Effect of add-on direct renin inhibitor aliskiren in patients with non-diabetes related chronic kidney disease

Current perspectives and trends of the research on hypertensive nephropathy: a bibliometric analysis from 2000 to 2023

Hypertensive nephropathy continues to be a major cause of end-stage renal disease and poses a significant global health burden. Despite the staggering development of research in hypertensive nephropathy, scientists and clinicians can only seek out useful information through articles and reviews, it remains a hurdle for them to quickly track the trend in this field. This study uses the bibliometric method to identify the evolutionary development and recent hotspots of hypertensive nephropathy. The Web of Science Core Collection database was used to extract publications on hypertensive nephropathy from January 2000 to November 2023. CiteSpace was used to capture the patterns and trends from multi-perspectives, including countries/regions, institutions, keywords, and references. In total, 557 publications on hypertensive nephropathy were eligible for inclusion. China (n = 208, 37.34%) was the most influential contributor among all the countries. Veterans Health Administration (n = 19, 3.41%) was found to be the most productive institution. Keyword bursting till now are renal fibrosis, outcomes, and mechanisms which are predicted to be the potential frontiers and hotspots in the future. The top seven references were listed, and their burst strength was shown. A comprehensive overview of the current status and research frontiers of hypertensive nephropathy has been provided through the bibliometric perspective. Recent advancements and challenges in hypertensive nephropathy have been discussed. These findings can offer informative instructions for researchers and scholars.

How renal toxins respond to renal function deterioration and oral toxic adsorbent in pH-controlled releasing capsule

The number of patients with chronic kidney disease (CKD) is increasing. Oral toxin adsorbents may provide some value. Several uremic toxins, including indoxyl sulfate (IS), p-cresol (PCS), acrolein, per- and poly-fluoroalkyl substances (PFAS), and inflammation markers (interleukin 6 [IL-6] and tumor necrosis factor [TNF]-alpha) have been shown to be related to CKD progression. A total of 81 patients taking oral activated charcoal toxin adsorbents (AC-134), which were embedded in capsules that dissolved in the terminal ileum, three times a day for 1 month, were recruited. The renal function, hemoglobulin (Hb), inflammation markers, three PFAS (PFOA, PFOS, and PFNA), and acrolein were quantified. Compared with the baseline, an improved glomerular filtration rate (GFR) and significantly lower acrolein were noted. Furthermore, the CKD stage 4 and 5 group had significantly higher concentrations of IS, PCS, IL-6, and TNF but lower levels of Hb and PFAS compared with the CKD Stage 3 group at baseline and after the intervention. Hb was increased only in the CKD Stage 3 group after the trial (p = .032). Acrolein did not differ between the different CKD stage groups. Patients with improved GFR (responders) (about 77%) and nonresponders had similar baseline GFR. Responders had higher acrolein and PFOA levels throughout the study and a more significant reduction in acrolein, indicating a better digestion function. Both the higher PFOA and lower acrolein may be related to improved eGFR (and possibly to improvements in proteinuria, which we did not measure. Proteinuria is associated with PFAS loss in the urine), AC-134 showed the potential to improve the GFR and decrease acrolein, which might better indicate renal function change. Future studies are needed with longer follow-ups.

Antifibrotic Roles of RAAS Blockers: Update

The rennin-angiotensin-aldosterone system (RAAS) has been well documented in regulating blood pressure, fluid volume, and sodium balance. Overactivity of RAAS promotes both systemic and regional glomerular capillary hypertension, which could induce hemodynamic injury to the glomerulus, leading to kidney damage and renal fibrosis via profibrotic and proinflammatory pathway. Therefore, the use of RAAS inhibitors (i.e., ACEIs, ARBs, and MRAs) as the optional therapy has been demonstrated to prevent proteinuria, and kidney fibrosis and slow the decline of renal function effectively in the process of kidney disease during the last few decades. Recently, several new components of the RAAS have been discovered, including ACE2 and the corresponding ACE2/Ang (1-7)/Mas axis, which are also present in the kidney. Besides the classic RAAS inhibitors target the angiotensin-AT1-aldosterone axis, with the expanding knowledge about RAAS, a number of potential therapeutic targets in this system is emerging. Newer agents that are more specific are being developed. The present chapter outlines the insights of the RAAS agents (classic RAAS antagonists/the new RAAS drugs), and discusses its clinical application in the combat of renal fibrosis.

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

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

Associations between perfluorinated chemicals and serum biochemical markers and performance status in uremic patients under hemodialysis

Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are commonly used perfluorinated chemicals (PFCs). PFCs are mainly excreted by urine. Uremic patients tend to accumulate toxins in their body and have poor functional status. We investigated the associations between PFCs and the clinical profile of uremic patients under hemodialysis (HD). Liquid chromatography tandem mass spectrometry coupled with isotope dilution was used to quantify PFOA and PFOS. We enrolled 126 patients under regular HD. Compared with previous research, the concentration of PFOA was lower, but that of PFOS was higher in uremic patients than in the general population. The levels of PFOA and PFOS in uremic patients before dialysis were 0.52 (ng/ml) and 21.84 (ng/ml) respectively. The PFOA level remained unchanged but that of PFOS decreased to1.85 ng/mL after dialysis. PFOS can be removed by HD. Patients using hypertensive medication had a lower PFOS then those who did not. The PFOS level was negatively correlated with the duration of the HD session and patient performance status, but positively correlated with levels of cholesterol, chloride (an indicator of acidemia), ferritin, and total protein. (p<0.05). The association with serum protein may explain the long half-life of PFCs in humans. This is the first study which investigated PFCs in uremic patients and showed PFCs are associated with adverse effects in this population.

Angiotensin receptor blockers are associated with lower mortality than ACE inhibitors in predialytic stage 5 chronic kidney disease: A nationwide study of therapy with renin-angiotensin system blockade

Dual renin angiotensin system (RAS) blockade using angiotensin-receptor blockers (ARBs) in combination with angiotensin converting enzyme inhibitors (ACEIs) is reported to improve proteinuria in both diabetic and non-diabetic patients. However, its renoprotective effect and safety remain uncertain in patients with advanced chronic kidney disease (CKD). From January 1, 2000 through June 30, 2009, we enrolled 14,117 pre-dialytic stage 5 CKD patients with serum creatinine >6mg/dL and hematocrit <28% under the treatment with erythropoiesis stimulating agents and RAS blockade. We used Cox proportional hazards regression models to estimate the hazard ratios (HRs) against the commencement of long-term dialysis and all-cause mortality for ACEI/ARB users. Over a median follow-up of 7 months, 9,867 patients (69.9%) required long-term dialysis and 2,805 (19.9%) died before progression to end-stage renal disease requiring dialysis. In comparison with the ARB-only users, dual blockade with ACEIs and ARBs was associated with a significantly higher risk of (1) death in all CKD patients (HR = 1.49, [95%CI, 1.30-1.71]; P = 0.02) and in diabetic subgroup (HR = 1.58, [95%CI, 1.34-1.86]; P = 0.02); (2) composite endpoint of long-term dialysis or death in diabetic subgroup (HR = 1.10, [95%CI, 1.01-1.20]; P = 0.04); (3) hyperkalemia-associated hospitalization in non-diabetic subgroup (HR, 2.74, [95%CI, 1.05-7.15]; P = 0.04). However, ACEIs users were associated with higher mortality than ARBs users in all CKD patients (HR = 1.17, [95%CI, 1.07-1.27]; P = 0.03) and in diabetic subgroup (HR = 1.32, [95%CI, 1.18-1.48]; P = 0.03). Monotherapy of RAS blockade, especially ARB, is more effective and safer than dual RAS blockade in pre-dialytic stage 5 CKD patients.

Direct inhibition of plasmatic renin activity with aliskiren: a promising but under-investigated therapeutic option for non-diabetic glomerulonephritis

Non-diabetic glomerulonephritis is a frequent cause of end-stage renal disease. The use of renin-angiotensin-aldosterone system blockers is a fundamental therapeutic approach. However, converting enzyme inhibitors (ACE-is) and angiotensin receptor blockers do not always achieve the desired target of proteinuria. The induction of the prorenin and renin up-regulation is a possible explanation. Aliskiren is the first drug acting as direct inhibitor of plasmatic renin activity, also able to interfere with the prorenin and renin profibrotic escape. We aimed at reviewing the literature for the assessment of potential efficacy and safety of aliskiren in the treatment of non-diabetic glomerulonephritis. The data on this topic are limited; however, we concluded for a possible usefulness of aliskiren. The renal safety profile appears potentially acceptable in non-diabetic patients although extreme carefulness, particularly with respect to long-term renal and cardiovascular tolerability, is recommended.

Efficacy of aliskiren, compared with angiotensin II blockade, in slowing the progression of diabetic nephropathy in db/db mice: should the combination therapy be a focus?

Although the intensive use of angiotensin II blockade (ACEI or ARB), progression of diabetic nephropathy is common. A feedback increase in renin production often accompanies angiotensin II blockade. We therefore examined whether aliskiren, a direct renin inhibitor, confers better renoprotection than angiotensin II blockade and whether the addition of aliskiren to an ACEI or ARB would enhance the efficacy in slowing the progression of glomerulosclerosis in diabetes. Untreated db/db mice developed progressive mesangial matrix expansion and albuminuria between weeks 18 and 22, associated with reduction of WT-1 immunopositive podocytes and nephrin and podocin production and induction of desmin and B7-1 generation and renal expression of TGFß1, PAI-1, fibronectin and type IV collagen. Treatment with aliskiren at 30 mg/kg/d inhibited the increases in albuminuria and markers of renal fibrosis and the changes that are indicative of podocyte injury seen in the db/db mice. Notably, the therapeutic effect of aliskiren was similar to that of either enalapril or valsartan given alone at maximally effective doses. Combined therapy caused the loss of 10% ~ 16.6% of db/db mice, yielded no further reduction in renal fibrosis and podocyte injury but further reduced albuminuria and renal production of TNFα, Nox2 and p47phox and urine MCP-1 and malondialdehyde levels, the markers of renal inflammation and oxidative stress. These results suggest that aliskiren, enalapril and valsartan are equally effective in slowing the progression of diabetic nephropathy. The use of combination therapy with aliskiren and ACEI/ARB may not be strongly supported.

Proteinuria and its relation to cardiovascular disease

Chronic kidney disease (CKD) and its associated morbidity pose a worldwide health problem. As well as risk of endstage renal disease requiring renal replacement therapy, cardiovascular disease is the leading cause of premature death among the CKD population. Proteinuria is a marker of renal injury that can often be detected earlier than any tangible decline in glomerular filtration rate. As well as being a risk marker for decline in renal function, proteinuria is now widely accepted as an independent risk factor for cardiovascular morbidity and mortality. This review will address the prognostic implications of proteinuria in the general population as well as other specific disease states including diabetes, hypertension and heart failure. A variety of pathophysiological mechanisms that may underlie the relationship between renal and cardiovascular disease have been proposed, including insulin resistance, inflammation, and endothelial dysfunction. As proteinuria has evolved into a therapeutic target for cardiovascular risk reduction in the clinical setting we will also review therapeutic strategies that should be considered for patients with persistent proteinuria.

The safety and short-term efficacy of aliskiren in the treatment of immunoglobulin a nephropathy--a randomized cross-over study

Background

Laboratory research and previous study suggest that aliskiren, a direct renin inhibitor, has anti-proteinuric effects. We conducted a randomized crossover study to evaluate the anti-proteinuric effect of aliskiren in patients with immunoglobulin A (IgA) nephropathy.

Methods

We studied 22 patients with biopsy-proven IgA nephropathy and persistent proteinuria despite angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). Patients were randomized to either oral aliskiren 300 mg/day or placebo for 16 weeks and then crossed over to the other treatment arm after a washout period. Proteinuria, estimated glomerular filtration rate (eGFR), blood pressure, and serum potassium were monitored.

Results

After aliskiren treatment, there was a significant reduction in proteinuria in 4 weeks (1.76±0.95 to 1.03±0.69 g:g-Cr, p<0.0001), which remained at a low level throughout the treatment period. There was a significant difference in proteinuria between the aliskiren and placebo groups from 4 to 16 weeks after treatment (p<0.01 for all comparisons). After aliskiren treatment, there were modest but statistically significant reductions in eGFR (57.2±29.1 to 54.8±29.3 ml/min/1.73 m², p = 0.013) and diastolic blood pressure (72.6±12.3 to 66.2±11.2 mmHg, p<0.0001). None of the patient developed severe hyperkalemia (serum potassium ≥6.0 mmol/l) during the study period.

Conclusions

Aliskiren has anti-proteinuric effect in patients with IgA nephropathy and persistent proteinuria despite ACE inhibitor or ARB. Further studies are needed to confirm the renal protecting effect of direct renin inhibition in chronic proteinuric kidney diseases.

Trial Registration

ClinicalTrials.gov NCT00870493

Aliskiren add-on therapy effectively reduces proteinuria in chronic kidney disease: an open-label prospective trial

INTRODUCTION

The combination therapy of aliskiren and renin-angiotensin-aldosterone system (RAAS) blocker in chronic kidney disease (CKD) is controversial. Whether such dual blockade can effectively apply to patients with CKD irrespective of stage and amount of proteinuria remains uncertain.

METHODS

We added aliskiren at a dosage of 150 mg/day for six months in 103 Chinese CKD patients who had been treated with angiotensin converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs) and still had significant proteinuria or uncontrolled hypertension. Blood pressure, serum creatinine, estimated glomerular filtration rate (eGFR), potassium, and spot urine protein-to-creatinine ratio (UPCR) were measured at three and six months after aliskiren add-on therapy and compared with baseline.

RESULTS

The combination of aliskiren and ACEi or ARB significantly reduced UPCR by 23% (p=0.001) and mean arterial pressure by 7.9 ± 13.8 mmHg (p<0.001) at six months. Twenty-five percent of subjects had a greater than 50% reduction in UPCR. No significant changes in eGFR and serum potassium level were noted at six months.

CONCLUSIONS

Adding aliskiren on ACEi or ARB in CKD patients, both in diabetes and non-diabetes, has a favorable effect on reducing residual proteinuria and inadequately controlled blood pressure.