatation and avoid baroreflex sympathetic activation (for example, nifedipine gastrointestinal therapeutic system [GITS] and a Japanese controlled-release formulation). Modified-release nifedipine had beneficial effects on a number of markers of vascular function, and nifedipine GITS reduced the need for coronary procedures in patients with coronary artery disease. In patients with hypertension, nifedipine GITS and nifedipine retard had beneficial effects on the overall incidence of major cardiovascular events, as did nifedipine retard in patients with concurrent hypertension and coronary artery disease.

Effect of nifedipine on adiponectin in hypertensive patients with type 2 diabetes mellitus

Nifedipine, a dihydropyridine calcium antagonist, improves endothelial function in patients with hypercholesterolaemia by enhancing nitric oxide (NO) activity, and increases endothelial NO bioavailability by antioxidant mechanisms. We administered a long-acting nifedipine formulation (controlled release (CR) nifedipine: 20 mg/day) to hypertensive patients for 6 months. There were no other changes of drug treatment during therapy with CR nifedipine. Clinical and biochemical data obtained before and after CR nifedipine administration were compared. All markers were measured by enzyme-linked immunosorbant assay. The levels of soluble markers (soluble CD40 ligand, soluble P-selectin, and soluble E-selectin), microparticles (MP) (platelet-derived MP, monocyte-derived MP, and endothelial cell-derived MP), and adiponectin differed between the control group and the hypertension group. The levels of these markers were also different in hypertensive patients with and without type 2 diabetes compared with the control group. In the hypertensive patients with type 2 diabetes, all markers except adiponectin decreased significantly after 3 months of CR nifedipine treatment. In contrast, markers were unchanged in the hypertensive patients without type 2 diabetes. Adiponectin was increased after 6 months of CR nifedipine treatment in hypertensive patients with type 2 diabetes. The effects of CR nifedipine on platelet/monocyte activation and adiponectin levels demonstrated in the present study indicate the potential effectiveness of calcium antagonist therapy for hypertensive patients with type 2 diabetes.

Long-term treatment with nifedipine modulates procoagulant marker and C-C chemokine in hypertensive patients with type 2 diabetes mellitus

In type 2 diabetes mellitus, there is increased risk of nephropathy and cardiovascular complications and the incidence of renal failure increases in advanced stages of the disease. Nifedipine, a dihydropyridine-type calcium antagonist, improves endothelial function in hypercholesterolemia by enhancing nitric oxide function, and increases endothelial nitric oxide bioavailability by antioxidative mechanisms. We administered nifedipine, 50 mg/day, to the hypertensive patients for 12 months. There were no other changes in any of the patient's pharmacologic regimen during nifedipine treatment. Clinical and biochemical data obtained before and after nifedipine administration were compared. All markers were measured by ELISA. The levels of platelet activation markers (CD62P, CD63, PAC-1, and Annexin V), microparticles (PDMP and MDMP), RANTES and soluble adhesion markers (sP-selectin and sVCAM-1) differed in the control group and the hypertension group. The levels of these markers were also different in hypertensive patients with and without type 2 diabetes but were unchanged in patients without diabetes in comparison to the control group. However, the concentrations of MDMPs, chemokines, and soluble adhesion markers in hypertensive patients without type 2 diabetes decreased significantly following nifedipine treatment, although the level of RANTES was unchanged. Systolic blood pressure correlated with CD62P, CD63, annexin V, and RANTES levels, and diastolic blood pressure with CD62P and annexin V levels. The effect of nifedipine on platelet activation markers and C-C chemokines in the present study indicates potential effectiveness of calcium antagonist therapy for hypertensive patients with type 2 diabetes.

A Prospective Open-Label Randomised Trial of Quinapril and/or Amlodipine in Progressive Non-Diabetic Renal Failure

BACKGROUND

Treatment of hypertension slows the progression of non-diabetic nephropathies, but the optimal regimen is unknown. Angiotensin-converting enzyme inhibitors are more effective than beta-blockers, but their merits relative to calcium channel blockers are less clear.

METHODS

73 hypertensive patients with progressive non-diabetic nephropathies were prospectively randomised to open-label quinapril (Q, n = 28), amlodipine (A, n = 28) or both drugs (Q&A, n = 17). Therapy was increased to achieve a diastolic blood pressure < 90 mm Hg. Patients were followed for 4 years or until death. The primary outcome was the combined endpoint of doubling serum creatinine, starting renal replacement therapy or death.

RESULTS

There was no significant difference in the primary outcome, or in the change of glomerular filtration rate. Blood pressure was equally controlled throughout the study period. 29 (40%) patients were withdrawn from the allocated therapy (Q 39%, A 36%, Q&A 47%). Because of the large crossover between trial arms, the data were re-analysed per protocol. The effect on preventing the need for renal replacement therapy then approached significance between the groups (p = 0.089) and the combined quinapril-containing groups were less likely than the amlodipine group to achieve the primary endpoint (p = 0.038), or the individual endpoints of renal replacement therapy (p = 0.030) or doubling creatinine (p = 0.051).

CONCLUSIONS

Quinapril is more effective than amlodipine at reducing the incidence of dialysis in patients with progressive renal failure, but only if they can tolerate the drug. The tolerability of these drugs in patients with advanced renal failure is poor.

Angiotensin-converting enzyme inhibition and renal protection in nondiabetic patients: the data of the meta-analyses

ESRD represents a major health problem. The number of patients who enter kidney replacement programs has increased at an average of 7% per year in the past 10 yr. A large number of experimental and clinical studies have demonstrated that chronic nephropathies share common pathogenic mechanisms that contribute to renal disease progression, even independent of the original cause. Clinical studies found a significant correlation between the extent of urinary protein excretion and the rate of GFR decline in both diabetic and nondiabetic chronic nephropathies. Randomized trials, in particular the Ramipril Efficacy In Nephropathy (REIN) study, also showed that treatments that reduce proteinuria (namely angiotensin-converting enzyme [ACE] inhibitors) are renoprotective and limit progression to ESRD. Meta-analyses of randomized clinical trials also evaluated the role of proteinuria and of ACE inhibition therapy in chronic renal disease progression. Their findings were consistent with those of the REIN study and confirmed in larger series of patients the predictive value of proteinuria and the renoprotective effect of proteinuria reduction by ACE inhibition therapy. Thus, the meta-analyses may confirm and extend previous findings generated by randomized clinical trials. Conceivably, well-designed studies in properly selected and carefully monitored patients who are at increased risk continue to be the best approach to test novel hypotheses. The meta-analyses, however, represent a valuable tool to evaluate the consistency and generalizability of trial results to larger cohorts of patients.

The effect of angiotensin-converting-enzyme inhibitors on progression of advanced polycystic kidney disease

BACKGROUND

It is not known whether angiotensin-converting-enzyme (ACE) inhibitors slow the progression of polycystic kidney disease (PKD). We performed a patient-level meta-analysis to compare the effect of antihypertensive regimens, including ACE inhibitors, to those without ACE inhibitors (controls) on kidney disease progression in patients with PKD.

METHODS

We analyzed a database of 11 randomized controlled trials including 1860 patients with nondiabetic kidney disease. We compared randomized groups for the decline in urine protein excretion and kidney disease progression (combined outcome of doubling of baseline serum creatinine or onset of kidney failure). We also performed multivariable linear regression and Cox proportional hazards analyses. Based on previous findings, we searched for interactions between the treatment effect (effect of ACE inhibitors vs. controls) and baseline urine protein excretion in both models.

RESULTS

Eight studies included a total of 142 subjects with PKD: 68 (48%) were randomized to ACE inhibitors and 74 (52%) were randomized to the control. Baseline mean (SD) urine protein excretion was 0.92 (1.40) g/day: 1.08 (1.50) g/day in the ACE inhibitor and 0.76 (1.28) g/day in the control group. During a mean follow-up of 2.3 years, mean (SD) urine protein excretion declined by 0.33 (1.11) g/day in the ACE inhibitor group and increased by 0.19 (0.88) g/day in the control group (P < 0.001). Kidney disease progression occurred in 50 patients: 20 patients (29%) in the ACE inhibitor group and 30 patients (41%) in the control group (P= 0.17). ACE inhibitors had a greater effect on lowering urine protein excretion and slowing kidney disease progression in patients with higher levels of baseline urine protein excretion (interaction P < 0.001 and P= 0.03, respectively).

CONCLUSION

As in other causes of non-diabetic kidney disease, antihypertensive regimens with ACE inhibitors are more effective in lowering urine protein excretion in patients with advanced PKD compared to regimens without ACE inhibitors, and this benefit is greater in patients with higher levels of baseline urine protein excretion. The effect of ACE inhibitors to slow kidney disease progression in PKD is inconclusive.

Benidipine improves oxidized LDL-dependent monocyte and endothelial dysfunction in hypertensive patients with type 2 diabetes mellitus

We investigated the effects of long-term benidipine treatment on levels of monocyte and endothelial cell activation markers in hypertensive patients with (n = 28) and without (n = 10) type 2 diabetes mellitus. Benidipine, 4 mg/day, was administered for 6 months; there were no other changes in any of the patients pharmacologic regimens during benidipine treatment. Clinical and biochemical data obtained before and after benidipine administration were compared; all markers were measured by ELISA. The levels of platelet activation markers (CD62P, CD63, and PAC-1), microparticles (monocyte-derived microparticles: MDMPs, and endothelial cell-derived microparticles: EDMPs), chemokines (monocyte chemotactic peptide 1: MCP-1, regulated on activation normally T-cell expressed and secreted: RANTES) and soluble adhesion markers (soluble E-selectin and soluble ICAM-1) differed in the control and hypertension groups. In addition, levels of platelet, monocyte, and endothelial cell activation markers, microparticles, chemokines, and soluble adhesion molecules were higher in hypertensive patients than in those without type 2 diabetes. Furthermore, benidipine administration decreased the concentrations of all these markers. The effect of this drug was significant in diabetes patients with high levels of antioxidized low-density lipoprotein (LDL) antibody. These results suggest that benidipine is effective for the treatment of oxLDL-dependent vascular disorders in hypertensive patients with type 2 diabetes.

Proteinuria predicting outcome in renal disease: nondiabetic nephropathies (REIN)

About two thirds of patients on renal replacement therapy irreversibly lose their kidney function because of progressive nephropathies, such as diabetic nephropathy and nondiabetic chronic renal disease. Halting the progression of these patients to end-stage renal disease (ESRD) is instrumental to substantially decrease the need and cost for renal replacement therapy. A large number of experimental studies have demonstrated that chronic nephropathies share common pathogenic mechanisms that contribute to renal disease progression, even independently of the original etiology. Actually, a variety of insults may result in a common pathway of systemic hypertension, increased glomerular pressure and protein ultrafiltration, glomerular and tubular protein overload, chronic inflammation and, ultimately, scarring. Experimental and clinical data converge to indicate that in chronic renal disease increased protein traffic is nephrotoxic, proteinuria predicts disease progression, and proteinuria reduction is renoprotective. Initial clinical trials, mostly in patients with no or mild proteinuria, failed to demonstrate that ACE inhibition therapy is renoprotective in nondiabetic chronic nephropathies. Consistently, meta-analyses based on data generated by these trials failed to detect a specific, blood pressure-independent, renoprotective effect of ACE inhibition therapy. The Ramipril Efficacy In Nephropathy (REIN) study found that ACE inhibitors, by reducing urinary proteins, may contribute to improve the outcome of nondiabetic renal disease, and reduce the risk of progression to ESRD by about 50%. Cumulative meta-analyses, including the REIN study results, confirmed and extended these findings. Thus, well-designed trials in properly selected and carefully monitored study populations continue to be the best approach to test the efficacy of novel treatments. The meta-analyses may help confirming the consistency of these findings and their generalizability to larger cohorts of patients.

Effects of calcium antagonists in hypertensive patients with renal dysfunction: a prospective, randomized, parallel trial comparing benidipine and nifedipine

BACKGROUND

Although calcium antagonists, derived from dihydropyridine (DHP), are important agents in achieving control in a majority of patients with high blood pressure and renal disease, there are no comparative data regarding their inhibitory effects on the progression of renal dysfunction in Japan.

METHODS

Benidipine and nifedipine retard both calcium antagonists derived from DHP and were compared in terms of their inhibitory effect on the progression of renal dysfunction in hypertensive patients. The primary end-points were defined as 1.5 times the serum creatinine value at baseline, progression to end-stage renal failure (ESRF) necessitating dialysis or renal transplantation, and death.

RESULTS

During the study period, a significant decline in blood pressure was observed in the two groups, with no significant difference between them. The worsening of nephropathy was significantly inhibited in the benidipine group as compared with the nifedipine retard group (log-rank test: P = 0.014, Wilcoxon's test: P = 0.022). Among the subjects who reached a primary end-point, one (33%) in the benidipine group and five (50%) in the nifedipine retard group were placed on haemodialysis within 1 year.

CONCLUSION

It appears that benidipine inhibits the progression of hypertensive renal diseases more effectively than nifedipine retard.

Renoprotective effect of Hemidesmus indicus, a herbal drug used in gentamicin-induced renal toxicity

BACKGROUND AND AIMS

Owing to the global trend towards improved 'quality of life', there is considerable evidence of an increase in demand for medicinal plants. The WHO guidelines define basic criteria for the standardization of herbal medicines. The present work is an effort in this direction to prove the safety and efficacy of Hemidesmus indicus Linn. in the management of nephrotoxicity induced by aminoglycosides such as gentamicin.

METHODS AND RESULTS

Simple, quality control methods using high performance thin layer chromatographic (HPTLC) phytochemical fingerprint, proximate analysis, and the stability of the H. indicus root powder were developed. From the toxicity study using albino Swiss mice, it was observed that the drug (H. indicus) was relatively safe up to 7 g/kg bodyweight dose. Efficacy was evaluated against gentamicin-induced nephrotoxicity in albino Wister rats. The study examined animals from the following groups: no treatment, gentamicin treated, gentamicin treated recovery, and gentamicin and plant treated. Animals from all groups were killed on day 13 of the study; those from gentamicin treated group were killed on the seventh day. Assessment of the drug efficacy drug was conducted by using haematological and histological examination.

CONCLUSION

The treatment with H. indicus helped in the management of renal impairment, which was induced by gentamicin in rats. This is evident from the results obtained for various kidney function tests for gentamicin, along with the results from the plant treated group, and is in comparison with the results found for the gentamicin recovery group. A histological examination of kidneys also supports the findings from haematological evaluations. The plant shows promise as an adjunct therapy along side aminoglycosides as it reduces nephrotoxicity caused by aminoglycosides.