The Long-Term Impact of Renin-Angiotensin System (RAS) Inhibition on Cardiorenal Outcomes (LIRICO): A Randomized, Controlled Trial

Angiotensin-converting-enzyme inhibitors and angiotensin receptor blockers for preventing the progression of diabetic kidney disease

BACKGROUND

Guidelines suggest that adults with diabetes and kidney disease receive treatment with angiotensin-converting-enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). This is an update of a Cochrane review published in 2006.

OBJECTIVES

We compared the efficacy and safety of ACEi and ARB therapy (either as monotherapy or in combination) on cardiovascular and kidney outcomes in adults with diabetes and kidney disease.

SEARCH METHODS

We searched the Cochrane Kidney and Transplants Register of Studies to 17 March 2024 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included studies evaluating ACEi or ARB alone or in combination, compared to each other, placebo or no treatment in people with diabetes and kidney disease.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

One hundred and nine studies (28,341 randomised participants) were eligible for inclusion. Overall, the risk of bias was high. Compared to placebo or no treatment, ACEi may make little or no difference to all-cause death (24 studies, 7413 participants: RR 0.91, 95% CI 0.73 to 1.15; I2 = 23%; low certainty) and with similar withdrawals from treatment (7 studies, 5306 participants: RR 1.03, 95% CI 0.90 to 1.19; I2 = 0%; low certainty). ACEi may prevent kidney failure (8 studies, 6643 participants: RR 0.61, 95% CI 0.39 to 0.94; I2 = 0%; low certainty). Compared to placebo or no treatment, ARB may make little or no difference to all-cause death (11 studies, 4260 participants: RR 0.99, 95% CI 0.85 to 1.16; I2 = 0%; low certainty). ARB have uncertain effects on withdrawal from treatment (3 studies, 721 participants: RR 0.85, 95% CI 0.58 to 1.26; I2 = 2%; low certainty) and cardiovascular death (6 studies, 878 participants: RR 3.36, 95% CI 0.93 to 12.07; low certainty). ARB may prevent kidney failure (3 studies, 3227 participants: RR 0.82, 95% CI 0.72 to 0.94; I2 = 0%; low certainty), doubling of serum creatinine (SCr) (4 studies, 3280 participants: RR 0.84, 95% CI 0.72 to 0.97; I2 = 32%; low certainty), and the progression from microalbuminuria to microalbuminuria (5 studies, 815 participants: RR 0.44, 95% CI 0.23 to 0.85; I2 = 74%; low certainty). Compared to ACEi, ARB had uncertain effects on all-cause death (15 studies, 1739 participants: RR 1.13, 95% CI 0.68 to 1.88; I2 = 0%; low certainty), withdrawal from treatment (6 studies, 612 participants: RR 0.91, 95% CI 0.65 to 1.28; I2 = 0%; low certainty), cardiovascular death (13 studies, 1606 participants: RR 1.15, 95% CI 0.45 to 2.98; I2 = 0%; low certainty), kidney failure (3 studies, 837 participants: RR 0.56, 95% CI 0.29 to 1.07; I2 = 0%; low certainty), and doubling of SCr (2 studies, 767 participants: RR 0.88, 95% CI 0.52 to 1.48; I2 = 0%; low certainty). Compared to ACEi plus ARB, ACEi alone has uncertain effects on all-cause death (6 studies, 1166 participants: RR 1.08, 95% CI 0.49 to 2.40; I2 = 20%; low certainty), withdrawal from treatment (2 studies, 172 participants: RR 0.78, 95% CI 0.33 to 1.86; I2 = 0%; low certainty), cardiovascular death (4 studies, 994 participants: RR 3.02, 95% CI 0.61 to 14.85; low certainty), kidney failure (3 studies, 880 participants: RR 1.36, 95% CI 0.79 to 2.32; I2 = 0%; low certainty), and doubling of SCr (2 studies, 813 participants: RR 1.14, 95% CI 0.70 to 1.85; I2 = 0%; low certainty). Compared to ACEi plus ARB, ARB alone has uncertain effects on all-cause death (7 studies, 2607 participants: RR 1.02, 95% CI 0.76 to 1.37; I2 = 0%; low certainty), withdrawn from treatment (3 studies, 1615 participants: RR 0.81, 95% CI 0.53 to 1.24; I2 = 0%; low certainty), cardiovascular death (4 studies, 992 participants: RR 3.03, 95% CI 0.62 to 14.93; low certainty), kidney failure (4 studies, 2321 participants: RR 1.15, 95% CI 0.67 to 1.95; I2 = 29%; low certainty), and doubling of SCr (3 studies, 2252 participants: RR 1.18, 95% CI 0.85 to 1.64; I2 = 0%; low certainty). Comparative effects of different ACEi or ARB and low-dose versus high-dose ARB were rarely evaluated. No study compared different doses of ACEi. Adverse events of ACEi and ARB were rarely reported.

AUTHORS' CONCLUSIONS

ACEi or ARB may make little or no difference to all-cause and cardiovascular death compared to placebo or no treatment in people with diabetes and kidney disease but may prevent kidney failure. ARB may prevent the doubling of SCr and the progression from microalbuminuria to macroalbuminuria compared with a placebo or no treatment. Despite the international guidelines suggesting not combining ACEi and ARB treatment, the effects of ACEi or ARB monotherapy compared to dual therapy have not been adequately assessed. The limited data availability and the low quality of the included studies prevented the assessment of the benefits and harms of ACEi or ARB in people with diabetes and kidney disease. Low and very low certainty evidence indicates that it is possible that further studies might provide different results.

The association between dual RAAS inhibition and risk of acute kidney injury and hyperkalemia in patients with diabetic kidney disease: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Dual renin-angiotensin-aldosterone system (RAAS) blockade involves dual therapy with a combination of angiotensin-converting enzyme inhibitors (ACEis), angiotensin-receptor blockers (ARBs), direct renin inhibitors (DRIs), or mineralocorticoid receptor antagonists (MRAs). It is hypothesized that dual RAAS blockade would result in a more complete inhibition of the RAAS cascade. However, large clinical trials on dual RAAS inhibition have shown increased risk of acute kidney injury (AKI) and hyperkalemia without additional benefit on mortality, cardiovascular events, or chronic kidney disease (CKD) progression compared to RAAS inhibitor monotherapy in patients with diabetic kidney disease (DKD). The development of newer, more selective non-steroidal MRAs as cardiorenal protective therapies has created a new opportunity for dual RAAS inhibition. We conducted a systematic review and meta-analysis of the risks of AKI and hyperkalemia with dual RAAS blockade in patients with DKD.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

This is a systematic review and meta-analysis of the randomized controlled trials (RCT) published from 1 January 2006 to 30 May 2022. The study population included adult patients with DKD receiving dual RAAS blockade. A total of 31 RCTs and 33 048 patients were included in the systematic review. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using random effects.

RESULTS

There were 208 AKI events in 2690 patients on ACEi + ARB versus 170 in 4264 patients with ACEi or ARB monotherapy (pooled RR 1.48, 95% CI: 1.23-1.39). There were 304 hyperkalemia events in 2818 patients on ACEi + ARB versus 208 in 4396 patients with ACEi or ARB monotherapy (pooled RR 1.97, 95% CI: 1.32-2.94). A non-steroidal MRA + ACEi or ARB showed no increase in the risk of AKI (pooled RR 0.97, 95% CI: 0.81-1.16) compared to ACEi or ARB monotherapy but had a 2-fold higher risk of hyperkalemia with 953 events in 7837 patients in dual therapy versus 454 events in 6895 patients in monotherapy (pooled RR 2.05, 95% CI: 1.84-2.28). A steroidal MRA + ACEi or ARB had a 5-fold higher risk of hyperkalemia with 28 events in 245 at risk in dual therapy versus five events in 248 at risk in monotherapy (pooled RR 5.42 95% CI: 2.15-13.67).

CONCLUSION

Dual therapy with RAASi is associated with an increased risk of AKI and hyperkalemia compared to RAASi monotherapy. Conversely, dual therapy with RAAS inhibitors and non-steroidal MRAs have no additional risk of AKI but a similar risk of hyperkalemia, which is lower than dual therapy with RAAS inhibitors and steroidal MRAs.

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for adults with early (stage 1 to 3) non-diabetic chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a long-term condition that occurs as a result of damage to the kidneys. Early recognition of CKD is becoming increasingly common due to widespread laboratory estimated glomerular filtration rate (eGFR) reporting, raised clinical awareness, and international adoption of the Kidney Disease Improving Global Outcomes (KDIGO) classifications. Early recognition and management of CKD affords the opportunity to prepare for progressive kidney impairment and impending kidney replacement therapy and for intervention to reduce the risk of progression and cardiovascular disease. Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) are two classes of antihypertensive drugs that act on the renin-angiotensin-aldosterone system. Beneficial effects of ACEi and ARB on kidney outcomes and survival in people with a wide range of severity of kidney impairment have been reported; however, their effectiveness in the subgroup of people with early CKD (stage 1 to 3) is less certain. This is an update of a review that was last published in 2011.

OBJECTIVES

To evaluate the benefits and harms of ACEi and ARB or both in the management of people with early (stage 1 to 3) CKD who do not have diabetes mellitus (DM).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 6 July 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and Embase, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) reporting the effect of ACEi or ARB in people with early (stage 1 to 3) CKD who did not have DM were selected for inclusion. Only studies of at least four weeks duration were selected. Authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out by two authors independently, using a standard data extraction form. The methodological quality of included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. When more than one study reported similar outcomes, data were pooled using the random-effects model. Heterogeneity was analysed using a Chi² test and the I² test. Results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach MAIN RESULTS: Six studies randomising 9379 participants with CKD stages 1 to 3 (without DM) met our inclusion criteria. Participants were adults with hypertension; 79% were male from China, Europe, Japan, and the USA. Treatment periods ranged from 12 weeks to three years. Overall, studies were judged to be at unclear or high risk of bias across all domains, and the quality of the evidence was poor, with GRADE rated as low or very low certainty. In low certainty evidence, ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo may make little or no difference to death (any cause) (2 studies, 8873 participants): RR 2.00, 95% CI 0.26 to 15.37; I² = 76%), total cardiovascular events (2 studies, 8873 participants): RR 0.97, 95% CI 0.90 to 1.05; I² = 0%), cardiovascular-related death (2 studies, 8873 participants): RR 1.73, 95% CI 0.26 to 11.66; I² = 54%), stroke (2 studies, 8873 participants): RR 0.76, 95% CI 0.56 to 1.03; I² = 0%), myocardial infarction (2 studies, 8873 participants): RR 1.00, 95% CI 0.84 to 1.20; I² = 0%), and adverse events (2 studies, 8873 participants): RR 1.33, 95% CI 1.26 to 1.41; I² = 0%). It is uncertain whether ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo reduces congestive heart failure (1 study, 8290 participants): RR 0.75, 95% CI 0.59 to 0.95) or transient ischaemic attack (1 study, 583 participants): RR 0.94, 95% CI 0.06 to 15.01; I² = 0%) because the certainty of the evidence is very low. It is uncertain whether ARB (losartan 50 mg) compared to placebo (1 study, 226 participants) reduces: death (any-cause) (no events), adverse events (RR 19.34, 95% CI 1.14 to 328.30), eGFR rate of decline (MD 5.00 mL/min/1.73 m2, 95% CI 3.03 to 6.97), presence of proteinuria (MD -0.65 g/24 hours, 95% CI -0.78 to -0.52), systolic blood pressure (MD -0.80 mm Hg, 95% CI -3.89 to 2.29), or diastolic blood pressure (MD -1.10 mm Hg, 95% CI -3.29 to 1.09) because the certainty of the evidence is very low. It is uncertain whether ACEi (enalapril 20 mg, perindopril 2 mg or trandolapril 1 mg) compared to ARB (olmesartan 20 mg, losartan 25 mg or candesartan 4 mg) (1 study, 26 participants) reduces: proteinuria (MD -0.40, 95% CI -0.60 to -0.20), systolic blood pressure (MD -3.00 mm Hg, 95% CI -6.08 to 0.08) or diastolic blood pressure (MD -1.00 mm Hg, 95% CI -3.31 to 1.31) because the certainty of the evidence is very low.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to determine the effectiveness of ACEi or ARB in patients with stage 1 to 3 CKD who do not have DM. The available evidence is overall of very low certainty and high risk of bias. We have identified an area of large uncertainty for a group of patients who account for most of those diagnosed as having CKD.

American Association of Clinical Endocrinology Consensus Statement: Comprehensive Type 2 Diabetes Management Algorithm - 2023 Update

OBJECTIVE

This consensus statement provides (1) visual guidance in concise graphic algorithms to assist with clinical decision-making of health care professionals in the management of persons with type 2 diabetes mellitus to improve patient care and (2) a summary of details to support the visual guidance found in each algorithm.

METHODS

The American Association of Clinical Endocrinology (AACE) selected a task force of medical experts who updated the 2020 AACE Comprehensive Type 2 Diabetes Management Algorithm based on the 2022 AACE Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan and consensus of task force authors.

RESULTS

This algorithm for management of persons with type 2 diabetes includes 11 distinct sections: (1) Principles for the Management of Type 2 Diabetes; (2) Complications-Centric Model for the Care of Persons with Overweight/Obesity; (3) Prediabetes Algorithm; (4) Atherosclerotic Cardiovascular Disease Risk Reduction Algorithm: Dyslipidemia; (5) Atherosclerotic Cardiovascular Disease Risk Reduction Algorithm: Hypertension; (6) Complications-Centric Algorithm for Glycemic Control; (7) Glucose-Centric Algorithm for Glycemic Control; (8) Algorithm for Adding/Intensifying Insulin; (9) Profiles of Antihyperglycemic Medications; (10) Profiles of Weight-Loss Medications (new); and (11) Vaccine Recommendations for Persons with Diabetes Mellitus (new), which summarizes recommendations from the Advisory Committee on Immunization Practices of the U.S. Centers for Disease Control and Prevention.

CONCLUSIONS

Aligning with the 2022 AACE diabetes guideline update, this 2023 diabetes algorithm update emphasizes lifestyle modification and treatment of overweight/obesity as key pillars in the management of prediabetes and diabetes mellitus and highlights the importance of appropriate management of atherosclerotic risk factors of dyslipidemia and hypertension. One notable new theme is an emphasis on a complication-centric approach, beyond glucose levels, to frame decisions regarding first-line pharmacologic choices for the treatment of persons with diabetes. The algorithm also includes access/cost of medications as factors related to health equity to consider in clinical decision-making.

Clinical outcomes of renin angiotensin system inhibitor-based dual antihypertensive regimens in chronic kidney disease: a network meta-analysis

This study comprehensively investigated clinical outcomes associated with renin angiotensin system inhibitor-based dual antihypertensive regimens in non-dialysis chronic kidney disease (CKD) patients. Keyword searches of databases were performed per PRISMA-NMA guidelines. Frequentist network meta-analysis were conducted with 16 head-to-head randomized controlled trials. The effect sizes of dichotomous and continuous variables were estimated with odds ratio (OR) and standard mean differences (SMD), respectively. The protocol is registered in PROSPERO (CRD42022365927). Dual antihypertensive regimens with combination of angiotensin receptor blockers (ARB) and calcium channel blockers (CCB) demonstrated substantially reduced odd of major cardiovascular disease (CVD) events over other regimens including angiotensin converting enzyme inhibitor (ACEI) monotherapy (OR 3.19) and ARB monotherapy (OR 2.64). Most significant reductions in systolic (SBP) and diastolic blood pressure (DBP) were observed with ARB-based CCB dual regimen over ACEI monotherapy (SMD 17.60 SBP and 9.40 for DBP), ACEI-based CCB regimen (SMD 12.90 for SBP and 9.90 for DBP), and ARB monotherapy (SMD 13.20 for SBP and 5.00 for DBP). However, insignificant differences were noticed for the odds of hyperkalemia, end stage renal disease progression, and all-cause mortality. ARB-based CCB regimen has the greatest benefits on BP reduction as well as major CVD risks in non-dialysis CKD patients.

The modulation of gut microbiota by herbal medicine to alleviate diabetic kidney disease - A review

The treatment of diabetic kidney disease (DKD) has been the key concern of the medical community. Herbal medicine has been reported to alleviate intestinal dysbiosis, promote the excretion of toxic metabolites, and reduce the secretion of uremic toxins. However, the current understanding of the modulation of the gut microbiota by herbal medicine to delay the progression of DKD is still insufficient. Consequently, we reviewed the knowledge based on peer-reviewed English-language journals regarding regulating gut microbiota by herbal medicines in DKD. It was found that herbal medicine or their natural extracts may have the following effects: modulating the composition of intestinal flora, particularly Akkermansia, Lactobacillus, and Bacteroidetes, as well as adjusting the F/B ratio; increasing the production of SCFAs and restoring the intestinal barrier; reducing the concentration of uremic toxins (p-cresol sulfate, indole sulfate, TMAO); inhibiting inflammation and oxidative stress.

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Exploring the Potential Mechanism of Tang-Shen-Ning Decoction against Diabetic Nephropathy Based on the Combination of Network Pharmacology and Experimental Validation

Background

Diabetic nephropathy (DN) has become one of the leading causes of the end-stage renal disease (ESRD). Tang-Shen-Ning (TSN) decoction, an effective Traditional Chinese formula for DN, can improve the renal function and inhibit renal fibrosis in DN. However, its potential mechanism is still unexplored.

Methods

A network pharmacology approach was employed in this study, including screening for differential expressed genes of DN (DN-DEGs), protein-protein interaction (PPI) network analysis, and GO and KEGG enrichment analysis. Besides, a rat model was established to verify the potential effect of TSN in DN.

Results

Twenty-three TSN-related DN-DEGs targets were identified. These genes were associated with decreased glomerular filtration rate (GFR) DN. The enrichment analysis suggested that the inhibition of renal fibrosis and inflammation through growth factors and chemokines is the potential mechanism through which TSN improves DN. TSN reduced renal fibrosis and improved pathological damage in the kidney in vivo through the regulation of GJA1, CTGF, MMP7, and CCL5, which are genes associated with ECM deposition.

Conclusion

This study revealed that TSN improves DN through a multicomponent, multitarget, and multipathway synergy. We provide a scientific basis for potential targets for TSN use to treat DN, yet further experimental validation is needed to investigate these targets and mechanisms.

Efficacy and safety of dual vs single renin-angiotensin-aldosterone system blockade in chronic kidney disease: An updated meta-analysis of randomized controlled trials

BACKGROUND

To lower albuminuria and to achieve blood pressure (BP) goals, dual renin-angiotensin-aldosterone system (RAAS) inhibitors are sometimes used in clinical practice for the treatment of CKD. However, the efficacy and safety of dual RAAS blockade therapy remains controversial.

METHODS

PubMed, EMBASE, and Cochrane Library were searched, and random effects model was used to calculate the effect sizes of eligible studies. Potential sources of heterogeneity were detected by meta-regression and subgroup analysis.

RESULTS

The present meta-analysis of 72 randomized controlled trials with 10,296 patients demonstrated that dual RAAS blockade therapy was superior to monotherapy in reducing the urine albumin excretion, urine protein excretion, and BP. These beneficial effects were related to the decrease of glomerular filtration rate, the increase of serum potassium level, and higher rates of hyperkalemia and hypotension. Meanwhile, these effects did not lead to improvements in short-term or long-term outcomes, including doubling of serum creatinine, acute kidney injury, end-stage renal disease, mortality, and hospitalization. Compared with the single therapy, angiotensin-converting enzyme inhibitor (ACEI) in combination with angiotensin-receptor blocker (ARB) was a better dual therapy than ACEI or ARB in combination with renin inhibitor or aldosterone receptor antagonist in decreasing urine albumin excretion, urine protein excretion and BP, and the combination was not associated with a lower glomerular filtration rate.

CONCLUSION

Compared with the single therapy, ACEI in combination with ARB was a better dual therapy than ACEI or ARB in combination with renin inhibitor or aldosterone receptor antagonist. Although ACEI in combination with ARB was associated with higher incidences of hyperkalemia and hypotension, careful individualized management and potassium binders may further expand its application (PROSPERO number CRD42020179398).

[Inhibition of the renin-angiotensin-aldosterone system]

Chronic kidney diseases (CKD) are often progressive and usually associated with a relatively slow loss of function. This principally offers the opportunity for drug interventions over a prolonged period. The prerequisite is that clear therapeutic targets can be identified. One of the most important targets is the renin-angiotensin-aldosterone system (RAAS), the activation of which is a key contributor to the progression and deterioration of renal function. This article reviews the pathomechanistic principles of RAAS-mediated renal damage and the pharmaceutical possibilities for inhibition of the RAAS. The evidence from clinical studies on nephroprotection is summarized and the international guideline recommendations are discussed. As a future perspective, the novel possibility of a combined add-on treatment with nonsteroidal mineralocorticoid receptor antagonists is discussed based on the FIDELIO-DKD study.

Preventing microalbuminuria with benazepril, valsartan, and benazepril-valsartan combination therapy in diabetic patients with high-normal albuminuria: A prospective, randomized, open-label, blinded endpoint (PROBE) study

BACKGROUND

Angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) prevent microalbuminuria in normoalbuminuric type 2 diabetic patients. We assessed whether combined therapy with the 2 medications may prevent microalbuminuria better than ACE inhibitor or ARB monotherapy.

METHODS AND FINDINGS

VARIETY was a prospective, randomized, open-label, blinded endpoint (PROBE) trial evaluating whether, at similar blood pressure (BP) control, combined therapy with benazepril (10 mg/day) and valsartan (160 mg/day) would prevent microalbuminuria more effectively than benazepril (20 mg/day) or valsartan (320 mg/day) monotherapy in 612 type 2 diabetic patients with high-normal albuminuria included between July 2007 and April 2013 by the Istituto di Ricerche Farmacologiche Mario Negri IRCCS and 8 diabetology or nephrology units in Italy. Time to progression to microalbuminuria was the primary outcome. Analyses were intention to treat. Baseline characteristics were similar among groups. During a median [interquartile range, IQR] follow-up of 66 [42 to 83] months, 53 patients (27.0%) on combination therapy, 57 (28.1%) on benazepril, and 64 (31.8%) on valsartan reached microalbuminuria. Using an accelerated failure time model, the estimated acceleration factors were 1.410 (95% CI: 0.806 to 2.467, P = 0.229) for benazepril compared to combination therapy, 0.799 (95% CI: 0.422 to 1.514, P = 0.492) for benazepril compared to valsartan, and 1.665 (95% CI: 1.007 to 2.746, P = 0.047) for valsartan compared to combination therapy. Between-group differences in estimated acceleration factors were nonsignificant after adjustment for predefined confounders. BP control was similar across groups. All treatments were safe and tolerated well, with a slight excess of hyperkalemia and hypotension in the combination therapy group. The main study limitation was the lower than expected albuminuria at inclusion.

CONCLUSIONS

Risk/benefit profile of study treatments was similar. Dual renin-angiotensin system (RAS) blockade is not recommended as compared to benazepril or valsartan monotherapy for prevention of microalbuminuria in normoalbuminuric type 2 diabetic patients.

TRIAL REGISTRATION

EudraCT 2006-005954-62; ClinicalTrials.gov NCT00503152.

Antiproteinuric and Hyperkalemic Mechanisms Activated by Dual Versus Single Blockade of the RAS in Renovascular Hypertensive Rats

This study aimed to investigate the antiproteinuric and hyperkalemic mechanisms activated by dual renin-angiotensin system (RAS) blockade in renovascular hypertensive rats (2-kidney 1-clip model [2K-1C]). Six weeks after clipping the left renal artery or sham operation (2K), rats were treated with losartan, enalapril, or both drugs for two weeks. We found that 2K-1C rats displayed higher tail-cuff blood pressure (BP), increased non-clipped kidney Ang II concentration, and more pronounced urinary albumin excretion than 2K. BP was decreased by the treatment with either enalapril or losartan, and the combination of both drugs promoted an additional antihypertensive effect in 2K-1C rats. Renal Ang II content and albuminuria were reduced by either enalapril or losartan in monotherapy and restored to control levels by dual RAS blockade. Albuminuria in 2K-1C rats was accompanied by downregulation of the glomerular slit protein podocin, reduction of the endocytic receptors megalin and cubilin, and a marked decrease in the expression of the ClC-5 chloride channel, compared to 2K animals. Treatment with losartan and enalapril in monotherapy or combination increased the expression of podocin, cubilin, and ClC-5. However, only the combined therapy normalized podocin, cubilin, and ClC-5 protein abundance in the non-clipped kidney of 2K-1C rats. Renovascular hypertensive 2K-1C rats had a lower concentration of plasma potassium compared to 2K rats. Single RAS blockade normalized potassium plasma concentration, whereas 2K-1C rats treated with dual RAS blockade exhibited hyperkalemia. Hypokalemia in 2K-1C rats was accompanied by an increase in the cleaved activated forms of α-ENaC and γ-ENaC and the expression of β-ENaC. Combined RAS blockade but not monotherapy significantly reduced the expression of these ENaC subunits in 2K-1C rats. Indeed, double RAS blockade reduced the abundance of cleaved-α-ENaC to levels lower than those of 2K rats. Collectively, these results demonstrate that the antiproteinuric effect of dual RAS blockade in 2K-1C rats is associated with the restored abundance of podocin and cubilin, and ClC-5. Moreover, double RAS blockade-induced hyperkalemia may be due, at least partially, to an exaggerated downregulation of cleaved α-ENaC in the non-clipped kidney of renovascular hypertensive rats.

Update on Treatment of Hypertension After Renal Transplantation

PURPOSE OF REVIEW

To incorporate novel findings on pathophysiology and treatment of posttransplant hypertension.

RECENT FINDINGS

(1) The sodium retaining effects of CNIs are mediated by stimulation of the thiazide-sensitive sodium chloride co-transporter in the distal convoluted tubule and in this regard chlorthalidone was proven to be an effective antihypertensive drug in renal transplantation. (2) Local and not systemic activation of the renin-angiotensin-aldosterone system plays a crucial role in the pathogenesis of posttransplant hypertension. (3) Recent randomized controlled trials failed to prove the presumed superiority of renin-angiotensin blockers in kidney transplantation. (4) Steroid-free and mammalian target of rapamycin-based immunosuppressive drug combinations did not show favorable effects on blood pressure control. (5) In a recent report the risk of non-melanoma skin cancer was higher with thiazide diuretics. But the increased cancer risk in transplant recipients is mainly attributed to comorbidities, such as diabetes and hypertension and of course to the transplantation condition itself or the obligatory application of immunosuppression, and has little to do with the antihypertensive medication Actual recommendations about BP targets in adult renal transplant recipients are coming from a post hoc analysis of a large randomized trial with another primary endpoint. Unless convincing studies on treatment of hypertension after renal transplantation are available, the ESC/ESH Guidelines 2018 should apply for these patients.

Efficacy and Safety of Angiotensin-Converting Enzyme Inhibitor in Combination with Angiotensin-Receptor Blocker in Chronic Kidney Disease Based on Dose: A Systematic Review and Meta-Analysis

Background: The purpose of this meta-analysis was to evaluate the controversy of angiotensin-converting enzyme inhibitor (ACEI) in combination with angiotensin-receptor blocker (ARB) in the treatment of chronic kidney disease (CKD) based on dose.

Methods: PubMed, EMBASE, and Cochrane Library were searched to identify randomized controlled trials (RCTs) from inception to March 2020. The random effects model was used to calculate the effect sizes. Potential sources of heterogeneity were detected using sensitivity analysis and meta-regression.

Results: This meta-analysis of 53 RCTs with 6,375 patients demonstrated that in patients with CKD, ACEI in combination with ARB was superior to low-dose ACEI or ARB in reducing urine albumin excretion (SMD, −0.43; 95% CI, −0.67 to −0.19; p = 0.001), urine protein excretion (SMD, −0.22; 95% CI, −0.33 to −0.11; p < 0.001), and blood pressure (BP), including systolic BP (WMD, −2.89; 95% CI, −3.88 to −1.89; p < 0.001) and diastolic BP (WMD, −3.02; 95% CI, −4.46 to −1.58; p < 0.001). However, it was associated with decreased glomerular filtration rate (GFR) (SMD, −0.13; 95% CI, −0.24 to −0.02; p = 0.02) and increased rates of hyperkalemia (RR, 2.07; 95% CI, 1.55 to 2.76; p < 0.001) and hypotension (RR, 2.19; 95% CI, 1.35 to 3.54; p = 0.001). ACEI in combination with ARB was more effective than high-dose ACEI or ARB in reducing urine albumin excretion (SMD, −0.84; 95% CI, −1.26 to −0.43; p < 0.001) and urine protein excretion (SMD, −0.24; 95% CI, −0.39 to −0.09; p = 0.002), without decrease in GFR (SMD, 0.02; 95% CI, −0.12 to 0.15; p = 0.78) and increase in rate of hyperkalemia (RR, 0.94; 95% CI, 0.65 to 1.37; p = 0.76). Nonetheless, the combination did not decrease the BP and increased the rate of hypotension (RR, 3.95; 95% CI, 1.13 to 13.84; p = 0.03) compared with high-dose ACEI or ARB.

Conclusion: ACEI in combination with ARB is superior in reducing urine albumin excretion and urine protein excretion. The combination is more effective than high-dose ACEI or ARB without decreasing GFR and increasing the incidence of hyperkalemia. Despite the risk of hypotension, ACEI in combination with ARB is a better choice for CKD patients who need to increase the dose of ACEI or ARB (PROSPERO CRD42020179398).

Intestinal microbiota and diabetic kidney diseases: the Role of microbiota and derived metabolites inmodulation of renal inflammation and disease progression

Diabetic kidney disease (DKD) represents a growing public health burden and is the leading cause of end-stage kidney diseases. In recent years, host-gut microbiota interactions have emerged as an integral part for host homeostasis. In the context of nephropathies, mounting evidence supports a bidirectional microbiota-kidney crosstalk, which becomes particularly manifest during progressive kidney dysfunction. Indeed, in chronic kidney disease (CKD), the "healthy" microbiota structure is disrupted and intestinal microbes produce large quantities of uremic solutes responsible for renal damage; on the other hand, the uremic state, fueled by reduced renal clearance, causes shifts in microbial metabolism and composition, hence creating a vicious cycle in which dysbiosis and renal dysfunction are progressively worsened. In this review, we will summarize the evidence from clinical/experimental studies concerning the occurrence of gut dysbiosis in diabetic and non-diabetic CKD, discuss the functional consequences of dysbiosis for CKD progression and debate putative therapeutic interventions targeting the intestinal microbiome.

Bidirectional link between diabetes mellitus and coronavirus disease 2019 leading to cardiovascular disease: A narrative review

Coronavirus disease 2019 (COVID-19) is a global pandemic where several comorbidities have been shown to have a significant effect on mortality. Patients with diabetes mellitus (DM) have a higher mortality rate than non-DM patients if they get COVID-19. Recent studies have indicated that patients with a history of diabetes can increase the risk of severe acute respiratory syndrome coronavirus 2 infection. Additionally, patients without any history of diabetes can acquire new-onset DM when infected with COVID-19. Thus, there is a need to explore the bidirectional link between these two conditions, confirming the vicious loop between "DM/COVID-19". This narrative review presents (1) the bidirectional association between the DM and COVID-19, (2) the manifestations of the DM/COVID-19 loop leading to cardiovascular disease, (3) an understanding of primary and secondary factors that influence mortality due to the DM/COVID-19 loop, (4) the role of vitamin-D in DM patients during COVID-19, and finally, (5) the monitoring tools for tracking atherosclerosis burden in DM patients during COVID-19 and "COVID-triggered DM" patients. We conclude that the bidirectional nature of DM/COVID-19 causes acceleration towards cardiovascular events. Due to this alarming condition, early monitoring of atherosclerotic burden is required in "Diabetes patients during COVID-19" or "new-onset Diabetes triggered by COVID-19 in Non-Diabetes patients".

Role of Albuminuria in Detecting Cardio-Renal Risk and Outcome in Diabetic Subjects

The clinical significance of albuminuria in diabetic subjects and the impact of its reduction on the main cardiorenal outcomes by different drug classes are among the most interesting research focuses of recent years. Although nephrologists and cardiologists have been paying attention to the study of proteinuria for years, currently among diabetics, increased urine albumin excretion ascertains the highest cardio-renal risk. In fact, diabetes is a condition by itself associated with a high-risk of both micro/macrovascular complications. Moreover, proteinuria reduction in diabetic subjects by several treatments lowers both renal and cardiovascular disease progression. The 2019 joint ESC-EASD guidelines on diabetes, prediabetes and cardiovascular (CV) disease assign to proteinuria a crucial role in defining CV risk level in the diabetic patient. In fact, proteinuria by itself allows the diabetic patient to be staged at very high CV risk, thus affecting the choice of anti-hyperglycemic drug class. The purpose of this review is to present a clear update on the role of albuminuria as a cardio-renal risk marker, starting from pathophysiological mechanisms in support of this role. Besides this, we will show the prognostic value in observational studies, as well as randomized clinical trials (RCTs) demonstrating the potential improvement of cardio-renal outcomes in diabetic patients by reducing proteinuria.

Dual Blockade of the Renin-Angiotensin System: A Strategy that Should Be Reconsidered in Cardiorenal Diseases?

Studies on pharmacological mechanisms demonstrated that a strategy of dual renin-angiotensin system (RAS) blockade may have a synergistic effect in the treatment of cardiorenal diseases and may reduce adverse reactions. However, some previous clinical studies reported that dual RAS blockade did not significantly benefit many patients with cardiorenal diseases and increased the risk of hyperkalemia, hypotension and renal function damage. Therefore, the current clinical guidelines suggest that the combined use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) should be used with caution in the clinic. However, these studies enrolled older patients with cardiovascular risk factors, and the results of these trials may not be generalized to the overall population. Some clinical evidence suggests that the combination of low-dose ACEIs and ARBs leads to more effective RAS blockade with few adverse effects. The advent of new RAS inhibitors with superior pharmacological effects provides a more suitable drug choice for individualized therapy for dual RAS blockade. Therefore, the choice of appropriate ARBs/ACEIs for individualized therapy based on patient condition may be a better way to improve the efficiency and safety of the dual RAS blockade strategy.

Knockout of aminopeptidase A in mice causes functional alterations and morphological glomerular basement membrane changes in the kidneys

Aminopeptidase A is one of the most potent enzymes within the renin-angiotensin system in terms of angiotensin II degradation. Here, we examined whether there is a kidney phenotype and any compensatory changes in other renin angiotensin system enzymes involved in the metabolism of angiotensin II associated with aminopeptidase A deficiency. Kidneys harvested from aminopeptidase A knockout mice were examined by light and electron microscopy, immunohistochemistry and immunofluorescence. Kidney angiotensin II levels and the ability of renin angiotensin system enzymes in the glomerulus to degrade angiotensin II ex vivo, their activities, protein and mRNA levels in kidney lysates were evaluated. Knockout mice had increased blood pressure and mild glomerular mesangial expansion without significant albuminuria. By electron microscopy, knockout mice exhibited a mild increase of the mesangial matrix, moderate thickening of the glomerular basement membrane but a striking appearance of knob-like structures. These knobs were seen in both male and female mice and persisted after the treatment of hypertension. In isolated glomeruli from knockout mice, the level of angiotensin II was more than three-fold higher as compared to wild type control mice. In kidney lysates from knockout mice angiotensin converting enzyme activity, protein and mRNA levels were markedly decreased possibly as a compensatory mechanism to reduce angiotensin II formation. Thus, our findings support a role for aminopeptidase A in the maintenance of glomerular structure and intra-kidney homeostasis of angiotensin peptides.

Single versus dual blockade of the renin-angiotensin system in patients with IgA nephropathy

Background

Inhibitors of the renin-angiotensin system (RAS) are cornerstones of supportive therapy in patients with IgA nephropathy (IgAN). We analyzed the effects of single versus dual RAS blockaQueryde during our randomized STOP-IgAN trial.

Methods

STOP-IgAN participants with available successive information on their RAS treatment regimen and renal outcomes during the randomized 3-year trial phase were stratified post hoc into two groups, i.e. patients under continuous single or dual RAS blocker therapy over the entire 3 years of the trial phase. Primary and secondary STOP-IgAN trial endpoints, i.e. frequencies of full clinical remission, eGFR-loss ≥ 15 and ≥ 30 ml/min/1.73 m² and ESRD onset, were analyzed by logistic regression and linear mixed effects models.

Results

Among the 112 patients included in the present analysis, 82 (73%) were maintained on single and 30 (27%) on dual RAS inhibitor therapy throughout the trial. Neither RAS blocker strategy significantly affected full clinical remission, eGFR-loss rates, onset of ESRD. Proteinuria moderately increased in patients under dual RAS blockade by 0.1 g/g creatinine during the 3-year trial phase. This was particularly evident in patients without additional immunosuppression during the randomized trial phase, where proteinuria increased by 0.2 g/g creatinine in the dual RAS blockade group. In contrast, proteinuria decreased in patients under single RAS blocker therapy by 0.3 g/g creatinine. The course of eGFR remained stable and did not differ between the RAS treatment strategies.

Conclusion

In the STOP-IgAN cohort, neither RAS blocker regimen altered renal outcomes. Patients on dual RAS blockade even exhibited higher proteinuria over the 3-year trial phase.

COVID-19: is there a link between the course of infection and pharmacological agents in diabetes?

BACKGROUND

The Coronavirus disease 2019 (COVID-19) and type 2 diabetes (T2D) are two pandemics that share the dramatic impact on global mortality and economic resources. COVID-19 largely exhibits mild to moderate clinical manifestations. However, severe pneumonia with high fatality rate may occur, especially in the elderly and in patients with underlying conditions, such as diabetes and cardiovascular disease. SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) binds to the angiotensin-converting enzyme 2 (ACE2), a ubiquitous trans-membrane carboxypeptidase, to enter the cells.

AIMS

This short review discusses some open questions about the link between COVID-19 and diabetes, principally focusing on the possible effects of commonly used drugs in patients with diabetes.

RESULTS

Preclinical studies have reported that angiotensin receptor blockers (ARBs) and ACE inhibitors might increase ACE2 expression in several cell types. Hence, it has been speculated that the treatment with these agents might influence the course of the infection, and both harmful and beneficial effects have been supposed. Other pharmacological agents are thought to increase ACE2 expression, including statins and proliferator-activated receptor gamma (PPAR-γ) agonists. All these drug classes are broadly adopted in T2D. Besides ACE2, other unknown co-factors might be involved in cell infection. It has been recently observed that dipeptidyl peptidase-4 (DPP4), the receptor for MERS-CoV (Middle East respiratory syndrome-related coronavirus) and ACE2 have similar expression profiles in the lung. DPP4 has important metabolic and immune functions and is a target for commonly used therapies in T2D.

CONCLUSIONS

Although clinical data supporting an influence of all these drugs on the course of the disease are limited, this is an interesting background for further research that might help unravel the complex mechanisms underlying the link between COVID-19 and diabetes.

Management of proteinuria: blockade of the renin-angiotensin-aldosterone system

Proteinuria, in particular albuminuria, is a potentially significant modifiable risk factor for cardiovascular disease and the progression of kidney disease. Current treatment guidelines for albuminuria recommend a single renin–angiotensin–aldosterone inhibitor. This can be an ACE inhibitor or an angiotensin receptor antagonist. The routine use of combined renin–angiotensin–aldosterone inhibition for albuminuria is not supported by current evidence. Combination therapy is associated with higher rates of adverse events such as hyperkalaemia and progressive renal impairment.

Effects of dual inhibition of renin-angiotensin-aldosterone system on cardiovascular and renal outcomes: balancing the risks and the benefits

Chronic kidney disease is a worldwide health problem often burdened by severe cardiovascular complications. Hypertension represents one of the most important risk factor in affecting cardiovascular profile of chronic kidney disease patients. Since renin-angiotensin-aldosterone system plays a major role in determining cardiovascular outcome, guidelines recommend the use of renin-angiotensin-aldosteron inhibitors in order to control hypertension.

Innate immunity in diabetic kidney disease

Increasing evidence suggests that renal inflammation contributes to the pathogenesis and progression of diabetic kidney disease (DKD) and that anti-inflammatory therapies might have renoprotective effects in DKD. Immune cells and resident renal cells that activate innate immunity have critical roles in triggering and sustaining inflammation in this setting. Evidence from clinical and experimental studies suggests that several innate immune pathways have potential roles in the pathogenesis and progression of DKD. Toll-like receptors detect endogenous danger-associated molecular patterns generated during diabetes and induce a sterile tubulointerstitial inflammatory response via the NF-κB signalling pathway. The NLRP3 inflammasome links sensing of metabolic stress in the diabetic kidney to activation of pro-inflammatory cascades via the induction of IL-1β and IL-18. The kallikrein-kinin system promotes inflammatory processes via the generation of bradykinins and the activation of bradykinin receptors, and activation of protease-activated receptors on kidney cells by coagulation enzymes contributes to renal inflammation and fibrosis in DKD. In addition, hyperglycaemia leads to protein glycation and activation of the complement cascade via recognition of glycated proteins by mannan-binding lectin and/or dysfunction of glycated complement regulatory proteins. Data from preclinical studies suggest that targeting these innate immune pathways could lead to novel therapies for DKD.