Effects of Aliskiren on blood pressure and the predictive biomarkers for cardiovascular disease in hemodialysis-dependent chronic kidney disease patients with hypertension

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.

Systematic Review and Meta-Analysis of Renin-Angiotensin-Aldosterone System Blocker Effects on the Development of Cardiovascular Disease in Patients With Chronic Kidney Disease

Background: Cardiovascular events are one of the most serious complications that increase the risk of mortality and morbidity in pre-dialysis and on-dialysis chronic kidney disease (CKD) patients. Activation of the renin-angiotensin-aldosterone system (RAAS) is considered to contribute to the development of cardiovascular events in these populations. Therefore, several kinds of RAAS blockers have been frequently prescribed to prevent cardiovascular events in patients with CKD; however, their effectiveness remains controversial. This systematic review focuses on whether RAAS blockers prevent cardiovascular events in patients with CKD. Method: PubMed were searched to retrieve reference lists of eligible trials and related reviews. Randomized prospective controlled trials that investigated the effects on cardiovascular events in CKD patients that were published in English from 2010 to 2020 were included. Results: Among 167 identified studies, 11 eligible studies (n = 8,322 subjects) were included in the meta-analysis. The meta-analysis showed that RAAS blockers significantly reduced cardiovascular events in on-dialysis patients with CKD [three studies; odds ratio (OR), 0.52; 95% confidence interval (CI), 0.36 to 0.74; p = 0.0003], but there was no significant difference in pre-dialysis patients with CKD because of the heterogeneity in each study (eight studies). We also investigated the effects of each kind of RAAS blocker on cardiovascular events in CKD patients. Among the RAAS blockers, mineralocorticoid receptor antagonists significantly decreased cardiovascular events in pre-dialysis or on-dialysis patients with CKD (four studies; OR, 0.60; 95%CI, 0.50 to 0.73, p < 0.0001). However, angiotensin receptor blockers did not show significant effects (four studies; OR, 0.65; 95%CI, 0.42 to 1.01; p = 0.0529). The effects of angiotensin converting enzyme inhibitors and direct renin inhibitors on cardiovascular events in patients with CKD could not be analyzed because there were too few studies. Conclusion: Mineralocorticoid receptor antagonists may decrease cardiovascular events in pre-dialysis or on-dialysis patients with CKD.

Early administration of empagliflozin preserved heart function in cardiorenal syndrome in rat

This study tested the hypothesis that early administration of empagliflozin (Empa), an inhibitor of glucose recycling in renal tubules, could preserve heart function in cardiorenal syndrome (CRS) in rat. Chronic kidney disease (CKD) was caused by 5/6 subtotal nephrectomy and dilated cardiomyopathy (DCM) by doxorubicin (DOX) treatment. In vitro results showed that protein expressions of cleaved-caspase3 and autophagy activity at 24 h/48 h in NRK-52P cells were significantly upregulated by para-Creso treatment; these were significantly downregulated by Empa treatment. Flow cytometric analysis showed that annexin-V (i.e., early/late apoptosis) in NRK-52P cells expressed an identical pattern to cleaved-caspase3 between the two groups (all p < 0.001). Adult-male-SD rats (n = 18) were equally categorized into group 1 (sham-control), group 2 (CRS) and group 3 [CRS + Empa; 20 mg/kg/day]. By day-42 after CRS induction, left-ventricular ejection fraction (LVEF) level exhibited an opposite pattern, whereas LV end-diastolic dimension and creatinine level displayed the same pattern, to cleaved-caspase3 among the three groups (all p < 0.0001). In LV tissues, protein expressions of inflammatory (tumor-necrosis factor-α/nuclear-factor-κB/interleukin-1ß/matrix-metalloprotianse-9), oxidative stress (NOX-1/NOX-2/oxidized protein), apoptotic (mitochondrial-Bax/cleaved-caspase-3/cleaved-PARP), fibrotic (transforming-growth factor-ß/Smad3), DNA/mitochondrial-damage (γ-H2AX/cytosolic-cytochrome-C) and heart failure (brain natriuretic peptide (BNP) levels displayed an opposite pattern to LVEF among the three groups (all p < 0.0001). Additionally, cellular expressions of DNA-damage/heart-failure (γ-H2AX+//XRCC1+CD90+//BNP+) biomarkers and histopathological findings of fibrotic/condensed collagen-deposition areas and apoptotic nuclei showed an identical pattern, whereas connexin43 and small-vessel number exhibited an opposite pattern, to inflammation among the three groups (all p < 0.0001). In conclusion, Empa therapy protected heart and kidney against CRS injury.

Immunologic Effects of the Renin-Angiotensin System

Inappropriate activation of the renin-angiotensin system (RAS) exacerbates renal and vascular injury. Accordingly, treatment with global RAS antagonists attenuates cardiovascular risk and slows the progression of proteinuric kidney disease. By reducing BP, RAS inhibitors limit secondary immune activation responding to hemodynamic injury in the target organ. However, RAS activation in hematopoietic cells has immunologic effects that diverge from those of RAS stimulation in the kidney and vasculature. In preclinical studies, activating type 1 angiotensin (AT₁) receptors in T lymphocytes and myeloid cells blunts the polarization of these cells toward proinflammatory phenotypes, protecting the kidney from hypertensive injury and fibrosis. These endogenous functions of immune AT₁ receptors temper the pathogenic actions of renal and vascular AT₁ receptors during hypertension. By counteracting the effects of AT₁ receptor stimulation in the target organ, exogenous administration of AT₂ receptor agonists or angiotensin 1-7 analogs may similarly limit inflammatory injury to the heart and kidney. Moreover, although angiotensin II is the classic effector molecule of the RAS, several RAS enzymes affect immune homeostasis independently of canonic angiotensin II generation. Thus, as reviewed here, multiple components of the RAS signaling cascade influence inflammatory cell phenotype and function with unpredictable and context-specific effects on innate and adaptive immunity.

Therapeutics targeting persistent inflammation in chronic kidney disease

Systemic inflammation is a condition intrinsically linked to chronic kidney disease (CKD) and its other typical sequelae, such as acquired immune dysfunction, protein-energy wasting (PEW), and accelerated vascular aging that promote premature cardiovascular disease (CVD) and infections, the two leading causes of death in CKD patients. Inflammation is a major contributor to complications in CKD, and inflammatory markers, such as C-reactive protein and pro- and anti-inflammatory cytokines, correlate with underlying causes and consequences of the inflamed uremic phenotype, such as oxidative stress, endothelial dysfunction, CVD, PEW, and infections, and are sensitive and independent predictors of outcome in CKD. Therefore, inflammation appears to be a logical target for potential preventive and therapeutic interventions in patients with CKD. Putative anti-inflammatory therapy strategies aiming at preventing complications and improving outcomes in CKD span over several areas: (1) dealing with the source of inflammation (such as cardiovascular, gastrointestinal or periodontal disease and depression); (2) providing nonspecific immune modulatory effects by promoting healthy dietary habits and other lifestyle changes; (3) promoting increased use of recognized pharmacologic interventions that have pleiotropic effects; and, (4) introducing novel targeted anticytokine interventions. This review provides a brief update on inflammatory biomarkers and possible therapeutic approaches targeting inflammation and the uremic inflammatory milieu in patients with CKD.

Some Aspects of the Renin-Angiotensin-System in Hemodialysis Patients

Understanding of the renin-angiotensin system (RAS) has changed remarkably over the past decade. Renin, angiotensin converting enzyme (ACE), angiotensin II (Ang II), and Ang II receptors are the main components of the RAS. Recent studies identified the ACE2/Ang 1–7/ Mas receptor axis, which counter-regulates the classical RAS. Many studies have examined the effects of the RAS on the progression of cardiovascular disease and chronic kidney disease (CKD). In addition, many studies have documented increased levels of ACE in hemodialysis (HD) patients, raising concerns about the negative effects of RAS activation on the progression of renal disease. Elevated ACE increases the level of Ang II, leading to vasoconstriction and cell proliferation. Ang II stimulation of the sympathetic system leads to renal and cardiovascular complications that are secondary to uncontrolled hypertension. This review provides an overview of the RAS, evaluates new research on the role of ACE2 in dialysis, and reviews the evidence for potentially better treatments for patients undergoing HD. Further understanding of the role of ACE and ACE2 in HD patients may aid the development of targeted therapies that slow the progression of CKD and cardiovascular disease.

Malnutrition in Dialysis Patients--The Need for Intervention Despite Uncertain Benefits

We are in the midst of an epidemic of overnutrition which has resulted in a widespread increase in obesity rates in modern societies. Yet for patients suffering from serious chronic illnesses such as end stage renal disease (ESRD), malnutrition (encompassing both inadequate quantity and quality of nutrient intake) represents a far more significant danger. Protein-energy wasting has been identified as one of the strongest risk factor for adverse outcomes in ESRD patients, and modeling studies have suggested that improving nutrition could result in substantial lowering of mortality rates and other benefits. To date there is ample evidence that various interventions can have a positive impact on the nutritional status of ESRD patients, yet we still lack randomized controlled clinical trials showing that the same interventions could indeed lead to better survival or other clinical benefits. This knowledge gap, which is all too common for clinical problems encountered in nephrology, should not act as a deterrent, but it should rather incentivize us to continue exploring novel interventions aimed at improving malnutrition in ESRD.

Effects of Febuxostat on Oxidative Stress

PURPOSE

We previously examined factors that affect the measured derivatives of reactive oxygen metabolites (d-ROMs), an indicator of reactive oxygen species production, and biological antioxidant potential (BAP), an indicator of antioxidant capacity, in typical health checkup examinees and reported the usefulness of measuring both indicators simultaneously. In addition, a positive correlation reportedly exists between d-ROMs and the visceral fat area measured by using computed tomography. A recent study of the relationship between uric acid levels and various obesity-related factors found that visceral fat was the factor most strongly related to uric acid levels. Uric acid is itself a potent endogenous antioxidant, but because reactive oxygen species are produced during uric acid generation, it is suggested that uric acid may have opposing effects. The objective of this study was to analyze the effect of febuxostat, a novel xanthine oxidase inhibitor, on oxidative stress.

METHODS

Study subjects were 43 hyperuricemia outpatients receiving care in the internal medicine department of our institution. The subjects were divided into a new administration group (29 patients) and a switched administration group (14 patients); the latter were allopurinol-treated patients with hyperuricemia who were switched to febuxostat. In addition to measuring the patients' uric acid and creatinine levels and estimated glomerular filtration rate before and after treatment, their d-ROMs and BAP as well as the BAP/d-ROMs ratio were also measured.

FINDINGS

Both groups exhibited significant decreases in uric acid levels, as well as significant decreases in d-ROMs and BAP. No significant changes were observed in the BAP/dROMs ratio or renal function, including creatinine levels and estimated glomerular filtration rate.

IMPLICATIONS

Febuxostat could significantly reduce d-ROMs. However, BAP levels were also significantly reduced concurrently. No changes were observed in the BAP/d-ROMs ratios. This regulatory mechanism is believed to have counteracted changes in the in vivo oxidative stress balance caused by febuxostat administration.

Successful treatment of hypertension in anuric hemodialysis patients with a direct Renin inhibitor, aliskiren

OBJECTIVE

A direct renin-inhibitor (DRI), aliskiren, was administered to anuric patients to investigate whether it can be a new optional therapy against hypertension in hemodialysis (HD) patients.

PATIENTS

The patients that received aliskiren comprised 8 males and 2 females with a mean ± SD age of 63 ± 8 years (43-72 years). They were exposed to dialysis therapy for 118 ± 73 months (8-251 months), with diabetes mellitus in 4 cases, chronic glomerulonephritis in 4 cases, and other diagnoses in 2 cases.

METHODS

After the plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured before an HD session, aliskiren, 150 mg as an initial dose, was administered to the patients. PRA and PAC were also examined a week after initiating aliskiren. The blood pressure (BP) levels at the start of each HD session for a period of 2 weeks (6 HD sessions) were compared between before and after administration of aliskiren. The change of doses in other antihypertensive agents was also counted.

RESULTS

The averaged reduction of mean blood pressure was 4 ± 5 mmHg, and doses of antihypertensives other than aliskiren were reduced in 4 patients. Of the examined parameters, only the reduction rate of PRA x PAC seemed correlated with the BP lowering effect of aliskiren, which was calculated as the sum of the mean BP reduction in mmHg and drug reduction with 1 tablet (capsule)/day considered to be 10 mmHg.

CONCLUSION

A DRI, aliskiren, was effective even in anuric dialysis patients, and monitoring of PRA and PAC was valuable for selecting cases responsive to aliskiren.

Skin autofluorescence is a predictor of cardiovascular disease in chronic kidney disease patients

Accelerated formation and tissue accumulation of advanced glycation end products (AGEs), reflecting cumulative glycemic and oxidative stress, occurs in age-related and chronic diseases like diabetes mellitus (DM) and renal failure, and contributes to vascular damage. Skin autofluorescence (AFR), a noninvasive measurement method, reflects tissue accumulation of AGEs. AFR has been reported to be an independent predictor of mortality in Caucasian hemodialysis patients. We assessed the relationship between levels of AFR and the prevalence of cardiovascular disease (CVD), and clarified the prognostic usefulness of skin AFR levels in Asian (non-Caucasian) hemodialysis (HD) patients. AFR was measured with an autofluorescence reader in 64 HD patients. Overall and cardiovascular mortality was monitored prospectively during the 3-year follow-up. During follow-up, CVD events occurred in 21 patients. The deaths of 10 HD patients were associated with CVD. Multivariate logistic regression analyses showed that initial AFR was an independent risk factor for de novo CVD in HD patients with or without diabetes. When patients were classified on the basis of AFR tertiles, Cochran-Armitage analysis demonstrated that the highest tertile of AFR level showed an increased odds ratio for the prevalence of CVD. These findings suggest that AFR levels can be used to detect the prevalence of CVD in HD patients with or without diabetes.

Direct renin inhibition in chronic kidney disease

For approximately 6 years, the only commercially available direct renin inhibitor, aliskiren, which inhibits the renin-angiotensin-aldosterone system at the initial rate limiting step, has been marketed for the treatment of hypertension. Concurrently, much attention has been given to the possibility that renin inhibition could hold potential for improved treatment in patients with chronic kidney disease, with diabetic nephropathy as an obvious group of patients to investigate, as the activity of the renin-angiotensin-aldosterone system is enhanced in these patients and as there is an unmet need for improved treatment and prognosis in these patients. Several short term studies have been performed in diabetic nephropathy, showing a consistent effect on the surrogate endpoint lowering of albuminuria, both as monotherapy and in combination with other blockers of the renin-angiotensin-aldosterone system. In addition, combination treatment also seemed safe and effective in patients with impaired kidney function. These initial findings formed the basis for the design of a large morbidity and mortality trial investigating aliskiren as add-on to standard treatment. The study has just concluded, but was terminated early as a beneficial effect was unlikely and there was an increased frequency of side effects. Also in non-diabetic kidney disease a few intervention studies have been carried out, but there is no ongoing hard outcome study. In this review we provide the current evidence for renin inhibition in chronic kidney disease by reporting the studies published so far as well as a perspective on the future possibilities.

Clinical Implication of the Renin-angiotensin-aldosterone Blockers in Chronic Kidney Disease Undergoing Hemodialysis

The renin-angiotensin-aldosterone system (RAAS) blockers have been widely used in chronic kidney disease patients undergoing hemodialysis; however, whether RAAS blockers have beneficial effects for cardiovascular disease in those patients has not been fully defined. This review focuses on the effects of RAAS blockers in chronic kidney disease undergoing hemodialysis for cardiovascular disease.

Effects of aliskiren on blood pressure and humoral factors in hypertensive hemodialysis patients previously on angiotensin II receptor antagonists

BACKGROUND

A direct renin inhibitor (DRI), aliskiren, may be effective for blood pressure (BP) control in hemodialysis patients. However, it is unclear whether aliskiren has a greater beneficial effect on BP and humoral factors than angiotensin II receptor antagonists (ARBs) in hypertensive patients on hemodialysis.

METHODS

Eighteen hemodialysis patients (58 ± 14 years) on the recommended dose of an ARB were prospectively randomized into two groups: ARB and DRI groups. Patients in the ARB group continued taking their previous ARB, whereas those in the DRI group switched to aliskiren (150 mg/day) for 12 weeks. Baseline measurements of BP and humoral factors such as plasma renin activity (PRA), plasma aldosterone concentration (PAC) and brain natriuretic peptide (BNP) were performed. Measurements were repeated every 4 weeks.

RESULTS

At baseline, no differences were observed in age, gender or BP between the two groups. Systolic BP was unaffected by treatment in either groups (group effect, p = 0.26; time effect, p = 0.38; group × time effect, p = 0.24). PRA decreased in DRI (p ≤ 0.02, group effect, p = 0.65; time effect, p = 0.13; group × time effect, p = 0.048), but not in ARB (p ≥ 0.94). PAC increased only in DRI (p ≤ 0.03), whereas BNP was unaffected in either group.

CONCLUSION

Aliskiren at a dose of 150 mg/day had a similar effect on BP compared with ARBs, but significantly lowered PRA.

Neutrophil gelatinase-associated lipocalin levels associated with cardiovascular disease in chronic kidney disease patients

BACKGROUND

Elevated levels of neutrophil gelatinase-associated lipocalin (NGAL) have been reported in patients with cardiovascular disease (CVD), heart failure, and stroke. We assessed the relationships between serum levels of NGAL and the prevalence of CVD, and clarified the prognostic usefulness of systemic NGAL levels in hemodialysis (HD) patients.

METHODS

Eighty-eight HD patients were followed up for 1 year. Logistic regression analyses were used to investigate the relationship between de novo CVD status and NGAL levels as well as other risk factors.

RESULTS

During follow-up, CVD events occurred in 20 patients. Initial serum levels of NGAL and brain natriuretic peptide of HD patients with de novo CVD were significantly higher than those of HD patients without de novo CVD. Multivariate logistic regression analyses showed that initial serum levels of NGAL were independent risk factors for de novo CVD in HD patients. When patients were classified on the basis of NGAL quartiles, multiple logistic regression analyses demonstrated that the highest quartile of NGAL level showed an increased odds ratio for the prevalence of CVD.

CONCLUSION

These findings suggest that NGAL levels can be used to detect the prevalence of CVD in HD patients with or without diabetes.

Neuroprotective effects of liraglutide for stroke model of rats

The number of diabetes mellitus (DM) patients is increasing, and stroke is deeply associated with DM. Recently, neuroprotective effects of glucagon-like peptide-1 (GLP-1) are reported. In this study, we explored whether liraglutide, a GLP-1 analogue exerts therapeutic effects on a rat stroke model. Wistar rats received occlusion of the middle cerebral artery for 90 min. At one hour after reperfusion, liraglutide or saline was administered intraperitoneally. Modified Bederson's test was performed at 1 and 24 h and, subsequently, rats were euthanized for histological investigation. Peripheral blood was obtained for measurement of blood glucose level and evaluation of oxidative stress. Brain tissues were collected to evaluate the level of vascular endothelial growth factor (VEGF). The behavioral scores of liraglutide-treated rats were significantly better than those of control rats. Infarct volumes of liraglutide-treated rats at were reduced, compared with those of control rats. The level of derivatives of reactive oxygen metabolite was lower in liraglutide-treated rats. VEGF level of liraglutide-treated rats in the cortex, but not in the striatum significantly increased, compared to that of control rats. In conclusion, this is the first study to demonstrate neuroprotective effects of liraglutide on cerebral ischemia through anti-oxidative effects and VEGF upregulation.

[Fluid overload and arterial hypertension in hemodialysis patients]

The water sodium overload is a factor of morbi-mortality and its treatment is one of the markers of adequacy of the hemodialysis treatment. Its first clinical assessment was improved by tools such as echocardiography and ultrasonography of the inferior vena cava, the per-dialytic curve of plasma volume, measuring BNP or proBNP and by impedancemetry. The combination of the evaluation of these parameters and of the clinical situation allows one to assess the extracellular overload, the state of the blood volume and the potential of plasma refilling. The latter is a key factor of the per-dialytic hemodynamic tolerance. It is itself a determining factor in weight can be achieved at the end of the session. Getting the "dry" weight can require modifications of the prescriptions of the hemodialysis sessions, a filling by albumin even a drugs support. Finally, the overload treatment is the central part of the treatment of arterial hypertension, which has to benefit however often from antihypertensive treatment the profit of which is demonstrated.

Aliskiren, a direct renin inhibitor, improves vascular endothelial function in patients on hemodialysis independent of antihypertensive effect ∼ a pilot study∼

AIMS

Aliskiren inhibits the first step in the renin-angiotensin system (RAS) and recently has been shown to modulate vascular diseases via RAS-dependent and independent pathways. This study aimed to determine the effect of aliskiren-associated direct renin inhibition on endothelial function in patients on hemodialysis via flow-mediated dilatation (FMD) and platelet-derived microparticles (PDMP), as biomarkers of atherosclerosis.

METHODS

A 12-week prospective study was performed with 24 patients on hemodialysis who were administered 150 mg orally aliskiren once daily for 12 weeks.

RESULTS

No significant difference were observed between pre-dialysis, home, and weekly averaged blood pressure at baseline and at 12 weeks (151.5 ± 8.5/80.9 ± 12.9 mmHg vs 150.3 ± 15.3/78.9 ± 21.2 mmHg, 151.4 ± 9.7/82.3 ± 14.7 mmHg vs 151.2 ± 17.7/81.4 ± 10.6 mmHg, and 156.0 ± 18.3/81.9 ± 9.4 mmHg vs 152.5 ± 18.9/81.7 ± 12.3 mmHg, respectively). FMD significantly increased from 2.54% ± 1.45% at baseline to 3.11% ± 1.37% at 12 weeks (P = 0.0267), and PDMP significantly decreased from 13.9 ± 5.8 U/mL at baseline to 10.9 ± 4.5 U/mL at 12 weeks (P = 0.0002).

CONCLUSION

Aliskiren improved vascular endothelial function and platelet-endothelium activation in patients on hemodialysis independent of antihypertensive effect.

Effects of direct renin inhibition on atherosclerotic biomarkers in patients with stable coronary artery disease and type 2 diabetes mellitus

OBJECTIVES

To evaluate whether the direct renin inhibitor, aliskiren, has a more favorable effect compared to amlodipine on atherosclerotic biomarkers in patients with stable coronary artery disease and diabetes currently receiving standard secondary prevention therapy.

METHODS

A total of 38 patients were randomly assigned initially to either aliskiren (150 mg daily) or amlodipine (5 mg daily) for 2 weeks after which the dose of either medication was increased to its maximum daily dose for 4 additional weeks. Baseline and 6-week blood samples were analyzed for changes from baseline and between treatment groups for vascular and intracellular cell adhesion molecule, C-reactive protein, nitric oxide, plasminogen activator inhibitor 1, 8-isoprostane, and thiobarbituric acid reactive substances.

RESULTS

Thirty-one patients completed the study. More of the dropouts occurred in patients receiving aliskiren. Systolic blood pressure decreased in both treatment arms with no differences between the groups being noted. Plasminogen activator inhibitor 1, nitric oxide, and C-reactive protein concentrations increased in both groups from baseline but changes from baseline or between groups were not significant. Vascular and intracellular cell adhesion molecule, thiobarbituric acid reactive substances, and isoprostane concentrations decreased in each treatment arm from baseline, but these changes were not significant and no differences were noted between the groups.

CONCLUSIONS

Treatment with either aliskiren or amlodipine did not significantly alter surrogate biomarkers of atherosclerosis in patients with both diabetes and established cardiovascular disease already receiving appropriate secondary cardiovascular prevention therapy. The study is limited in its size and duration to see an effect.

Aliskiren reduces morning blood pressure in hypertensive patients with diabetic nephropathy on hemodialysis

Our previous study indicated that the exchange from an angiotensin receptor blocker (ARB) to aliskiren reduced morning blood pressure and albuminuria in hypertensive patients with diabetic nephropathy. We extended the above study and assessed the effects of exchanging from an ARB to aliskiren on home blood pressure in hypertensive patients with diabetic nephropathy on chronic hemodialysis. The patients who were persistently hypertensive despite antihypertensive therapy, including ARB, were considered as candidates for the exchange from the ARB to aliskiren. Patients' age and durations of diabetes and hemodialysis were averaged as 62 ± 9 years old, 15 ± 8 and 7 ± 3 years, respectively. Aliskiren decreased morning systolic blood pressure (149 ± 14 to 144 ± 13 mm Hg, n = 30, P < .01) and plasma renin activity (3.5 ± 1.1 to 1.2 ± 0.6 ng/mL/h, P < .01) without changes in serum potassium. Aliskiren also reduced interdialytic weight gain (2.7 ± 0.6 to 2.5 ± 0.5 kg/interval, P < .05) and attenuated the magnitude of intradialytic declines in systolic (-20 ± 11 to -17 ± 10 mm Hg, P < .05) and diastolic blood pressure (-9 ± 6 to -5 ± 5 mm Hg, P < .01). The exchange from an ARB to aliskiren is safe and useful to control home blood pressure in hypertensive hemodialysis patients with diabetic nephropathy. Aliskiren reduced both intradialytic blood pressure drops and interdialytic weight gain in patients with DN.

Long-term antihypertensive effects of aliskiren, a direct renin inhibitor, in chronic hemodialysis patients

The renin-angiotensin-aldosterone system is not necessarily suppressed in end-stage renal disease patients undergoing dialysis. Of all the inhibitors of this system, the clinical efficacy of the renin inhibitor, aliskiren, has not been well demonstrated in dialysis patients. We evaluated the antihypertensive effect of aliskiren, administered as a single daily dose of 150 mg for 24 weeks, in 23 chronic hemodialysis patients (age 65 ± 12 years, 15 men and eight women) with blood pressure ≥140/90 mm Hg, and assessed the factors relating to blood pressure reduction. At 4 weeks, the average systolic blood pressure before the dialysis session was insignificantly reduced from 163 ± 10 mm Hg to 160 ± 15 mm Hg, while it was significantly lowered at 12 (154 ± 13 mm Hg) and 24 weeks (155 ± 10 mm Hg), although the pulse rate was not significantly altered. Serum K increased at 24 weeks from 4.9 ± 0.6 mEq/L to 5.2 ± 0.8 mEq/L. Only 10 out of 23 patients showed systolic blood pressure reduction by ≥10 mm Hg. Naturally, plasma renin immunoreactivity increased, while plasma renin activity, along with angiotensin II and aldosterone levels decreased. Basal levels of the components of the renin-angiotensin-aldosterone system were not significantly different in patients showing systolic blood pressure reduction by ≥10 mm Hg (n = 10) vs. those with <10 mm Hg changes (n = 13). The reduction in systolic blood pressure in all 23 patients taken as a whole correlated with changes in plasma renin activity (r = -0.432, P < 0.05) and angiotensin II (r = 0.467, P < 0.05). In chronic hemodialysis patients, aliskiren modestly lowers blood pressure over the long term, although the antihypertensive effect seems dependent on the changes, but not on the basal levels of plasma renin activity and angiotensin II.

Direct Renin inhibitor: aliskiren in chronic kidney disease

The renin-angiotensin-aldosterone system (RAAS) plays pivotal roles in the pathogenesis of chronic kidney disease (CKD) progression and its increased complications such as hypertension (HT) and cardiovascular diseases (CVD). Previous studies suggested that aliskiren a direct renin inhibitor, blocks RAAS and may be effective for the management of CKD and its complications. This review focuses on the effects of aliskiren on CKD.

Aliskiren suppresses the renin-angiotensin-aldosterone system and reduces blood pressure and albuminuria in elderly chronic kidney disease patients with hypertension

Background:

We investigated the effects of aliskiren in terms of its inhibition of the renin–angiotensin–aldosterone system (RAAS) as well as that on blood pressure (BP), and renal and cardiac protection in elderly chronic kidney disease (CKD) patients with hypertension.

Methods:

Nineteen elderly CKD patients (nine males, ten females, aged 74.6 ± 5.8 years) were assigned to receive 150 mg/day of aliskiren added to existing antihypertensives for 6 months. Changes in plasma renin activity (PRA), angiotensin I (Ang I), angiotensin II (Ang II), aldosterone (Ald), BP, estimated glomerular filtration rate (eGFR), urine albumin/creatinine ratio (UACR), left ventricular ejection fraction (LVEF), interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPWT), and plasma brain natriuretic peptide (BNP) levels were evaluated.

Results:

Aliskiren suppressed the RAAS as follows: PRA 1.3 ± 1.0 to 0.3 ± 0.3 ng/mL/hour, P < 0.05; Ang I 59.5 ± 32.1 to 26.0 ± 17.3 pg/mL, P < 0.05; Ang II 58.4 ± 62.1 to 14.3 ± 9.0 pg/mL, P < 0.05; and Ald 86.1 ± 38.3 to 80.1 ± 52.6 pg/mL, not significant (NS). Aliskiren reduced BP (153.6/77.2 ± 14.9/10.4 to 130.9/72.2 ± 15.6/9.9 mmHg, P < 0.05). It also reduced UACR (747.1 ± 1121.4 to 409.6 ± 636.8 mg/g, P < 0.05), whereas it did not change eGFR (52.1 ± 29.2 to 51.2 ± 29.3 mL/min/1.73 m², NS), LVEF (66.8 ± 7.9 to 66.5% ± 6.8%, NS), IVST (10.1 ± 1.8 to 9.9 ± 1.8 mm, NS), LVPWT (10.0 ± 1.6 mm to 10.0 ± 1.4 mm, NS), or BNP (48.2 ± 46.0 to 54.9 ± 41.1 pg/mL, NS).

Conclusion:

Aliskiren was effective for BP control and reduced UACR while maintaining eGFR and heart function in elderly CKD patients with hypertension.

A comparison of the antihypertensive and anti-inflammatory effects of aliskiren and ramipril add-on therapy in peritoneal dialysis patients--a pilot open label study

Most hypertensive dialysis patients are currently treated with angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB). Aliskiren, the direct renin inhibitor, has not been specifically studied in peritoneal dialysis patients. The aim of the study was to compare hypotensive effects of aliskiren and ramipril and their influence on serum potassium and inflammatory parameters in hypertensive peritoneal dialysis patients. Eighteen hypertensive patients on chronic peritoneal dialysis were enrolled in an open-label comparative fixed-order study. The patients had been off RAAS blocking drugs for ≥4 weeks prior to an inclusion. At each of 3 study visits (baseline and after each of the treatment periods) blood pressure, serum lipids, potassium, renin, aldosterone, C-reactive protein (CRP) and monocyte chemotactic protein-1 (MCP-1) were measured. After the baseline visit aliskiren was started (150 mg/d) and after 12 weeks replaced with ramipril (5 mg/d) for the next 12 weeks. Blood pressure was 142/88±15/11 mmHg at baseline, 137/84±10/8 mmHg after aliskiren (ns) and 126/81±11/7 mmHg after ramipril (p<0.05 vs baseline and aliskiren). No incidents of hyperkalemia were observed. Plasma renin concentration increased significantly during aliskiren treatment compared to ramipril (227,6±844 vs. 58,3±765 pg/mL). CRP was similar after both therapies (8,8±34 vs. 8,4±32 µg/mL) but MCP-1 concentration was significantly lower after aliskiren than after ramipril (294,0±172,6 vs. 358,9±183,3 pg/mL). Aliskiren 150 mg/day decreases blood pressure less effectively than ramipril 5 mg/day in peritoneal dialysis patients. It does not influence serum potassium. The decrease of MCP-1 concentration after aliskiren treatment may provide an indirect evidence for its blood pressure independent cardioprotective and anti-inflammatory effects.

Long-term effects of aliskiren on blood pressure and the renin-angiotensin-aldosterone system in hypertensive hemodialysis patients

OBJECTIVE

The long-term effects of aliskiren in hypertensive hemodialysis patients remain to be elucidated.

DESIGN

In this post hoc analysis, we followed up 25 hypertensive hemodialysis patients who completed 8-week aliskiren treatment in a previous study for 20 months to investigate the blood pressure-lowering effect and inhibitory effect on the renin-angiotensin-aldosterone system.

RESULTS

Among the 25 patients, eleven patients continued with aliskiren treatment. Blood pressure (± standard deviation) decreased from 175 ± 18/80 ± 11 mmHg at baseline to 156 ± 20/76 ± 9 mmHg at month 20. Plasma renin activity, angiotensin I, and angiotensin II decreased from baseline to month 20 (plasma renin activity (ng/mL/h): 2.3 ± 2.6 to 0.3 ± 0.4 (P < 0.05), angiotensin I (pg/mL): 909.1 ± 902.5 to 41.5 ± 14.8 (P < 0.05), angiotensin II (pg/mL): 41.5 ± 45.8 to 11.0 ± 4.9 (P < 0.05)).

CONCLUSION

Long-term treatment with aliskiren provides effective blood pressure lowering and inhibition of the renin-angiotensin-aldosterone system, which are sustained over 20 months in hypertensive hemodialysis patients.

Efficacy of aliskiren in Japanese chronic kidney disease patients with hypertension

BACKGROUND

Aliskiren, a novel direct renin inhibitor, is hypothesized to inhibit the renin-angiotensin- system. This study attempted to provide insight into this mechanism by examining the antihypertensive and renoprotective effects of aliskiren in hypertensive chronic kidney disease (CKD) patients.

METHODS

After recruitment, 43 hypertensive CKD patients (mean age, 53.7 years) began treatment of aliskiren. The patients were classified into high (over 30 mL/min/1.73 m(2)) estimated glomerular filtration rate (eGFR) group or low (under 30 mL/min/1.73 m(2)) eGFR group for comparison of measurements of various parameters over the 6-month observation period.

RESULTS

Systolic blood pressure/diastolic blood pressure of 150 mg/day group decreased to an average of 126.8 ± 21.6 mmHg/69.3 ± 15.1 mmHg (average decrease: -7.4/-8.3 mmHg) over the 6-month observation period, while that of 300 mg/day group significantly decreased to an average of 133.5 ± 14.0 mmHg/71.5 ± 11.7 mmHg (average decrease: -21.1/-14.6 mmHg). Urinary protein of all patients decreased slightly and insignificantly to 1.1 ± 1.7 g/gCr from 1.4 ± 2.5 g/gCr. The serum creatinine (Cr) level of all patients decreased from 1.81 ± 1.10 mg/dL to 1.78 ± 0.82 mg/dL. Although the serum Cr level of the high eGFR group decreased from 1.28 ± 0.45 mg/dL to 1.27 ± 0.57 mg/dL, that of the low eGFR group slightly but insignificantly increased from 2.49 ± 0.64 mg/dL to 2.69 ± 1.11 mg/dL.

CONCLUSION

Administration of aliskiren exerts an antihypertensive effect on hypertensive CKD patients that may lead to a decrease in urinary protein and an improvement in renal functioning.

A meta-analysis of the association between angiotensin-converting enzyme insertion/deletion gene polymorphism and steroid-sensitive nephrotic syndrome in children

BACKGROUND AND OBJECTIVE

Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism correlates with circulating and cellular ACE concentration. Association between ACE I/D gene polymorphism and steroid-sensitive nephrotic syndrome (SSNS) risk in children is still controversial. This meta-analysis was performed to evaluate the relation between ACE I/D gene polymorphism and SSNS susceptibility in children.

METHODS

The relevant investigations were screened from the search engines of PubMed, Cochrane Library and CBM-disc (China Biological Medicine Database) as of 1 March 2011, and eligible studies were synthesized using meta-analysis methods.

RESULTS

Ten studies were identified for the analysis of association between ACE I/D gene polymorphism and SSNS risk in children, including seven in Asians, one for Caucasians and two in Africans. There was no markedly positive association between D allele or DD genotype and SSNS susceptibility in Asians, Caucasians and Africans (D: Asians OR = 1.24, p = 0.28; Caucasians OR = 1.61, p = 0.15; Africans OR = 1.61, p = 0.53; DD: Asians OR = 1.72, p = 0.15; Caucasians OR = 1.39, p = 0.48; Africans OR = 1.80, p = 0.56). Furthermore, II homozygous seemed not to play a protective role against SSNS onset for Asians, Caucasians and Africans (Asians OR = 0.95, p = 0.85; Caucasians OR = 0.30, p = 0.11; Africans OR = 0.60, p = 0.65).

CONCLUSIONS

There was no association between ACE I/D gene polymorphism and SSNS susceptibility in Asians, Caucasians and Africans. However, the conclusions for Caucasians and Africans were less powerful.

Significance of measuring oxidative stress in lifestyle-related diseases from the viewpoint of correlation between d-ROMs and BAP in Japanese subjects

In recent years, oxidative stress has been postulated to be an important factor in the pathogenesis and development of lifestyle-related diseases. In this study, we investigated the association between the derivatives of reactive oxygen metabolites (d-ROMs), as an index of products of reactive oxygen species (ROS), and biological antioxidant potential (BAP), as an index of antioxidant potential. We also investigated the associations between d-ROMs or BAP and the risk factors for lifestyle-related diseases or metabolic syndrome-associated factors to evaluate their usefulness in preventive medicine. There were 442 subjects who underwent health checkup examination in our facilities. In addition to standard medical checkup items, we analyzed d-ROMs, BAP, brachial-ankle pulse wave velocity, high-sensitivity C-reactive protein level and visceral fat area (VFA) visualized on a computed tomography scan. The mean d-ROM value in females was significantly higher than that in males. There was a positive correlation between the d-ROM and VFA levels. On correlation analysis, there was a negative correlation between the d-ROM and creatinine levels. As factors that influence d-ROMs, the level of VFA was selected, suggesting the significance of oxidative stress measurement with d-ROMs. In addition, there was a positive correlation between d-ROMs and BAP values. Further research is required to resolve whether increased production of ROS or the antioxidant potential that can compensate for such an increase of ROS is more important in vivo.

Mechanism by which chronic kidney disease causes cardiovascular disease and the measures to manage this phenomenon

In Japan, the number of chronic kidney disease (CKD) patients is thought to be 13,300,000, next in size after those with hypertension and diabetes. Although the number of patients with CKD seems large, it does not mean that all these patients require special treatment. Among them, nephrologists should pay special attention to patients with glomerular filtration rate below 50 mL/min/1.73 m(2) and progressive deterioration of renal function. Treatment of these CKD patients by a limited number of specialists is simply impossible; hence, it is essential to request treatment from physicians who are involved in general internal medicine and primary care. It is well known that not only does CKD cause end-stage renal failure, it also causes the onset of cardiovascular diseases (CVD) such as cardiac infarction and cerebral stroke; however, the question is how much significance does CKD have as a risk factor for CVD. It is understandable that hypertension and CVD are often complications of CKD; however, in addition to what is conventionally mentioned, there are three or four mechanisms that we would like to emphasize, and discuss herein. Among them, we would like to stress the role of klotho genes with special reference to the generation of CVD in CKD patients. When patients develop CKD, it is therefore necessary to remove as far as possible any factors that could represent a risk for CVD. Moreover, by taking appropriate measures against clinical conditions that often complicate CKD, such as hypertension, renal anemia, hyperuricemia, and hyperlipidaemia, the development of CVD can be prevented.