Renin-angiotensin-aldosterone pathway modulators in chronic kidney disease: A comparative review

Risk factors for chronic kidney disease in middle eastern patients with type 2 diabetes mellitus: A cross-sectional study using the KDIGO classification

AIMS

Chronic kidney disease (CKD) is prevalent in patients with type 2 diabetes mellitus (T2DM). This study aimed to investigate risk factors for CKD progression across the kidney disease-Improving Global Outcomes (KDIGO)categories in a Middle Eastern population beyond hyperglycemia as emphasized by KDIGO guidelines which classifying CKD by cause and severity.

METHODS

This cross-sectional study targeted 1603 patients with T2DM. Risk factors for CKD progression were determined using odds ratios (ORs) and 95 % confidence intervals (CIs).

RESULTS

Overall, 35.5 %, 31.7 %, and 32.8 % of patients were classified as low-risk, moderate-risk, and high-/very high-/highest-risk, respectively. Several factors were associated with high/very high/highest risk categorization, including being aged >45 years (OR: 1.85, 95 % CI: 1.36-2.49; P < 0.001), male gender (OR: 1.87, 95 % CI: 1.38-2.54; P < 0.001), hypertension (OR: 3.66, 95 % CI: 2.32-5.78; P < 0.001), and T2DM duration of ≥15 years (OR: 3.2, 95 % CI: 2.27-4.5; P < 0.001). Patients with more concurrent risk factors were notably represented in the high/very high/highest risk category.

CONCLUSIONS

Male patients, older patients, and those with comorbid hypertension, longstanding T2DM, and additional concurrent risk factors have a significantly higher risk of advanced CKD. Such findings should be considered when planning management approaches for patients with CKD.

Cardiac and Renal Fibrosis, the Silent Killer in the Cardiovascular Continuum: An Up-to-Date

Cardiovascular disease (CVD) and chronic kidney disease (CKD) often coexist and have a major impact on patient prognosis. Organ fibrosis plays a significant role in the pathogenesis of cardio-renal syndrome (CRS), explaining the high incidence of heart failure and sudden cardiac death in these patients. Various mediators and mechanisms have been proposed as contributors to the alteration of fibroblasts and collagen turnover, varying from hemodynamic changes to the activation of the renin-angiotensin system, involvement of FGF 23, and Klotho protein or collagen deposition. A better understanding of all the mechanisms involved has prompted the search for alternative therapeutic targets, such as novel inhibitors of the renin-angiotensin-aldosterone system (RAAS), serelaxin, and neutralizing interleukin-11 (IL-11) antibodies. This review focuses on the molecular mechanisms of cardiac and renal fibrosis in the CKD and heart failure (HF) population and highlights the therapeutic alternatives designed to target the responsible pathways.

Expanding options of supportive care in IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, with a potentially serious prognosis. At present, management of IgAN is primarily based on therapeutic lifestyle changes, and excellent blood pressure control and maximized supportive treatment with the combination of inhibition of the renin-angiotensin-aldosterone system with either inhibitors of angiotensin-converting enzyme or angiotensin II receptor blockers and inhibitors of sodium-glucose cotransporter-2, and possibly in the future also with endothelin antagonists. Supportive care currently represents the cornerstone of treatment of IgAN. Targeted-release formulation of budesonide should replace systemic corticosteroids in patients with higher proteinuria and active histological lesions. New treatment options are aimed at immunopathogenesis of IgAN including depletion or modulation of Galactose-deficient-Immunoglobulin A1-producing B cells, plasma cells, and the alternate and/or lectin pathway of complement. The exact place of monoclonal antibodies and complement inhibitors will need to be determined. This article reviews potential supportive therapies currently available for patients with IgAN.

Phloretin as an add-on therapy to losartan attenuates diabetes-induced AKI in rats: A potential therapeutic approach targeting TLR4-induced inflammation

AIM

Targeting Toll-like receptor 4 (TLR4) and Angiotensin II type 1 receptor (AT1R) could provide renoprotection during acute kidney injury (AKI) mainly by regulating inflammation, oxidative stress, mitochondrial dysfunction, and apoptosis. Phloretin (TLR4 inhibitor) as an add-on therapy to losartan (AT1R inhibitor) could provide more therapeutic benefits against AKI under diabetic condition. We aimed to study the effect of phloretin as an add-on therapy to losartan against AKI under diabetic condition.

MAIN METHODS

To mimic diabetic AKI condition, bilateral ischemia-reperfusion injury (BIRI) was done in diabetic male Wistar rats, and sodium azide treatment was given to high glucose NRK52E cells to mimic hypoxia-reperfusion injury. In diabetic rats, phloretin (50 mg/kg/per os (p.o.)) and losartan (10 mg/kg/p.o.) treatment was given for 4 days and 1 h prior to surgery while in NRK52E cells, both drugs (phloretin 50 μM and losartan 10 μM) were given 24 h prior to the hypoxia condition. The in vivo and in vitro samples were further used for different experiments.

KEY FINDINGS

Treatment with phloretin and losartan decreased diabetic and AKI biomarkers such as plasma creatinine, blood urea nitrogen (BUN), and kidney injury molecular 1 (KIM1). Moreover, a combination of phloretin and losartan significantly preserved ΔΨm and kidney morphology potentially by inhibiting TLR4-associated inflammation and AT1R-associated mitochondrial dysfunction, thereby oxidative stress.

SIGNIFICANCE

Combination therapy of phloretin and losartan was more effective than monotherapies. Both drugs target TLR4/MyD88/NF-κB pathway and reduce inflammation and mitochondrial dysfunction in AKI under diabetic condition.

Heart Failure in Patients with Chronic Kidney Disease

The function of the kidney is tightly linked to the function of the heart. Dysfunction/disease of the kidney may initiate, accentuate, or precipitate of the cardiac dysfunction/disease and vice versa, contributing to a negative spiral. Further, the reciprocal association between the heart and the kidney may occur on top of other entities, usually diabetes, hypertension, and atherosclerosis, simultaneously affecting the two organs. Chronic kidney disease (CKD) can influence cardiac function through altered hemodynamics and salt and water retention, leading to venous congestion and therefore, not surprisingly, to heart failure (HF). Management of HF in CKD is challenging due to several factors, including complex interplays between these two conditions, the effect of kidney dysfunction on the metabolism of HF medications, the effect of HF medications on kidney function, and the high risk for anemia and hyperkalemia. As a result, in most HF trials, patients with severe renal impairment (i.e., eGFR 30 mL/min/1.73 m2 or less) are excluded. The present review discusses the epidemiology, pathophysiology, and current medical management in patients with HF developing in the context of CKD.