Metabolic syndrome and renal injury

Association of proteinuria and risk of incident atrial fibrillation in the general population: A prospective study of Kailuan study participants

BACKGROUND

Proteinuria is a well-known cardiovascular risk factor, but whether it independently increases the risk for atrial fibrillation (AF) in Chinese population is unknown. To address this deficiency, herein, we investigated the association between proteinuria detected using urine dipstick test and the risk of AF.

METHODS

This was a prospective cohort study of Kailuan study participants who underwent the 2006-2007 and 2010-2011 health checkups and was free from AF. Participants were classified into four groups based on the level of proteinuria: [-, trace (±), 1+, ≥2+]. The outcome was incident AF as confirmed by 12-lead electrocardiography.

RESULTS

During a median of 11.90 years of follow-up, we documented 514 incident AF cases among 60,599 participants. Proteinuria was found in 6302 (10.40%) participants. Relative to participants without proteinuria at the baseline, those with proteinuria (≥2+) had an 83.9% higher risk (95% confidence interval [CI], 1.073-3.154, p = .0267) of developing AF, after adjusted for confounding variables. The result was consistent in the sensitivity analysis. Compared to consistently negative proteinuria, the risk of AF significantly increased in the aggravated proteinuria group (hazard ratio [HR] 1.552, 95% CI 1.140-2.114) and the persistent proteinuria group (HR 2.485, 95% CI 1.414-4.366). Among participants with resolved proteinuria (from positive to negative), the risk of incident AF was not significantly increased compared to those with persistently negative proteinuria (HR 1.300, 95% CI 0.743-2.276).

CONCLUSIONS

Proteinuria could be a modifiable risk factor for predicting AF development. Knowing the presence of proteinuria may improve risk stratification for decision-making about AF prevention.

Therapeutic propensity of ginsenosides Rg1 and Rg3 in rhabdomyolysis-induced acute kidney injury and renohepatic crosstalk in rats

BACKGROUND

Ginseng is a traditional herbal medicine used for thousands of years in Southeast Asian countries because of its medicinal properties. Ginsenosides Rg1 and Rg3 have demonstrated therapeutic properties against a broad spectrum of diseases.

PURPOSE

Here in this study, we investigated the therapeutic efficacy of Rg1 and Rg3 in alleviating glycerol-induced acute kidney injury, also known as rhabdomyolysis-induced acute kidney injury (RAKI).

METHODS

AKI was induced in male Wistar rats through intramuscular injection of 10 mL/kg glycerol and simultaneous oral treatment of ginsenosides Rg1 and Rg3 for 3 days. We also evaluated the therapeutic potential of Rg1 and Rg3 on human embryonic kidney epithelial (HEK-293). Cell viability and LDH assay were performed on HEK-293 cells to evaluate the toxicity of Rg1 and Rg3. Evaluation of important kidney damage markers such as creatinine and blood urea nitrogen (BUN) was carried out at different time points from the rat serum. Histopathological analysis was performed on kidney tissues. We also performed experiments such as ELISA assay, immunohistochemistry, immunofluorescence staining, COMET assay, western blotting, TUNEL assay, and flow cytometry to obtain results.

RESULTS

Rg1 and Rg3 significantly downregulated the expression of kidney damage markers such as creatinine and BUN in a dose-dependent manner. Histopathological analysis revealed damage across the glomerulus, tubules, and collecting duct rendering the kidney dysfunctional in glycerol treatment groups. However, Rg1 and Rg3 treated groups showed a significant reduction in tubular necrosis at both 10 and 20 mg/kg. There was also a sharp downregulation of oxidative and ER stress markers. Additionally, we observed nuclear translocation of Nrf2 which were more prominent in kidney tissues. Rg1 and Rg3 were also able to mitigate apoptotic cell death in vitro and in vivo evaluated through immunofluorescence staining for p53, TUNEL assay, flow cytometry, and immunoblotting for intrinsic apoptosis markers.

CONCLUSION

In summary, we conclude that Rg1 and Rg3 exhibited natural therapeutic remedy against AKI.

Activation of angiotensin-converting enzyme 2 ameliorates metabolic syndrome-induced renal damage in rats by renal TLR4 and nuclear transcription factor κB downregulation

BACKGROUND

Metabolic syndrome (MetS) is an independent risk factor for chronic kidney disease (CKD) through many mechanisms, including activation of the renin-angiotensin system. The deleterious effects of angiotensin II (Ang II) can be counterbalanced by angiotensin-converting enzyme 2 (ACE2). Diminazene aceturate (DIZE), an anti-trypanosomal drug, can activate ACE2.

OBJECTIVE

This study aimed to investigate the possible reno-protective effects of DIZE in MetS rats with elucidation of related mechanisms.

MATERIALS AND METHODS

Thirty adult male Wistar albino rats were divided equally into control, MetS, and MetS + DIZE groups. Body weight, systolic blood pressure (SBP), and urinary albumin levels were measured. Serum levels of fasting blood glucose (FBG), insulin, uric acid, lipid profile, urea, and creatinine were measured. Homeostasis Model Assessment Index (HOMA-IR) was estimated. Subsequently, renal levels of ACE2, Ang II, malondialdehyde (MDA), reduced glutathione (GSH), and tumor necrosis factor-α (TNF-α) were measured with histopathological and immunohistochemical assessment of TLR4 and NF-κB in renal tissues.

RESULTS

MetS caused dyslipidemia with significant increases in body weight, SBP, FBG, serum insulin, HOMA-IR, uric acid, urea, creatinine, urinary albumin, and renal levels of Ang II, MDA, and TNF-α, whereas renal ACE2 and GSH were significantly decreased. Renal TLR4 and NF-κB immunoreactivity in MetS rats was upregulated. DIZE supplementation of MetS rats induced significant improvements in renal function parameters; this could be explained by the ability of DIZE to activate renal ACE2 and decrease renal Ang II levels with downregulation of renal TLR4 and NF-κB expression.

CONCLUSION

DIZE exerts a reno-protective effect in MetS, mainly by downregulating renal TLR4 and NF-κB levels.

A triglyceride-rich lipoprotein environment exacerbates renal injury in the accelerated nephrotoxic nephritis model

Hyperlipidaemia accompanies chronic renal disease either as a consequence of the renal dysfunction or as part of generalized metabolic derangements. Under both situations, the lipid profile is characterized by accumulation of triglyceride-rich lipoproteins (TGRLs). This lipid profile is recognized as a risk factor for cardiovascular complications. Whether it may pose a risk for renal injury as well remains unclear. A hyper-TGRL state was generated in C57BL/6 mice using poloxamer-407 (P-407) and immune complex-mediated renal injury was triggered using the accelerated nephrotoxic nephritis (ANTN) model. The hyper-TGRL animals were hypersensitive to ANTN demonstrated by greater haematuria and glomerular cellularity. These changes were accompanied by increased glomerular accumulation of CD68⁺ macrophages. The hypersensitive response to ANTN was not seen in low-density lipoprotein receptor knock-out mice fed with a high fat diet, where triglyceride levels were lower but cholesterol levels comparable to those obtained using P-407. These data indicate that a hyper-TGRL state might be more detrimental to the kidneys than low-density lipoprotein-driven hypercholesterolaemia during immune complex-mediated nephritis. We speculate that the hyper-TGRL environment primes the kidney to exacerbated renal damage following an inflammatory insult with increased accumulation of macrophages that may play a key role in mediating the injurious effects.

Systolic blood pressure as a predictor of incident albuminuria and rapid renal function decline in type 2 diabetic patients

AIMS

Albuminuria and a reduced estimated glomerular filtration rate (eGFR) are known risk factors of poor cardiovascular outcomes in diabetic patients. We here aimed to investigate the determinants of incident albuminuria and rapid progression of renal dysfunction in patients with type 2 diabetes.

METHODS

Type 2 diabetic outpatients (n=215) with a mean baseline eGFR of 87±20 mLmin(-1)1.73 m(-2) were followed for 12 months. Urinary albuminuria was defined according to the urine albumin-to-creatinine ratio (UACR).

RESULTS

Among 132 patients with normoalbuminuria at baseline, 20 (15.2%) progressed to a more advanced stage of albuminuria within 1 year, and 20.5% of the 215 patients experienced a rapid decline in eGFR (eGFR reduction >5 mLmin(-1)1.73 m(-2)year(-1)). After adjusting for potential confounders, both baseline UACR and systolic blood pressure (SBP) were found to be significant independent factors for incident albuminuria and a rapid decline of eGFR in separate models. Using receiver operating characteristic curves, systolic blood pressures of 132 and 138 mmHg were found to predict incident albuminuria and a rapid decline of eGFR, respectively.

CONCLUSIONS

In addition to baseline UACR, SBP is one of the most powerful modifiable independent risk factors for incident albuminuria and a rapid renal function decline in type 2 diabetic patients without symptomatic cardiovascular disease.

Chronic Kidney Disease—Effect of Oxidative Stress

Chronic kidney disease (CKD) is a growing health problem with increasing incidence. The annual mortality of end-stage renal disease patients is about 9%, which is 10–20 fold higher than the general population, approximately 50% of these deaths are due to cardiovascular (CV) disease. CV risk factors, such as diabetes, hypertension, and hyperlipidemia, are strongly associated with poor outcome. Many other nontraditional risk factors such as inflammation, infection, oxidative stress, anemia, and malnutrition are also present. In this review we will focus on the role of oxidative stress in chronic kidney disease.

Peripheral arterial stiffness is independently associated with a rapid decline in estimated glomerular filtration rate in patients with type 2 diabetes

Introduction. Diabetes and its vascular complications are main noncommunicable chronic diseases and major global health issues. Peripheral arterial disease (PAD) is highly prevalent in diabetes with nephropathy. We evaluated the associations of variables of arterial stiffness and the decline in estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes. Materials and Methods. A total of 577 type 2 diabetic patients (mean ± SD: age, 63 ± 11 years) were enrolled. A rapid decline in eGFR was defined as progressively lower eGFR detected at both the 6- and 12-month follow-up visits, plus a reduction in eGFR more than 3 mL·min⁻¹per 1.73 m² per year. Results. Higher glycated hemoglobin (HbA1c), systolic blood pressure (SBP), pulse pressure (PP), and brachial-ankle pulse wave velocity (ba-PWV) at baseline were independently associated with a rapid decline in eGFR. The adjusted odds ratios (95% confidence intervals) for a rapid decline in eGFR for ba-PWV, SBP, and PP were 1.072 (1.011–1.136), 1.014 (1.004–1.025), and 1.025 (1.008–1.041), respectively, after adjustment for gender, age, body mass index, smoking, HbA1c, and baseline eGFR in separated models. Conclusions. Ba-PWV may serve as a simple and noninvasive predictor of rapid renal function progression in type 2 diabetic patients.

Usefulness of albuminuria as a prognostic indicator in patients with chronic heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

Albuminuria is an established risk factor for mortality and cardiovascular events in the general population. Albuminuria might be a marker of the various pathophysiologic changes, such as diffuse vascular injury and systemic inflammation, that arise in patients with chronic heart failure (CHF). However, the relation between albuminuria and CHF has not yet been fully elucidated. Therefore, the purpose of the present study was to assess the prevalence and prognostic significance of albuminuria in patients with CHF secondary to ischemic or idiopathic dilated cardiomyopathy. Of the 712 patients with CHF, 311 had normoalbuminuria, 304 had microalbuminuria, and 97 had macroalbuminuria. The patients with albuminuria had more cardiovascular co-morbidity and worse renal function than those with normoalbuminuria. A total of 152 cardiac events occurred during the follow-up period. Kaplan-Meier analysis demonstrated that patients with albuminuria had a greater incidence of cardiac events than those without albuminuria. Furthermore, albuminuria was significantly associated with an increased risk of cardiac events, even after adjustment for other prognostic variables. In conclusion, albuminuria is a powerful and independent predictor of adverse prognosis in patients with CHF and could be useful for risk stratification of patients with CHF.