Angiotensin receptor blockers in diabetic nephropathy: renal and cardiovascular end points

Association between the triglyceride glucose index and the risk of acute kidney injury in critically ill patients with hypertension: analysis of the MIMIC-IV database

Background

The triglyceride glucose (TyG) index, a metric computed from the levels of fasting triglyceride (TG) and fasting plasma glucose (FPG), has emerged as a simple surrogate measure for insulin resistance (IR) in recent years. In multiple critical care scenarios, such as contrast-induced acute kidney injury (AKI) and cardiorenal syndrome, a high TyG index levels shows a notable correlation with AKI incidence. However, its predictive value for AKI in critically ill hypertensive patients remains uncertain.

Methods

Participants were selected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database and divided into quartiles based on the TyG index. The primary focus of the study was to investigate the risk of acute kidney injury (AKI), with in-hospital mortality as a secondary endpoint, assessed among all study subjects as well as specifically among AKI patients. The use of renal replacement therapy (RRT), indicative of AKI progression, was also considered a secondary endpoint reflecting renal outcomes. To explore the correlation between the TyG index and AKI risk in critically ill hypertensive patients, the study employed a restricted cubic splines model and Cox proportional hazards (CPH) models. Additionally, Kaplan-Meier survival analysis was utilized to assess differences in primary and secondary outcomes across groups categorized by their TyG index. Analyses were conducted to ensure the consistency of the predictive capability of TyG index across various subgroups.

Results

Our study included 4,418 participants, with 57% being male patients. AKI occurred in 56.1% of cases. Through the CPH analysis, we identified a significant association between the TyG index and AKI occurrence in critically ill hypertensive patients. With the help of a restricted cubic splines model, we observed a direct relationship between an elevated TyG index and an increased AKI. Subgroup examinations consistently proved the predictive value of the TyG index across categories. Furthermore, Kaplan-Meier survival analysis revealed notable differences in RRT among AKI patients.

Conclusion

The findings underscore the importance of the TyG index as a reliable predictor for the occurrence of AKI and adverse renal outcomes among hypertensive patients in critical ill states. Nevertheless, validating causality mandates extensive prospective investigations.

A Prospective, Multicentered, Randomized, Double-Blind, Placebo-Controlled Clinical Trial of Keluoxin Capsules in the Treatment of Microalbuminuria in Patients with Type 2 Early Diabetic Kidney Disease

Background: To evaluate the efficacy and safety of Keluoxin (KLX) capsules and provide validated evidence for the application of KLX in the treatment of diabetic kidney disease (DKD). Methods: A multicenter, randomized, double-blind, placebo-controlled trial design was used to screen 129 patients with DKD (urinary albumin-to-creatinine ratio [UACR]: male, 2.5-30 mg/mmol; female, 3.5-30 mg/mmol) and with Qi and Yin deficiency and blood stasis symptoms. Written informed consent was obtained from all patients. The patients were randomly divided into KLX and control groups. The KLX group was orally administered KLX (6 g/day) and irbesartan tablets (150 mg/day), whereas the control group was administered KLX placebo (6 g/day) and irbesartan tablets (150 mg/day). Patients were observed for 24 weeks to evaluate the natural logarithm of the UACR (log-UACR), the odds ratio (OR) for a sustained increase in the UACR of at least 30% and 40%, estimated glomerular filtration rate (eGFR), changes in symptoms and quality-of-life scores, and adverse events. Results: The changes of the natural log-UACR during the 24 weeks compared with baseline in the KLX group were better than those in the control group (LS mean ± standard error, -0.26 ± 0.10 vs. 0.01 ± 0.09, p = 0.0292). The incidence of a sustained increase in the UACR of at least 30% and 40% was found to be significantly lower in the KLX group (OR, 0.26; 95% confidence interval [CI], 0.09-0.75; OR, 0.29; 95% CI, 0.10-0.82). Changes in symptoms and quality-of-life scores in the KLX group were better than those in the control group. There was no statistically significant difference in eGFR or the incidence of adverse events between the groups. Conclusions: Overall, these results suggest that KLX capsules combined with irbesartan can reduce microalbuminuria, relieve the symptoms, and improve the quality of life for patients with type 2 early DKD compared with the use of irbesartan alone. Trial registration: Chinese Clinical Trial Registry, registration number: ChiCTR2100052764.

[The role of mineralocorticoid receptors hyperactivation in the development of cardiorenal complications in patients with diabetes mellitus, perspective of the selective nonsteroidal mineralocorticoid receptors antagonist's treatment: A review]

The renin-angiotensin-aldosterone system (RAAS) activation plays a key role in the chronic kidney disease (CKD) progression and in the cardiovascular complications (CVC) development in patients with diabetes mellitus (DM). RAAS blockers alone are not sufficient to prevent CVC and CVC progression. RAAS upregulation in CKD associated with DM triggers the mineralocorticoid receptors (MCR) hyperactivation which results in fibrosis and inflammation in the heart and kidneys. This review presents the current data about the variety of MCR hyperactivation manifestations, as well as about of multiplicity of MCR hyperactivation ways in DM. The efficacy and safety of finerenone, a new MCR nonsteroidal selective antagonist, are discussed.

miR-802-5p is a key regulator in diabetic kidney disease

Background

Diabetic kidney disease has substantial burden and limited therapeutic options. An inadequate understanding of the complex gene regulatory circuits underlying this disorder contributes to the insufficiency of current treatment strategies. MicroRNAs (miRNAs) play a crucial role as regulators of functionally related gene networks. Previously, mmu-mir-802-5p was identified as the sole dysregulated miRNA in both the kidney cortex and medulla of diabetic mice. This study aims to investigate the role of miR-802-5p in diabetic kidney disease.

Materials and Methods

The validated and predicted targets of miR-802-5p were identified using miRTarBase and TargetScan databases, respectively. The functional role of this miRNA was inferred using gene ontology enrichment analysis. The expression of miR-802-5p and its selected targets were assessed by qPCR. The expression of the angiotensin receptor (Agtr1a) was measured by ELISA.

Results

miR-802-5p exhibited dysregulation in both the kidney cortex and medulla of diabetic mice, with two- and four-fold over-expressions, respectively. Functional enrichment analysis of the validated and predicted targets of miR-802-5p revealed its involvement in the renin-angiotensin pathway, inflammation, and kidney development. Differential expression was observed in the Pten transcript and Agtr1a protein among the examined gene targets.

Conclusion

These findings suggest that miR-802-5p is a critical regulator of diabetic nephropathy in the cortex and medulla compartments, contributing to disease pathogenesis through the renin-angiotensin axis and inflammatory pathways.

Bibliometric Analysis and Visualization of Research Progress in the Diabetic Nephropathy Field from 2001 to 2021

Methods

The PubMed database was searched to identify all studies related to DN that were published from 2001 to 2021, with these studies being separated into four time-based groups. The characteristics of these studies were analyzed and extracted using BICOMB. Biclustering analyses for each of these groups were then performed using gCLUTO, with these results then being analyzed and GraphPad Prism 5 being used to construct strategy diagrams. The social network analyses (SNAs) for each group of studies were conducted using NetDraw and UCINET.

Results

In total, 18,889 DN-associated studies published from 2001 to 2021 and included in the PubMed database were incorporated into the present bibliometric analysis. Biclustering analysis and strategy diagrams revealed that active areas of research interest in the DN field include studies of the drug-based treatment, diagnosis, etiology, pathology, physiopathology, and epidemiology of DN. The specific research topics associated with these individual areas, however, have evolved over time in a dynamic manner. Strategy diagrams and SNA results revealed podocyte metabolism as an emerging research hotspot in the DN research field from 2010 to 2015, while DN-related microRNAs, signal transduction, and mesangial cell metabolism have emerged as more recent research hotspots in the interval from 2016 to 2021.

Conclusion

Through analyses of PubMed-indexed studies pertaining to DN published since 2001, the results of this bibliometric analysis offer a knowledge framework and insight into active and historical research hotspots in the DN research space, enabling investigators to readily understand the dynamic evolution of this field over the past two decades. Importantly, these analyses also enable the prediction of future DN-related research hotspots, thereby potentially guiding more focused and impactful research efforts.

Efficacy of Tripterygium wilfordii Hook F on animal model of Diabetic Kidney Diseases: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium wilfordii Hook F (TwHF) has been clinically applied in the treatment of Diabetic Kidney Diseases (DKD). A large number of animal experiments focused on the TwHF treatment of DKD were conducted every year, but the evidence for these preclinical studies is unclear.

AIM OF THE STUDY

This study aims to evaluate the efficacy of TwHF on diabetic nephropathy through a stematic reviews and meta-analysis of animal models, and whether it has an effect on improving kidney pathology, renal function indicators and blood sugar levels, it also summarizes the use of TwHF for treatment the underlying mechanism of DKD.

MATERIALS AND METHODS

We systematically searched studies from PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang database from inception to May 2020. Chinese studies from the list of Chinese Core Journals would be included. SYRCLE's risk of bias tool for animal studies was applied to assess the methodological quality of studies. A meta-analysis was performed by using RevMan 5.3.

RESULTS

Out of 429 records identified in the initial search, 32 studies were selected. The results indicated that, compared with control group, TwHF treatment improved 24 h urine protein (24 h-UP) level (SMD - 4.21, 95% CI - 5.38 to - 3.04, P < 0.001), serum creatinine (Scr) (MD - 14.97, 95% CI - 20.42 to - 9.53, P < 0.001), blood urea nitrogen (BUN) (MD - 4.07, 95% CI - 5.49 to - 2.66, P < 0.001), blood glucose (Glu) (MD - 2.40, 95% CI - 4.304 to - 0.49, P = 0.01), Triglyceride (TG) (MD - 1.57, 95% CI - 2.06 to - 1.08, P < 0.001), and Cholesterol (TC) (MD - 1.49, 95% CI - 2.23 to - 0.75 P < 0.001); and increased the level of albumin (Alb) (MD 3.40, 95% CI 1.69 to 5.11, P < 0.001) and weight (MD 30.89, 95% CI 24.35 to 37.42, P < 0.001). There were no statistical difference on Alanine aminotransferase (ALT) (MD 3.00, 95% CI - 7.80 to 13.81, P = 0.59) and Aspartate aminotransferase (AST) (MD 0.77, 95% CI -15.05 to 16.60, P = 0.92) after TwHF. Meta regression analysis showed that the DKD model induced by different methods (type I/II), the dose of Tripterygium wilfordii and the intervention time were not the reasons for the heterogeneity of 24 h-UP, Alb, Glu, Scr, and BUN (p > 0.05).

CONCLUSIONS

TwHF is an effective and safe to treat DKD, which can protect the kidneys through anti-inflammation, improving oxidative stress and podocyte damage, and inhibiting mesangial cell proliferation and extracellular matrix proliferation.

TGF-Beta as a Master Regulator of Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the most common complications in diabetes mellitus and the leading cause of end-stage renal disease. TGF-β is a pleiotropic cytokine and has been recognized as a key mediator of DN. However, anti-TGF-β treatment for DN remains controversial due to the diverse role of TGF-β1 in DN. Thus, understanding the regulatory role and mechanisms of TGF-β in the pathogenesis of DN is the initial step towards the development of anti-TGF-β treatment for DN. In this review, we first discuss the diverse roles and signaling mechanisms of TGF-β in DN by focusing on the latent versus active TGF-β1, the TGF-β receptors, and the downstream individual Smad signaling molecules including Smad2, Smad3, Smad4, and Smad7. Then, we dissect the regulatory mechanisms of TGF-β/Smad signaling in the development of DN by emphasizing Smad-dependent non-coding RNAs including microRNAs and long-non-coding RNAs. Finally, the potential therapeutic strategies for DN by targeting TGF-β signaling with various therapeutic approaches are discussed.

Diabetic kidney disease in patients with type 2 diabetes mellitus: a cross-sectional study

Aim

Diabetic kidney disease (DKD) is a major long-term complication of diabetes mellitus (DM). Given the paucity of data on DKD in Jordan, we aimed to evaluate the prevalence, characteristics and correlates of DKD in Jordanian patients with type 2 DM.

Methods

This cross-sectional study included 1398 adult patients with type 2 DM who sought medical advice in the endocrinology clinic between March and September 2019. Demographic, clinical and laboratory data were reviewed. DKD was defined as reduced eGFR, and/or albuminuria. Three regression models were constructed to identify factors associated with CKD stages, albuminuria and DKD.

Results

Overall, 701 (50.14%) patients had DKD, with a median age of 59.71 ± 11.36  years. Older age, high triglycerides, and low high-density lipoprotein were associated with DKD (multivariable odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01–1.03, p < 0.01; OR: 1.1, 95% CI: 1.01–1.2; and OR: 0.98, 95% CI: 0.97–0.99, p < 0.01 respectively). Metformin and renin-angiotensin system blockers were negatively associated with albuminuria and chronic kidney disease stages (p < 0.01).

Conclusion

Our study demonstrated that approximately one half of patients with type 2 DM had DKD. Further studies are necessary to understand this high prevalence and the underlying factors. Future research are needed to assess implementing targeted community-based intervention.

Efficacy of telmisartan for the treatment of persistent renal proteinuria in dogs: A double-masked, randomized clinical trial

BACKGROUND

Information regarding efficacy of the angiotensin II receptor blocker, telmisartan, for treatment of proteinuria in dogs is limited.

OBJECTIVE

To evaluate the antiproteinuric efficacy of telmisartan, as compared to enalapril, in dogs with chronic kidney disease and persistent, renal proteinuria.

ANIMALS

Thirty-nine client-owned dogs with chronic kidney disease and urinary protein-to-creatinine ratio (UPC) > 0.5 (if azotemic) or ≥ 1.0 (if nonazotemic).

METHODS

In this prospective, randomized, double-masked clinical trial, dogs were block randomized, according to presence or absence of azotemia and systemic arterial hypertension, to receive telmisartan (1.0 mg/kg PO q24h), or enalapril (0.5 mg/kg PO q12h), and followed for 120 days. Up-titration of study drug dosage on days 30 and 60, and addition of the other study drug at day 90, were performed if UPC > 0.5 was noted at these visits. Percentage change in UPC relative to baseline was calculated for all time points. Data are presented as median (range).

RESULTS

Thirty-nine (20 telmisartan-treated, 19 enalapril-treated) dogs were included. At day 30, percentage change in UPC was greater for telmisartan-treated (-65% [-95% to 104%]) vs enalapril-treated (-35% [-74% to 87%]) dogs (P = .002). Among dogs persistently proteinuric at earlier visits, telmisartan remained superior to enalapril at days 60 (P = .02) and 90 (P = .02). No difference in percentage change in UPC between study groups was observed at day 120, when combination therapy was allowed. Combination therapy resulted in relevant azotemia in 4/13 (31%) dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Telmisartan might be a suitable first-line therapy for dogs with renal proteinuria.

Role of aromatic amino acids in pathogeneses of diabetic nephropathy in Chinese patients with type 2 diabetes

BACKGROUND

We aimed to estimate the associations between aromatic amino acids (AAAs) and diabetic nephropathy (DN) in patients with type 2 diabetes (T2D).

METHODS

We collected clinical and metabolomic data from 132 healthy subjects (HS group), 132 type 2 diabetes patients without diabetic nephropathy (T2D group) and 132 diabetic nephropathy patients (DN group) in tertiary hospital from May 2015 to August 2016. The odds ratio (OR) and 95% confidence interval (CI) were obtained by logistic regression.

RESULTS

The odds ratio of tyrosine for DN increased gradually. High tyrosine was associated with an increased OR of DN (model 3, OR:0.329, 95%CI, 0.144-0.750) when comparing extreme quantiles.

CONCLUSION

In Chinese patients with T2D, elevated tyrosine was associated with increased risk of DN.

Hypertension with diabetes mellitus: physiology and pathology

Elevated blood pressure is closely related to increased circulatory fluid volume and peripheral vascular resistance. Patients with diabetes mellitus experience increased peripheral artery resistance caused by vascular remodeling and increased body fluid volume associated with insulin resistance-induced hyperinsulinemia and hyperglycemia. Both of these mechanisms elevate systemic blood pressure. Thus, fully understanding the pathophysiology of hypertension in diabetes mellitus requires knowing the natural history of type 2 diabetes. Patients exhibit hyperinsulinemia with insulin resistance due to impaired glucose tolerance and early-stage diabetes. Hypertension occurs because of increased body fluid volume. After reaching mid-stage diabetes the vascular remodeling has progressed and peripheral vascular resistance also contributes to hypertension. Moreover, vascular remodeling strongly influences diabetic complications. Specifically, afferent arteriolar remodeling during diabetic nephropathy leads to increased glomerular pressure. Thus, treatment with a renin-angiotensin system inhibitor that promotes renal damage regression is critical to lowering the systemic blood pressure and dilating efferent arterioles to reduce glomerular pressure.

Effects of Valsartan vs Amlodipin on renal function in salt loaded spontaneously hypertensive rats

The goal of this study was to compare the effects of valsartan and amlodipin on the systolic blood pressure and parameters specific to the renal function in salt loaded spontaneously hypertensive rats (SHR). 32 male SHR were used at age of 20 weeks and body weight ranging between 265-300 g. From 8 weeks of age tab water was replaced with a solution of NaCl (1%) given ad libitum. Rats were divided into 2 groups: valsartan treated group SHRVAL (n=16) in which valsartan was given at a dose of 10 mg/kg b. w. and amlodipine treated group SHRAMLO (n=16) in which amlodipine was given at a dose of 5 mg/kg b. w. For a period of 12 weeks we have evaluated the effect of the investigated drugs on systolic blood pressure, body weight and renal function tests. In salt loaded rats amlodipine was more effective in reducing the systolic blood pressure in contrast to valsartan who had more pronounced effect on renal parameters most evident in proteinuria. Since both treatment groups have different mechanism of action a combination therapy may be beneficial in improving renal function in SHR rats.

New insight into the molecular drug target of diabetic nephropathy

Diabetic nephropathy (DN) lowered quality of life and shortened life expectancy amongst those affected. Evidence indicates interaction between advanced glycation end products (AGEs), activated protein kinase C (PKC) and angiotensin II exacerbate the progression of DN. Inhibitors of angiotensin-converting enzyme (ACEIs), renin angiotensin aldosterone system (RAAS), AGEs, and PKC have been tested for slowing down the progression of DN. The exact molecular drug targets that lead to the amelioration of renal injury in DN are not well understood. This review summarizes the potential therapeutic targets, based on putative mechanism in the progression of the disease.

Combination use of angiotensin converting enzyme inhibitors and angiotensin receptor blockers in diabetic kidney disease

Angiotensin converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARB) have played a major role in slowing the progression of diabetic kidney disease, since they lower urine protein levels, lower blood pressure, and slow progression. Studies have suggested that the combination of ACE-I and ARB offered greater benefits for patients with diabetic kidney disease. In 2008, the large ONTARGET study reported no benefit with combination therapy, as compared with monotherapy. This study has changed practice patterns, but few patients in this study had diabetic kidney disease. In this review, the data in favor of the combination use of these agents in patients with diabetic kidney disease and data against the combination are reviewed. At this time, there is little support for using the combination in diabetic patients with no kidney disease or early stage diabetic kidney disease. But there are patients who may benefit from combination use.

Reappraisal of role of angiotensin receptor blockers in cardiovascular protection

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have shown cardioprotective and renoprotective properties. These agents are recommended as first-line therapy for the treatment of hypertension and the reduction of cardiovascular risk. Early studies pointed to the cardioprotective and renoprotective effects of ARBs in high-risk patients. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) established the clinical equivalence of the cardioprotective and renoprotective effects of telmisartan and ramipril, but did not find an added benefit of the combination over ramipril alone. Similar findings were observed in the Telmisartan Randomized AssessmeNt Study in aCE INtolerant subjects with cardiovascular Disease (TRANSCEND) trial conducted in ACEI-intolerant patients. In ONTARGET, telmisartan had a better tolerability profile with similar renoprotective properties compared with ramipril, suggesting a potential clinical benefit over ramipril. The recently completed Olmesartan Reducing Incidence of Endstage Renal Disease in Diabetic Nephropathy Trial (ORIENT) and Olmesartan and Calcium Antagonists Randomized (OSCAR) studies will further define the role of ARBs in cardioprotection and renoprotection for high-risk patients.

Effective antihypertensive strategies for high-risk patients with diabetic nephropathy

AIM

Clinical guidelines recommend blood pressure (BP) lowering and renin-angiotensin-aldosterone system inhibition to slow kidney disease progression in patients with diabetic nephropathy. This study's purpose was to determine whether an antihypertensive regimen including a maximally dosed angiotensin-converting enzyme inhibitor could safely achieve target BP in indigent, predominantly minority patients with this disease.

METHODS

We studied 81 hypertensive adults (52% Hispanic and 31% African American) with nephropathy attributed to type 1 or 2 diabetes during the run-in period of a randomized controlled trial. The subjects received lisinopril titrated to 80 mg daily and additional antihypertensives to target a systolic BP (SBP) lower than 130 mm Hg. Blood pressure and serum potassium level were measured weekly, and a 4-gram sodium diet was prescribed. The primary outcome variable was SBP change from screening to randomization. Success in achieving SBP goal, change in urine albumin-creatinine ratio, hyperkalemia (serum potassium ≥5.5 mmol/L) and hypotension (SBP < 100 mm Hg) were also analyzed.

RESULTS

The median SBP decreased from 144 to 133 mm Hg (median change, -9.6%.) Fifty-eight (71%) achieved goal SBP during run-in. The median UACR decreased from 206.8 to 112.7 mg/mmol (median change, -42.7%). The UACR reduction correlated with SBP reduction. Seventeen subjects experienced hyperkalemia responsive to dietary/medical management. Two subjects experienced hypotension responsive to medication adjustments.

CONCLUSION

A regimen using a maximally dosed angiotensin-converting enzyme inhibitor is safe and effective for achieving BP goal in high-risk, predominantly minority patients with diabetic nephropathy. Implementing this regimen necessitates close monitoring of serum potassium level.

Year-long antihypertensive therapy with candesartan completely prevents development of cardiovascular organ injuries in spontaneously hypertensive rats

Most previous studies have examined the effects of antihypertensive drugs in hypertensive animals for only a few months, and little information has been provided as to the protective effects of lifetime antihypertensive medication against cardiovascular organ injury. In this study, spontaneously hypertensive rats (SHR) were treated for 1 year with an angiotensin-II receptor antagonist (ARB) and the development of hypertensive organ injury was evaluated. Male 15-week-old SHR (n = 9) were given 25 mg/L candesartan (CS) in their drinking water for 1 year. Twelve SHR and 9 normotensive Wistar-Kyoto rats (WKY) were given normal tap water. Tail-cuff blood pressure was almost normalized by CS throughout 1 year (at 12-months: WKY 132 ± 3, SHR 229 ± 3, CS 137 ± 4 mmHg). After 1 year, cardiac ventricular weight (SHR +33%, CS -2% versus WKY) and aortic thickness (SHR +34%, CS +4% versus WKY) in the CS-treated SHR rats were not different than those of WKY. Echocardiographic midwall fractional shortening (SHR -18%, CS -1% versus WKY) and left ventricular hydroxyproline content (SHR +47%, CS +11% versus WKY) were also improved by CS to the WKY level. With respect to kidney function, GFR (SHR -24%, CS +9% versus WKY) was preserved, proteinuria (SHR +312%, CS +12% versus WKY) was reduced, and the histological glomerular injury rate (SHR +186%, CS +6% versus WKY) was reduced by CS. These results suggest that long-term antihypertensive therapy with CS can completely prevent hypertensive cardiovascular and renal injuries in SHR.

New standards in hypertension and cardiovascular risk management: focus on telmisartan

Blockade of the renin–angiotensin system is an important approach in managing high blood pressure, and has increasingly been shown to affect cardiovascular disease processes mediated by angiotensin II throughout the cardiovascular and renal continua. Telmisartan is an angiotensin II receptor blocker (ARB) displaying unique pharmacologic properties, including a longer half life than any other ARB, that result in large and sustained reductions of blood pressure. In patients with mild-to-moderate hypertension, telmisartan has proved superior to other antihypertensive agents (valsartan, losartan, ramipril, perindopril, and atenolol) in controlling blood pressure particularly towards the end of the dosing interval. There is also clinical evidence that telmisartan reduces left ventricular hypertrophy, reduces arterial stiffness and the recurrence of atrial fibrillation, and confers renoprotection. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET^®) study has demonstrated that telmisartan has similar cardiovascular protective effects to ramipril in a large, high-risk patient population but was better tolerated. The powerful and sustained blood pressure control apparent in clinical trials, together with cardiovascular protection and tolerability demonstrated in ONTARGET^® means that telmisartan may be a preferred option for patients with hypertension.

Pharmacologic therapy in patients with chronic heart failure and chronic kidney disease: a complex issue

Chronic kidney disease is common in patients with chronic heart failure and has important clinical implications. The coexistence of these two syndromes is associated with a higher risk of adverse outcome and increases the difficulties of heart failure treatment because of the complex interplay between renal dysfunction and pharmacologic therapy. The underrepresentation of patients with chronic kidney disease in most heart failure trials contributes to the suboptimal treatment of this high-risk population in clinical practice. In the present review, we briefly examine the pathophysiologic mechanisms connecting chronic kidney disease and chronic heart failure and discuss the therapeutic approach to patients affected by both conditions.

Statins, ACE inhibitors and ARBs in cardiovascular disease

Atherosclerotic cardiovascular disease (CVD) is the main cause of death in developed and developing countries. It is well accepted that several diseases - including hypertension, dyslipidemia and diabetes mellitus - increase CVD. More recently also chronic inflammatory diseases, such as rheumatoid arthritis, have been shown to accelerate CVD. This association further supports a responsible role for inflammatory processes in all stages of CVD pathophysiology. Clinically, CVD ranges through different acute and chronic syndromes with ischemic symptoms in distal tissues, including heart, cerebral region or peripheral arteries. Several treatments for reducing CVD are under investigation. In this review we focus on statins, angiotensin-converting-enzyme (ACE) inhibitors, and angiotensin-II receptor blockers (ARBs), updating therapeutic evidence from the last clinical trials with particular relevance to diabetic patients.

Reduction of proteinuria with angiotensin receptor blockers

Renal pathophysiology is elicited by activation of angiotensin II type 1 (AT(1)) receptors at all stages of renovascular disease. Angiotensin receptor blockers (ARBs) that specifically block the AT(1) receptor offer the potential to prevent or delay progression to end-stage renal disease independently of reductions in blood pressure. Proteinuria--an early and sensitive marker for progressive renal dysfunction--is reduced by ARB use in patients with type 2 diabetic nephropathy and microalbuminuria or macroalbuminuria. Retrospective analysis of data available from early trials has confirmed this finding and has shown that albuminuria reduction is associated with lessening of cardiovascular risk. The ARB telmisartan is equivalent to enalapril in preventing glomerular filtration rate decline, and equivalent to valsartan in reducing proteinuria. Telmisartan is more effective than conventional therapy in lowering the risk of transition to overt nephropathy in hypertensive and normotensive patients. An additive effect has been seen in smaller studies when telmisartan has been added to lisinopril therapy, and high-dose telmisartan reduces albuminuria better than low-dose telmisartan. Similar data were obtained with other ARBs such as candesartan, losartan, valsartan, or irbesartan. These data support the proposition that blockade of the renin-angiotensin system beyond that required for maximum blood pressure reduction provides optimum renal protection.

Albuminuria, but not estimated glomerular filtration rate, is associated with maladaptive arterial remodeling: the Hoorn Study

OBJECTIVE

Arterial remodeling aims to maintain a constant circumferential wall stress (sigmac). A failing remodeling process is associated with stroke. Data on the relationship between chronic kidney disease and arterial remodeling are scarce.

METHODS

We investigated the association between a lower glomerular filtration rate (GFR) and microalbuminuria with arterial remodeling of the common carotid artery (CCA) in a population-based study of 806 patients. CCA properties including intima-media thickness and interadventitial diameter (IAD) were assessed. Lumen diameter, circumferential wall tension (CWT), and circumferential wall stress (sigmac) were calculated. GFR was estimated (eGFR) by the Modification of Diet in Renal Disease formula. Albuminuria was expressed as urinary albumin/creatinine ratio.

RESULTS

Mean eGFR was 60.3 (+/-10.8) ml/min/1.73 m2; median urinary albumin/creatinine ratio was 0.57 (range 0.10-26.6 mg/mmol). After adjustment for age, sex, glucose tolerance status, and prevalent cardiovascular disease, eGFR was not independently associated with CCA properties. A greater urinary albumin/creatinine ratio (per quartile) was associated with a greater lumen diameter [regression coefficient beta with 95% confidence interval, 0.14 (0.08-0.20; P < 0.01)], IAD [0.15 (0.09-0.21; P < 0.01)], CWT [0.95 (0.52-1.38; P < 0.01)], and sigmac [1.7 (0.5-2.9; P < 0.01)] but not with a greater IMT [0.01 (-0.002-0.02; P = 0.12)]. Additional adjustments for mean arterial pressure, pulse pressure, and eGFR did not change the results.

CONCLUSION

Greater albuminuria is independently associated with an increase in lumen diameter and IAD of the CCA. In addition, greater albuminuria is associated with a maladaptive carotid remodeling process as shown by an increase in CWT and sigmac. These findings may explain, why microalbuminuria is associated with a greater risk of cardiovascular disease and especially stroke.

Silencing megalin and cubilin genes inhibits myeloma light chain endocytosis and ameliorates toxicity in human renal proximal tubule epithelial cells

Using target-specific short interfering (si) RNAs, we silenced the tandem endocytic receptors megalin and cubilin genes in cultured human renal proximal tubule epithelial cells. Transfection by siRNA resulted in up to 90% suppression of both megalin and cubilin protein and mRNA expression. In HK-2 cells exposed to kappa-light chain for up to 24 h, light chain endocytosis was reduced in either megalin- or cubilin-silenced cells markedly but incompletely. Simultaneous silencing of both the cubilin and megalin genes, however, resulted in near-complete inhibition of light chain endocytosis, as determined by measuring kappa-light chain protein concentration in cell cytoplasm and by flow cytometry using FITC-labeled kappa-light chain. In these cells, light chain-induced cytokine responses (interleukin-6 and monocyte chemoattractant protein-1) and epithelial-to-mesenchymal transition as well as the associated cellular and morphological alterations were also markedly suppressed. The results demonstrate that light chain endocytosis is predominantly mediated by the megalin-cubilin tandem endocytic receptor and identify endocytosis as a key step in light chain cytotoxicity. Blocking light chain endocytosis prevents its nephrotoxic effects on human kidney proximal tubule cells.

Comparison of renal function and cardiovascular risk following acute myocardial infarction in patients with and without diabetes mellitus

Renal dysfunction is an independent risk factor for cardiovascular (cv) disease and its associated complications. Diabetes mellitus (dm) is a common cause of renal dysfunction. Whether the presence or absence of dm modifies the relation between renal dysfunction and cv disease is unclear. The valiant trial identified 14,527 patients with acute myocardial infarction complicated by either clinical or radiologic signs of heart failure and/or left ventricular dysfunction for whom baseline creatinine was measured. Patients were randomly assigned to receive captopril, valsartan, or both. Glomerular filtration rate (gfr) was estimated using the 4-component modification of diet in renal disease equation. Using multivariable cox proportional modeling, the relation of overall mortality and composite cardiovascular events with estimated gfr (egfr) between patients with and without dm was compared. Mean egfrs were 66.8 +/- 22.0 and 71.2 +/- 21.0 ml/min/1.73 m2 for patients with (n = 3,358) and without dm (n = 11,169), respectively. The likelihood of experiencing death or the composite end point was higher in patients with than without dm for each level of renal function. the augmentation in risk of cv events based on reduced renal function was similar between groups. Each decrease in egfr by 10 units was associated with hazards of 1.09 (95% confidence interval 1.06 to 1.12, p <0.001) in patients with dm and 1.08 (95% confidence interval 1.06 to 1.10, p <0.001) in patients without dm for risk of fatal and nonfatal cv outcomes independent of treatment assignment. In conclusion, although dm is associated with higher risk of renal dysfunction and adverse cv outcomes, patients without dm had a relation between renal function and cv risk similar to that for patients with dm after high-risk acute myocardial infarction.

Estimated Glomerular Filtration Rate and Urinary Albumin Excretion Are Independently Associated with Greater Arterial Stiffness: The Hoorn Study

Mild renal insufficiency is a risk factor for cardiovascular disease (CVD). Both a decline in GFR and (micro)albuminuria are associated with greater cardiovascular mortality. In ESRD, arterial stiffness, an important cause of CVD, is known to be greater, but few data exist in individuals with mild renal insufficiency or microalbuminuria. This study investigated the association of impaired renal function expressed as lower GFR or greater urinary albumin excretion with arterial stiffness. In a population-based study in 806 individuals (402 men), mean age 68 yr (range 50 to 87), peripheral arterial stiffness (by compliance and distensibility of the carotid, brachial, and femoral arteries and by the carotid elastic modulus [E(inc)]) and central arterial stiffness (by total systemic arterial compliance, carotid-femoral transit time, and aortic augmentation index) were measured ultrasonically. GFR was estimated (eGFR) by the Modification of Diet in Renal Disease (MDRD) formula. Urinary albumin excretion was expressed as urinary albumin/creatinine ratio (UACR). eGFR was 60.6 +/- 11.1 ml/min per 1.73 m(2). Median UACR was 0.57 mg/mmol (range 0.1 to 26.6). After adjustment for age, mean arterial pressure (MAP), gender, and glucose tolerance status (GTS), each 5-ml/min per 1.73 m(2) lower eGFR was associated with a lower distensibility coefficient of the carotid (regression coefficient beta -0.20 10(-3)/kPa; 95% confidence interval [CI] -0.34 to -0.07 10(-3)/kPa) and brachial artery (-0.15 10(-3)/kPa; 95% CI -0.28 to -0.03 10(-3)/kPa) and a greater carotid E(inc) (0.02 kPa; 95% CI 0.0004 to 0.04 kPa). No statistically significant association was found of eGFR with other arterial stiffness indices. After adjustment for age, MAP, gender, and GTS, a greater UACR (per quartile) was associated with a greater E(inc) (0.03 kPa; 95% CI 0.001 to 0.07 kPa) and a trend to a lower distensibility coefficient (-0.24 10(-3)/kPa; 95% CI -0.49 to 0.02 10(-3)/kPa) of the carotid artery. After adjustment for age, MAP, gender, and GTS, a greater UACR (per quartile) was in addition associated with a shorter carotid-femoral transit time (-1.67 ms; 95% CI -3.24 to -0.10 ms). These associations were not substantially changed by mutual adjustment for eGFR and UACR. In individuals with mild renal insufficiency, both a lower eGFR and a greater albumin excretion, even below levels that are considered to reflect microalbuminuria, are independently associated with greater arterial stiffness. Moreover, these associations were mutually independent. These findings may explain, in part, why eGFR and microalbuminuria are associated with greater risk for CVD and suggest that amelioration of arterial stiffness could be a target of intervention.

Preventing renal complications in type 2 diabetes: results of the diabetics exposed to telmisartan and enalapril trial

Patients with type 2 diabetes are prone to hypertension and persistent protein leakage from the kidney (microalbuminuria or macroalbuminuria). A progressive decline in renal function can lead to overt diabetic nephropathy and ESRD. The likelihood of cardiovascular disease also is increased. Control of hypertension is paramount to prevent these life-threatening complications. Agents that target the renin-angiotensin system--angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers--have been shown to be renoprotective. The groundbreaking Diabetics Exposed to Telmisartan And enalaprIL (DETAIL) trial was designed to address the absence of comparative data on the long-term effects of an angiotensin II receptor blocker versus an angiotensin-converting enzyme inhibitor on renoprotection and survival in 250 patients with hypertension and early type 2 diabetic nephropathy. The primary purpose of the 5-yr double-blind, double-dummy, randomized study was to establish whether 40 to 80 mg of telmisartan conferred similar (i.e., noninferior) renoprotection to 10 to 20 mg of enalapril as determined by the change from baseline in GFR, measured by the plasma clearance of iohexol. Secondary end points included the emergence of ESRD and all-cause mortality. Telmisartan was not inferior to enalapril in reducing the decline in GFR: Mean annual declines in GFR were 3.7 and 3.3 ml/min per 1.73 m(2) with telmisartan and enalapril, respectively. During the 5-yr study period, no patient developed a serum creatinine >200 micromol/L, and none required dialysis. There were only six deaths in each treatment group during the study, with half being due to cardiovascular events.

Antiproteinuric effect of losartan in non-diabetic renal disease is not dependent on ACE insertion/deletion polymorphism

BACKGROUND

The antiproteinuric effect of angiotensin-converting enzyme (ACE) inhibitors appears to vary depending on the ACE insertion (I)/deletion (D) genotype in non-diabetic nephropathy. This interaction may be overcome by using an angiotensin II receptor blocker. We evaluated the short-term antiproteinuric effect of losartan according to the ACE I/D genotype in patients with non-diabetic proteinuric renal diseases.

METHODS

Ninety-nine (II/ID/DD: 36/52/11) non-diabetic patients with overt proteinuria were enrolled. The patients received losartan 50 mg daily followed by 100 mg in two treatment periods each lasting 12 weeks. Clinical parameters including proteinuria were measured at baseline and at the end of each period.

RESULTS

At baseline each genotype (II/ID/DD) had comparable mean arterial blood pressure (mean +/- SD) 103.2 +/- 11.1/102.7 +/- 10.6/104.1 +/- 15.3; proteinuria (geometric mean, 95% CI, mg/day) 1,839 (1,518-2,227)/1,998 (1,683-2,372)/1,613 (1,072-2,427), and creatinine clearance (ml/min/1.73 m(2)) 65.7 +/- 28.4/63.2 +/- 27.8/68.8 +/- 25.3, respectively. Both doses of losartan significantly lowered blood pressure and proteinuria (p < 0.05 vs. baseline), and losartan 100 mg was more effective than 50 mg in reducing proteinuria (52.5 +/- 29.0 vs. 40.5 +/- 30.8%, respectively, p = 0.001). No differences in the antiproteinuric effect of losartan was observed among the ACE I/D genotype. Losartan 100 mg demonstrated a comparable degree of mean arterial pressure (mean +/- SD, %) (II/ID/DD, 13.3 +/- 7.6/10.8 +/- 9.8/13.0 +/- 11.6, respectively, p = NS) and proteinuria reduction (mean, 95% CI) among the three genotypes (51.4% (40.3-62.5%)/53.4% (45.5-61.4%)/51.4% (40.0-63.8%), respectively, p = NS).

CONCLUSION

Our data suggest that losartan provides a similar short-term antiproteinuric response for all three genotypes of ACE I/D genotype in non-diabetic proteinuric chronic renal disease.

Managing hypertension in patients with type 2 diabetes mellitus

PURPOSE

Current guideline recommendations for effective strategies to optimize the treatment of patients with concomitant hypertension and type 2 diabetes mellitus are reviewed.

SUMMARY

Current estimates indicate that 20 million people in the United States have diabetes, 90-95% of whom have type 2 diabetes mellitus. Type 2 diabetes mellitus is associated with an increased risk of premature death from cardiovascular disease (CVD), stroke, and end-stage renal disease. Hypertension is an extremely common comorbidity in patients with type 2 diabetes mellitus. The coexistence of hypertension in patients with type 2 diabetes is particularly destructive because of the strong linkage of the two conditions with CVD, stroke, progression of renal disease, and diabetic nephropathy. Current guidelines, including those issued by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, the National Kidney Foundation, and the American Diabetes Association, provide evidence-based recommendations for the treatment of hypertension in patients with type 2 diabetes mellitus. However, studies indicate that guidelines are not widely followed. Therefore, the beneficial effects of appropriate hypertension treatment observed in clinical trials are often not recognized in clinical practice. Pharmacists are ideally positioned to help improve guideline implementation and patient outcome.

CONCLUSION

Pharmacists must become more vigilant about following current guidelines for the treatment of patients with concomitant hypertension and type 2 diabetes mellitus. Strategies such as patient education and medication assessment can help to optimize care for these patients and slow the progression to diabetic nephropathy.

Prevention of loss of renal function over time in patients with diabetic nephropathy

Management of hypertension is the mainstay of prevention and treatment of diabetic renal disease; evidence suggests that tight blood pressure control slows renal disease progression in established diabetic nephropathy. Inhibition of the renin-angiotensin-aldosterone system (RAAS) has renoprotective effects over and above those achieved by lowering systemic blood pressure. To date, however, no long-term study using hard end points has directly compared current mechanisms for RAAS inhibition, angiotensin II receptor blockade (ARB) and angiotensin-converting enzyme (ACE) inhibition. This issue was addressed in the recently published Diabetics Exposed to Telmisartan and Enalapril (DETAIL) study, a head-to-head comparison of telmisartan and enalapril in 250 patients with hypertension and type 2 diabetes mellitus and early-stage nephropathy. After 5 years' treatment, change in glomerular filtration rate (GFR), the primary efficacy end point, was equivalent in the 2 treatment groups, as were all secondary end points. The expected steep decline in GFR in the first year was followed by a lesser decrease in the second year and then almost complete stabilization of renal function at > or =3 years. Over 5 years, no patient went into end-stage renal disease or required dialysis. There were also no increases in albumin excretion rate, nor was there an increase in creatinine beyond 200 mumol/L. Incidence of cardiovascular morbidity and mortality was extremely low in both treatment groups, a remarkable outcome given that almost 50% of patients had evidence of cardiovascular disease at randomization. Inhibition of the RAAS should play a major part in management of patients with type 2 diabetes with nephropathy, for which both telmisartan and enalapril provide long-term renoprotection.

Effects of valsartan on the progression of chronic renal insufficiency in patients with nondiabetic renal diseases

The present study tested the effects of valsartan, an angiotensin II receptor blocker, on the progression of renal insufficiency in patients with nondiabetic renal diseases. The study subjects were 22 patients with nondiabetic renal diseases whose serum creatinine (Cr) ranged from 1.5 to 3.0 mg/dl. Valsartan (40-80 mg) or placebo was given once daily for 1 year each in a random crossover manner. In both periods, antihypertensive medications were titrated when the blood pressure was not lower than 140/90 mmHg. Blood sampling and urinalysis were performed bimonthly throughout the study periods. The average blood pressure was comparable between the valsartan and the placebo periods (130 +/- 9/86 +/- 6 vs. 131 +/- 8/86 +/- 6 mmHg). Serum Cr significantly increased from 1.9 +/- 0.5 to 2.3 +/- 0.8 mg/dl (p < 0.001) during the placebo period, but the change was insignificant in the valsartan period (2.1 +/- 0.6 to 2.2 +/- 0.9 mg/dl). The slope of decrease in the reciprocal of serum Cr was steeper in the placebo period than in the valsartan period (-0.064 +/- 0.070/year vs. -0.005 +/- 0.050/year, p < 0.01). During the valsartan period, urinary protein excretion was less than that during the placebo period (0.75 +/- 0.73 vs. 1.24 +/- 0.92 g/g Cr, p < 0.001). Serum K was significantly higher in the valsartan period than in the placebo period (4.6 +/- 0.5 vs. 4.4 +/- 0.5 mEq/l, p < 0.05); however, no patients discontinued taking valsartan as a result of hyperkalemia. It is possible that long-term treatment with an angiotensin II receptor blocker, valsartan, is effective at retarding the deterioration of renal function in patients with nondiabetic renal disease by a mechanism independent of blood pressure reduction.

Transplantation of adult recipients by single cadaveric kidneys from pediatric donors weighing < or = 25 kg can be a reliable option

The evidence in favor of transplanting single allografts from cadaveric pediatric donors into adult recipients is equivocal. This study was performed to assess the outcome of transplantation of single kidneys from pediatric donors weighing < 25 kg. Thirty-five adults transplanted by renal allografts from pediatric donors weighing < 25 kg were compared with 30 matched recipients of kidneys from adult donors. Donors in study group were aged 4.2 +/- 2.1 years weighing 16.0 +/- 5.3 kg. In the study group, surgical complications occurred in five of 35 patients, in the control group four of 30. Serum creatinine reached nadir in 47.5 days in study group versus 30 days in controls (P < 0.01). Serum creatinine at 1 and 3 years were comparable in both groups. A 38.9% had proteinuria at 1 year in the study group compared with 22.7% in controls (P = 0.36). One-year graft survival was 91.7% in the study group versus 92.8% for controls. The surgical complications and graft survival in the study group was comparable with that of controls. The incidence of proteinuria may be more frequent, but does not appear to impact graft function. The use of single, as compared with paired, pediatric donor kidneys would allow more patients to be transplanted with equivalent results.

Improved prognosis in type 1 diabetic patients with nephropathy: a prospective follow-up study

BACKGROUND

In early studies, a median survival time of 5 to 7 years from onset of diabetic nephropathy was observed. Furthermore, end-stage renal disease (ESRD) was the main cause of death. We prospectively assessed the impact of reno- and cardiovascular protective treatment on prognosis in type 1 diabetic patients with diabetic nephropathy.

METHODS

We prospectively followed 199 type 1 diabetic patients with diabetic nephropathy and 192 patients with normoalbuminuria for 10 years. Aggressive antihypertensive treatment was initiated in patients with diabetic nephropathy in mid 1980s, whereas statins and aspirin were not prescribed routinely until April 2002. The primary end point was cardiovascular mortality and morbidity. Secondary end points were all-cause mortality and ESRD.

RESULTS

During follow-up, 79 patients (40%) with nephropathy reached the primary end point versus 19 (10%) of normoalbuminuric patients, log rank test P < 0.0001. Predictors of the primary end point were: nephropathy (hazard ratio 3.26; 95% confidence interval 1.89 to 5.62), previous event (3.19; 2.04 to 4.97), age (1.27; 1.04 to 1.55), and systolic blood pressure (1.13; 1.03 to 1.24). In the nephropathy group, 60 patients (30%) died; hereof, 25 deaths (42%) were ascribed to cardiovascular causes while 30 patients (50%) with nephropathy died with ESRD. The estimate of median survival time from onset of diabetic nephropathy was 21.7 years, SE 3.3 years.

CONCLUSION

The survival of patients with diabetic nephropathy has improved most likely due to aggressive antihypertensive treatment and improved glycaemic control.

Antiproteinuric effect of RAS blockade: New mechanisms

Experimental and clinical studies have shown that blockade of the renin-angiotensin system (RAS) is effective in reducing proteinuria in conditions such as diabetes by reducing systemic and intraglomerular hydrostatic pressure. However, increasing evidence suggests that nonhemodynamic effects, such as preservation of the podocyte slit diaphragm structure and function, may also mediate the antiproteinuric effects of RAS blockade. In this review, we analyze in detail the evidence for known and novel mechanisms considered to play important roles in mediating the antiproteinuric effect of RAS blockers, with a particular focus on diabetic nephropathy.