Cardiovascular co-morbidity in chronic kidney disease: Current knowledge and future research needs

Key regulators of vascular calcification in chronic kidney disease: Hyperphosphatemia, BMP2, and RUNX2

Vascular calcification is quite common in patients with end-stage chronic kidney disease and is a major trigger for cardiovascular complications in these patients. These complications significantly impact the survival rate and long-term prognosis of individuals with chronic kidney disease. Numerous studies have demonstrated that the development of vascular calcification involves various pathophysiological mechanisms, with the osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs) being of utmost importance. High phosphate levels, bone morphogenetic protein 2 (BMP2), and runt-related transcription factor 2 (RUNX2) play crucial roles in the osteogenic transdifferentiation process of VSMCs. This article primarily reviews the molecular mechanisms by which high phosphate, BMP2, and RUNX2 regulate vascular calcification secondary to chronic kidney disease, and discusses the complex interactions among these factors and their impact on the progression of vascular calcification. The insights provided here aim to offer new perspectives for future research on the phenotypic switching and osteogenic transdifferentiation of VSMCs, as well as to aid in optimizing clinical treatment strategies for this condition, bearing significant clinical and scientific implications.

Chinese herbal medicine may reduce major adverse cardiovascular events in patients with dialysis hypotension: A taiwan nationwide cohort study

Background

The association between Chinese herbal medicine (CHM) and the risk of developing major adverse cardiovascular events (MACEs) in patients with dialysis hypotension is unclear and has not yet been investigated. This study aimed to determine whether CMH intervention could reduce the risk of MACEs in patients with dialysis hypotension.

Methods

The study data from the Taiwan National Health Insurance Research Database were analyzed to clarify this association. For this study, a case-control design with a cohort of patients who received hemodialysis (HD) from 2008 to 2018, 20 295 HD patients who had received blood pressure (BP) raising drugs were identified. After 1:1 frequency-matching, 730 patients were identified as CHM users and CHM non-users. Vascular access revision/reconstruction and MACEs were observed as the main outcomes during the follow-up period.

Results

The occurrence of vascular access revision/reconstruction in HD patients receiving BP raising drugs was associated with a 0.34-fold lower risk in CHM users than in CHM non-users [adjusted hazard ratio (aHR) = 0.34, 95% confidence interval (CI) = 0.26, 0.45]. The occurrences of MACEs in HD patients receiving BP raising drugs was associated with a 0.41-fold lower risk in CHM users than in CHM non-users (aHR = 0.41, 95% CI = 0.33, 0.51). A markedly predominant effect was observed in those receiving CHM for more than 180 days (aHR = 0.32; 95% CI = 0.22, 0.45).

Conclusion

The findings revealed lower vascular access dysfunction and MACEs risk correlated with the use of CHM treatment among HD patients who received BP raising drugs.

Homocysteine contributes to atherogenic transformation of the aorta in rabbits in the absence of hypercholesterolemia

Atherosclerosis, the leading cause of cardiovascular disease, cannot be sufficiently explained by established risk factors, including cholesterol. Elevated plasma homocysteine (Hcy) is an independent risk factor for atherosclerosis and is closely linked to cardiovascular mortality. However, its role in atherosclerosis has not been fully clarified yet. We have previously shown that rabbits fed a diet deficient in B vitamins and choline (VCDD), which are required for Hcy degradation, exhibit an accumulation of macrophages and lipids in the aorta, aortic stiffening and disorganization of aortic collagen in the absence of hypercholesterolemia, and an aggravation of atherosclerosis in its presence. In the current study, plasma Hcy levels were increased by intravenous injections of Hcy into balloon-injured rabbits fed VCDD (VCDD+Hcy) in the absence of hypercholesterolemia. While this treatment did not lead to thickening of aortic wall, intravenous injections of Hcy into rabbits fed VCDD led to massive accumulation of VLDL-triglycerides as well as significant impairment of vascular reactivity of the aorta compared to VCDD alone. In the aorta intravenous Hcy injections into VCDD-fed rabbits led to fragmentation of aortic elastin, accumulation of elastin-specific electron-dense inclusions, collagen disorganization, lipid degradation, and autophagolysosome formation. Furthermore, rabbits from the VCDD+Hcy group exhibited a massive decrease of total protein methylated arginine in blood cells and decreased creatine in blood cells, serum and liver compared to rabbits from the VCDD group. Altogether, we conclude that Hcy contributes to atherogenic transformation of the aorta not only in the presence but also in the absence of hypercholesterolemia.

The microbial metabolite p-cresol compromises the vascular barrier and induces endothelial cytotoxicity and inflammation in a 3D human vessel-on-a-chip

Increased protein-bound uremic toxins (PBUTs) in patients with chronic kidney disease (CKD) are associated with cardiovascular diseases (CVDs); however, whether retention of PBUTs causes CVD remains unclear. Previous studies assessing the impacts of PBUTs on the vasculature have relied on 2D cell cultures lacking in vivo microenvironments. Here, we investigated the impact of various PBUTs (p-cresol (PC), indoxyl sulfate (IS), and p-cresyl sulfate (PCS)) on microvascular function using an organ-on-a-chip (OOC). Human umbilical vein endothelial cells were used to develop 3D vessels. Chronic exposure to PC resulted in significant vascular leakage compared with controls, whereas IS or PCS treatment did not alter the permeability of 3D vessels. Increased permeability induced by PC was correlated with derangement of cell adherens junction complex, vascular endothelial (VE)-cadherin and filamentous (F)-actin. Additionally, PC decreased endothelial viability in a concentration-dependent manner with a lower IC50 in 3D vessels than in 2D cultures. IS slightly decreased cell viability, while PCS did not affect viability. PC induced inflammatory responses by increasing monocyte adhesion to endothelial surfaces of 3D vessels and IL-6 production. In conclusion, this study leveraged an OOC to determine the diverse effects of PBUTs, demonstrating that PC accumulation is detrimental to ECs during kidney insufficiency.

Polypharmacy in Patients with CKD: A Systematic Review and Meta-Analysis

Key Points

The prevalence of polypharmacy in patients with CKD was over 80%. Polypharmacy was highest in patients with a kidney transplant and those receiving dialysis. Polypharmacy is associated with worse clinical outcomes, lower quality of life, and medication-related problems in patients with CKD.

Background

Despite the high prevalence of polypharmacy in patients with CKD, the extent of polypharmacy across patients with (different stages of) CKD, as well as the association with clinical outcomes remains unknown. This systematic review aimed to evaluate the prevalence of polypharmacy in (different subgroups of) patients with CKD and assess the association between polypharmacy and patient-important outcomes.

Methods

MEDLINE, Embase, and the Cochrane Library were searched from inception until July 2022. Studies that reported the prevalence of polypharmacy, medication use, or pill burden in patients with CKD (including patients receiving dialysis and kidney transplant recipients) and their association with patient-important outcomes (i.e ., mortality, kidney failure, quality of life [QoL], and medication nonadherence) were included. Two reviewers independently screened title and abstract and full texts, extracted data, and assessed risk of bias. Data were pooled in a random-effects single-arm meta-analysis.

Results

In total, 127 studies were included (CKD 3–5 n =39, dialysis: n =38, kidney transplant n =13, different CKD stages n =37). The pooled prevalence of polypharmacy, based on 63 studies with 484,915 patients, across all patients with CKD was 82% (95% confidence interval, 76% to 86%), and the pooled mean number of prescribed medications was 9.7 (95% confidence interval, 8.4 to 11.0). The prevalence of polypharmacy was higher in patients who received dialysis or a kidney transplant compared with patients with CKD 3–5 but did not differ between studies with regards to region or patients' mean age or sex. In patients with CKD, polypharmacy was associated with a higher risk of all-cause mortality, kidney failure, faster eGFR decline, lower QoL, and higher medication nonadherence, adverse drug reactions, and potentially inappropriate medications.

Conclusions

The prevalence of polypharmacy in patients with CKD was over 80%, and highest in patients with a kidney transplant and those receiving dialysis. No causes of heterogeneity were identified, indicating that polypharmacy is an issue for all patients with CKD. Polypharmacy is associated with worse clinical outcomes, lower QoL, and medication-related problems in patients with CKD.

Clinical Trial registry name and registration number:

PROSPERO (CRD42022331941).

Advances in uremic toxin detection and monitoring in the management of chronic kidney disease progression to end-stage renal disease

Patients with end-stage kidney disease (ESKD) rely on dialysis to remove toxins and stay alive. However, hemodialysis alone is insufficient to completely remove all/major uremic toxins, resulting in the accumulation of specific toxins over time. The complexity of uremic toxins and their varying clearance rates across different dialysis modalities poses significant challenges, and innovative approaches such as microfluidics, biomarker discovery, and point-of-care testing are being investigated. This review explores recent advances in the qualitative and quantitative analysis of uremic toxins and highlights the use of innovative methods, particularly label-mediated and label-free surface-enhanced Raman spectroscopy, primarily for qualitative detection. The ability to analyze uremic toxins can optimize hemodialysis settings for more efficient toxin removal. Integration of multiple omics disciplines will also help identify biomarkers and understand the pathogenesis of ESKD, provide deeper understanding of uremic toxin profiling, and offer insights for improving hemodialysis programs. This review also highlights the importance of early detection and improved understanding of chronic kidney disease to improve patient outcomes.

Prevalence and Risk Factors of Cardiovascular Disease in Chronic Kidney Disease Patients at King Abdulaziz University Hospital (KAUH)

BACKGROUND

Chronic kidney disease (CKD) has emerged as a significant global health concern, with its incidence doubling over the past three decades. Cardiovascular diseases (CVD) pose a major threat to CKD patients, surpassing the risk of progressing to end-stage renal disease. While previous studies worldwide have shed light on this association, limited research has been conducted in Saudi Arabia regarding this burden. This study aims to fill this gap by identifying the prevalence and risk factors of CVD in CKD patients at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia, between 2017 and 2022.

METHODS

A six-year retrospective review of medical records at KAUH was conducted, including 465 non-end-stage CKD patients aged 30 to 79. Data, including demographics, clinical information, and laboratory results, were collected and statistically analyzed to investigate the association between variables.

RESULTS

Out of 465 CKD patients, 262 (56.3%) were diagnosed with CVD, with congestive heart failure and ischemic heart disease being the most common types. The majority were male 259 (55.7%), non-Saudi 278 (59.8%), and aged 60 years and older 291 (62.6%). Hypertension 394 (84.7%) and diabetes mellitus 336 (72.3%) were prevalent comorbidities. Severely reduced left ventricular ejection fraction, proteinuria, diabetes mellitus, and higher BMI were identified as significant risk factors for CVD in CKD patients.

CONCLUSION

This research contributes valuable insights into the prevalence and risk factors of CVD in CKD patients in Saudi Arabia, emphasizing the need for early detection and intervention. The identified risk factors provide a basis for developing targeted preventive strategies to mitigate this population's CVD burden.

The antihypertensive action of C-phycocyanin is related to the prevention of angiotensin II-caused vascular dysfunction in chronic kidney disease

C-phycocyanin (CPC) is a photosynthetic protein found in Arthrospira maxima with a nephroprotective and antihypertensive activity that can prevent the development of hemodynamic alterations caused by chronic kidney disease (CKD). However, the complete nutraceutical activities are still unknown. This study aims to determine if the antihypertensive effect of CPC is associated with preventing the impairment of hemodynamic variables through delaying vascular dysfunction. Twenty-four normotensive male Wistar rats were divided into four groups: (1) sham + 4 mL/kg/d vehicle (100 mM of phosphate buffer, PBS) administered by oral gavage (og), (2) sham + 100 mg/kg/d og of CPC, (3) CKD induced by 5/6 nephrectomy (CKD) + vehicle, (4) CKD + CPC. One week after surgery, the CPC treatment began and was administrated daily for four weeks. At the end treatment, animals were euthanized, and their thoracic aorta was used to determine the vascular function and expression of AT1, AT2, and Mas receptors. CKD-induced systemic arterial hypertension (SAH) and vascular dysfunction by reducing the vasorelaxant response of angiotensin 1-7 and increasing the contractile response to angiotensin II. Also, CKD increased the expression of the AT1 and AT2 receptors and reduced the Mas receptor expression. Remarkably, the treatment with CPC prevented SAH, renal function impairment, and vascular dysfunction in the angiotensin system. In conclusion, the antihypertensive activity of CPC is associated with avoiding changes in the expression of AT1, AT2, and Mas receptors, preventing vascular dysfunction development and SAH in rats with CKD.

Association of aortic stiffness with abdominal vascular and coronary calcifications in patients with stage 3 and 4 chronic kidney disease

RATIONALE AND OBJECTIVES

Increased central (aortic) arterial stiffness has hemodynamic repercussions that affect the incidence of cardiovascular and renal disease. In chronic kidney disease (CKD) there may be an increase in aortic stiffness secondary to multiple metabolic alterations including calcification of the vascular wall (VC). The objective of this study was to analyze the association of central aortic pressures and aortic stiffness with the presence of VC in abdominal aorta (AAC) and coronary arteries(CAC).

MATERIALS AND METHODS

We included 87 pacientes with CKD stage 3 and 4. Using applanation tonometry, central aortic pressures and aortic stiffness were studied. We investigated the association of aortic pulse wave velocity (Pvc-f) and Pvc-f adjusted for age, blood pressure, sex and heart rate (Pvc-f index) with AAC obtained on lumbar lateral radiography and CAC assessed by multidetector computed tomography. AAC and CAC were scored according to Kauppila and Agatston methods, respecti-vely. For the study of the association between Pvc-f index, Kauppila score, Agatston score, central aortic pressures, clinical parameters and laboratory data, multiple and logistic regression were used. We investigated the diagnosis performance of the Pvc-f index for prediction of VC using receiver-operating characteristic (ROC).

RESULTS

Pvc-f and Pvc-f index were 11.3 ± 2.6 and 10.6 m/s, respectively. The Pvc-f index was higher when CKD coexisted with diabetes mellitus (DM). AAC and CAC were detected in 77% and 87%, respectively. Albuminuria (β = 0.13, p = 0.005) and Kauppila score (β = 0.36, p = 0.001) were independently associated with Pvc-f index. In turn, Pvc-f index (β = 0.39, p = 0.001), DM (β = 0.46, p = 0.01), and smoking (β = 0.53; p = 0.006) were associated with Kauppila score, but only Pvc-f index predicted AAC [OR: 3.33 (95% CI: 1.6-6.9; p = 0.001)]. The Kauppila score was independently associated with the Agatston score (β = 1.53, p = 0.001). The presence of AAC identified patients with CAC with a sensitivity of 73%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 38%. The Vpc-f index predicted the presence of CAC [OR: 3.35 (95% CI: 1.04-10.2, p = 0.04)]. In the ROC curves, using the Vpc-f index, the AUC for AAC and CAC was 0.82 (95%CI: 0.71-0.93, p = 0.001) and 0.81 (95% CI: 0.67-0.96, p = 0.02), respectively.

CONCLUSIONS

When stage 3-4 CKD coexists with DM there is an increase in aortic stiffness determined by the Vpc-f index. In stage 3-4 CKD, AAC and CAC are very prevalent and both often coexist. The Vpc-f index is independently associated with AAC and CAC and may be useful in identifying patients with VC in these territories.

Resistin: A Potential Indicator of Aortic Stiffness in Non-Dialysis Chronic Kidney Disease Patients

Background and Objectives: In the progression and development of atherosclerosis, resistin plays a significant role. Chronic kidney disease (CKD), frequently associated with atherosclerosis, exhibits a marked increase in morbidity and mortality rates. This study set out to explore the association between aortic stiffness and serum levels of resistin in non-dialysis-dependent CKD patients ranging from stages 3 to 5. Materials and Methods: We collected fasting blood samples from 240 CKD patients across stages 3 to 5. The concentration of resistin in serum was determined using a commercially available enzyme immunoassay kit. Those patients who exhibited a carotid-femoral pulse wave velocity (cfPWV) greater than 10 m/s were identified as the aortic stiffness group. Results: Out of the 240 CKD patients, 88 (36.7%) were classified within the aortic stiffness group. This group demonstrated higher incidences of diabetes, advanced age, increased body weight, body mass index, body fat mass, systolic and diastolic blood pressure, fasting glucose, and serum resistin levels. Multivariate logistic regression analysis highlighted resistin, diabetes, and body weight as independent predictors of aortic stiffness. Additionally, body fat mass, logarithmically transformed cfPWV (log-cfPWV) values and log-triglyceride levels were independent predictors of log-resistin levels by multivariate stepwise linear regression analysis. Conclusions: In CKD patients from stages 3 to 5, a positive correlation exists between elevated serum resistin levels and cfPWV values, identifying resistin as a potential predictor of aortic stiffness.

A comparative study of the effects of chronic kidney disease on sonographic arterial stiffness parameters in geriatric and normal population

Aim: Due to its growing incidence rate worldwide, chronic kidney disease is a crucial public health problem which is strongly associated with cardiovascular disease. Cardiovascular disease in chronic kidney disease patients is characterized by arteriosclerosis and increased arterial stiffness, and is the leading cause of morbidity and mortality. A correlation was reported between an increased arterial stiffness and cardiovascular disease in high risk groups such as chronic kidney disease or hypertension as well as general undiagnosed population. Our aim was to show the changes in arterial stiffness parameters in patients with chronic kidney disease in the geriatric population. Material and Method: 44 chronic kidney disease patients and 44 control group cases of the same age were included in the study. There were 20 female and 24 male cases in each group. Systolic and diastolic diameter were measured for all cases. Intima-media thickness was measured in carotid and femoral arteries. Arterial stiffness parameters were calculated using formulas. Systolic and diastolic arterial blood pressure and body mass index were measured. Their urea and creatinine values were recorded. Results: There were no differences between two groups in terms of age and sex (p=0.069). Body mass index in the patient group was significantly lower compared to the control group (p=0.025). Systolic arterial blood pressure was higher in the patient group (p

Application of nanoparticles in the diagnosis and treatment of chronic kidney disease

With the development of nanotechnology, nanoparticles have been used in various industries. In medicine, nanoparticles have been used in the diagnosis and treatment of diseases. The kidney is an important organ for waste excretion and maintaining the balance of the internal environment; it filters various metabolic wastes. Kidney dysfunction may result in the accumulation of excess water and various toxins in the body without being discharged, leading to complications and life-threatening conditions. Based on their physical and chemical properties, nanoparticles can enter cells and cross biological barriers to reach the kidneys and therefore, can be used in the diagnosis and treatment of chronic kidney disease (CKD). In the first search, we used the English terms "Renal Insufficiency, Chronic" [Mesh] as the subject word and terms such as "Chronic Renal Insufficiencies," "Chronic Renal Insufficiency," "Chronic Kidney Diseases," "Kidney Disease, Chronic," "Renal Disease, Chronic" as free words. In the second search, we used "Nanoparticles" [Mesh] as the subject word and "Nanocrystalline Materials," "Materials, Nanocrystalline," "Nanocrystals," and others as free words. The relevant literature was searched and read. Moreover, we analyzed and summarized the application and mechanism of nanoparticles in the diagnosis of CKD, application of nanoparticles in the diagnosis and treatment of renal fibrosis and vascular calcification (VC), and their clinical application in patients undergoing dialysis. Specifically, we found that nanoparticles can detect CKD in the early stages in a variety of ways, such as via breath sensors that detect gases and biosensors that detect urine and can be used as a contrast agent to avoid kidney damage. In addition, nanoparticles can be used to treat and reverse renal fibrosis, as well as detect and treat VC in patients with early CKD. Simultaneously, nanoparticles can improve safety and convenience for patients undergoing dialysis. Finally, we summarize the current advantages and limitations of nanoparticles applied to CKD as well as their future prospects.

Rethinking Chronic Kidney Disease in the Aging Population

The process of aging population will inevitably increase age-related comorbidities including chronic kidney disease (CKD). In light of this demographic transition, the lack of an age-adjusted CKD classification may enormously increase the number of new diagnoses of CKD in old subjects with an indolent decline in kidney function. Overdiagnosis of CKD will inevitably lead to important clinical consequences and pronounced negative effects on the health-related quality of life of these patients. Based on these data, an appropriate workup for the diagnosis of CKD is critical in reducing the burden of CKD worldwide. Optimal management of CKD should be based on prevention and reduction of risk factors associated with kidney injury. Once the diagnosis of CKD has been made, an appropriate staging of kidney disease and timely prescriptions of promising nephroprotective drugs (e.g., RAAS, SGLT-2 inhibitors, finerenone) appear crucial to slow down the progression toward end-stage kidney disease (ESKD). The management of elderly, comorbid and frail patients also opens new questions on the appropriate renal replacement therapy for this subset of the population. The non-dialytic management of CKD in old subjects with short life expectancy features as a valid option in patient-centered care programs. Considering the multiple implications of CKD for global public health, this review examines the prevalence, diagnosis and principles of treatment of kidney disease in the aging population.

Atherosclerosis Specific Features in Chronic Kidney Disease (CKD)

Atherosclerosis is the major cause of cardiovascular disease, leading to a high mortality rate worldwide. Several risk factors are known to favor atherogenesis, among which are high blood pressure, smoking, diabetes mellitus, and others. Chronic kidney disease is another serious health problem associated with significant health care costs, morbidity, and mortality. Chronic kidney disease shares several risk factors with atherosclerosis and cardiovascular diseases, such as hypertension and diabetes mellitus. Additional risk factors for cardiovascular disease development should be considered in patients with chronic kidney disease. Interestingly, patients suffering from chronic kidney disease are more prone to cardiovascular problems than the general population. Moreover, chronic kidney disease is characterized by an increased atherosclerotic burden from the very early stages. The purpose of this review was to summarize data on atherosclerosis in chronic kidney disease, highlighting the specific features of the disease combination.

Bibliometric analysis on the progress of chronic heart failure

BACKGROUND

Chronic heart failure (CHF) is the terminal stage of a variety of heart diseases with higher morbidity and mortality. Although CHF has been studied for decades, the comprehensive analysis by bibliometrics has not been done. So, we analyzed the scientific outputs of global chronic heart failureresearches, explored the current research status and hotpots from 2009 to 2019.

METHODS

Web of Science Core Collection (WOSCC) was the data source, and the data was retrieved on June 25, 2020, according to the set search strategy. Bibliometrics tools- CiteSpace V (Drexel university, Chaomei Chen) and VOS viewer (Leiden University, van Eck NJ)-were used for analyzing published literature and exploring research hotspots and frontier directions.

RESULTS

A total of 21,484 articles were included, and the rate of published articles increased from 2009 to 2019 annually. United States of America (USA) was the leading country, Duke University was the leading institution, and Stefan D Anker was the most productive researcher in this field. The analysis of keywords showed that mortality, risk, outcomes, association, and dysfunction were the main hotpots and frontier directions of CHF.

CONCLUSION

Bibliometric analysis of the outputs on CHF shows an overall view about the current status of the research on CHF. Clinical treatment and the associations among organs in the patients with CHF are the major research frontiers. However, further research and collaboration are still required worldwide. Our findings can help researchers grasp the research status of CHF and determine new directions for future researches as soon as possible.

The Nutraceutical Antihypertensive Action of C-Phycocyanin in Chronic Kidney Disease Is Related to the Prevention of Endothelial Dysfunction

C-phycocyanin (CPC) is an antihypertensive that is not still wholly pharmacologically described. The aim of this study was to evaluate whether CPC counteracts endothelial dysfunction as an antihypertensive mechanism in rats with 5/6 nephrectomy (NFx) as a chronic kidney disease (CKD) model. Twenty-four male Wistar rats were divided into four groups: sham control, sham-treated with CPC (100 mg/Kg/d), NFx, and NFx treated with CPC. Blood pressure was measured each week, and renal function evaluated at the end of the treatment. Afterward, animals were euthanized, and their thoracic aortas were analyzed for endothelium functional test, oxidative stress, and NO production. 5/6 Nephrectomy caused hypertension increasing lipid peroxidation and ROS production, overexpression of inducible nitric oxide synthase (iNOS), reduction in the first-line antioxidant enzymes activities, and reduced-glutathione (GSH) with a down-expression of eNOS. The vasomotor response reduced endothelium-dependent vasodilation in aorta segments exposed to acetylcholine and sodium nitroprusside. However, the treatment with CPC prevented hypertension by reducing oxidative stress, NO system disturbance, and endothelial dysfunction. The CPC treatment did not prevent CKD-caused disturbance in the antioxidant enzymes activities. Therefore, CPC exhibited an antihypertensive activity while avoiding endothelial dysfunction.

A practical approach to chronic kidney disease in primary care

Chronic kidney disease (CKD), a common clinical problem in primary care, can be defined as any abnormality of the kidney structure and/or function that has been present for at least 3 months. Over the past 20 years, the incidence and prevalence of CKD have been increasing in Malaysia in line with the rising number of non-communicable diseases. At present, CKD has no cure. The treatment of CKD is very much dependent on early diagnosis and prevention of CKD progression. In this article, we aim to illustrate a practical approach to CKD in primary care, including diagnosis, evaluation, and management of CKD.

A Consistency Model for Identifying the Effects of n-3 and n-6 Fatty Acids on Lipoproteins in Dialysis Patients

Numerous randomized controlled trials (RCTs) and meta-analyses have assessed the effects of supplemental dietary polyunsaturated fatty acids (PUFAs) on levels of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) and the LDL/HDL ratio in patients receiving renal replacement therapy (RRT). However, results are ambiguous due to mixed reports of various nutrients used in the intervention group. We performed a network meta-analysis of RCTs to assess the effects of PUFAs on lipid profiles in patients undergoing RRT. RCTs performed before November 2021 were gathered from three databases. The means, standard deviations and the number of cases for each arm were independently extracted by two authors to form a network meta-analysis of LDL and HDL levels and the LDL/HDL ratio in a random effects model. Twenty-eight RCTs (n = 2017 subjects) were included in this study. The pooled results revealed that the combination of omega-3 fatty acids (n-3) and omega-6 fatty acids (n-6) produced significantly lower LDL (standardized mean difference (SMD) = −1.43, 95% confidence interval: −2.28 to −0.57) than the placebo. Both n-3 fatty acids (SMD = 0.78) and the combination of n-3 + n-6 (SMD = 1.09) benefited HDL significantly compared with placebo. Moreover, n-3 alone also exhibited a significantly lower LDL/HDL ratio than placebo. Collectively, PUFAs seem to be adequate nutrients for controlling lipoproteins in patients undergoing RRT. Specifically, n-3 + n-6 supplementation improved LDL levels, while n-3 improved HDL levels and the LDL/HDL ratio. However, our data provide limited information on specific dosages of PUFAs to form a concrete recommendation.

Kidney Tissue Biopsy

Kidney tissue biopsy is a commonly performed procedure which is valuable in the work-up for patients with medical renal disease and renal transplant. This article will review indications, contraindications, technique and potential complications of kidney biopsy.

Establishing target systolic and diastolic blood pressure in diabetic patients with hypertension: what do we need to consider?

INTRODUCTION

The optimum target for systolic and diastolic blood pressure remains divisive. In particular, the conflicting outcomes of the SPRINT and ACCORD trials have led to a divergence of guideline-recommended blood pressure targets for adults with diabetes.

AREAS COVERED

Here, we review the existing recommendations for blood pressure targets in diabetes, discussing the evidence base behind them and their limitations. We start by outlining the risks and benefits of lower systolic blood pressure targets among diabetics. We then follow with a separate appraisal of diastolic blood pressure targets, which necessitates examination of the 'J curve' and isolated diastolic hypertension.

EXPERT OPINION

Current and emerging evidence supports, on balance, a blood pressure therapeutic target of < 130/90 mmHg in adults at increased risk for cardiovascular disease, including diabetics. Whether certain diabetics with systolic BPs of 120-130 and/or diastolic BPs 80-90 mmHg require drug treatment to a target of <120/80 mmHg is less clear and requires more research.

Urinary Protein and Peptide Markers in Chronic Kidney Disease

Chronic kidney disease (CKD) is a non-specific type of kidney disease that causes a gradual decline in kidney function (from months to years). CKD is a significant risk factor for death, cardiovascular disease, and end-stage renal disease. CKDs of different origins may have the same clinical and laboratory manifestations but different progression rates, which requires early diagnosis to determine. This review focuses on protein/peptide biomarkers of the leading causes of CKD: diabetic nephropathy, IgA nephropathy, lupus nephritis, focal segmental glomerulosclerosis, and membranous nephropathy. Mass spectrometry (MS) approaches provided the most information about urinary peptide and protein contents in different nephropathies. New analytical approaches allow urinary proteomic-peptide profiles to be used as early non-invasive diagnostic tools for specific morphological forms of kidney disease and may become a safe alternative to renal biopsy. MS studies of the key pathogenetic mechanisms of renal disease progression may also contribute to developing new approaches for targeted therapy.

Impact of Physical Activity and Natural Bioactive Compounds on Endothelial Dysfunction in Chronic Kidney Disease

Chronic kidney disease (CKD) represents a world-wide public health problem. Inflammation, endothelial dysfunction (ED) and vascular calcifications are clinical features of CKD patients that increase cardiovascular (CV) mortality. CKD-related CV disease pathogenic mechanisms are not only associated with traditional factors such as arterial hypertension and dyslipidemia, but also with ED, oxidative stress and low-grade inflammation. The typical comorbidities of CKD contribute to reduce the performance and the levels of the physical activity in nephropathic patients compared to healthy subjects. Currently, the effective role of physical activity on ED is still debated, but the available few literature data suggest its positive contribution. Another possible adjuvant treatment of ED in CKD patients is represented by natural bioactive compounds (NBCs). Among these, minor polar compounds of extra virgin olive oil (hydroxytyrosol, tyrosol and oleocanthal), polyphenols, and vitamin D seem to exert a beneficial role on ED in CKD patients. The objective of the review is to evaluate the effectiveness of physical exercise protocols and/or NBCs on ED in CKD patients.

Uremic Toxins and Their Relation with Oxidative Stress Induced in Patients with CKD

The presence of toxins is believed to be a major factor in the development of uremia in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Uremic toxins have been divided into 3 groups: small substances dissolved in water, medium molecules: peptides and low molecular weight proteins, and protein-bound toxins. One of the earliest known toxins is urea, the concentration of which was considered negligible in CKD patients. However, subsequent studies have shown that it can lead to increased production of reactive oxygen species (ROS), and induce insulin resistance in vitro and in vivo, as well as cause carbamylation of proteins, peptides, and amino acids. Other uremic toxins and their participation in the damage caused by oxidative stress to biological material are also presented. Macromolecules and molecules modified as a result of carbamylation, oxidative stress, and their adducts with uremic toxins, may lead to cardiovascular diseases, and increased risk of mortality in patients with CKD.

Prevalence, risk factors and predicted risk of cardiac events in chronic kidney disease of uncertain aetiology in Sri Lanka: A tubular interstitial nephropathy

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with 'traditional' chronic kidney disease (CKD). However, chronic kidney disease of uncertain aetiology (CKDu), a tubular interstitial nephropathy is typically minimally proteinuric without high rates of associated hypertension or vascular disease and it is unknown if the rates of CVD are similar. This study aimed to identify the prevalence and the risk of CVD in patients with CKDu. This cross-sectional study included patients with confirmed CKDu who were attending two renal clinics in CKDu endemic-area. A detailed medical history, blood pressure, electrocardiogram (resting and six minutes vigorous walking), echocardiograms, appropriate laboratory parameters and medical record reviews were used to collect data at baseline. The WHO/Pan American Health Organization, cardiovascular risk calculator was employed to determine the future risk of CVD. The clinics had recorded 132 number of patients with CKDu, of these 119 consented to participation in the study. The mean age was 52 (± 9.5) years and mean eGFR was 51.1 (± 27.61); a majority (81.5% (n = 97)) were males. Thirty-four patients (28.6%) had evidence of ischaemic heart disease (IHD). Troponin-I (p = 0.02), Age >50 years (p = 0.01) and hyperuricemia (p = 0.01) were significantly associated with IHD in CKDu. Left ventricular hypertrophy was reported in 20.2% (n = 24). According to the risk calculator, 97% of the enrolled patients were at low risk (<10%) for experiencing a cardiovascular event within the next 10 years. Patients with CKDu have low prevalence and risk for CVD, implying that a majority are likely to survive to reach end-stage kidney disease. Our findings highlight the need for developing strategies to minimize the progression of CKDu to end-stage renal disease.

Prevalence of non-alcoholic fatty liver disease among patients with non-diabetic chronic kidney disease detected by transient elastography

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) shares a close relationship with cardiovascular morbidity and mortality. The purpose of this study is to evaluate the frequency of NAFLD in the patients with non-diabetic chronic kidney disease (CKD).

METHODS

This cross-sectional study included 80 patients with non-diabetic CKD, of which, 50 patients were on hemodialysis (HD) and 30 patients had CKD stage G3-5 not on dialysis. These patients were randomly selected from Ain Shams University Hospitals, Cairo, Egypt. Patients with diabetes mellitus, obesity, alcohol intake, viral hepatitis, or drug-induced liver steatosis were excluded from this study. Importantly, the controlled attenuation parameter (CAP) (dB/m) of liver steatosis (S0-S3) and liver stiffness/fibrosis measurement (F0-F4) were measured using transient elastography (Fibroscan^®). Other evaluations included complete blood count, routine blood chemistry, and C-reactive protein (CRP) titer.

RESULTS

In total, 45 (56.25%) (30 males, 15 females) out of total 80 studied patients were reported to have NAFLD. There were 29 patients with end-stage renal disease who were on regular HD and 16 patients with pre-dialysis CKD G3-5. The mean CAP values of hepatic steatosis in the patients with CKD on dialysis and patients with pre-dialysis CKD were 265.41 ± 52.73 and 259 ± 44.8 dB/m, respectively. A significant association between the severity of hepatic steatosis degree with decreased glomerular filtration rate and increased CKD stage was observed in this study. The degree of liver stiffness was significantly related to an increased hepatic steatosis grade. A significant positive correlation was found between the degree of NAFLD and serum levels of alanine aminotransferase, aspartate transaminase, total cholesterol, triglycerides, low-density lipoprotein, and CRP titer (P < 0.05). Importantly, NAFLD was significantly associated with an evident history of cardiovascular disease (CVD) among the studied patients.

CONCLUSION

A high frequency of NAFLD (56%) was observed among the patients with non-diabetic CKD on hemodialysis and patients with pre-dialysis CKD. NAFLD may be associated with an increased liver stiffness grade and CVD among those patients.

Prevalence and risk factors for elevated anxiety symptoms and anxiety disorders in chronic kidney disease: A systematic review and meta-analysis

BACKGROUND

Anxiety is associated with poor health outcomes among chronic kidney disease (CKD) patients. This review summarizes the prevalence and risk factors associated with elevated anxiety symptoms and disorders among CKD patients.

METHODS

Articles evaluating the prevalence and risk factors associated with elevated anxiety symptoms and disorders among CKD patients, as diagnosed via DSM 4th or 5th edition criteria, clinical interviews or validated questionnaires, were searched in Medline®, Embase®, PsychINFO® and CINAHL®. Using random-effects meta-analyses, the prevalence of elevated anxiety symptoms and disorders were estimated. A narrative review on the risk factors associated with elevated anxiety symptoms and disorders was presented.

RESULTS

From 4941 articles, 61 studies were included. The pooled prevalence of anxiety disorders (9 studies, n = 1071) among CKD patients across studies was 19% while that of elevated anxiety symptoms (52 studies, n = 10,739) was 43%. Across continents, prevalence of elevated anxiety symptoms was highest in Europe and Asia. Between pre-dialysis and dialysis patients, the prevalence of elevated anxiety symptoms was not statistically different at 31% and 42% respectively. Common risk factors associated with elevated anxiety symptoms included concomitant depression, lower parathyroid hormone levels, increased comorbidities, increased duration of hospitalization, reduced perceived quality of life, and decreased vitality levels.

CONCLUSION

Given the high prevalence of anxiety disorders and elevated anxiety symptoms, more studies are required to assess the role and outcomes of anxiety screening among CKD patients. This could facilitate early identification of at-risk patients and potentially improve their clinical outcomes.

Usefulness of statins in end-stage renal disease

End-stage renal disease (ESRD) is considered an independent risk factor of cardiovascular and cerebrovascular events. This review highlights atherosclerotic risk, lipid metabolism alterations, and four studies on the use of statins in ESRD-two of which showed a statistically significant effect of statins on the primary endpoints and two of which did not. Since effects were seen with higher doses of statins, further research is needed on the protective effects of intermediate to higher doses of statins in ESRD patients.

Uremic Toxins and Vascular Calcification-Missing the Forest for All the Trees

The cardiorenal syndrome relates to the detrimental interplay between the vascular system and the kidney. The uremic milieu induced by reduced kidney function alters the phenotype of vascular smooth muscle cells (VSMC) and promotes vascular calcification, a condition which is strongly linked to cardiovascular morbidity and mortality. Biological mechanisms involved include generation of reactive oxygen species, inflammation and accelerated senescence. A better understanding of the vasotoxic effects of uremic retention molecules may reveal novel avenues to reduce vascular calcification in CKD. The present review aims to present a state of the art on the role of uremic toxins in pathogenesis of vascular calcification. Evidence, so far, is fragmentary and limited with only a few uremic toxins being investigated, often by a single group of investigators. Experimental heterogeneity furthermore hampers comparison. There is a clear need for a concerted action harmonizing and standardizing experimental protocols and combining efforts of basic and clinical researchers to solve the complex puzzle of uremic vascular calcification.

Quality of Life of End Stage Renal Disease Patients Undergoing Dialysis in Southern Part of Kerala, India: Financial Stability and Inter-dialysis Weight Gain as Key Determinants

Background: Quality of Life (QoL) reflects the quality and outcome of healthcare along with key indicators of performance such as mortality and morbidity.

Objective: The aim of the study was to measure the QoL among patients with End Stage Renal Disease (ESRD) on maintenance hemodialysis and to understand various correlates of QoL.

Methods: A total of 95 ESRD patients from three dialysis centres in Southern districts of Kerala were interviewed. QoL was measured using vernacular version of World Health Organization Quality Of Life – Brief Version (WHOQOL-BREF) questionnaire.

Results: The mean age of the patients was 56.2 ± 13 years and 73.7% were males. Mean converted scores for overall QoL was 42.37 ± 21.3 and Health-related QoL (HRQoL) was 43.3 ± 18.3, indicating poor QoL. Males had significantly higher physical domain scores (p < 0.03). Occupation, income and Socio-economic Status (SES) influenced overall HRQoL while better income and higher SES predicted better scores in psychological and environmental domains.

Conclusion: Patients with better control over inter-dialysis weight gain (≤1600 g) had significantly higher scores. This study highlights the importance of using QoL tools in assessing the QoL of patients and the factors contributing to it.

Decreased insulin-like growth factor-1 (IGF-1) concentration correlates with reduced left-ventricle ejection fraction (LVEF) in hemodialysis patients

PURPOSE

The main purpose of this study is to determine the correlation between the serum IGF-1 concentration and certain cardiac indexes in hemodialysis patients.

METHODS

The study was conducted at the Clinical Center of Montenegro and three regional hemodialysis centers. The echocardiographic studies were performed the day after the hemodialysis sessions. Blood samples were taken before dialysis for the measurement of IGF1 and PTH.

RESULTS

A total of 102 patients were divided into two groups according to their left-ventricular ejection fraction (EF). Patients in the group with the higher EF had higher IGF-1 concentration (p = 0.024). IGF-1 was positively correlated with EF (ρ = 0.251, p = 0.012), and negatively correlated with LVMI (ρ = - 0.621, p < 0.001), SW (ρ = - 0.632, p < 0.001), and LW (ρ = - 0.632, p < 0.001). Multiple linear regression analysis was performed to determine the possible independent association between the EF and IGF-1 and the clinical data. The age of patients, their gender, and smoking habits did not have any combined influence on EF, but IGF-1 had a strong influence and was independently associated with the ejection fraction.

CONCLUSION

Our results may indicate the possible protective role of IGF-1 in the maintenance of heart structure and function in hemodialysis patients.

Editorial on the Special Issue "Comorbidities in Chronic Kidney Disease"

With a mean worldwide prevalence of 13 [...].

Gla-Rich Protein (GRP) as an Early and Novel Marker of Vascular Calcification and Kidney Dysfunction in Diabetic Patients with CKD: A Pilot Cross-Sectional Study

Vascular calcification (VC) is one of the strongest predictors of cardiovascular risk in chronic kidney disease (CKD) patients. New diagnostic/prognostic tools are required for early detection of VC allowing interventional strategies. Gla-rich protein (GRP) is a cardiovascular calcification inhibitor, whose clinical utility is here highlighted. The present study explores, for the first time, correlations between levels of GRP in serum with CKD developmental stage, mineral metabolism markers, VC and pulse pressure (PP), in a cohort of 80 diabetic patients with mild to moderate CKD (stages 2–4). Spearman’s correlation analysis revealed a positive association of GRP serum levels with estimated glomerular filtration rate (eGFR) and α-Klotho, while a negative correlation with phosphate (P), fibroblast growth factor 23 (FGF-23), vascular calcification score (VCS), PP, calcium (x) phosphate (CaxP) and interleukin 6 (IL-6). Serum GRP levels were found to progressively decrease from stage 2 to stage 4 CKD. Multivariate analysis identified low levels of eGFR and GRP, and high levels of FGF-23 associated with both the VCS and PP. These results indicate an association between GRP, renal dysfunction and CKD-mineral and bone disorder. The relationship between low levels of GRP and vascular calcifications suggests a future, potential utility for GRP as an early marker of vascular damage in CKD.

High-sensitivity troponin and the risk of atrial fibrillation in chronic kidney disease: Results from the Chronic Renal Insufficiency Cohort Study

BACKGROUND

Patients with chronic kidney disease (CKD) are at an increased risk of atrial fibrillation (AF). There is a need for novel biomarkers to reliably and accurately predict AF in this population. High-sensitivity troponin (HsTP) allows the detection of low troponin concentrations. The utility of HsTP for evaluating the risk of AF in CKD has not been established.

OBJECTIVE

We sought to explore the association between HsTP and the risk of incident AF in CKD.

METHODS

The Chronic Renal Insufficiency Cohort is a prospective cohort of 3939 individuals with mild to moderate CKD. HsTP was measured at study enrollment. Patients with a history of AF were excluded. Patients were followed for new-onset AF, and the association between HsTP and incident AF was examined using the Cox regression model.

RESULTS

A total of 3217 participants were included. Over a median follow-up period of 7.1 years (interquartile range 5.0-8.4 years), 252 patients developed new-onset AF (12 events per 1000 person-years of follow-up). The incidence of new-onset AF was 2.46%, 7.06%, and 11.5% at 3, 6, and 9 years, respectively. Compared with the lowest quartile of HsTP, patients in the third quartile of HsTP (hazard ratio 2.40; 95% confidence interval 1.58-3.65; P < .001) and the fourth quartile of HsTP (hazard ratio 4.43; 95% confidence interval 2.98-6.59; P < .001) had a higher incidence of AF.

CONCLUSION

HsTP levels are associated with an increased risk of AF in patients with mild to moderate CKD. This association remains significant despite adjustment for traditional AF risk factors and chronic renal disease.

Stromal Cell-derived Factor-1 and CXC Chemokine Receptor Type-4 are Associated with Cardiovascular Disease in Patients under Hemodialysis

Background

Cardiovascular disease (CVD) is the most common cause of death among patients with end-stage renal disease especially whom under hemodialysis (HD). Stromal cell-derived factor-1 (SDF-1) and its receptor CXC chemokine receptor type-4 (CXCR4) could contribute to CVD. The main aim of this study was to evaluate the association between SDF-1 and CXCR4 with CVD and its related risk factors in patients under HD.

Methods

Sixty patients under HD and 29 healthy subjects were recruited in the study. The serum levels and relative messenger RNA (mRNA) expressions of SDF-1 and CXCR4 were measured using enzyme-linked immunosorbent assay and real-time polymerase chain reaction in patients and controls, respectively. CVD history of the patients was obtained.

Results

Twenty patients (33.3%) had a history of CVD. The mean levels of serum and relative mRNA expressions of SDF-1 and CXCR4 were higher in patients than controls and also in patients with a history of CVD than patients without it. The serum levels and relative expressions of SDF-1 and CXCR4 were positively correlated with blood urea nitrogen, parathyroid hormone, and high-sensitivity C-reactive protein and inversely correlated with hemoglobin. The history of CVD was the independent predictor of serum levels of SDF-1 and CXCR4 and also relative mRNA expression of CXCR4.

Conclusions

The higher levels of serum and relative mRNA expressions of SDF-1 and CXCR4 were associated with CVD in patients under HD. Furthermore, SDF-1 and CXCR4 were associated with several traditional and uremia-related CVD risk factors in such patients.

The association of positive affect and cardiovascular health in Hispanics/Latinos with chronic kidney disease: Results from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

The beneficial influence of positive affect (e.g., joy) remains unexplored in relation to heart health in adults with chronic kidney disease (CKD)-a population at increased risk for poor cardiovascular health (CVH). Therefore, we evaluated the association of positive affect and CVH in a diverse U.S. population of Hispanics/Latinos with CKD. We analyzed cross-sectional data of adults ages 18-74 enrolled between 2008 and 2011 in the Hispanic Community Health Study/Study of Latinos with prevalent CKD (N = 1712). Positively worded items from the Center for Epidemiologic Studies Depression Scale were used to create a composite positive affect score (0-6; higher scores indicate greater positive affect). Prevalent CKD was defined as estimated glomerular filtration <60 ml/min/1.73 m² or urine albumin-to-creatinine ratio ≥30 mg/g. A composite CVH score was calculated using diet, body mass index, physical activity, cholesterol, blood pressure, fasting glucose, and smoking status. Each metric was defined as ideal, intermediate, or poor to compute an additive score. Linear regression was used for continuous scores of CVH and logistic regression for binary treatment (e.g., ≥4 Ideal). In participants with CKD, each unit increase in the positive affect score was associated with higher CVH scores when modeling CVH as a continuous outcome (β = 0.06, 95% CI = 0.01, 0.11). Similarly, a 1-unit increase in positive affect was associated with 1.15 times the odds of having >4 (vs. <4) ideal CVH indicators. Positive affect is associated with favorable CVH profiles in Hispanics/Latinos with CKD. Replication and prospective studies are needed to elucidate whether emotional well-being is a potential therapeutic target for intervention.

The interplay between mineral metabolism, vascular calcification and inflammation in Chronic Kidney Disease (CKD): challenging old concepts with new facts

Chronic kidney disease (CKD) is one of the most powerful predictors of premature cardiovascular disease (CVD), with heightened susceptibility to vascular intimal and medial calcification associated with a high cardiovascular mortality. Abnormal mineral metabolism of calcium (Ca) and phosphate (P) and underlying (dys)regulated hormonal control in CKD-mineral and bone disorder (MBD) is often accompanied by bone loss and increased vascular calcification (VC). While VC is known to be a multifactorial process and a major risk factor for CVD, the view of primary triggers and molecular mechanisms complexity has been shifting with novel scientific knowledge over the last years. In this review we highlight the importance of calcium-phosphate (CaP) mineral crystals in VC with an integrated view over the complexity of CKD, while discuss past and recent literature aiming to highlight novel horizons on this major health burden. Exacerbated VC in CKD patients might result from several interconnected mechanisms involving abnormal mineral metabolism, dysregulation of endogenous calcification inhibitors and inflammatory pathways, which function in a feedback loop driving disease progression and cardiovascular outcomes. We propose that novel approaches targeting simultaneously VC and inflammation might represent valuable new prognostic tools and targets for therapeutics and management of cardiovascular risk in the CKD population.

Carotid Intima-Media Thickness: A Surrogate Marker for Cardiovascular Disease in Chronic Kidney Disease Patients

Background:

Cardiovascular disease (CVD) is the leading cause of mortality in patients with chronic kidney disease (CKD). Carotid intima-media thickness (CIMT) is a measure of atherosclerotic vascular disease and considered a comprehensive picture of all alterations caused by multiple cardiovascular risk factors over time on the arterial walls. We therefore sought to determine the CIMT of the common carotid artery in patients with CKD and to evaluate the clinical pattern and prevalence of CVD in CKD patients.

Methods:

A case-control study involving 100 subjects made of 50 patients with CKD stages 2 to 4 and 50 age and sex matched apparently normal individuals. Carotid intima-media thickness of the common carotid artery was considered thickened if it measured greater than 0.8 mm. All subjects had laboratory investigations, 12-lead electrocardiogram, transthoracic echocardiography, and ankle-brachial index.

Results:

The mean CIMT was higher in CKD population compared with controls (P < .001). Eighty-four percent of the study population was found to have thickened CIMT compared with 18% of controls (P < .001). Patients with CKD had significantly higher blood pressure and heart rate than controls. Cardiovascular disease was also more prevalent among patients with CKD as compared with controls. Carotid intima-media thickness positively correlated with age, blood pressure, and random blood sugar.

Conclusions:

As CIMT was well correlated with many cardiovascular risk factors among CKD patients, it may serve as a surrogate marker for CVD and its early assessment may target patients who may need more aggressive therapy to retard the progression of kidney disease and improve outcome.

Plasma Polymer Coatings To Direct the Differentiation of Mouse Kidney-Derived Stem Cells into Podocyte and Proximal Tubule-like Cells

Kidney disease is now recognized as a global health problem and is associated with increased morbidity and mortality, along with high economic costs. To develop new treatments for ameliorating kidney injury and preventing disease progression, there is a need for appropriate renal culture systems for screening novel drugs and investigating the cellular mechanisms underlying renal pathogenesis. There is a need for in vitro culture systems that promote the growth and differentiation of specialized renal cell types. In this work, we have used plasma polymerization technology to generate gradients of chemical functional groups to explore whether specific concentrations of these functional groups can direct the differentiation of mouse kidney-derived stem cells into specialized renal cell types. We found that amine-rich (-NH₂) allylamine-based plasma-polymerized coatings could promote differentiation into podocyte-like cells, whereas methyl-rich (CH₃) 1,7-octadiene-based coatings promoted differentiation into proximal tubule-like cells (PTC). Importantly, the PT-like cells generated on the substrates expressed the marker megalin and were able to endocytose albumin, indicating that the cells were functional.

Potential Role of H-Ferritin in Mitigating Valvular Mineralization

Objective- Calcific aortic valve disease is a prominent finding in elderly and in patients with chronic kidney disease. We investigated the potential role of iron metabolism in the pathogenesis of calcific aortic valve disease. Approach and Results- Cultured valvular interstitial cells of stenotic aortic valve with calcification from patients undergoing valve replacement exhibited significant susceptibility to mineralization/osteoblastic transdifferentiation in response to phosphate. This process was abrogated by iron via induction of H-ferritin as reflected by lowering ALP and osteocalcin secretion and preventing extracellular calcium deposition. Cellular phosphate uptake and accumulation of lysosomal phosphate were decreased. Accordingly, expression of phosphate transporters Pit1 and Pit2 were repressed. Translocation of ferritin into lysosomes occurred with high phosphate-binding capacity. Importantly, ferritin reduced nuclear accumulation of RUNX2 (Runt-related transcription factor 2), and as a reciprocal effect, it enhanced nuclear localization of transcription factor Sox9 (SRY [sex-determining region Y]-box 9). Pyrophosphate generation was also increased via upregulation of ENPP2 (ectonucleotide pyrophosphatase/phosphodiesterase-2). 3H-1, 2-dithiole-3-thione mimicked these beneficial effects in valvular interstitial cell via induction of H-ferritin. Ferroxidase activity of H-ferritin was essential for this function, as ceruloplasmin exhibited similar inhibitory functions. Histological analysis of stenotic aortic valve revealed high expression of H-ferritin without iron accumulation and its relative dominance over ALP in noncalcified regions. Increased expression of H-ferritin accompanied by elevation of TNF-α (tumor necrosis factor-α) and IL-1β (interleukin-1β) levels, inducers of H-ferritin, corroborates the essential role of ferritin/ferroxidase via attenuating inflammation in calcific aortic valve disease. Conclusions- Our results indicate that H-ferritin is a stratagem in mitigating valvular mineralization/osteoblastic differentiation. Utilization of 3H-1, 2-dithiole-3-thione to induce ferritin expression may prove a novel therapeutic potential in valvular mineralization.

Health benefits of resveratrol: Evidence from clinical studies

Resveratrol is a polyphenolic nutraceutical that exhibits pleiotropic activities in human subjects. The efficacy, safety, and pharmacokinetics of resveratrol have been documented in over 244 clinical trials, with an additional 27 clinical trials currently ongoing. Resveretrol is reported to potentially improve the therapeutic outcome in patients suffering from diabetes mellitus, obesity, colorectal cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Alzheimer's disease, stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The polyphenol is reported to be safe at doses up to 5 g/d, when used either alone or as a combination therapy. The molecular basis for the pleiotropic activities of resveratrol are based on its ability to modulate multiple cell signaling molecules such as cytokines, caspases, matrix metalloproteinases, Wnt, nuclear factor-κB, Notch, 5'-AMP-activated protein kinase, intercellular adhesion molecule, vascular cell adhesion molecule, sirtuin type 1, peroxisome proliferator-activated receptor-γ coactivator 1α, insulin-like growth factor 1, insulin-like growth factor-binding protein 3, Ras association domain family 1α, pAkt, vascular endothelial growth factor, cyclooxygenase 2, nuclear factor erythroid 2 like 2, and Kelch-like ECH-associated protein 1. Although the clinical utility of resveratrol is well documented, the rapid metabolism and poor bioavailability have limited its therapeutic use. In this regard, the recently produced micronized resveratrol formulation called SRT501, shows promise. This review discusses the currently available clinical data on resveratrol in the prevention, management, and treatment of various diseases and disorders. Based on the current evidence, the potential utility of this molecule in the clinic is discussed.

Factors associated with carotid intima-media thickness in patients on maintenance hemodialysis

PURPOSE

The aim of this study was to analyze the association of the carotid intima-media thickness (CIMT) with various parameters in patients on maintenance hemodialysis (mHD).

METHODS

A cross-sectional study was conducted, enrolling 68 subjects (41 men, 27 women) on mHD in the Hemodialysis Unit, Sanglah Hospital, Denpasar, Indonesia. CIMT was measured with B-mode ultrasonography using a USG Sonoace 8000 and a 7.5 MHz linear transducer.

RESULTS

CIMT was higher in subjects with cardiovascular disease (CVD) compared with those without CVD (0.6494 vs 0.7288 mm; P=0.026), and in men compared with women (0.7056 vs 0.6141 mm; P=0.003). CIMT was correlated with age (R=0.607; P<0.001), plasma albumin (R=-0.291, P=0.016), serum phosphate (R=-0.294, P=0.015), calcium-phosphate product (R=-0.284, P=0.011), and plasma high-sensitivity C-reactive protein (R=0.279, P=0.030). However, after multiple linear regression testing, only age consistently had a role in determining the CIMT value (β=0.452, P<0.001).

CONCLUSION

Subjects with CVD have higher CIMT than those without CVD and men had higher CIMT than women. In addition, older age, higher high-sensitivity C-reactive protein, and lower albumin, phosphate, and calcium-phosphate product levels were correlated with higher CIMT. Age was the most important marker for CIMT in subjects on mHD.

Role of Toxic Elements in Chronic Kidney Disease

BACKGROUND

The kidney is central to many complex pathways in the body and kidney injury can precipitate multiple negative clinical outcomes. The resultant effect on nutrition and elemental body burden is bi-directional, confounding the very complex pathways that maintain homeostasis. These elemental changes themselves increase the risk of nutritional and biochemical disturbances.

OBJECTIVES

The aim of the present study was to describe how toxic elements interface with complications of chronic kidney disease (CKD).

METHODS

The present review included studies focusing on the molecular mechanisms induced by exposure to elements with known nephrotoxic effects and associated health complications in CKD patients.

DISCUSSION

Many non-essential elements have nephrotoxic activity. Chronic injury can involve direct tubular damage, activation of mediators of oxidative stress, genetic modifications that predispose poor cardiovascular outcomes, as well as competitive uptake and element mobilization with essential elements, found to be deficient in CKD. Cardiovascular disease is the most common cause of mortality among CKD patients. Oxidative stress, a common denominator of both deficient and excess element body constitution, underlies many pathological derivatives of chronic kidney disease. Bone disorders, hematological dysfunction and dysregulation of acid-base balance are also prevalent in kidney patients. The largest contribution of toxic element body burden results from environmental exposure and lifestyle practices. However, standard medical therapies may also potentiate toxic element accumulation and re-injury of vulnerable tissue.

CONCLUSIONS

For CKD patients, the cumulative effect of toxic elements persists throughout the disease and potentiates complications of CKD. Medical management should be coordinated between a medical team, dietitians and clinical researchers to mitigate those harmful effects.

COMPETING INTERESTS

The authors declare no competing financial interests.

Oxidative Stress and Cardiovascular Complications in Chronic Kidney Disease, the Impact of Anaemia

Patients with chronic kidney disease (CKD) have significant cardiovascular morbidity and mortality as a result of risk factors such as left ventricular hypertrophy (LVH), oxidative stress, and inflammation. The presence of anaemia in CKD further increases the risk of LVH and oxidative stress, thereby magnifying the deleterious consequence in uraemic cardiomyopathy (UCM), and aggravating progression to failure and increasing the risk of sudden cardiac death. This short review highlights the specific cardio-renal oxidative stress in CKD and provides an understanding of the pathophysiology and impact of uraemic toxins, inflammation, and anaemia on oxidative stress.