Oxidative stress in hemodialysis: Causative mechanisms, clinical implications, and possible therapeutic interventions

Exosomes derived from human umbilical cord mesenchymal stem cells attenuate senescence of peritoneal mesothelial cells by inhibiting oxidative stress

OBJECTIVE

Aging is a natural process that affects cellular function. In peritoneal dialysis (PD), chronic exposure to dialysate induces oxidative stress (OS) in peritoneal mesothelial cells (PMCs), leading to cellular aging, fibrosis, and reduced dialysis efficacy. Mesenchymal stem cells (MSCs) have shown potential in alleviating cellular aging. This study investigates the role of exosomes (hUMSC-Exos) derived from human umbilical cord MSCs (hUMSCs) in mitigating PMC senescence and explores the underlying mechanisms.

METHODS

Human peritoneal mesothelial cells (HMrSV5) were cultured with 2.5 % glucose to induce senescence. Aging markers were assessed via Western blotting, β-galactosidase staining, and cell cycle analysis. hUMSC-Exos were characterized using Western blot, electron microscopy, and nanoparticle tracking analysis. Their uptake by HMrSV5 cells was confirmed through fluorescence microscopy. Various concentrations of hUMSC-Exos were tested, and OS levels were evaluated using reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) assays. The impact of the OS inhibitor N-acetyl-L-cysteine (NAC) on aging markers was also examined.

RESULTS

HMrSV5 cells treated with 2.5 % glucose exhibited increased expression of P53, P21, and P16, along with G0/G1 cell cycle arrest. Treatment with 150 μg/mL hUMSC-Exos reduced aging markers, decreased ROS and MDA levels, and increased SOD activity. Similar effects were observed with NAC treatment.

CONCLUSION

hUMSC-Exos alleviate PMCs aging by inhibiting OS, highlighting their potential to improve PD outcomes.

Hemocompatible chitosan nanoparticle diallyl disulfide-modified polysulfone hollow fibre membrane with antithrombotic and antioxidant properties for haemodialysis applications

The study aims to enhance the biocompatibility of haemodialysis membranes to reduce mortality risks in end-stage renal disease (ESRD) patients by addressing oxidative stress and thrombus formation. A novel Chitosan Diallyl Disulfide Nanoparticle (CNP/DADS) complex was immobilised into PSF membranes at various concentrations. The most optimal membrane, with 0.3 wt% CNP, demonstrated the highest KUF of 116 mL/m2.h.mmHg, 95.7 % BSA rejection, and significant urea, creatinine, and lysozyme clearance rates. This was attributed to increased hydrophilicity, improved morphological structure with higher porosity, and a thinner membrane skin layer. However, CNP/DADS-immobilised PSF HFM showed reduced performance due to denser morphological structures. Despite this, CNP/DADS-immobilised membranes met high-flux standards and exhibited enhanced biocompatibility, low haemolysis percentage, reduced protein adsorption and platelet adhesion, and less complement activation. They also significantly prolonged clotting times (P < 0.001) and demonstrated superior antioxidant activity against nitric oxide and hydrogen peroxide compared to CNP alone. Overall, the study suggests the successful development of PSF-based haemodialysis membranes with excellent antioxidant and antithrombotic properties, which is deemed suitable for safely and effectively removing uremic toxins during haemodialysis therapy.

Effects of a Functional Food Mixture on Patients Undergoing Hemodialysis: Preliminary Results Highlighting the Modulation of Uremic Toxins Derived From Microbiota and Antioxidant Markers

Combining functional foods may mitigate oxidative stress and gut dysbiosis complications in patients with chronic kidney disease (CKD). This study evaluated the impact of a mixture of turmeric and propolis on redox balance markers and microbiota-derived uremic toxins in patients undergoing hemodialysis (HD). Patients received 10 mL of a compound containing Curcuma longa L. (130 mg curcuminoids/day) and green propolis extract (110 mg/day of green propolis [EPP-AF]), along with ginger and lemon juice, or a placebo, once a day for 8 weeks. Antioxidant capacity was analyzed using the oxygen radical absorption capacity (ORAC) test, iron reduction power (FRAP) test, and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Malondialdehyde (MDA) was determined to estimate lipid peroxidation, and HPLC was used to evaluate uremic toxins. The study involved 35 patients: 17 in the intervention group (51 [19] years; body mass index [BMI], 23.7 [5.4] kg/m2) and 18 in the placebo group (51.5 [12.2] years; BMI, 23.4 [3.8] kg/m2). The intervention with functional foods significantly increased the FRAP test levels compared to the placebo group (p < 0.01), and there was a tendency to reduce indole-3-acetic acid plasma levels. Combining functional foods such as turmeric and propolis extracts can improve CKD patients' antioxidant capacity.

The Clinical Utility and Plausibility of Oxidative and Antioxidant Variables in Chronic and End-Stage Kidney Disease: A Review of the Literature

Oxidative stress (OS) is caused by an imbalance between the production of reactive oxygen species (ROS) in cells and tissues and the ability of the biological system to detoxify these products. In chronic kidney disease (CKD), OS contributes to deterioration of kidney function and disease progression. In patients with end-stage kidney disease undergoing hemodialysis or peritoneal dialysis, OS is further increased and associated with adverse clinical outcomes, including deterioration and subsequent loss of residual renal function, atherosclerosis, hypertension, cardiovascular disease and death. However, currently, there is no consensus or guidelines for the diagnosis and treatment of OS in these patients. Herein, we aim to present the existing data regarding biomarkers of OS, pro-oxidants (oxidized albumin, advanced oxidation protein products, xanthine oxidase/dehydrogenase, nitrite/nitrate, malondialdehyde) and antioxidants (superoxide dismutase, catalase, vitamin E, total antioxidant capacity, N-acetylcysteine) that are most clinically relevant and have been more extensively studied in patients with chronic kidney disease, aiming to provide a clearer understanding of this complex area.

Efficacy of antioxidant intervention and exercise intervention for lipid peroxidation in dialysis patients: a meta-analysis

Background

Lipid peroxidation is a major factor known to contribute to occurrence of cardiovascular events in dialysis patients. This study aims to investigate whether antioxidant interventions can improve lipid peroxidation damage in dialysis patients.

Methods

A comprehensive search in PubMed, Embase, and the Cochrane Library was conducted to identify eligible randomized controlled trials (RCTs) up to June 2024. Endpoints of interest included biomarkers related to Lipid peroxidation. The results from eligible studies were performed using RevMan 5.3 and Stata17.0 software.

Results

A total of 25 RCTs were included, involving eight interventions such as vitamin C supplementation, vitamin E supplementation, vitamin E-coated dialyzer, ω-fatty acid supplementation, curcumin supplementation, pomegranate juice supplementation, exercise intervention, and multiple antioxidant interventions. Outcome indicators included malondialdehyde (MDA) and oxidized low-density lipoprotein (Ox-LDL). The meta-analysis revealed that vitamin E supplementation caused significant reductions in MDA (p = 0.01). Treatment with vitamin E-coated dialyzer markedly decreased MDA levels (p < 0.0001). Curcumin supplementation significantly reduced Ox-LDL levels (p = 0.03). Exercise intervention decreased MDA levels (p < 0.0001). Multiple antioxidant interventions significantly decreased MDA (p = 0.01).

Conclusion

Supplementation of vitamin E, vitamin E-coated dialyzer treatment, curcumin supplementation, exercise intervention, and multiple antioxidant interventions can effectively reduce the level of lipid peroxidation biomarkers in dialysis patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO (CRD42023455399).

Comprehensive Insights into Sarcopenia in Dialysis Patients: Mechanisms, Assessment, and Therapeutic Approaches

Sarcopenia, defined as the progressive loss of muscle mass, strength, and function, is largely prevalent but still clinically underrecognized among patients undergoing chronic dialysis therapy. The pathogenesis involves a complex interplay of chronic inflammation, oxidative stress, metabolic acidosis, hormonal imbalances, protein waste, malnutrition, and reduced physical activity. This multifactorial condition profoundly impairs quality of life and may lead to significant clinical consequences, including frailty, an increased risk of falls and hospitalization, and elevated mortality. Despite its clinical relevance, sarcopenia often remains underdiagnosed due to inconsistent diagnostic criteria and challenges in assessing body composition in dialysis populations. Therapeutic strategies, including tailored exercise programs, nutritional interventions, and pharmacological treatments, are essential to mitigate muscle loss and improve patient outcomes. Early identification and routine sarcopenia assessment in clinical practice could play a pivotal role in enhancing the management of dialysis patients. A multidisciplinary, personalized approach is necessary to address the diverse factors contributing to sarcopenia and to improve the overall prognosis and quality of life for this vulnerable population.

The role of hyperuricemia in the progression of end-stage kidney disease and its molecular prospective in inflammation and cardiovascular diseases: A general review

With the ongoing development of the Chinese economy, the occurrence of chronic kidney disease (CKD) has experienced a remarkable upsurge recently, and due to uremia caused by CKD, the number of patients undergoing dialysis has shown a dramatic increase. China has been ranked first in the world for patients undergoing hemodialysis (HD) and peritoneal dialysis (PD) with approximately one million patients across the country. Due to the loss of kidney function caused by CKD, the kidneys tend to lose their ability to excrete uric acid (UA) out of the body; therefore, most patients undergoing dialysis are complicated with hyperuricemia (HUA). HUA is an abnormal disease of purine metabolism, and it's considered a chronic disease. More than 90% of patients suffering from HUA will not show any symptoms on physical examination. According to statistics, if high serum UA is left untreated, 55% of patients will develop severe problems due to the purine crystallization in the body, and the kidneys are the most affected organs by HUA causing renal insufficiency that can promote end-stage kidney disease (ESKD) by activating the renin-angiotensin system (RAS), which will lead to inflammation, arteriosclerosis, cardiovascular diseases (CVD), and other diseases. Lifestyle modifications and pharmacological interventions are the first primary choice for lowering UA, although dialysis will tend to reduce the high UA levels in the blood, drugs are also necessary. This review will summarize the mechanisms and metabolism of UA, the relationship between HUA and ESKD progression, HUA and inflammation, HUA and CVD, and pharmacological treatment of HUA.

Alterations in Autophagic Function and Endoplasmic Reticulum Stress Markers in the Peripheral Blood Mononuclear Cells of Patients on Hemodialysis

Oxidative stress, endoplasmic reticulum (ER) stress, and alterations in autophagy activity have been described as prominent factors mediating many pathological processes in chronic kidney disease (CKD). The accumulation of misfolded proteins in the ER may stimulate the unfolded protein response (UPR). The interplay between autophagy and UPR in hemodialysis (HD) patients remains unclear. The aim of the present study was to explore the associations between serum oxidative stress markers, autophagy activity, and ER stress markers in the peripheral blood mononuclear cells (PBMCs) of patients on HD. Autophagy and ER stress-related protein expression levels in PBMCs were measured using western blotting. The redox state of human serum albumin was measured via high-performance liquid chromatography. Levels of the microtubule associated protein light chain 3 (LC3)-II, BECLIN1, and p62/SQSTM1 proteins were significantly increased in PBMCs of HD patients compared to healthy subjects. The PBMCs in HD patients also displayed augmented glucose-regulated protein 78 kDa (GRP78), phosphorylated eukaryotic translation initiation factor 2, subunit 1 alpha (p-eIF2α), and activating transcription factor 6 (ATF6) levels (p < 0.05). Additionally, nuclear factor erythroid 2 (NF-E2)-related factor 2 (NRF2) levels were elevated in the PBMCs of HD patients, compared to those of healthy subjects. Correlation analysis showed that the redox status of albumin was significantly correlated with the p62 protein level in PBMCs. Compared to healthy controls, we found elevated autophagosome formation in HD patients. Increased expression of ER stress markers was also observed in HD patients. Furthermore, increased p62 expression was positively correlated with the protein expression of NRF2, as well as a reduced form of serum albumin (human mercaptalbumin; HMA), in HD patients.

Association of the oxidative balance score and chronic kidney disease: insights from the national health and nutrition examination survey 2009-2018

Introduction

Oxidative stress plays a pivotal role in the pathogenesis of chronic kidney disease (CKD). The oxidative balance score (OBS) was devised to quantify the overall oxidative state, integrating pro-oxidant and antioxidant influences from both dietary intake and lifestyle practices. The aim of this study was to delve into the relationship between the OBS and CKD within the adult population of the United States.

Methods

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 2009-2018, we derived the OBS from 16 dietary and four lifestyle factors. We employed weighted multivariate regression to probe the link between OBS and CKD. Additionally, we undertook subgroup analyses and applied Restricted Cubic Spline Regression (RCS) for further data analyses.

Results

This study encompassed 19,444 participants. Logistic regression analysis consistently demonstrated a protective effect of higher OBS on CKD. In Model 3, each unit increase in OBS was associated with a 2% reduction in the risk of CKD (95% CI: 0.97-0.99, p < 0.001) and a 4% reduction in the risk of reduced estimated glomerular filtration rate (eGFR) (95% CI: 0.95-0.98, p < 0.001). The highest OBS quintile (Q4) also showed significant reductions in the risk of CKD (OR: 0.66, 95% CI: 0.53-0.82, p < 0.001) and reduced eGFR (OR: 0.51, 95% CI: 0.37-0.69, p < 0.001) in Model 3. RCS analysis revealed a linear relationship between OBS and CKD. Subgroup analyses indicated significant associations between OBS and CKD in most subgroups, except for those without hypertension or with cardiovascular disease. Additionally, interaction analyses demonstrated that age, hypertension, and diabetes significantly modify the association between OBS and CKD risk.

Conclusion

An elevated OBS, reflecting a predominance of antioxidants, correlates with a diminished CKD risk in the American adult demographic. These insights emphasize the potential influence of oxidative equilibrium on the development of CKD.

Association of physical performance with cognitive impairment in middle-aged to older haemodialysis patients: a multicentre cross-sectional observational study

OBJECTIVE

To determine the prevalence of cognitive impairment (CI) among middle-aged to older patients receiving maintenance haemodialysis (MHD) and to investigate the potential association between CI and physical performance.

METHODS

This cross-sectional observational study enrolled participants aged 55-85 years who received MHD. Cognitive status was assessed using the Mini Mental State Examination (MMSE). Physical performance was measured by hand grip strength, the Timed Up and Go Test (TUGT) and the 4-m walking speed. Sociodemographic, clinical and laboratory parameters were recorded for each patient.

RESULTS

The study included 592 patients (363 males); and of these, 126 (21.3%) were diagnosed with CI. Compared with patients with normal cognitive function, those with CI were significantly older and had significantly longer dialysis duration, lower educational level, higher Malnutrition Inflammation Score, higher depression and higher Charlson Comorbidity Index score. After adjustment for covariates, multiple regression analysis suggested that grip strength (odds ratio [OR] = 0.959, 95% confidence interval [CI] = 0.924, 0.996) and 4-m walking speed (OR = 0.161, 95% CI = 0.070, 0.368) were protective factors. TUGT (OR = 1.037, 95%CI = 1.003, 1.071) was a risk factor.

CONCLUSION

Physical performance was correlated with CI and might be a significant indicator for the early identification of CI in middle-aged to older MHD patients.

Preparation and Hemocompatibility of Novel Antioxidant-Modified Polyethersulfone Membranes as Red Blood Cell Thrombosis Inhibitors

The contact between the dialysis membrane and blood can induce oxidative stress and thrombosis, causing oxidative organ damage and impaired toxin clearance. To date, the selection of anticoagulants has focused on mechanisms inhibiting white, but not red (erythrocytes) thrombus formation. In the present study, polyethersulfone (PES) membranes are modified with the antioxidant drug tiopronin; the physicochemical properties and dialysis performance of the Tio-PES membranes are evaluated. The effects on erythrocyte thrombosis are evaluated in terms of erythrocyte morphology, prothrombotic properties (adhesion, aggregation, viscosity, sedimentation, and hemolysis), and fibrinogen (FIB)-erythrocyte interactions. The regular anticoagulant and antiplatelet properties are also assessed. Superoxide dismutase, malondialdehyde, plasma protein, and complement C3a are further determined. Finally, the biosafety of the Tio-PES membranes is evaluated both in vitro and in vivo. The Tio-PES membranes exhibit excellent physicochemical properties and improved dialysis performance. It is found that the Tio-PES membranes stabilize erythrocyte morphology, reduce erythrocyte prothrombotic properties, decrease FIB adsorption, and prevent red thrombus formation. In addition, the Tio-PES membranes exhibit excellent antioxidant properties and show biosafety in primary toxicity studies. Thus, Tio-PES membranes hold promise as novel, safe, and effective dialysis materials for potential clinical application.

Pre-Infection Nutritional Status, Oxidative Stress, and One-Year-Long COVID Persistence in Patients Undergoing Hemodialysis: A Prospective Cohort Study

BACKGROUND

Nutritional status's role in long COVID is evident in the general population, yet unexplored in patients undergoing hemodialysis (HD), posing a research gap. We hypothesized that pre-infection undernutrition in HD patients might impact long COVID persistence by accelerating oxidative stress. The present study aimed to investigate the association between pre-infection nutritional status, oxidative stress, and one-year-long COVID persistence in HD patients.

METHODS

This prospective observational cohort study enrolled 115 HD patients with confirmed COVID-19. Nutritional status was assessed using the Controlling Nutritional Status (CONUT) score twice: before infection and three months post-infection. Oxidative markers included malondialdehyde (MDAs), ceruloplasmin, transferrin, and sulfhydryl groups. The endpoint was one-year-long COVID persistence.

RESULTS

Moderate pre-infection CONUT scores were associated with heightened severe undernutrition risk (p < 0.0001), elevated MDAs (p < 0.0001), and reduced ceruloplasmin levels (p = 0.0009) at three months post-COVID-19 compared to light CONUT scores. Pre-infection CONUT score independently predicted post-COVID oxidative damage [OR 2.3 (95% CI 1.2; 4.6), p < 0.0001] and one-year-long COVID persistence [HR 4.6 (95% CI 1.4; 9.9), p < 0.0001], even after adjusting for potential confounders.

CONCLUSION

Moderate pre-infection undernutrition heightens post-COVID oxidative stress and increases the risk of one-year-long COVID persistence in HD patients.

Oxidative stress in patients with coronavirus disease and end-stage renal disease: a pilot study

BACKGROUND

Oxidative stress, an imbalance between reactive oxygen species production and antioxidant capacity, increases in patients with coronavirus disease (COVID-19) or renal impairment. We investigated whether combined COVID-19 and end-stage renal disease (ESRD) would increase oxidative stress levels compared to each disease alone.

METHODS

Oxidative stress was compared among three groups. Two groups comprised patients with COVID-19 referred to the hospital with or without renal impairment (COVID-ESRD group [n = 18]; COVID group [n = 17]). The third group (ESRD group [n = 18]) comprised patients without COVID-19 on maintenance hemodialysis at a hospital.

RESULTS

The total oxidative stress in the COVID-ESRD group was lower than in the COVID group (p = 0.047). The total antioxidant status was higher in the COVID-ESRD group than in the ESRD (p < 0.001) and COVID (p < 0.001) groups after controlling for covariates. The oxidative stress index was lower in the COVID-ESRD group than in the ESRD (p = 0.001) and COVID (p < 0.001) groups. However, the three oxidative parameters did not differ significantly between the COVID and COVID-ESRD groups.

CONCLUSIONS

The role of reactive oxygen species in the pathophysiology of COVID-19 among patients withESRD appears to be non-critical. Therefore, the provision of supplemental antioxidants may not confer a therapeutic advantage, particularly in cases of mild COVID-19 in ESRD patients receiving hemodialysis. Nonetheless, this area merits further research.

Cataract Surgery and Chronic Kidney Disease: A Hospital-based Prospective Cohort Study

Objective Cataract and chronic kidney disease (CKD) occur with increasing frequency with age and share common risk factors including smoking, diabetes, and hypertension. We evaluated the risk of incident cataract surgery in patients with non-dialysis-dependent CKD and dialysis-dependent CKD compared to non-CKD patients, while taking into account the competing risk of death. Methods The participants included 1,839 patients from Sado General Hospital enrolled in the Project in Sado for Total Health (PROST) between June 2008 and December 2016 (54% men; mean age, 69 years). Among these patients, 50%, 44%, and 6% had non-CKD, non-dialysis-dependent CKD, and dialysis-dependent CKD, respectively. Results During a median follow-up of 5.6 years (interquartile range, 4.7-7.1), 193 participants underwent cataract surgery [18.7 (95% confidence interval (CI), 16.2-21.5)/1,000 person-years] and 425 participants died without undergoing cataract surgery [41.0 (95% CI, 37.4-45.2)/1,000 person-years]. The cumulative incidence of cataract surgery was the highest in the dialysis-dependent CKD group, followed by the non-dialysis-dependent CKD and non-CKD groups (log-rank p=0.002). After adjusting for potential confounding factors, the dialysis-dependent CKD group [hazard ratio (HR) 2.48; 95% CI 1.43-4.31], but not the non-dialysis-dependent CKD group (HR, 1.01; 95% CI 0.74-1.38), had a higher risk of cataract surgery than the non-CKD group. However, this association was no longer significant according to a competing risk analysis (sub-hazard ratio, 1.67; 95% CI 0.93-3.03). Conclusion Dialysis-dependent CKD patients were found to have an increased risk of cataract surgery; however, the association was attenuated and no longer significant when death was considered a competing risk.

Role of Natural Antioxidants in Cancer

The oxidative stress defined as an event caused by an imbalance between production and accumulation of reactive oxygen species (ROS), which lead to a damage in the structure of proteins, lipids, and DNA. Therefore, the production of ROS may alter the normal physiological process by provoking damage to multiple cellular organelles and processes. Oxidative stress has been linked to heart disease, cancer, respiratory diseases, immune deficiency, stroke, Parkinson's disease, and other inflammatory or ischemic conditions. Antioxidants are substances that can prevent or slow damage to cells and tissues caused by ROS, unstable molecules that the body produces as a reaction to environmental and other pressures. The β-carotene, catechins, flavonoids, polyphenols, lycopene, lutein, selenium, vitamins A, C, D, E, and zeaxanthin are all common types of antioxidants and found in plant-based foods, especially fruits and vegetables. Each antioxidant has its own role and can interact with others to process and remove free radicals efficiently. Several studies have been conducted to investigate whether the use of dietary antioxidant supplements is associated with decreased risks of developing cancer in humans, mixed results were reported. For instance, daily use of supplement such as vitamin c, vitamin E, β-Carotene, and minerals such as selenium and zinc have shown its effectiveness by reducing the risk of developing prostate cancer among men and skin cancer among women.

The effect of aerobic exercise on oxidative stress in patients with chronic kidney disease: a systematic review and meta-analysis with trial sequential analysis

PURPOSE

The purpose of this study was to investigate how aerobic exercise affects oxidative stress (OS) in patients with chronic kidney disease (CKD).

METHODS

Retrieval dates range from the date the database was established to 19 July 2023, without languages being restricted. A meta-analysis and sensitivity analysis were conducted using RevMan 5.3 and Stata 16.0.

RESULTS

The meta-analysis showed that, compared to usual activity or no exercise, aerobic exercise significantly reduced the oxidative markers malondialdehyde (MDA) (mean differences (MD) - 0.96 (95% CI -1.33, - 0.59); p < 0.00001), advanced oxidation protein product (AOPP) (MD - 3.49 (95% CI - 5.05, - 1.93); p < 0.00001), F2-isoprostanes (F2-iso) (MD - 11.02 (95% CI - 17.79, - 4.25); p = 0.001). Aerobic exercise also increased the antioxidant marker superoxide dismutase (SOD) in CKD patients (standardized mean differences (SMD) 1.30 (95% CI 0.56, 2.04); p = 0.0005). Subgroup analysis showed a significant increase in glutathione peroxidase (GPX) in patients aged ≥60 years (SMD 2.11 (95% CI 1.69, 2.54); p < 0.00001). The change in total antioxidant capacity (TAC) after aerobic exercise was insignificant in patients with CKD. The trial sequential analysis supported aerobic exercise's effectiveness in improving MDA, SOD, AOPP, and F2-iso in patients with CKD.

CONCLUSION

The results of this review suggest that aerobic exercise improves OS indicators (MDA, SOD, AOPP, and F2-iso) in CKD patients compared to conventional treatment or no exercise and that the effects on GPX and TAC indicators need further confirmation. For better validation of benefits and exploration of the best aerobic exercise regimen to improve OS status with CKD, further studies with high methodological quality and large sample sizes are needed.

Alleviation of Oxidative Stress during Hemodialysis Sessions by Hemodialysis Membrane Innovation: A Multidisciplinary Perspective

Oxidative stress is prevalent in end-stage kidney disease patients receiving chronic hemodialysis and is associated with heavy cardiovascular disease burdens and increased mortality risks. Hemoincompatible hemodialysis membranes per se contribute to the activation of oxidative reactions and the generation of oxygen free radicals. Since the early 1990s, vitamin E-coated membranes have been extensively used in hemodialysis patients to reduce oxidative stress during hemodialysis sessions. However, the beneficial effects of vitamin E-coated membranes versus unmodified synthetic membranes on long-term patient-centered outcomes, such as survival, quality of life, and prevalence of cardiovascular diseases, remain controversial. Accordingly, novel antioxidant hemodialysis membranes were prepared to replace the use of vitamin E-coated membranes despite the translational research on these membranes unfortunately coming to a standstill. In this review, we first summarize the state-of-the-art on the use of vitamin E-coated membranes in hemodialysis patients to highlight their strengths and limitations. Then, we discuss the latest advances in fabricating antioxidant hemodialysis membranes and provide perspectives to bridge knowledge gaps between laboratorial investigations and clinical practice in fabricating antioxidant hemodialysis membranes.

The Role of Oxidative Stress in Kidney Injury

Acute kidney injury and chronic kidney disease are among the most common non-communicable diseases in the developed world, with increasing prevalence. Patients with acute kidney injury are at an increased risk of developing chronic kidney disease. One of kidney injury's most common clinical sequelae is increased cardiovascular morbidity and mortality. In recent years, new insights into the pathophysiology of renal damage have been made. Oxidative stress is the imbalance favoring the increased generation of ROS and/or reduced body's innate antioxidant defense mechanisms and is of pivotal importance, not only in the development and progression of kidney disease but also in understanding the enhanced cardiovascular risk in these patients. This article summarizes and emphasizes the role of oxidative stress in acute kidney injury, various forms of chronic kidney disease, and also in patients on renal replacement therapy (hemodialysis, peritoneal dialysis, and after kidney transplant). Additionally, the role of oxidative stress in the development of drug-related nephrotoxicity and also in the development after exposure to various environmental and occupational pollutants is presented.

Unveiling the Clinical Benefits of High-Volume Hemodiafiltration: Optimizing the Removal of Medium-Weight Uremic Toxins and Beyond

Dialysis treatment has improved the survival of patients with kidney failure. However, the hospitalization and mortality rates remain alarmingly high, primarily due to incomplete uremic toxin elimination. High-volume hemodiafiltration (HDF) has emerged as a promising approach that significantly improves patient outcomes by effectively eliminating medium and large uremic toxins, which explains its increasing adoption, particularly in Europe and Japan. Interest in this therapy has grown following the findings of the recently published CONVINCE study, as well as the need to understand the mechanisms behind the benefits. This comprehensive review aims to enhance the scientific understanding by explaining the underlying physiological mechanisms that contribute to the positive effects of HDF in terms of short-term benefits, like hemodynamic tolerance and cardiovascular disease. Additionally, it explores the rationale behind the medium-term clinical benefits, including phosphorus removal, the modulation of inflammation and oxidative stress, anemia management, immune response modulation, nutritional effects, the mitigation of bone disorders, neuropathy relief, and amyloidosis reduction. This review also analyzes the impact of HDF on patient-reported outcomes and mortality. Considering the importance of applying personalized uremic toxin removal strategies tailored to the unique needs of each patient, high-volume HDF appears to be the most effective treatment to date for patients with renal failure. This justifies the need to prioritize its application in clinical practice, initially focusing on the groups with the greatest potential benefits and subsequently extending its use to a larger number of patients.

Advances in Enhancing Hemocompatibility of Hemodialysis Hollow-Fiber Membranes

Hemodialysis, the most common modality of renal replacement therapy, is critically required to remove uremic toxins from the blood of patients with end-stage kidney disease. However, the chronic inflammation, oxidative stress as well as thrombosis induced by the long-term contact of hemoincompatible hollow-fiber membranes (HFMs) contribute to the increase in cardiovascular diseases and mortality in this patient population. This review first retrospectively analyzes the current clinical and laboratory research progress in improving the hemocompatibility of HFMs. Details on different HFMs currently in clinical use and their design are described. Subsequently, we elaborate on the adverse interactions between blood and HFMs, involving protein adsorption, platelet adhesion and activation, and the activation of immune and coagulation systems, and the focus is on how to improve the hemocompatibility of HFMs in these aspects. Finally, challenges and future perspectives for improving the hemocompatibility of HFMs are also discussed to promote the development and clinical application of new hemocompatible HFMs.

Graphical Abstract

Anthocyanins-rich interventions on oxidative stress, inflammation and lipid profile in patients undergoing hemodialysis: meta-analysis and meta-regression

The aim of this systematic review and meta-analysis was to evaluate the effects of anthocyanins-interventions on oxidative stress, inflammation, and lipid profile in patients undergoing hemodialysis. This systematic review and meta-analysis were registered on the International Prospective Register of Systematic Reviews (PROSPERO CRD42020209742). The primary outcome was anthocyanins-rich intervention on OS parameters and secondary outcome was anthocyanins-rich intervention on inflammation and dyslipidemia. RevMan 5.4 software was used to analyze the effect size of anthocyanins-rich intervention on OS, inflammation and dyslipidemia. Meta-analysis effect size calculations incorporated random-effects model for both outcomes 1 and 2. Eight studies were included in the systematic review (trials enrolling 715 patients; 165 men and 195 women; age range between 30 and 79 years). Anthocyanin intervention in patients undergoing hemodialysis decrease the oxidant parameters (std. mean: -2.64, 95% CI: [-3.77, -1.50], P ≤ 0.0001, I² = 97%). Specially by reduction of malondialdehyde products in favor of anthocyanins-rich intervention (std. mean: -14.58 µmol.L, 95% CI: [-26.20, -2.96], P ≤ 0.0001, I² = 99%) and myeloperoxidase (std. mean: -1.28 ηg.mL, 95% CI: [-2.11, -0.45], P = 0.003, I² = 77%) against placebo group. Decrease inflammatory parameters (std. mean: -0.57, 95% CI: [-0.98, -0.16], P = 0.007, I² = 79%), increase HDL cholesterol levels (std. mean: 0.58 mg.dL, 95% CI: [0.23, 0.94], P = 0.001, I² = 12%) against placebo group. Anthocyanins-rich intervention seems to reduce oxidative stress, inflammatory parameters and improve lipid profile by increasing HDL cholesterol levels in patients with chronic kidney disease undergoing hemodialysis.

The Characteristics of Dialysis Membranes: Benefits of the AN69 Membrane in Hemodialysis Patients

Patients undergoing hemodialysis (HD) experience serious cardiovascular complications, through malnutrition, inflammation, and atherosclerosis. Amputation for peripheral arterial disease (PAD) is more prevalent in patients undergoing HD than in the general population. In addition, revascularization procedures in dialysis patients are often associated with subsequent amputation and high mortality rates. To improve the prognosis of dialysis patients, malnutrition and inflammation must be properly treated, which necessitates a better understanding of the characteristics of dialysis membranes. Herein, the characteristics of several dialysis membranes were studied, with a special reference to the AN69 membrane, noting several similarities to low-density lipoprotein (LDL)-apheresis, which is also applicable for the treatment of PAD. Both systems (LDL-apheresis and AN69) have anti-inflammatory and anti-thrombogenic effects because they use a negatively charged surface for extracorporeal adsorptive filtration from the blood/plasma, and contact phase activation. The concomitant use of both these therapeutic systems may have additive therapeutic benefits in HD patients. Here, we reviewed the characteristics of dialysis membranes and benefits of the AN69 membrane in dialysis patients.

N-Acetylcysteine: more than preventing contrast-induced nephropathy in uremic patients-focus on the antioxidant and anti-inflammatory properties

Oxidative stress (OS) has been recognized as a pathophysiologic mechanism underlying the development and progression of chronic kidney disease (CKD). OS, which results from the disturbance of balance among pro-oxidants and antioxidants favoring the pro-oxidants, is present even in early CKD and increases progressively along with deterioration of kidney function to end-stage kidney disease (ESKD). In ESKD, OS is further exacerbated mainly due to dialysis procedures per se and predisposes to increased cardiovascular morbidity and mortality. Therefore, since OS plays a pivotal role in the pathogenesis and progression of atherosclerosis in uremic patients, several strategies aiming to ameliorate OS in these patients have been proposed. Among those, N-acetylcysteine (NAC), a thiol-containing antioxidant agent, has attracted special attention due to its pleiotropic functions and beneficial effect in various OS-related entities including paracetamol overdose and prevention of contrast-induced nephropathy. In this review, we present the currently available literature on the antioxidant and anti-inflammatory properties of NAC in CKD, including hemodialysis and peritoneal dialysis.

Association between serum uric acid/HDL-cholesterol ratio and chronic kidney disease: a cross-sectional study based on a health check-up population

OBJECTIVE

Evidence suggests that both serum uric acid (SUA) and high-density lipoprotein cholesterol (HDL-C) are risk factors for chronic kidney disease (CKD). The SUA-to-HDL-C ratio (UHR) has recently attracted attention as a new biomarker to evaluate the role between inflammatory and anti-inflammatory substances. Thus, we explored the association between UHR and CKD in a large Chinese population.

DESIGN

A cross-sectional study.

SETTING

Annual health check-up population in Nanjing.

PARTICIPANTS

19 458 individuals who underwent an annual health check-up in 2019 were included in our study.

MAIN OUTCOME MEASURE

CKD was diagnosed according to an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m².

RESULTS

Correlation analysis showed that UHR was negatively associated with eGFR after adjusting for confounding factors (r=-0.34). In addition, participants in the highest quartile of UHR had a higher risk of CKD than those in the lowest quartiles (OR=9.28, p<0.001).

CONCLUSION

We found that high UHR values were positively associated with CKD risk in health check-up population. An increased UHR may be a useful measure by which to assess CKD risk in the preclinical stage.

Effect of hypoxia and uremia on oxidative stress on erythrocytes from hemodialysis patients

Oxidative stress (OS) is essential in uremia-associated comorbidities, including renal anemia. Complications experienced by hemodialysis (HD) patients, such as hypoxemia and uremic toxins accumulation, induce OS and premature death of red blood cells (RBC). We aimed to characterize reactive oxygen species (ROS) production and antioxidant pathways in HD-RBC and RBC from healthy controls (CON-RBC) and evaluate the role of uremia and hypoxia in these pathways. ROS production, xanthine oxidase (XO) and superoxide dismutase (SOD) activities, glutathione (GSH), and heme oxygenase-1 (HO-1) levels were measured using flow cytometry or spectrophotometry in CON-RBC and HD-RBC (pre- and post-HD), at baseline and after 24 h incubation with uremic serum (S-HD) and/or under hypoxic conditions (5% O₂ ). Ketoprofen was used to inhibit RBC uremic toxins uptake. HD-RBC showed higher ROS levels and lower XO activity than CON-RBC, particularly post-HD. GSH levels were lower, while SOD activity and HO-1 levels of HD-RBC were higher than control. Hypoxia per se triggered ROS production in CON-RBC and HD-RBC. S-HD, on top of hypoxia, increased ROS levels. Inhibition of uremic toxins uptake attenuated ROS of CON and HD-RBC under hypoxia and uremia. CON-RBC in uremia and hypoxia showed lower GSH levels than cells in normoxia and non-uremic conditions. Redox mechanisms of HD-RBC are altered and prone to oxidation. Uremic toxins and hypoxia play a role in unbalancing these systems. Hypoxia and uremia participate in the pathogenesis of OS in HD-RBC and might induce RBC death and thus compound anemia.

Engineering Antioxidative Cascade Metal-Phenolic Nanozymes for Alleviating Oxidative Stress during Extracorporeal Blood Purification

Oxidative stress is a compelling risk factor in chronic kidney diseases and is further aggravated for individuals during extracorporeal blood purification, ultimately leading to multiple complications. Herein, antioxidative cascade metal-phenolic nanozymes (metal-tannic acid nanozymes, M-TA NMs) are synthesized via metal ions-mediated oxidative coupling of polyphenols; then M-TA NMs engineered hemoperfusion microspheres (Cu-TAn@PMS) are constructed for alleviating oxidative stress. M-TA NMs show adjustable broad-spectrum antioxidative activities toward multiple reactive nitrogen and oxygen species (RNOS) due to the adjustable catalytic active centers. Importantly, M-TA NMs could mimic the cascade processes of superoxide dismutase and catalase to maintain intracellular redox balance. Detailed structural and spectral analyses reveal that the existence of a transition metal could decrease the electronic energy band gaps of M-TA NMs to offer better electron transfers for RNOS scavenging. Notably, dynamic blood experiments demonstrate that Cu-TAn@PMS could serve as an antioxidant defense system for blood in hemoperfusion to scavenge intracellular reactive oxygen species (ROS) effectively even in the complex blood environment and further protect endogenous antioxidative enzymes and molecules. In general, this work developed antioxidative cascade nanozymes engineered microspheres with excellent therapeutic efficacy for the treatment of oxidative stress-related diseases, which exhibited potential for clinical blood purification and extended the biomedical applications of nanozymes.

Turmeric supplementation with piperine is more effective than turmeric alone in attenuating oxidative stress and inflammation in hemodialysis patients: A randomized, double-blind clinical trial

PURPOSE

Turmeric has renop rotective effects that can act to reduce oxidative stress and inflammation in hemodialysis (HD) patients. Piperine has been indicated as a bioavailability enhancer of turmeric and consequently of its biological effects. However, data on the efficacy of the turmeric/piperine combination in HD patients are limited. We aimed to verify whether turmeric supplementation in combination with piperine has a superior effect to turmeric alone in increasing antioxidant capacity and reducing oxidative stress and inflammation in HD patients.

METHODS

This randomized, double-blind clinical trial was conducted in HD patients (age 20-75 years). Patients were supplemented with turmeric (3 g/day) or turmeric/piperine (3 g turmeric + 2 mg piperine/day) for 12 weeks. Malondialdehyde (MDA), antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), high-sensitivity C-reactive protein (hs-CRP), and ferritin were evaluated at baseline and the end of the study.

RESULTS

There was a reduction in the MDA and ferritin levels in the turmeric/piperine group and in the comparison between groups at the end of the study [MDA: -0.08(-0.14/0.01) nmol/mL versus -0.003(-0.10/0.26) nmol/mL, p = 0.003; ferritin: -193.80 ± 157.29 mg/mL versus 51.99 ± 293.25 mg/mL, p = 0.018]. In addition, GPx activity reduced in the turmeric group (p = 0.029). No changes were observed for CAT, GR, and hs-CRP.

CONCLUSION

Turmeric plus piperine was superior to turmeric alone in decreasing MDA and ferritin levels. The use of a combination of turmeric and piperine as a dietary intervention may be beneficial for modulating the status oxidative and inflammation in HD patients.

BRAZILIAN REGISTRY OF CLINICAL TRIALS NUMBER

RBR-2t5zpd; Registration Date: May 2, 2018.

Energy Homeostasis Gene Nucleotide Variants and Survival of Hemodialysis Patients-A Genetic Cohort Study

Background: Patients undergoing hemodialysis (HD) therapy have an increased risk of death compared to the general population. We investigated whether selected single nucleotide variants (SNVs) involved in glucose and lipid metabolism are associated with mortality risk in HD patients. Methods: The study included 805 HD patients tested for 11 SNVs in FOXO3, IGFBP3, FABP1, PCSK9, ANGPTL6, and DOCK6 using HRM analysis and TaqMan assays. FOXO3, IGFBP3, L-FABP, PCSK9, ANGPTL6, and ANGPTL8 plasma concentrations were measured by ELISA in 86 individuals. The Kaplan–Meier method and Cox proportional hazards models were used for survival analyses. Results: We found out that the carriers of a C allele in ANGPTL6 rs8112063 had an increased risk of all-cause, cardiovascular, and cardiac mortality. In addition, the C allele of DOCK6 rs737337 was associated with all-cause and cardiac mortality. The G allele of DOCK6 rs17699089 was correlated with the mortality risk of patients initiating HD therapy. The T allele of FOXO3 rs4946936 was negatively associated with cardiac and cardiovascular mortality in HD patients. We observed no association between the tested proteins’ circulating levels and the survival of HD patients. Conclusions: The ANGPTL6 rs8112063, FOXO3 rs4946936, DOCK6 rs737337, and rs17699089 nucleotide variants are predictors of survival in patients undergoing HD.

Evaluation of the combination effect of rutin and vitamin C supplementation on the oxidative stress and inflammation in hemodialysis patients

Background: Hemodialysis (HD) patients are at risk of malnutrition, cardiovascular complications, and all-cause mortality due to oxidative stress and inflammation. Some studies have demonstrated that rutin attenuates oxidative stress and inflammation in CKD rats, but its effects in HD patients are unknown to date. Aim: The aim of this study was to evaluate the effect of rutin and vitamin C versus vitamin C alone on oxidative stress and inflammation in HD patients. Methods: A prospective randomized, open-label, controlled trial enrolled on hundred and five HD patients divided into three groups as follows: patients in group 1 were given a rutin/vitamin C combination (Ruta C group as the combination trade name is known as Ruta C 60 tablets), patients in group 2 were given vitamin C (1 g) (vitamin C group), and group 3 was the control group; the study period was 16 weeks. The following were assessed at baseline and at the end of the study: serum malondialdehyde (MDA), glutathione peroxidase (GPx), high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), lipid profile levels, and erythrocyte sedimentation rate. Results: It was found that vitamin C significantly increased serum GPx in group 2 (p = 0.001) compared to a non-significant result in both group 1 and 3; in addition, serum MDA and TNF-α values had decreased significantly in the three groups compared to their baselines; however, a non-significant difference was seen among the studied groups at the end of the study. On the other hand, MDA levels were reduced by 50% in interventional groups compared to 28% in the control group, while the Ruta C group showed an 80% reduction in the level of TNF α compared to the 78% reduction observed in the vitamin C group, and finally, the interventional drugs showed a significant improvement in the lipid profile. Conclusion: Vitamin C supplementation alone for 16 weeks had a potential effect on the antioxidant's GPx activity. Moreover, it was reported that both vitamin C alone or the rutin/vitamin C combination (Ruta C) showed a protective role against lipid peroxidation, evidenced by the reduced levels of MDA. Finally, rutin had a favorable synergistic effect with vitamin C in reducing TG and TNF-α levels and increasing HDL-C level.

Assessment of the effect of perineural dexmedetomidine on oxidative stress during peritoneal dialysis catheter insertion: a randomized, controlled trial

Purpose

This study aimed to evaluate the effect of the addition of dexmedetomidine to ropivacaine on oxidative stress during transversus abdominis plane (TAP) and rectus sheath (RS) blockades for patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD) catheter insertion.

Methods

Sixty patients with ESRD undergoing PD catheter insertion to receive left ultrasound-guided TAP and RS blockades were randomly divided into two groups: the dexmedetomidine plus ropivacaine group (25 mL of 0.3% ropivacaine + 1 μg/kg dexmedetomidine) and the ropivacaine group (25 mL of 0.3% ropivacaine). Primary outcomes were oxidative stress marker levels during the procedure.

Results

A total of 60 patients (30 patients in each group) were evaluated. Compared with the ropivacaine group, the dexmedetomidine plus ropivacaine group had significantly lower serum malondialdehyde levels (P < 0.05) and increased glutathione peroxidase (P < 0.01) and superoxide dismutase levels at 24 h after the procedure (P < 0.01).

Conclusion

The addition of 1 μg/kg of dexmedetomidine to ropivacaine for ultrasound-guided TAP and RS blockades could inhibit oxidative stress in patients with ESRD undergoing PD catheter insertion.

Trial registration This study was registered at www.chictr.org.cn on June 7, 2021 (ChiCTR2100047050).

Natural Antioxidant Evaluation: A Review of Detection Methods

Antioxidants have drawn the attention of the scientific community due to being related to the prevention of various degenerative diseases. The antioxidant capacity has been extensively studied in vitro, and different methods have been used to assess its activity. However, the main issues related to studying natural antioxidants are evaluating whether these antioxidants demonstrate a key role in the biological system and assessing their bioavailability in the organism. The majority of outcomes in the literature are controversial due to a lack of method standardization and their proper application. Therefore, this study aims to compile the main issues concerning the natural antioxidant field of study, comparing the most common in vitro methods to evaluate the antioxidant activity of natural compounds, demonstrating the antioxidant activity in biological systems and the role of the main antioxidant enzymes of redox cellular signaling and explaining how the bioavailability of bioactive compounds is evaluated in animal models and human clinical trials.

Vitamin E‑coated dialyzer alleviates erythrocyte deformability dysfunction in patients with end‑stage renal disease undergoing hemodialysis

Patients with end-stage renal disease (ESRD) are characterized by augmented oxidative stress (OS) due to the imbalance between the generation of increased concentrations of oxidative molecules and decreased antioxidant capacity. Vitamin E-coated dialyzer membranes (VEMs) have previously been reported to alleviate the imbalance of redox metabolism in patients with ESRD undergoing hemodialysis (HD); however, their effect on the deformability of red blood cells (RBCs) remains unknown. In the present study, 48 patients with ESRD undergoing HD were enrolled and randomly assigned into two groups: HD with VEMs (VEM group; n=24) and HD with polysulfone dialyzer membranes (PM group; n=24), and another 24 healthy volunteers served as the control group. The present study investigated the morphological changes and deformability of RBCs in patients with ESRD and healthy volunteers. The concentration of serum vitamin E, the parameters of antioxidant stress and OS, and the degree of oxidative phosphorylation and clustering of anion exchanger 1 (Band 3) in RBCs were measured. The results obtained suggested that VEM treatment markedly ameliorated the abnormalities of RBC morphology and deformability in patients with ESRD undergoing HD. Mechanistic studies showed that VEM treatment led to a marked improvement in the concentration of serum vitamin E, which was positively associated with the restored antioxidant capacity, and decreased oxidative phosphorylation and clustering of Band 3 in RBCs of patients with ESRD undergoing HD. Taken together, the results of the present study have demonstrated that VEM treatment effectively restored the imbalance of redox metabolism, and improved the oxidative phosphorylation and clustering of Band 3 in RBCs of patients with ESRD undergoing HD via delivering vitamin E, which may alleviate the abnormal morphological and mechanical properties of RBCs. These findings are anticipated to be useful with respect to improving the nursing care and cure rate of patients with ESRD.

Effect of Near-Infrared Blood Photobiomodulation on Red Blood Cell Damage from the Extracorporeal Circuit during Hemodialysis In Vitro

The contact of blood with the bioincompatible membranes of the dialyzer, which is part of the extracorporeal circuit during hemodialysis (HD), causes upregulation of various cellular and non-cellular processes, including massive generation and release of reactive oxygen species (ROS), (which is one of the primary causes of anemia in chronic renal failure). We hypothesize that near-infrared (NIR) radiation possesses antioxidant properties and is considered to protect the red blood cell (RBC) membrane by enhancing its resilience to negative pressures. Our experimental setup consisted of an HD machine equipped with a dialyzer with a polyamide membrane; whole bovine blood was examined in vitro in blood-treated circulation. Blood samples were taken at 0, 5, 15, and 30 min during the HD therapy. We also assessed osmotic fragility, hematocrit, hemolysis, and oxidative stress as a concentration of reactive thiobarbituric acid substances (TBARS). Our results have shown that RBC membrane peroxidation increased significantly after 30 min of circulation, whereas the TBARS level in NIR-treated blood remained relatively steady throughout the experiment. The osmotic fragility of NIR-irradiated samples during dialysis was decreased compared to control samples. Our studies confirm that in vitro, blood photobiomodulation using NIR light diminishes oxidative damage during HD and can be considered a simultaneous pretreatment strategy for HD.

Effect of Nigella Sativa Oil on Oxidative Stress, Inflammatory, and Glycemic Control Indices in Diabetic Hemodialysis Patients: A Randomized Double-Blind, Controlled Trial

Background and Aims

Diabetes is a leading cause of renal failure. High levels of oxidative stress and inflammation in patients with renal diabetes lead to various disorders and mortality. This study was performed to determine the effect of Nigella sativa (NS) supplementation on superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (TAC), high-sensitivity C-reactive protein (hs-CRP), glycosylated hemoglobin (HbA1c), fasting blood sugar (FBS), and insulin (INS) in patients with diabetes mellitus undergoing hemodialysis (HD).

Methods

In this randomized, double-blind, placebo-controlled clinical trial, a total of 46 diabetic HD patients were randomly divided into NS (n = 23) and placebo (n = 23) groups. NS group received 2 g/day of NS oil, and the placebo group received paraffin oil for 12 weeks. Serum levels of SOD, MDA, TAC, hs-CRP, HbA1C, FBS, and INS were measured before and after the study.

Results

Compared to baseline values, SOD, TAC, and INS levels increased, whereas MDA, hs-CRP, HbA1c, and FBS significantly decreased. After adjusting for covariates using the ANCOVA test, changes in the concentrations of SOD (p = .040), MDA (p = .025), TAC (p=<.001), hs-CRP (p = .017), HbA1c (p = .014), and FBS (p = .027) were statistically significant compared to the placebo group. Intergroup changes in INS were not significant. Additionally, there were no notable side effects during the research.

Conclusions

This study found that NS supplementation significantly enhanced the levels of SOD, MDA, TAC, hs-CRP, HbA1c, and FBS in diabetic HD patients.

Erythropoietin Resistance Development in Hemodialysis Patients: The Role of Oxidative Stress

Oxidative stress (OS) is considered a significant risk factor for the development of anemia in patients treated by regular hemodialysis (HD). Moreover, OS represents a risk factor for the development of erythropoietin (EPO) resistance in these patients. The aim of this study was to examine the role of OS regarding EPO resistance development in patients treated by regular HD. 96 patients treated with standard HD and on-line hemodiafiltration were included in this study. The patients were treated with short-acting and long-acting EPOs for anemia. The concentration of superoxide anion radical, hydrogen peroxide, thiobarbituric acid reactive substances, and nitric oxide in the form of nitrites and the activity of catalase, superoxide dismutase and reduced glutathione were measured in patients' blood spectrophotometrically. Standard biochemical analysis, inflammatory markers, nutritional status, HD parameters, and erythropoietin resistance index were also determined. Patients with resistance to short-acting EPO had significantly lower concentration of hemoglobin in the blood and hematocrit value, a significantly higher serum ferritin concentration, and significantly lower catalase activity in erythrocytes than patients without EPO resistance. Patients with resistance to long-acting EPO have a significantly lower hemoglobin concentration in the blood, hematocrit values, and serum concentration of prealbumin and vitamin D, as well as significantly higher concentration of C-reactive protein, superoxide anion, and hydrogen peroxide concentration than those without resistance. OS significantly contributes to EPO resistance development. OS, higher ferritin and CRP levels, lower hemoglobin, hematocrit and prealbumin levels, and vitamin D deficiency represent significant risk factors for EPO resistance development in HD patients.

Inflammation and Cardiovascular Disease Associated With Hemodialysis for End-Stage Renal Disease

Chronic kidney disease (CKD) and cardiac insufficiency often co-exist, particularly in uremic patients on hemodialysis (HD). The occurrence of abnormal renal function in patients with cardiac insufficiency is often indicative of a poor prognosis. It has long been established that in patients with cardiac insufficiency, poorer renal function tends to indicate poorer cardiac mechanics, including left atrial reserve strain, left ventricular longitudinal strain, and right ventricular free wall strain (Unger et al., Eur J Heart Fail, 2016, 18(1), 103-12). Similarly, patients with chronic kidney disease, particularly uremic patients on HD, often have cardiovascular complications in addition to abnormal endothelial function with volume overload, persistent inflammatory states, calcium overload, and imbalances in redox responses. Cardiac insufficiency due to uremia is therefore mainly due to multifaceted non-specific pathological changes rather than pure renal insufficiency. Several studies have shown that the risk of adverse cardiovascular events is greatly increased and persistent in all patients treated with HD, especially in those who have just started HD treatment. Inflammation, as an important intersection between CKD and cardiovascular disease, is involved in the development of cardiovascular complications in patients with CKD and is indicative of prognosis (Chan et al., Eur Heart J, 2021, 42(13), 1244-1253). Therefore, only by understanding the mechanisms underlying the sequential development of inflammation in CKD patients and breaking the vicious circle between inflammation-mediated renal and cardiac insufficiency is it possible to improve the prognosis of patients with end-stage renal disease (ESRD). This review highlights the mechanisms of inflammation and the oxidative stress that co-exists with inflammation in uremic patients on dialysis, as well as the mechanisms of cardiovascular complications in the inflammatory state, and provides clinical recommendations for the anti-inflammatory treatment of cardiovascular complications in such patients.

Association between Biomarkers of Oxidative Stress and Inflammation with Cardiac Necrosis and Heart Failure in Non-ST Segment Elevation Myocardial Infarction Patients and Various Degrees of Kidney Function

The aim of this study was to explore the possible association between markers of inflammation and oxidative stress (OS) and markers of cardiac function and necrosis in 100 NSTEMI (non-ST-elevation myocardial infarction) patients with various degrees of kidney dysfunction. At admission, ejection fraction (EF), brain natriuretic peptide (BNP), troponin (TnI), creatinine phosphokinase (CPK), alanine transaminase (ALT), aspartate transaminase (AST), high-sensitive C-reactive protein (hs-CRP), interleukins 6 and 10 (IL-6, IL10), myeloperoxidase (MPO), transforming growth factor beta (TGF-β1), glomerular filtration rate (GFR), and albuminuria were assessed. Study participants were divided into 2 subgroups based on the median level of EF. Compared to the high, patients in the low EF group had higher GFR, BNP, CPK, hs-CRP, IL-10, IL-6, and MPO values and lower albuminuria levels. The levels of EF decreased in parallel with the progression of CKD, whereas the levels of BNP, IL-6, and TGF-β were significantly higher in late stages of CKD. Spearman's rho correlation analysis showed that EF was inversely correlated with MPO (r = -0.20, p = 0.05) BNP (r = -0.30, p = 0.002), hs-CRP (r = -0.38, p < 0.0001), IL-10 (r = -0.30, p = 0.003), and IL-6 (r = -0.24, p = 0.02) and positively with GFR (r = 0.27, p = 0.008). TnI was correlated with CPK (r = 0.44, p < 0.0001), CPK-MB (r = 0.31, p = 0.002), ALT (r = 0.50, p < 0.0001), AST (r = 0.29, p = 0.004), IL-10 (r = 0.22, p = 0.03), and MPO (r = -0.28, p = 0.006). In multivariate regression analysis, only BNP (β = -0.011, p = 0.004), hs-CRP (β = -0.11, p = 0.001), and GFR (β = 0.12, p = 0.0029) were independent determinants of EF. Similarly, MPO (β = -1.69, p = 0.02), IL-10 (β = 0.15, p = 0.006), and AST (β = 0.04, p = 0.001) were the 3 major determinants of TnI. Based on these associations, we built a predictive model including markers of inflammation and OS (MPO, IL-10, and hs-CRP) to identify patients with the most severe cardiac injury (combined EF below median and troponin above median values). Receiver-operator characteristic (ROC) analysis showed that the area under the ROC curve of this model to detect patients with low EF and high TnI was 0.67 (p = 0.015, 95%confidence interval = 0.53-0.81).

Oxidative Stress Genes in Diabetes Mellitus Type 2: Association with Diabetic Kidney Disease

Diabetic type 2 patients compared to nondiabetic patients exhibit an increased risk of developing diabetic kidney disease (DKD), the leading cause of end-stage renal disease. Hyperglycemia, hypertension, oxidative stress (OS), and genetic background are some of the mechanisms and pathways implicated in DKD pathogenesis. However, data on OS pathway susceptibility genes show limited success and conflicting or inconclusive results. Our study is aimed at exploring OS pathway genes and variants which could be associated with DKD. We recruited 121 diabetes mellitus type 2 (DM2) patients with DKD (cases) and 220 DM2, non-DKD patients (control) of Greek origin and performed a case-control association study using genome-wide association data. PLINK and EIGENSOFT were used to analyze the data. Our results indicate 43 single nucleotide polymorphisms with their 21 corresponding genes on the OS pathway possibly contributing or protecting from DKD: SPP1, TPO, TTN, SGO2, NOS3, PDLIM1, CLU, CCS, GPX4, TXNRD2, EPHX2, MTL5, EPX, GPX3, ALOX12, IPCEF1, GSTA, OXR1, GPX6, AOX1, and PRNP. Therefore, a genetic OS background might underlie the complex pathogenesis of DKD in DM2 patients.

Preliminary experience on the use of sucrosomial iron in hemodialysis: focus on safety, hemoglobin maintenance and oxidative stress

PURPOSE

Iron is usually administered in hemodialysis patients by parenteral route, as oral absorption is poor due to high hepcidin levels. However, administrations of intravenous iron and iron overload are associated with high oxidative stress and systemic inflammation that can affect patient survival. With this study, we evaluated an alternative type of oral iron for the treatment of anemia in hemodialysis patients. The formulation consists in ferric pyrophosphate covered by phospholipids plus sucrose ester of fatty acid matrix, named sucrosomial iron, whose absorption is not influenced by hepcidin.

METHODS

Twenty-four (24) patients undergoing chronic hemodialysis switched iron supplementation from intravenous (ferric gluconate 62.5 mg weekly) to oral (sucrosomial iron, 90 mg weekly in 3 administrations of 30 mg) route for 3 months. Classical anemia, iron metabolism, inflammation and nutritional biomarkers were monitored, as well as biomarkers of oxidative stress, such as protein-bound di-tyrosines, protein carbonylation, advanced oxidation protein products and protein thiols.

RESULTS

Over the 3 months, hemoglobin values remained stable, as the values of hematocrit and mean corpuscular volume. In parallel, other anemia parameters dropped, including ferritin, transferrin saturation and serum iron. On the other side, nutritional biomarkers, such as total proteins and transferrin, increased significantly during the time frame. We also observed a significant decrease in white blood cells as well as a non-significant reduction in C-reactive protein and some oxidative stress biomarkers, such as protein carbonyls and di-tyrosines.

CONCLUSION

Our study demonstrates that a therapy with sucrosomial iron in hemodialysis patients is safe and can maintain stable hemoglobin levels in a three-month period with a possible beneficial effect on oxidative stress parameters. However, the reduction of ferritin and transferrin saturation suggests that a weekly dosage of 90 mg is not sufficient in hemodialysis patients in the long time to maintain hemoglobin.

Oxidative Stress in Patients with Advanced CKD and Renal Replacement Therapy: The Key Role of Peripheral Blood Leukocytes

Oxidative stress plays a key role in the pathophysiology of chronic kidney disease (CKD). Most studies have investigated peripheral redox state focus on plasma, but not in different immune cells. Our study analyzed several redox state markers in plasma and isolated peripheral polymorphonuclear (PMNs) and mononuclear (MNs) leukocytes from advanced-CKD patients, also evaluating differences of hemodialysis (HD) and peritoneal dialysis (PD) procedures. Antioxidant (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH)) and oxidant parameters (xanthine oxidase (XO), oxidized glutathione (GSSG), malondialdehyde (MDA)) were assessed in plasma, PMNs and MNs from non-dialysis-dependent-CKD (NDD-CKD), HD and PD patients and healthy controls. Increased oxidative stress and damage were observed in plasma, PMNs and MNs from NDD-CKD, HD and PD patients (increased XO, GSSG and MDA; decreased SOD, CAT, GPX and GSH; altered GSSG/GSH balance). Several oxidative alterations were more exacerbated in PMNs, whereas others were only observed in MNs. Dialysis procedures had a positive effect on preserving the GSSG/GSH balance in PMNs. Interestingly, PD patients showed greater oxidative stress than HD patients, especially in MNs. The assessment of redox state parameters in PMNs and MNs could have potential use as biomarkers of the CKD progression.

Hemodialysis raises oxidative stress through carbon-centered radicals despite improved biocompatibility

Leukocyte activation and the resulting oxidative stress induced by bioincompatible materials during hemodialysis impact the prognosis of patients. Despite multiple advances in hemodialysis dialyzers, the prognosis of hemodialysis patients with complications deeply related to oxidative stress, such as diabetes mellitus, remains poor. Thus, we re-evaluated the effects of hemodialysis on multiple reactive oxygen species using electron spin resonance-based methods for further improvement of biocompatibility in hemodialysis. We enrolled 31 patients in a stable condition undergoing hemodialysis using high-flux polysulfone dialyzers. The effects of hemodialysis on reactive oxygen species were evaluated by two methods: MULTIS, which evaluates serum scavenging activities against multiple hydrophilic reactive oxygen species, and i-STrap, which detects lipophilic carbon-center radicals. Similar to previous studies, we found that serum hydroxyl radical scavenging activity significantly improved after hemodialysis. Unlike previous studies, we discovered that scavenging activity against alkoxyl radical was significantly reduced after hemodialysis. Moreover, patients with diabetes mellitus showed a decrease in serum scavenging activity against alkyl peroxyl radicals and an increase in lipophilic carbon-center radicals after hemodialysis. These results suggest that despite extensive improvements in dialyzer membranes, the forms of reactive oxygen species that can be eliminated during dialysis are limited, and multiple reactive oxygen species still remain at increased levels during hemodialysis.

Antioxidant and anti-inflammatory response to curcumin supplementation in hemodialysis patients: A randomized, double-blind, placebo-controlled clinical trial

BACKGROUND AND OBJECTIVES

Hemodialysis (HD) patients are vulnerable to malnutrition and cardiovascular complications due to many factors, including oxidative stress and inflammation. Curcumin supplementation is associated with attenuation of proinflammatory cytokines and increased activity of antioxidant enzymes, but its effects in HD patients are unknown. This study aimed to evaluate the effect of curcumin supplementation on oxidative stress and inflammation in HD patients.

METHODS

This randomized, double-blind, placebo-controlled trial enrolled 43 HD patients and divided them into two groups: supplemented with curcumin (1 g/day) or placebo (corn starch) for 12 weeks. Demographic information and blood samples were taken at the start and the end of the study to determine serum malondialdehyde (MDA) concentrations, antioxidant enzyme activity, and high-sensitivity C-reactive protein (hs-CRP).

RESULTS

The curcumin group showed a significant increase in catalase activity [Δ = 1.13 ± 2.87 versus Δ = -1.08 ± 2.68; p = 0.048] and preserved glutathione peroxidase activity [Δ = -4.23 ± 11.50 versus Δ = -14.44 ± 13.96; p < 0.01] compared with the placebo group. However, no significant changes were found in MDA concentrations, glutathione reductase activity, and hs-CRP concentrations after the intervention.

CONCLUSION

Curcumin supplementation for 12 weeks had potential effects on antioxidant response, but it was not enough to reduce oxidative stress markers and inflammation in HD patients. This trial was registered at EnsaiosClínicos.gov.br under registration number RBR-2t5zpd.

Machine learning approach in mortality rate prediction for hemodialysis patients

Kernel support vector machine algorithm and K-means clustering algorithm are used to determine the expected mortality rate for hemodialysis patients. The national nephrology database of Montenegro has been used to conduct this research. Mortality rate prediction is realized with accuracy up to 94.12% and up to 96.77%, when a complete database is observed and when a reduced database (that contains data for the three most common basic diseases) is observed, respectively. Additionally, it is shown that just a few parameters, most of which are collected during the sole patient examination, are enough for satisfying results.

Possible benefits of exogenous melatonin for individuals on dialysis: a narrative review on potential mechanisms and clinical implications

Prevention of oxidative stress and inflammation in chronic kidney disease patients (CKD) on dialysis may reduce dialysis-associated complications. Administration of powerful antioxidants may improve the consequences of peritoneal dialysis (PD) and hemodialysis (HD). This narrative review aimed to show the potential therapeutic effects of melatonin (MLT) on the consequences of CKD patients receiving HD or PD. The results of preclinical and clinical studies have proven that CKD and dialysis are accompanied by reduced endogenous MLT levels and related complications such as sleep disorders. Enhanced oxidative stress, inflammation, cellular damages, and renal fibrosis, along with dysregulation of the renin-angiotensin system (RAS), have been observed in CKD and patients on dialysis. Results of studies have revealed that the restoration of MLT via the exogenous source may regulate oxidative stress, inflammation, and RAS functions, inhibit fibrosis, and improve complications in patients with long-term dialysis patients. In summary, treatment of patients with CKD and dialysis with exogenous MLT is suggested as a practical approach in reducing the outcomes and improving the quality of life in patients via antioxidant, anti-inflammatory, and anti-fibrotic signaling pathways. Therefore, this hormone can be considered in clinical practice to manage dialysis-related complications.

Could Antioxidant Supplementation Delay Progression of Cardiovascular Disease in End-Stage Renal Disease Patients?

In end-stage renal disease patients, the leading causes of mortality are of cardiovascular (CV) origin. The underlying mechanisms are complex, given that sudden heart failure is more common than acute myocardial infarction. A contributing role of oxidative stress is postulated, which is increased even at early stages of chronic kidney disease, is gradually augmented in parallel to progression to endstage renal disease and is further accelerated by renal replacement therapy. Oxidative stress ensues when there is an imbalance between reactive pro-oxidants and physiologically occurring electron donating antioxidant defence systems. During the last decade, a close association of oxidative stress with accelerated atherosclerosis and increased risk for CV and all-cause mortality has been established. Lipid peroxidation has been identified as a trigger for endothelial dysfunction, the first step towards atherogenesis. In order to counteract the deleterious effects of free radicals and thereby ameliorate, or delay, CV disease, exogenous administration of antioxidants has been proposed. Here, we attempt to summarize existing data from studies that test antioxidants for CV protection, such as vitamins E and C, statins, omega-3 fatty acids and N-acetylcysteine.

Protective Effect of Autologous Arteriovenous Fistulae Against Oxidative Stress in Hemodialyzed Patients

Introduction: Oxidative stress (OS) is ubiquitous in chronic kidney disease (CKD) and is exacerbated by hemodialysis (HD). OS is also associated with anemia, malnutrition, and cardiovascular (CV) disease and is an independent predictor of mortality and morbidity in patients undergoing HD. HD vascular access (VA) types are strongly correlated with CKD patient outcomes. Prolonged use of central venous catheters (CVC) for HD and arteriovenous grafts (AVG) promotes inflammation and OS. However, the effects of the VA type on OS have been poorly studied in HD patients. This study investigated OS prevalence in an HD population to determine the relationship between the VA type and HD.

Methods: The oxidative stress index (OSI) was used to assess the HD patients’ OS status. OSI summarizes information derived from the reactive oxygen metabolites (d-ROMs) fast test and the plasma antioxidant test (PAT) in a single value, using the hydrogen peroxide concentration (for d-ROMs) and ascorbic acid (for PAT) as reference standards. The OSI was created to indicate how far the OS status deviates from normal (i.e., fully compensated oxidative balance). An index increase may be from an increase or decrease in peroxide or antioxidant concentrations. Patients undergoing chronic HD were evaluated by dividing the cases according to the OSI status: normal (N-OSI), borderline (BL-OSI), high (H-OSI), and very high (VH-OSI). Patients with clinical evidence of active infections were excluded.

Results: In total, 129 patients were included; 86.8% used high-flux dialyzers, 13.2% used hemodiafiltration (HDF), and 24.5% were diabetic. An altered OSI was observed in 86 of 129 patients (66.7%). An increased OSI correlated with a significant increase in d-ROMs (r = 0.420) and PAT (r = 0.710). There were no differences between sex, diabetes status, age, dialysis vintage, or dialysis modalities. d-ROMs were inversely correlated with hemoglobin levels (r = −0.209). The iron dose by month correlated with the OSI (r = 0.189) and was significantly lower in the N-OSI group. N- and BL-OSI patients had a significantly higher rate of autologous arteriovenous fistula (AVF) compared to the other groups, and VH-OSI patients had a higher rate of permanent tunneled CVC.

Conclusion: Most HD patients had more OS, indicated by the OSI scores. In chronic HD patients, AVF had a protective effect against imbalanced peroxidation-antioxidation.

Oxidized LDL Modifies the Association between Proteinuria and Deterioration of Kidney Function in Proteinuric Diabetic Kidney Disease

Proteinuria is characterized by low accuracy for predicting onset and development of diabetic kidney disease (DKD) because it is not directly associated with molecular changes that promote DKD, but is a result of kidney damage. Oxidized low-density lipoprotein (ox-LDL) reflects oxidative stress and endothelial dysfunction, both underlying the development of proteinuria and loss of kidney function in DKD. We aimed to investigate whether ox-LDL modifies the association between proteinuria and progression of DKD in a cohort of 91 patients with proteinuric DKD and diabetic retinopathy, followed for 10 years. The primary endpoint was a combined kidney outcome of eGFR decline ≥30% or progression to end-stage kidney disease. After the end of the study, we considered the percentage change of eGFR over time as our secondary outcome. Proteinuria was associated with both outcomes, and ox-LDL amplified the magnitude of this link (p < 0.0001 for primary and p < 0.0001 for secondary outcome, respectively). After adjustment for duration of diabetes, history of cardiovascular disease and serum albumin, ox-LDL remained a significant effect modifier of the association between proteinuria and eGFR decline over time (p = 0.04). Our study shows that in proteinuric DKD, circulating ox-LDL levels amplified the magnitude of the association between proteinuria and progression of DKD.

Implications of oxidative stress in chronic kidney disease: a review on current concepts and therapies

Moderate levels of endogenous reactive oxygen species (ROS) are important for various cellular activities, but high levels lead to toxicity and are associated with various diseases. Levels of ROS are maintained as a balance between oxidants and antioxidants. Accumulating data suggest that oxidative stress is a major factor in deterioration of renal function. In this review, we highlight the possible mechanism by which oxidative stress can lead to chronic kidney disease (CKD). This review also describes therapies that counter the effect of oxidative stress in CKD patients. Numerous factors such as upregulation of genes involved in oxidative phosphorylation and ROS generation, chronic inflammation, vitamin D deficiency, and a compromised antioxidant defense mechanism system cause progressive detrimental effects on renal function that eventually lead to loss of kidney function. Patients with renal dysfunction are highly susceptible to oxidative stress, as risk factors such as diabetes, renal hypertension, dietary restrictions, hemodialysis, and old age predispose them to increased levels of ROS. Biomolecular adducts (DNA, proteins, and lipids) formed due to reaction with ROS can be used to determine oxidative stress levels. Based on the strong correlation between oxidative stress and CKD, reversal of oxidative stress is being explored as a major therapeutic option. Xanthine oxidase inhibitors, dietary antioxidants, and other agents that scavenge free radicals are gaining interest as treatment modalities in CKD patients.

A high magnesium concentration in citrate dialysate prevents oxidative stress and damage in human monocytes in vitro

BACKGROUND

The use of dialysis fluids (DFs) during haemodialysis has been associated with increased oxidative stress and reduced serum magnesium (Mg) levels, contributing to chronic inflammation. Since the role of Mg in modulating immune function and reducing oxidative stress has been demonstrated, the aim of this study was to characterize in vitro whether increasing the Mg concentration in DFs could protect immune cells from oxidative stress and damage.

METHODS

The effect of citrate [citrate dialysis fluid (CDF), 1 mM] or acetate [acetate dialysis fluid (ADF), 3 mM] dialysates with low (0.5 mM; routinely used) or high (1 mM, 1.25 mM and 2 mM) Mg concentrations was assessed in THP-1 human monocytes. The levels of reactive oxygen species (ROS), malondialdehyde (MDA) and oxidized/reduced (GSSG/GSH) glutathione were quantified under basal and inflammatory conditions (stimulation with lipopolysaccharide, LPS).

RESULTS

The increase of Mg in CDF resulted in a significant reduction of ROS production under basal and inflammatory conditions (extremely marked in 2 mM Mg; P < 0.001). These effects were not observed in ADF. Interestingly, in a dose-dependent manner, high Mg doses in CDF reduced oxidative stress in monocytes under both basal and inflammatory conditions. In fact, 2 mM Mg significantly decreased the levels of GSH, GSSG and MDA and the GSSG/GSH ratio in relation to 0.5 mM Mg.

CONCLUSIONS

CDF produces lower oxidative stress than ADF. The increase of Mg content in DFs, especially in CDF, could have a positive and protective effect in reducing oxidative stress and damage in immune cells, especially under inflammatory conditions.

Serum Adropin Levels in Patients on Hemodialysis

Adropin is a novel pleotropic peptide involved in energy homeostasis, with possible contribution to cardiovascular protection through production of nitric oxide and subsequent blood pressure regulation. Given that patients undergoing hemodialysis (HD) are related with high cardiovascular risk, hyperlipidemia, chronic low-grade inflammation, and malnutrition the aim of our study was to investigate serum adropin levels in HD patients to evaluate possible associations with nutritional status and other relevant clinical and laboratory parameters. The study included 70 patients on HD and 60 healthy controls. Serum adropin levels were determined by an enzyme-linked immunosorbent assay in a commercially available diagnostic kit. Serum adropin levels were significantly lower in the HD group compared to the control group (2.20 ± 0.72 vs. 4.05 ± 0.93 ng/mL, p < 0.001). Moreover, there was a significant negative correlation with malnutrition-inflammation score (r = −0.476, p < 0.001), dialysis malnutrition score (r = −0.350, p = 0.003), HD duration (r = −0.305, p = 0.010), and high sensitivity C-reactive protein (hsCRP) (r = −0.646, p < 0.001). Additionally, there was a significant negative correlation between adropin levels and pre-dialysis systolic (r = −0.301, p = 0.011) and diastolic blood pressure (r = −0.299, p = 0.011). These results are implying that adropin is potentially involved in the pathophysiological mechanisms of chronic kidney disease (CKD)/HD and its complications. However, future larger scale longitudinal studies need to further address it.