Oxidative Stress and Inflammation as Predictors of Mortality and Cardiovascular Events in Hemodialysis Patients: The DREAM Cohort

The mechanisms underlying acute myocardial infarction in chronic kidney disease patients undergoing hemodialysis

Cardiovascular disease (CVD) is a leading cause of death in chronic kidney disease (CKD). Hemodialysis is one of the main treatments for patients with end-stage kidney disease. Epidemiological data has shown that acute myocardial infarction (AMI) accounts for the main reason for death in patients with CKD under hemodialysis therapy. Immune dysfunction and changes in metabolism (including a high level of inflammatory cytokines, a disorder of lipid and mineral ion homeostasis, accumulation of uremic toxins et al.) during CKD can deteriorate stability of atherosclerotic plaque and promote vascular calcification, which are exactly the pathophysiological mechanisms underlying the occurrence of AMI. Meanwhile, the hemodialysis itself also has adverse effects on lipoprotein, the immune system and hemodynamics, which contribute to the high incidence of AMI in these patients. This review aims to summarize the mechanisms and further promising methods of prevention and treatment of AMI in CKD patients undergoing hemodialysis, which can provide an excellent paradigm for exploring the crosstalk between the kidney and cardiovascular system.

Prodromic Inflammatory-Oxidative Stress in Peritoneal Leukocytes of Triple-Transgenic Mice for Alzheimer's Disease

Inflammatory-oxidative stress is known to be pivotal in the pathobiology of Alzheimer's disease (AD), but the involvement of this stress at the peripheral level in the disease's onset has been scarcely studied. This study investigated the pro-inflammatory profile and oxidative stress parameters in peritoneal leukocytes from female triple-transgenic mice for AD (3xTgAD) and non-transgenic mice (NTg). Peritoneal leukocytes were obtained at 2, 4, 6, 12, and 15 months of age. The concentrations of TNFα, INFγ, IL-1β, IL-2, IL-6, IL-17, and IL-10 released in cultures without stimuli and mitogen concanavalin A and lipopolysaccharide presence were measured. The concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), lipid peroxidation, and Hsp70 were also analyzed in the peritoneal cells. Our results showed that although there was a lower release of pro-inflammatory cytokines by 3xTgAD mice, this response was uncontrolled and overstimulated, especially at a prodromal stage at 2 months of age. In addition, there were lower concentrations of GSH in leukocytes from 3xTgAD and higher amounts of lipid peroxides at 2 and 4 months, as well as, at 6 months, a lower concentration of Hsp70. In conclusion, 3xTgAD mice show a worse pro-inflammatory response and higher oxidative stress than NTg mice during the prodromal stages, potentially supporting the idea that Alzheimer's disease could be a consequence of peripheral alteration in the leukocyte inflammation-oxidation state.

Triglyceride-glucose index predicts all-cause mortality, but not cardiovascular mortality, in rural Northeast Chinese patients with metabolic syndrome: a community-based retrospective cohort study

BACKGROUND

Metabolic syndrome (MetS) includes a group of metabolic irregularities, including insulin resistance (IR), atherogenic dyslipidemia, central obesity, and hypertension. Consistent evidence supports IR and ongoing low-grade inflammation as the main contributors to MetS pathogenesis. However, the association between the triglyceride-glucose (TyG) index and mortality in people with MetS remains uncertain. The objective of this study was to examine the correlation between the baseline TyG index and all-cause and cardiovascular (CV) mortality in rural Northeast Chinese individuals with MetS.

METHODS

For the Northeast China Rural Cardiovascular Health Study, 3918 participants (mean age, 55 ± 10; 62.4% women) with MetS at baseline were enrolled in 2012-2013 and followed up from 2015 to 2017. The TyG index was calculated using the equation TyG index = ln [fasting TG (mg/dL) × fasting glucose (mg/dL)/2] and subdivided into tertiles [Q1(< 8.92); Q2 (8.92-9.36); Q3 (≥ 9.36)]. Multivariate Cox proportional hazards models were developed to examine the correlations between mortality and the baseline TyG index.

RESULTS

During a median of 4.66 years of follow-up, 196 (5.0%) all-cause deaths and 108 (2.8%) CV disease-related deaths occurred. The incidence of all-cause mortality was significantly different among TyG index tertiles of the overall population (P = 0.045). Kaplan-Meier analysis demonstrated a significantly increased risk of all-cause mortality in rural Chinese patients with a higher TyG index (log-rank P < 0.05). After adjusting for possible confounders, Cox proportional hazard analysis revealed that the TyG index could effectively predict all-cause mortality (HR for the third vs. first tertile of TyG was 1.441 [95% confidence interval, 1.009-2.059]), but not CV mortality, in rural Chinese patients with MetS.

CONCLUSIONS

The TyG index is an effective predictor of all-cause mortality in rural Chinese patients with MetS. This indicates that the TyG index may be useful for identifying rural Chinese individuals with MetS at a high risk of death.

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.

The relationship between oxidative stress and psychotic disorders in 22q11.2 deletion syndrome

BACKGROUND

22q11.2 Deletion syndrome (22q11.2DS) is the most common microdeletion syndrome in humans. This condition is associated with a wide range of symptoms including immune and neuropsychiatric disorders. Notably, psychotic disorders including schizophrenia have a prevalence of ∼ 30%. A growing body of evidence indicates that neuroinflammation and oxidative stress (OS) play a role in the pathophysiology of schizophrenia. In this study, we aim to assess the interaction between 22q11.2DS, OS and schizophrenia.

METHODS

Blood samples were collected from 125 participants (including individuals with 22q11.2DS [n = 73] and healthy controls [n = 52]) from two sites: Sheba Medical Center in Israel, and University Hospital Gasthuisberg in Belgium. Baseline OS levels were evaluated by measuring Myeloperoxidase (MPO) activity. A sub-sample of the Israeli sample (n = 50) was further analyzed to examine survival of Peripheral Blood Mononuclear Cells (PBMCs) following induction of OS using vitamin K3.

RESULTS

The levels of MPO were significantly higher in all individuals with 22q11.2DS, compared to healthy controls (0.346 ± 0.256 vs. 0.252 ± 0.238, p =.004). In addition, when comparing to healthy controls, the PBMCs of individuals with 22q11.2DS were less resilient to induced OS, specifically the group diagnosed with psychotic disorder (0.233 ± 0.206 for the 22q11.2DS individuals with psychotic disorders, 0.678 ± 1.162 for the 22q11.2DS individuals without psychotic disorders, and 1.428 ± 1.359 for the healthy controls, p =.003, η2 = 0.207).

CONCLUSIONS

Our results suggest that dysregulation of OS mechanisms may play a role in the pathophysiology of the 22q11.2DS phenotype. The 22q11.2DS individuals with psychotic disorders were more sensitive to induction of OS, but did not present significantly different levels of OS at baseline. These results may be due to the effect of antipsychotic treatment administered to this sup-group. By elucidating novel molecular pathways, early identification of biochemical risk markers for 22q11.2DS and psychotic disorders can be detected. This can ultimately pave the way to the design of early and more precise interventions of individuals with 22q11.2DS.

Distinct WBC Trajectories are Associated with the Risks of Incident CVD and All-Cause Mortality

AIMS

To examine the trajectory of white blood cell (WBC) and their potential impacts on cardiovascular disease (CVD) and all-cause mortality (ACM) risks.

METHODS

This prospective cohort included 61,666 participants without CVD on or before June 1, 2012. Latent mixture modeling was used to identify WBC trajectories in 2006-2012 as predictors of CVD and ACM. Incident CVD and ACM in 2012-2019 were the outcomes. Cox proportional hazards models were fitted to analyze the risks of incident CVD and ACM.

RESULTS

According to WBC ranges and dynamics, five distinct WBC trajectories were identified: low-stable (n=18,432), moderate-stable (n=26,656), elevated-stable (n=3,153), moderate-increasing (n=11,622), and elevated-decreasing (n=1,803). During 6.65±0.83 years of follow-up, we documented 3773 incident CVD cases and 3304 deaths. Relative to the low-stable pattern, the moderate-increasing pattern was predictive of an elevated risk of CVD (HR=1.36, 95% CI: 1.24-1.50), especially acute myocardial infarction (AMI) (HR=1.91, 95% CI: 1.46-2.51), while the elevated-stable pattern was predictive of an elevated risk of ACM (HR=1.77, 95% CI: 1.52-2.06). Among participants with hs-CRP ＜2 mg/L or ≥2 mg/L, similar associations were observed between the moderate-increasing pattern with CVD (HR=1.41, 95% CI: 1.24-1.61) and ACM (HR=1.54, 95% CI: 1.18-2.01, HR=1.89, 95% CI: 1.57-2.29, respectively).

CONCLUSIONS

We found that distinct WBC trajectories were differentially associated with CVD and ACM risks in Chinese adults.

Advanced glycosylation end products as metabolic predictors of systemic pro-inflammatory and prooxidant status in patients with end-stage renal disease

Controlling systemic proinflammatory and prooxidant effectors is essential for mitigating cardiovascular risk and mortality in patients with end-stage renal disease (ESRD). However, monitoring these processes is still challenging due to the high uncertainty about their determinants and predictors. Thus, we investigated the relationship between advanced glycosylation end products (AGE), proinflammatory and prooxidant effectors in ESRD patients undergoing hemodialysis (HD). In addition to nutritional profile and dialysis efficiency, AGE, cytokines, chemokines, C-reactive protein (CRP), total (TAC) and non-protein (npAC) antioxidant capacity, lipid and protein oxidation were analyzed in blood samples from 43 HD patients. AGE, CRP, cytokines, chemokines, protein carbonyl (PCn), and malondialdehyde (MDA) were upregulated, while TAC and npAC were down-regulated in HD patients compared to heath subjects. Dialysis efficiency, TAC and npAC were reduced, while leucocytes counting, pre- and post-HD urea, TNF, IL-6, IL-10, CCL-2, MIP-1β, PCn, and MDA were increased in patients with higher AGE accumulation compared to those with lower AGE levels. Serum levels of CRP, protein carbonyl, malondialdehyde, and all cytokines and chemokines analyzed were correlated with AGE circulating levels for patients with higher AGE accumulation. AGE was inversely correlated with IL-10, TAC and npAC in patients with higher AGE accumulation. AGE exhibited predictive value (determination coefficient) to explain CRP, cytokines, chemokines, PCN, MDA, TAC and npAC variability in patients with higher AGE levels. Taken together, our findings provide evidence that AGE accumulation is associated with important proinflammatory and prooxidant effectors in patients with ESRD undergoing hemodialysis. Thus, AGE monitoring may be relevant to predict systemic inflammatory stress and the balance between oxidant and antioxidant status in these patients.

Prognostic value of creatinine-to-cystatin c ratio in patients with type 2 diabetes mellitus: a cohort study

BACKGROUND

The serum creatinine-to-cystatin C ratio (Scr/Scys) has been suggested as a surrogate marker of muscle mass and a predictor of adverse outcomes in many diseases. However, the prognostic value of Scr/Scys in patients with type 2 diabetes mellitus (T2DM) is unknown. The aim of this study is to assess the prognostic value of Scr/Scys in patients with T2DM.

METHODS

In this retrospective observational study, we enrolled 3668 T2DM patients undergoing coronary angiography (CAG). Serum creatinine (Scr) and serum cystatin C (Scys) levels were measured at admission. The study population was separated into low muscle mass (low-MM) and normal muscle mass (normal-MM) groups by Scr/Scys cut-off point. The association between muscle mass and long-term all-cause mortality was examined using Cox regression analysis.

RESULTS

During a median follow-up of 4.9 (3.0-7.1) years, a total of 352 (9.6%) patients died. The mortality was higher in patients with low-MM as compared with patients with normal-MM (11.1% vs. 7.3%; p < 0.001). Low muscle mass was associated with increased risk for long-term all-cause mortality, regardless of whether Scr/Scys were used as a continuous variable (adjusted hazard ratio: 1.08 [95% confidence interval (CI) 1.03 to 1.13]; p = 0.009) or a categorial variable (adjusted hazard ratio: 1.36 [95% CI 1.03 to 1.75]; p = 0.021).

CONCLUSION

Low muscle mass assessed by Scr/Scys was associated with increased risk of long-term all-cause mortality in diabetic patients.

Anthropometric parameters of obesity can be alternative biomarkers for the potential cardiac dysfunction in obese children

Childhood obesity, as one of the potential risk factors of cardiovascular diseases, is closely associated with the incidence of cardiovascular disease at a younger age and has become a public health concern worldwide. However, its potential effects on the cardiovascular system have still remained elusive. In this study, we systematically evaluated the cardiovascular characteristics of 79 obese children and 161 normal weight children in Guangzhou (China) using the potential biomarkers for cardiovascular disease. Compared with normal weight children, obese children not only exhibited significantly higher levels of creatine kinase (CK), lactate dehydrogenase (LHD), soluble fms-like tyrosine kinase-1 (s-Flt-1), high-sensitivity C-reactive protein (hs-CRP), and uric acid (UA) (p = 0.0062, 0.0012, 0.0013, 0.0225, and <0.0001, respectively) but also significantly higher diastolic blood pressure (p = 0.0074) and the heart rate (p = 0.0049) were found in obese children. Of 79 obese children, cardiac functions of 40 cases were further assessed by color Doppler echocardiography. The results showed that there were significant differences between the obesity group and the healthy weight group in terms of interventricular septal wall thickness at end-diastolic (IVSd), the left ventricular posterior wall thickness at end-diastolic (LVPWD), and aortic annulus (AO) (p < 0.0001, 0.0003, and p < 0.0001, respectively). Besides, the left and/or right ventricular functions were declined in 52.4% of obese children. Correlation analysis revealed that the anthropometric parameters of obesity were not only significantly correlated with a blood lipid profile but also exhibited a more significant correlation with most of the parameters of cardiac dysfunction than a blood lipid profile. Therefore, our study indicated that obese children in Guangzhou suffered from functional damages related to cardiovascular events, which were characterized by cardiac dysfunction, and the anthropometric parameters of obesity could be economically alternative biomarkers for monitoring of cardiac dysfunction in obese children.

Serum phosphate as an independent factor associated with cholesterol metabolism in patients undergoing hemodialysis: a cross-sectional analysis of the DREAM cohort

Background

Hyperphosphatemia is a risk factor for cardiovascular outcomes in patients with chronic kidney disease. In an experimental model, hyperphosphatemia promotes atherosclerosis by activating sterol regulatory element-binding protein 2 which controls cholesterol homeostasis. In the present study, we hypothesized that serum phosphate level is associated with cholesterol metabolism in patients with kidney failure.

Methods

We conducted a single center cross-sectional study including 492 patients undergoing hemodialysis and 100 healthy controls not on statin or ezetimibe treatment. Serum lathosterol and campesterol levels were measured as a marker of cholesterol synthesis and absorption, respectively. As compared to the control group, the hemodialysis patients had higher median (interquartile range) phosphate [5.8 (5.0 to 6.6) vs. 3.3 (3.0 to 3.6) mg/dL, P &lt; 0.001], lower lathosterol [1.2 (0.8 to 1.7) vs. 2.6 (1.9 to 3.4) µg/mL, P &lt; 0.001] and higher campesterol levels [4.5 (3.6 to 6.0) vs. 4.1 (3.2 to 5.4) µg/mL, P = 0.02]. Serum phosphate correlated positively to campesterol in the control group (Spearman's r = 0.21, P = 0.03) and in the hemodialysis patients (Spearman's r = 0.19, P &lt; 0.001). The positive association between phosphate and campesterol levels in the hemodialysis group remained significant in multivariable-adjusted linear regression analysis. There was no significant association between phosphate and lathosterol in either group.

Conclusions

An independent association was found between phosphate and campesterol levels in patients with kidney failure. This study suggests a novel relationship between phosphate and cholesterol metabolism, both of which could affect cardiovascular outcomes in this population.

Oxidative Stress Biomarkers and Their Association with Mortality among Patients Infected with SARS-CoV-2 in Mexico

Background

Activation of the immune system response is associated with the generation of oxidative stress (OS). Several alterations are involved in OS, such as excessive production of reactive oxygen species (ROS) and decreased antioxidant activity, which together lead to an imbalance in redox status. The role of OS during SARS-CoV-2 infection is not fully understood. The aim of this study was to determine OS biomarkers and assess their usefulness as a predictor of mortality in COVID-19 patients.

Methods

Baseline characteristics and serum samples were collected from hospitalized COVID-19 patients and compared with healthy controls. The serum OS biomarkers, including malondialdehyde (MDA) and total antioxidant capacity (TAC), were assessed by spectrophotometric and oxygen radical absorbance capacity (ORAC) methods, respectively.

Results

A total of 152 individuals were analyzed (COVID-19 patients vs. healthy controls). Compared with healthy controls (n = 76), patients infected with SARS-CoV-2 (n = 76) presented higher levels of MDA (p < 0.001) and decreased TAC (p < 0.001). A total of 37 (49%) patients with COVID-19 died. The area under the receiver operating characteristic (ROC) curve (AUC) estimated that the combination of the OS biomarkers (MDA+TAC) (AUC = 0.6394, p = 0.037) was a significant predictor of mortality. A higher level of MDA was associated with mortality (HR, 1.05, 95% CI, 1.00-1.10, p = 0.045).

Conclusion

This study concludes that OS is increased in patients with COVID-19 and is associated with mortality. To our knowledge, this is the first evidence of the expression of OS biomarkers and their association with mortality among the Mexican population.

The Core Role of Neutrophil–Lymphocyte Ratio to Predict All-Cause and Cardiovascular Mortality: A Research of the 2005–2014 National Health and Nutrition Examination Survey

Objective

To further supplement the previous research on the relationship between neutrophil–lymphocyte ratio (NLR) and all-cause and cardiovascular mortality, and construct clinical models to predict mortality.

Methods

A total number of 2,827 observers were included from the National Health and Nutrition Examination Survey (NHANES) database in our research. NLR was calculated from complete blood count. According to the quartile of baseline NLR, those observers were divided into four groups. A multivariate weighted Cox regression model was used to analyze the association of NLR with mortality. We constructed simple clinical prognosis models by nomograms. Kaplan–Meier survival curves were used to depict cause-specific mortality. Restricted cubic spline regression was used to make explicit relationships between NLR and mortality.

Results

This study recruited 2,827 subjects aged ≥ 18 years from 2005 to 2014. The average age of these observers was 51.55 ± 17.62, and 57.69% were male. NLR is still an independent predictor, adjusted for age, gender, race, drinking, smoking, dyslipidemia, and other laboratory covariates. The area under the receiver operating characteristic curves (AUCs) of NLR for predicting all-cause mortality and cardiovascular mortality were 0.632(95% CI [0599, 0.664]) and 0.653(95% CI [0.581, 0.725]), respectively, which were superior to C-reactive protein (AUCs: 0.609 and 0.533) and WBC (AUCs: 0.522 and 0.513). The calibration and discrimination of the nomograms were validated by calibration plots and concordance index (C-index), and the C-indexes (95% CIs) of nomograms for all-cause and cardiovascular mortality were 0.839[0.819,0.859] and 0.877[0.844,0.910], respectively. The restricted cubic spline showed a non-linear relationship between NLR and mortality. NLR > 2.053 might be a risk factor for mortality.

Conclusion

There is a non-linear relationship between NLR and mortality. NLR is an independent factor related to mortality, and NLR > 2.053 will be a risk factor for prognosis. NLR and nomogram should be promoted to medical use for practicality and convenience.

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.

Monocyte-to-high-density lipoprotein ratio and systemic inflammation response index are associated with the risk of metabolic disorders and cardiovascular diseases in general rural population

BACKGROUND

The present study aimed to clarify the effects of four inflammatory indicators (monocyte-to-high-density lipoprotein ratio [MHR], neutrophil-to-lymphocyte ratio [NLR], systematic immune-inflammation index [SII], and systemic inflammation response index [SIRI]) in evaluating the risk of metabolic diseases and cardiovascular disease (CVD), filling the gap of inflammation-metabolism system research in epidemiology.

METHODS

We conducted a cross-sectional study and multivariable logistic regression analysis to elucidate the association between inflammatory indicators and metabolic diseases and CVD risk. Metabolic diseases were defined as metabolic disorders (MetDs) or their components, such as metabolic syndrome (MetS), dyslipidemia, and central obesity. We calculated the Framingham risk score (FRS) to evaluate 10-year CVD risk.

RESULTS

Odds ratios for the third vs. the first tertile of MHR were 2.653 (95% confidence interval [CI], 2.142-3.286) for MetD, 2.091 (95% CI, 1.620-2.698) for MetS, 1.547 (95% CI, 1.287-1.859) for dyslipidemia, and 1.515 (95% CI, 1.389-1.652) for central obesity. Odds ratios for the third vs. the first tertile of SIRI were 2.092 (95% CI, 1.622-2.699) for MetD, 3.441 (95% CI, 2.917-4.058) for MetS, 1.417 (95% CI, 1.218-1.649) for dyslipidemia, and 2.080 (95% CI, 1.613-2.683) for central obesity. The odds ratio of a 10-year CVD risk of >30% for the third vs. the first tertile of MHR was 4.607 (95% CI, 2.648-8.017) and 3.397 (95% CI, 1.958-5.849) for SIRI.

CONCLUSIONS

MHR and SIRI had a significant association with MetD and its components, in which a higher level of MHR or SIRI tended to accompany a higher risk of metabolic diseases. Furthermore, they also correlated with CVD, and the increment of these indicators caused a gradually evaluated risk of 10-year CVD risk.

Association of Reduced Free T3 to Free T4 Ratio with Lower Serum Creatinine in Japanese Hemodialysis Patients

PURPOSE

Low T3 syndrome is defined by a fall in free triiodothyronine (FT3) in spite of normal serum thyroid-stimulating hormone (TSH) and often normal free thyroxin (FT4). A low FT3/FT4 ratio, a relevant marker for low T3 syndrome, is known as a risk of mortality in hemodialysis (HD) patients, as well as low muscle mass in the general population. Because of the local activation of T4 to FT3 in muscle tissue, we examined the association of FT3/FT4 ratio with serum creatinine, a marker of muscle mass and strength in HD patients to investigate the significance of muscle tissue in the development of low T3 syndrome in HD patients.

METHODS

This was a cross-sectional study derived from our prospective cohort study, named DREAM, of Japanese HD patients. After the exclusion of patients with treated and untreated thyroid dysfunction, 332 patients were analyzed in the study.

RESULTS

The serum FT4 and TSH of HD patients (n = 332) were 0.9 ± 0.1 ng/dL. and 2.0 ± 0.9 μIU/mL, which were within the respective normal range, while serum FT3 was 2.2 ± 0.3 pg/mL. As many as 101 out of 332 (30.4%) HD patients exhibited a serum FT3 less than the normal lower limit of 2.2 pg/mL. The serum FT3/FT4 ratio correlated significantly positively with serum creatinine, and inversely with serum log CRP and total cholesterol, while it exhibited a tendency towards positive correlation with serum albumin. Multiple regression analysis, which included serum creatinine, albumin, and log CRP, simultaneously, in addition to sex, age, diabetic kidney disease or not, log HD duration, body mass index, systolic blood pressure, and Kt/V, as independent variables, revealed an independent and significant positive association of serum creatinine, but not serum albumin or CRP, with the serum FT3/FT4 ratio.

CONCLUSIONS

The present study demonstrated an independent and positive correlation of serum creatinine with the serum FT3/FT4 ratio in HD patients. The lack of association of the serum FT3/FT4 ratio with serum albumin and CRP suggested the presence of a creatinine-specific mechanism to associate with serum FT3/FT4 ratio. Because of the local activation of T4 to T3 at muscle tissue, a lower muscle mass may be causatively associated with low T3 syndrome.

Circulating Vascular Adhesion Protein-1 Level Predicts the Risk of Cardiovascular Events and Mortality in Hemodialysis Patients

Background: Vascular adhesion protein-1 (VAP-1) is an oxidative enzyme of primary amines that facilitates the transmigration of inflammatory cells. Its oxidative and inflammatory effects are prominently increased in pathological conditions, such as metabolic, atherosclerotic, and cardiac diseases. However, the clinical significance of circulating VAP-1 levels in hemodialysis (HD) patients is unclear.

Methods: A total of 434 HD patients were enrolled in a prospective multicenter cohort study between June 2016 and April 2019. Plasma VAP-1 levels were measured at the time of data entry, and the primary endpoint was defined as a composite of cardiovascular (CV) and cardiac events.

Results: Circulating VAP-1 levels were positively correlated with plasma levels of cardiac remodeling markers, including brain natriuretic peptide, galectin-3, and matrix metalloproteinase-2. Multivariable logistic regression analysis revealed that patients with higher circulating VAP-1 levels were more likely to have left ventricular diastolic dysfunction [odds ratio, 1.40; 95% confidence interval [CI], 1.04–1.88]. The cumulative event rate of the composite of CV events was significantly greater in VAP-1 tertile 3 than in VAP-1 tertiles 1 and 2 (P = 0.009). Patients in tertile 3 were also associated with an increased cumulative event rate of cardiac events (P = 0.015), with a 2.06-fold higher risk each for CV (95% CI, 1.10–3.85) and cardiac (95% CI, 1.03–4.12) events after adjusting for multiple variables.

Conclusions: Plasma VAP-1 levels were positively associated with left ventricular diastolic dysfunction and the risk of incident CV and cardiac events in HD patients. Our results indicate that VAP-1 may aid clinicians in identifying HD patients at a high risk of CV events.

Biomarkers and Mechanisms of Oxidative Stress-Last 20 Years of Research with an Emphasis on Kidney Damage and Renal Transplantation

Oxidative stress is an imbalance between pro- and antioxidants that adversely influences the organism in various mechanisms and on many levels. Oxidative damage occurring concomitantly in many cellular structures may cause a deterioration of function, including apoptosis and necrosis. The damage leaves a molecular “footprint”, which can be detected by specific methodology, using certain oxidative stress biomarkers. There is an intimate relationship between oxidative stress, inflammation, and functional impairment, resulting in various diseases affecting the entire human body. In the current narrative review, we strengthen the connection between oxidative stress mechanisms and their active compounds, emphasizing kidney damage and renal transplantation. An analysis of reactive oxygen species (ROS), antioxidants, products of peroxidation, and finally signaling pathways gives a lot of promising data that potentially will modify cell responses on many levels, including gene expression. Oxidative damage, stress, and ROS are still intensively exploited research subjects. We discuss compounds mentioned earlier as biomarkers of oxidative stress and present their role documented during the last 20 years of research. The following keywords and MeSH terms were used in the search: oxidative stress, kidney, transplantation, ischemia-reperfusion injury, IRI, biomarkers, peroxidation, and treatment.

Associations of Baseline and Changes in Leukocyte Counts with Incident Cardiovascular Events: The Dongfeng-Tongji Cohort Study

Aim: The aim of the present study was to investigate the associations of baseline and longitudinal changes in leukocyte counts with incident cardiovascular disease (CVD).

Methods: We conducted a prospective study to investigate the associations of baseline and 5-year changes in leukocyte counts with incident CVD and its subtypes in middle-aged and elderly Chinese. We estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD using the Cox proportional-hazards models.

Results: In the analyses of baseline total leukocyte count of 26,655 participants, compared with the lowest quartile (＜4.71×10⁹/L), participants in the fourth quartile (＞6.70×10⁹/L) had 11% higher risk for CVD. Consistent with total leukocyte count, neutrophil count also exhibited a significant positive association with the risk of CVD. In the analyses of 5-year changes in total leukocyte count of 11,594 participants, the changes in leukocyte count were categorized into three groups, i.e., the decreased group (＜25%), stable group (25%–75%), and increased group (＞75%). Compared with participants in the stable group (−1.18 to 0.44×10⁹/L), participants in the increased group (＞0.44×10⁹/L) had 14% higher risk for CVD. We also observed significant positive associations of the changes in neutrophil and monocyte counts with the risk of CVD. Furthermore, the total leukocyte count in the second or third tertile at the first follow-up with a 5-year increase was related to higher CVD risk.

Conclusion: High baseline total leukocyte count and a 5-year increase in total leukocyte count were related to higher CVD risk.

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.

Comorbidity burden may explain adiponectin's paradox as a marker of increased mortality risk in hemodialysis patients

Despite experimental evidence of beneficial metabolic, antiatherosclerotic and antiinflammatory effects of the 30 kDa adipokine, adiponectin, maintenance hemodialysis (MHD) patients with high adiponectin blood levels have paradoxically high mortality rates. We aimed to examine the direction of the associations between adiponectin and all-cause and cardiovascular mortality as well as with markers of oxidative stress, inflammation and nutrition in MHD patients with varying degrees of comorbidities. A cohort of 261 MHD patients (mean age 68.6 ± 13.6 years, 38.7% women), grouped according to baseline comorbidity index (CI) and serum adiponectin levels, were followed prospectively for six years. High and low concentrations were established according to median CI and adiponectin levels and cross-classified. Across the four CI-adiponectin categories, the group with low comorbidities and high adiponectin exhibited the best outcomes. Conversely, the high comorbidity group with high adiponectin levels had the lowest survival rate in both all-cause mortality (log rankχ² = 23.74, p < 0.001) and cardiovascular mortality (log rankχ² = 34.16, p < 0.001). Further data adjustment for case-mix covariates including fat mass index did not substantially affect these results. In conclusion, the direction of adiponectin’s prognostic associations in MHD patients is inverse in those with few comorbidities and direct in those with many comorbidities.