Association of serum markers of oxidative stress with myocardial infarction and stroke: pooled results from four large European cohort studies

Factors associated with oxidative stress in virologically suppressed people living with HIV on long-term antiretroviral therapy

BACKGROUND

Oxidative stress (OS) is the imbalance between oxidant and antioxidant molecules, in favour of oxidants, that has been associated with an increased risk of morbidity and mortality in ART-treated people living with HIV (PLWH). We aimed to assess factors associated with OS in virologically suppressed PLWH on long-term modern ART.

METHOD

In this cross-sectional study we evaluated OS by measuring both the levels of derivatives-reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP). We also calculated the BAP/d-ROMs ratio, (OS index, OSi); a cut-off value < 7.3 indicated OS. Factors associated with OS markers were explored by linear regression model.

RESULTS

We enrolled 299 experienced PLWH with virological suppression (HIV-RNA < 50cps/mL). The mean of the d-ROMs levels was 409 UCARR (95%CI 394-422), whereas the mean of the BAP levels was 1.809 µmol/L (95%CI 1706-1851). The OSi mean value was 4.84, and 91.6% of the participants were below the cut-off value. By regression analysis, higher production of oxidants was associated with female sex (p < 0.001), current exposition to PIs (p = 0.030) and HCV co-infection (p = 0.006). Higher antioxidant capacity was correlated with higher HDL levels (p = 0.001). A lower OSi was associated with female sex (p = 0.003) and the current use of triple vs. dual regimen (p = 0.036). The OSi correlated negatively with cholesterol levels (p = 0.002) and positively with HDL (p < 0.001).

CONCLUSIONS

Virologically suppressed PLWH on long-term ART showed a marked OS. Female sex, the exposure to PIs, and HCV co-infection were associated with higher oxidants, while higher HDL levels were linked to better antioxidant capacity. Interestingly, dual therapy, especially INSTI-based regimens, was associated with lower oxidative stress compared to triple therapy.

Triglyceride-glucose index mediates the association between residual cholesterol and stroke among middle-aged and older adults in China: a prospective, nationwide, population-based study

Background

Both triglyceride-glucose (TyG) index and residual cholesterol (RC) are predictors of stroke; however, to what extent the RC is associated with stroke through TyG index is unclear. This study examined whether the TyG index mediates the association of RC with incident stroke and the extent of interaction or joint relations of RC and TyG index with stroke in middle-aged and older Chinese adults.

Methods

This is an ongoing prospective cohort study initiated in 2011 that included 10,569 middle-aged and older Chinese adults without stroke at baseline. The exposure was RC, the mediator was TyG index, and the outcome was stroke which followed up from June, 2011, to June, 2018. Mediation analysis was used to explore whether the TyG index mediated the association between RC and stroke risk.

Results

Of the 10,569 participants, 4,978 (47.1%) were men; the mean (SD) age was 59.01 (9.43) years. During a median follow-up of 7.1 years, 734 (7.0%) participants experienced a stroke. In the adjusted Cox models, A one SD increase in RC was associated with an elevated risk of stroke (HR, 1.09; 95% CI, 1.02-1.16), as well as TyG index (HR, 1.14; 95% CI, 1.06-1.23). No significant multiplicative or additive interactions were found between the TyG index and RC on stroke risk (HR for multiplicative: 1.07, 95% CI, 0.67-1.70; Synergy index: 1.05, 95% CI, 0.16-6.88). TyG index mediated the association between RC and stroke (b, -0.16; 95% CI, -0.30 to -0.03). Subgroup analyses and sensitivity analyses showed consistent results.

Conclusions

This study evidence that the TyG index completely mediates the association between RC and stroke risk among middle-aged and older Chinese adults. These findings highlight the importance of considering RC and the TyG index in stroke risk assessment.

Gaps in the usage and reporting of multiple imputation for incomplete data: findings from a scoping review of observational studies addressing causal questions

BACKGROUND

Missing data are common in observational studies and often occur in several of the variables required when estimating a causal effect, i.e. the exposure, outcome and/or variables used to control for confounding. Analyses involving multiple incomplete variables are not as straightforward as analyses with a single incomplete variable. For example, in the context of multivariable missingness, the standard missing data assumptions ("missing completely at random", "missing at random" [MAR], "missing not at random") are difficult to interpret and assess. It is not clear how the complexities that arise due to multivariable missingness are being addressed in practice. The aim of this study was to review how missing data are managed and reported in observational studies that use multiple imputation (MI) for causal effect estimation, with a particular focus on missing data summaries, missing data assumptions, primary and sensitivity analyses, and MI implementation.

METHODS

We searched five top general epidemiology journals for observational studies that aimed to answer a causal research question and used MI, published between January 2019 and December 2021. Article screening and data extraction were performed systematically.

RESULTS

Of the 130 studies included in this review, 108 (83%) derived an analysis sample by excluding individuals with missing data in specific variables (e.g., outcome) and 114 (88%) had multivariable missingness within the analysis sample. Forty-four (34%) studies provided a statement about missing data assumptions, 35 of which stated the MAR assumption, but only 11/44 (25%) studies provided a justification for these assumptions. The number of imputations, MI method and MI software were generally well-reported (71%, 75% and 88% of studies, respectively), while aspects of the imputation model specification were not clear for more than half of the studies. A secondary analysis that used a different approach to handle the missing data was conducted in 69/130 (53%) studies. Of these 69 studies, 68 (99%) lacked a clear justification for the secondary analysis.

CONCLUSION

Effort is needed to clarify the rationale for and improve the reporting of MI for estimation of causal effects from observational data. We encourage greater transparency in making and reporting analytical decisions related to missing data.

Albumin Redox Modifications Promote Cell Calcification Reflecting the Impact of Oxidative Status on Aortic Valve Disease and Atherosclerosis

Calcific aortic valve disease (CAVD) and coronary artery disease (CAD) are related cardiovascular diseases in which common mechanisms lead to tissue calcification. Oxidative stress plays a key role in these diseases and there is also evidence that the redox state of serum albumin exerts a significant influence on these conditions. To further explore this issue, we used multimarker scores (OxyScore and AntioxyScore) to assess the global oxidative status in patients with CAVD, with and without CAD, also evaluating their plasma thiol levels. In addition, valvular interstitial cells were treated with reduced, oxidized, and native albumin to study how this protein and its modifications affect cell calcification. The differences we found suggest that oxidative status is distinct in CAVD and CAD, with differences in redox markers and thiol levels. Importantly, the in vitro interstitial cell model revealed that modified albumin affects cell calcification, accelerating this process. Hence, we show here the importance of the redox system in the development of CAVD, emphasizing the relevance of multimarker scores, while also offering evidence of how the redox state of albumin influences vascular calcification. These data highlight the relevance of understanding the overall redox processes involved in these diseases, opening the door to new studies on antioxidants as potential therapies for these patients.

Associations of systemic oxidative stress with functional outcomes after ST-segment elevation myocardial infarction

BACKGROUND

Ischemia-reperfusion is accompanied by oxidative stress. Serum free thiols (FTs; sulfhydryl groups) reliably reflect systemic oxidative stress. This study evaluates longitudinal changes in FTs and their associations with outcomes after ST-segment elevation myocardial infarction (STEMI).

METHODS

FTs were detected in archived serum samples from 378 participants of a neutral randomized trial on metformin therapy after STEMI. FT levels were determined at presentation with STEMI and at 24 h, 2 weeks, 4 months and 1 year thereafter. Outcomes included infarct size and left ventricular ejection fraction (LVEF), both determined with cardiac magnetic resonance imaging after 4 months, and 5-year major adverse cardiovascular events (MACE).

RESULTS

Serum FT concentrations at presentation and at 24 h were 356 ± 91 and 353 ± 76 μmol/L, respectively. The change in FTs between presentation and 24 h (ΔFTs) was associated with outcomes in age- and sex-adjusted analysis (per 100 μmol/L FT increase, β = -0.87 for infarct size, 95% confidence interval (CI): -1.75 to -0.001, P = 0.050; β = 1.31, 95% CI: 0.37 to 2.25 for LVEF, P = 0.007). Associations between ΔFTs and LVEF were markedly stronger in patients with Thrombolysis in Myocardial Infarction flow of 0 or 1 before percutaneous coronary intervention (PCI)(β = 2.73, 95% CI: 0.68 to 4.77, P = 0.009). Declining FTs during the first 24 h might be associated with higher incidence of 5-year MACE (P = 0.09).

CONCLUSIONS

Changes in oxidative stress early post-PCI may predict functional outcomes after STEMI. Our findings warrant validation in larger cohorts, and then may be used as rationale for development of thiol-targeted therapy in ischemic heart disease.

Monomethyl lithospermate alleviates ischemic stroke injury in middle cerebral artery occlusion mice in vivo and protects oxygen glucose deprivation/reoxygenation induced SHSY-5Y cells in vitro via activation of PI3K/Akt signaling

Stroke is a fatal neurological disease, which seriously threatens human health and life. Ischemic stroke (IS) is the most common type of stroke in clinic. Its pathogenesis is very complex, mainly caused by nerve damage caused by brain blood supply disorder. Previous studies have confirmed that natural products play important roles in improving neurological disorders. Furthermore, our previous results also suggested that Shenxiong Tongmai granule, a clinically used herbal medicines’ prescription, has a good ameliorating effect on IS. In the present study, we found that Monomethyl lithospermate (MOL), a constituent of Shenxiong Tongmai granule, significantly improved the neurological damage in middle cerebral artery occlusion (MCAO) rats. MOL can significantly improve the neurological deficit score of MCAO rats, and improve the damage of hippocampal neurons caused by ischemia-reperfusion (IR). At the same time, we also found that MOL could reduce the level of oxidative stress in the brain tissues of MCAO rats. Furthermore, the oxygen and glucose deprivation/Reoxygenation (OGD/R)-induced SHSY-5Y cell model was established in vitro to investigate the pharmacological activity and molecular mechanisms of MOL in improving the nerve injury of IS rats. The results showed that MOL could increase the cell viability of SHSY-5Y cells, inhibit the mitochondrial membrane potential (MMOP) collapse and suppress apoptosis. In addition, MOL also ameliorated the elevated oxidative stress level caused by OGR/R treatment in SHSY-5Y cells. Further mechanistic studies showed that MOL could activate the PI3K/AKT pathway via promoting the phosphorylation of PI3K and AKT in MCAO rats and OGR/R-induced SHSY-5Y cells, which could be partially blocked by addition of PI3K/AKT pathway inhibitor of LY294002. Taken together, our current study suggested that MOL exerts a protective effect against neural damage caused by IS in vivo and in vitro by activating the PI3K/AKT pathway.

Single and Combined Associations of Plasma and Urine Essential Trace Elements (Zn, Cu, Se, and Mn) with Cardiovascular Risk Factors in a Mediterranean Population

Trace elements are micronutrients that are required in very small quantities through diet but are crucial for the prevention of acute and chronic diseases. Despite the fact that initial studies demonstrated inverse associations between some of the most important essential trace elements (Zn, Cu, Se, and Mn) and cardiovascular disease, several recent studies have reported a direct association with cardiovascular risk factors due to the fact that these elements can act as both antioxidants and pro-oxidants, depending on several factors. This study aims to investigate the association between plasma and urine concentrations of trace elements and cardiovascular risk factors in a general population from the Mediterranean region, including 484 men and women aged 18−80 years and considering trace elements individually and as joint exposure. Zn, Cu, Se, and Mn were determined in plasma and urine using an inductively coupled plasma mass spectrometer (ICP-MS). Single and combined analysis of trace elements with plasma lipid, blood pressure, diabetes, and anthropometric variables was undertaken. Principal component analysis, quantile-based g-computation, and calculation of trace element risk scores (TERS) were used for the combined analyses. Models were adjusted for covariates. In single trace element models, we found statistically significant associations between plasma Se and increased total cholesterol and systolic blood pressure; plasma Cu and increased triglycerides and body mass index; and urine Zn and increased glucose. Moreover, in the joint exposure analysis using quantile g-computation and TERS, the combined plasma levels of Zn, Cu, Se (directly), and Mn (inversely) were strongly associated with hypercholesterolemia (OR: 2.03; 95%CI: 1.37−2.99; p < 0.001 per quartile increase in the g-computation approach). The analysis of urine mixtures revealed a significant relationship with both fasting glucose and diabetes (OR: 1.91; 95%CI: 1.01−3.04; p = 0.046). In conclusion, in this Mediterranean population, the combined effect of higher plasma trace element levels (primarily Se, Cu, and Zn) was directly associated with elevated plasma lipids, whereas the mixture effect in urine was primarily associated with plasma glucose. Both parameters are relevant cardiovascular risk factors, and increased trace element exposures should be considered with caution.

The Prognostic Value of Derivatives-Reactive Oxygen Metabolites (d-ROMs) for Cardiovascular Disease Events and Mortality: A Review

Oxidative stress participates in the development and exacerbation of cardiovascular diseases (CVD). The ability to promptly quantify an imbalance in an individual reductive-oxidative (RedOx) state could improve cardiovascular risk assessment and management. Derivatives-reactive oxygen metabolites (d-ROMs) are an emerging biomarker of oxidative stress quantifiable in minutes through standard biochemical analysers or by a bedside point-of-care test. The current review evaluates available data on the prognostic value of d-ROMs for CVD events and mortality in individuals with known and unknown CVD. Outcome studies involving small and large cohorts were analysed and hazard ratio, risk ratio, odds ratio, and mean differences were used as measures of effect. High d-ROM plasma levels were found to be an independent predictor of CVD events and mortality. Risk begins increasing at d-ROM levels higher than 340 UCARR and rises considerably above 400 UCARR. Conversely, low d-ROM plasma levels are a good negative predictor for CVD events in patients with coronary artery disease and heart failure. Moreover, combining d-ROMs with other relevant biomarkers routinely used in clinical practice might support a more precise cardiovascular risk assessment. We conclude that d-ROMs represent an emerging oxidative-stress-related biomarker with the potential for better risk stratification both in primary and secondary cardiovascular prevention.

Oxidative Stress Parameters as Biomarkers of Cardiovascular Disease towards the Development and Progression

Cardiovascular disease (CVD) remains the leading cause of death globally, with unhealthy lifestyles today greatly increasing the risk. Over the decades, scientific investigation has been carried out on reactive oxygen species (ROS) and their resultant oxidative stress based on their changes made on biological targets such as lipids, proteins, and DNA. Since the existing clinical studies with antioxidants failed to provide relevant findings on CVD prediction, the focus has shifted towards recognition of oxidised targets as biomarkers to predict prognosis and response to accurate treatment. The identification of redox markers could help clinicians in providing risk stratification for CVD events beyond the traditional prognostic and diagnostic targets. This review will focus on how oxidant-related parameters can be applied as biomarkers for CVD based on recent clinical evidence.

Post-Bariatric Hypoglycemia Is Associated with Endothelial Dysfunction and Increased Oxidative Stress

Post-bariatric hypoglycemia (PBH) is a potentially serious complication that may occur after bariatric surgery. Recurrent hypoglycemia may exert detrimental effects on vascular function. The aim of the present study was to evaluate endothelial function and oxygen reactive compounds in patients who experience PBH compared with controls. We performed a cross-sectional study on subjects with PBH (HYPO) and those without (NO-HYPO), detected by seven-day continuous glucose monitoring (CGM) performed at least twelve months after bariatric surgery. We enrolled 28 post-bariatric subjects (17.9% males, mean age 40.6 ± 10.7 years), with 18 in the HYPO group and 10 in the NO-HYPO group. In the two groups, we measured brachial artery flow-mediated dilation (FMD), oxidized low-density lipoproteins (oxLDL) and reactive oxygen metabolites (D-ROMs). The HYPO group had significantly lower FMD values than the NO-HYPO group (3.8% ± 3.0 vs. 10.5% ± 2.0, p < 0.001). A significant correlation was found between FMD and the time spent in hypoglycemia (rho = −0.648, p < 0.001), the number of hypoglycemic events (rho = −0.664, p < 0.001) and the mean glucose nadir (rho = 0.532, p = 0.004). The HYPO group showed significantly higher levels of D-ROMs (416.2 ± 88.7 UCARR vs. 305.5 ± 56.3 UCARR, p < 0.001) and oxLDLs (770.5 ± 49.7 µEq/L vs. 725.1 ± 51.6 µEq/L, p = 0.035) compared to the NO-HYPO group. In the multiple linear regression analysis, hypoglycemia independently predicted FMD values (β = −0.781, p < 0.001), D-ROMs (β = 0.548, p = 0.023) and oxLDL levels (β = 0.409, p = 0.031). PBH is associated with impaired endothelial function accompanied by increased oxidative stress.

Death-Associated Protein Kinase 1 (DAPK1) Protects against Myocardial Injury Induced by Myocardial Infarction in Rats via Inhibition of Inflammation and Oxidative Stress

Objective

Heart failure and ventricular remodeling after acute myocardial infarction (AMI) are important factors affecting the prognosis of patients. Therefore, we expected to explore the therapeutic target of AMI by studying the effect of death-associated protein kinase 1 (DAPK1) on AMI rat model.

Materials and Methods

We used male Sprague-Dawley rats to make AMI model, and after 1, 3, 7, and 14 d, we detect the success rate of modeling and the expression change of DAPK1 through 2, 3, 5-triphenyl tetrazolium chloride staining, myocardial injury markers detection, echocardiographic detection, and histological experiment. In addition, we determined the effect of DAPK1 on AMI by subcutaneous injection of the DAPK1 inhibitor (TC-DAPK 6). The effect of DAPK1 on cardiomyocytes has also been verified in cell experiments on H9c2 cells.

Results

The expression of DAPK1 in AMI rats was significantly higher than that in sham group, and it increased with time. The expression of inflammatory factors (interleukin- (IL-) 1β, IL-6, and tumor necrosis factor-α) in AMI rats treated by TC-DAPK 6 was reduced. In addition, TC-DAPK 6 also reduced the activity of malonaldehyde and increased the activities of superoxide dismutase, glutathione, and catalase. The expression of antioxidant molecules such as peroxiredoxin1/4 and glutathione peroxidase1/3 was also promoted by TC-DAPK 6. In H9c2 cells, TC-DAPK 6 also reduced its oxidative stress level.

Conclusions

The increase of DAPK1 may be related to the pathogenesis of AMI. DAPK1 inhibitors protect cardiomyocytes from AMI-induced myocardial injury by reducing levels of inflammation and oxidative stress in myocardial tissue and cells.

Endothelial Dysfunction: An Intermediate Clinical Feature between Urolithiasis and Cardiovascular Diseases

An epidemiological relationship between urolithiasis and cardiovascular diseases has extensively been reported. Endothelial dysfunction is an early pathogenic event in cardiovascular diseases and has been associated with oxidative stress and low chronic inflammation in hypertension, coronary heart disease, stroke or the vascular complications of diabetes and obesity. The aim of this study is to summarize the current knowledge about the pathogenic mechanisms of urolithiasis in relation to the development of endothelial dysfunction and cardiovascular morbidities.

METHODS

A non-systematic review has been performed mixing the terms "urolithiasis", "kidney stone" or "nephrolithiasis" with "cardiovascular disease", "myocardial infarction", "stroke", or "endothelial dysfunction".

RESULTS

Patients with nephrolithiasis develop a higher incidence of cardiovascular disease with a relative risk estimated between 1.20 and 1.24 and also develop a higher vascular disease risk scores. Analyses of subgroups have rendered inconclusive results regarding gender or age. Endothelial dysfunction has also been strongly associated with urolithiasis in clinical studies, although no systemic serum markers of endothelial dysfunction, inflammation or oxidative stress could be clearly related. Analysis of urine composition of lithiasic patients also detected a higher expression of proteins related to cardiovascular disease. Experimental models of hyperoxaluria have also found elevation of serum endothelial dysfunction markers.

CONCLUSIONS

Endothelial dysfunction has been strongly associated with urolithiasis and based on the experimental evidence, should be considered as an intermediate and changeable feature between urolithiasis and cardiovascular diseases. Oxidative stress, a key pathogenic factor in the development of endothelial dysfunction has been also pointed out as an important factor of lithogenesis. Special attention must be paid to cardiovascular morbidities associated with urolithiasis in order to take advantage of pleiotropic effects of statins, angiotensin receptor blockers and allopurinol.

Oxidative stress in youth with type 1 diabetes: Not only a matter of gender, age, and glycemic control

AIMS

We assessed whether oxidative stress (OS) is increased in children/adolescents with type 1 diabetes (T1D) compared to healthy peers. Moreover, we searched for OS predictors in the T1D population.

METHODS

We compared the concentration of serum derivatives of reactive oxygen metabolites (d-ROMs) in 412 children/adolescents with T1D (3.6-23.5 years old) to that of 138 healthy children/adolescents (1.2-19.2 years old) by ANOVA adjusted for age, gender, and BMI z-score (z-BMI). Applying a general linear model, in a subgroup of 331 patients using continuous glucose monitoring, we searched for predictors of d-ROMs among 3-day, 2-week, and 4-week metrics of glucose control and variability, such as mean blood glucose, percent time in range (70-180 mg/dl,TIR_70-180), coefficient of variation, and others, as well as among conventional cardiovascular risk factors like current and average HbA1c, z-BMI, blood pressure percentiles, and lipid concentrations recorded retrospectively over the entire follow-up period.

RESULTS

D-ROMs levels were significantly higher in children/adolescents with T1D compared to controls [371.9 (64.2) versus 324.9 (46.3), p < 10^-16]. Sex (B = 49.1, ƞ² = 0.14, p = 1.3 * 10^-9), age < 12 years in boys (B = 79.4, ƞ² = 0.074, p = 10^-7),3-day TIR_70-180 (B = -0.87, ƞ² = 0.048, p = 6.5 * 10^-5), and z-BMI (B = 7.4, ƞ² = 0.016, p = 0.022) predicted d-ROMs with an overall R² of 0.278.

CONCLUSIONS

OS is increased in youth with T1D and only partially predicted by gender, age, glucose control, and anthropometry. Other potential determinants of OS in this population should be targeted in future studies.

Chaya Leaf Decreased Triglycerides and Improved Oxidative Stress in Subjects With Dyslipidemia

Chaya is an edible leaf popular in Mexico and Central America because of its high nutritional value. Studies in animal models have demonstrated the beneficial effects of Chaya, which include reduction of circulating lipids and increase in antioxidant activity. However, its hypolipidemic and antioxidant effects have not been demonstrated in humans. Thus, the aim of the present study was to evaluate the effect of Chaya on the lipid profile, lipid peroxidation, inflammation, and peripheral blood mononuclear cell gene expression in a population with dyslipidemia. We performed a single-arm trial in 30 participants with dyslipidemia who consumed 500 mL of Chaya beverage per day over a 6-week period. Interestingly, we observed a significant decrease in serum triglyceride concentration (P < 0.05) and an increase in plasma antioxidant activity and polyphenol concentration (P < 0.005) after 6 weeks of Chaya consumption. This was accompanied by a reduction in the oxidative stress marker MDA (P < 0.0001) and by an increase in the antioxidant enzyme CAT expression in peripheral blood mononuclear cells (P < 0.001). Altogether, our results demonstrate that consumption of Chaya has hypotriglyceridemic and antioxidant effects in subjects with dyslipidemia.

Circadian rhythm and time-of-day-effects of (anti)oxidant biomarkers for epidemiological studies

Various biomarkers of oxidative stress and redox status have been used in a number of clinical and epidemiological studies related to diseases and conditions that involve disturbances of the redox balance. However, a comprehensive study of diurnal variations of a set of biomarkers has not been conducted so far. Therefore, the aim of this study is to investigate circadian rhythm and time-of-day-effects of a set of frequently used biomarkers of oxidative stress, redox and antioxidant status in serum/plasma. These biomarkers include Reactive Oxygen Metabolites (ROM), Biological Antioxidant Potency (BAP), Total Thiols in Proteins (TTP), high-sensitive C-Reactive Protein (CRP) and Uric Acid (UA). During a 24-hr study, blood sampling was conducted 6 times at 4-hr intervals. The presence of circadian rhythm was analyzed with CircWave analysis, whereas the effect of time was analyzed with Repeated Measures ANOVA (RM-ANOVA). Thereby, the main focus was on the time points in working hours (8, 12 and 16 hr), which are used frequently in practice. Of all investigated biomarkers, only TTP in males demonstrated statistically significant circadian rhythm (p = 0.040). A statistically significant effect between all six time points with RM-ANOVA was observed for ROM, TTP and UA in both genders, and for BAP in females only. No statistically significant differences were observed between the time points 8 hr and 12 hr for any of the biomarkers that were assessed in our study. In conclusion, diurnal variations in some of the studied biomarkers that we demonstrate here should be taken into account when designing and conducting clinical and epidemiological studies. It is advised to standardize the time of sampling with a preference in the morning hours.

Redox-related biomarkers in human cardiovascular disease - classical footprints and beyond

Global epidemiological studies show that chronic non-communicable diseases such as atherosclerosis and metabolic disorders represent the leading cause of premature mortality and morbidity. Cardiovascular disease such as ischemic heart disease is a major contributor to the global burden of disease and the socioeconomic health costs. Clinical and epidemiological data show an association of typical oxidative stress markers such as lipid peroxidation products, 3-nitrotyrosine or oxidized DNA/RNA bases with all major cardiovascular diseases. This supports the concept that the formation of reactive oxygen and nitrogen species by various sources (NADPH oxidases, xanthine oxidase and mitochondrial respiratory chain) represents a hallmark of the leading cardiovascular comorbidities such as hyperlipidemia, hypertension and diabetes. These reactive oxygen and nitrogen species can lead to oxidative damage but also adverse redox signaling at the level of kinases, calcium handling, inflammation, epigenetic control, circadian clock and proteasomal system. The in vivo footprints of these adverse processes (redox biomarkers) are discussed in the present review with focus on their clinical relevance, whereas the details of their mechanisms of formation and technical aspects of their detection are only briefly mentioned. The major categories of redox biomarkers are summarized and explained on the basis of suitable examples. Also the potential prognostic value of redox biomarkers is critically discussed to understand what kind of information they can provide but also what they cannot achieve.

Longitudinal association of dietary carbohydrate and the risk cardiovascular disease: a dose-response meta-analysis

Previous findings on the association of dietary carbohydrate with cardiovascular disease (CVD) events and mortality are inconsistent. We aimed to assess the relationship between dietary carbohydrate and the incidence of cardiovascular events and mortality. A comprehensive literature search of MEDLINE (PubMed), Scopus, ISI Web of Science, and EMBASE, was performed up to June 2019. Prospective cohort studies which examined dietary carbohydrate in relation to fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, heart failure, and sudden cardiac death were included in our study. Summary HRs and 95% CIs were estimated using a random-effects model. A total of 19 cohort studies including 15,663,111 participants were identified. Combining 27 effect sizes with 1,577,225 CVD cases led to a significant association between dietary carbohydrate and total CVD events (HR= 1.05, 95% CI: 1.00, 1.10; I² = 38.5%), but no association was observed between dietary carbohydrate and CVD mortality (HR = 1.02; 95% CI: 0.91, 1.14; I²=27.1%, derived from 8 effect sizes with 106,412 events), and CHD events (HR = 1.03, 95% CI: 0.98, 1.09; I² = 46.6%, derived from 18 effect sizes with 1,549,281 events). Moreover, using 8 effect sizes with 6,829 cases, higher carbohydrate intake was associated with increased risk of stroke (HR = 1.13; 95% CI: 1.01, 1.27; I²= 0.0%). In subgroup analysis by sex, higher carbohydrate intake increased the risk of total CVD events (HR: 1.10; 95% CI: 1.03, 1.17; I² = 0.0%), and CHD (HR: 1.10; 95% CI: 1.01, 1.20; I²= 15.0%), but not stroke and CVD mortality in women. No significant association was found in men. Low- to very-low-certainty evidence suggests that higher carbohydrate intake is directly but slightly associated with CVD and stroke risk, while no association was found for CHD and CVD mortality. We also found sex-specific associations.

Oxidative Stress, Telomere Shortening, and Apoptosis Associated to Sarcopenia and Frailty in Patients with Multimorbidity

BACKGROUND

The presence of oxidative stress, telomere shortening, and apoptosis in polypathological patients (PP) with sarcopenia and frailty remains unknown.

METHODS

Multicentric prospective observational study in order to assess oxidative stress markers (catalase, glutathione reductase (GR), total antioxidant capacity to reactive oxygen species (TAC-ROS), and superoxide dismutase (SOD)), absolute telomere length (aTL), and apoptosis (DNA fragmentation) in peripheral blood samples of a hospital-based population of PP. Associations of these biomarkers to sarcopenia, frailty, functional status, and 12-month mortality were analyzed.

RESULTS

Of the 444 recruited patients, 97 (21.8%), 278 (62.6%), and 80 (18%) were sarcopenic, frail, or both, respectively. Oxidative stress markers (lower TAC-ROS and higher SOD) were significantly enhanced and aTL significantly shortened in patients with sarcopenia, frailty or both syndromes. No evidence of apoptosis was detected in blood leukocytes of any of the patients. Both oxidative stress markers (GR, p = 0.04) and telomere shortening (p = 0.001) were associated to death risk and to less survival days.

CONCLUSIONS

Oxidative stress markers and telomere length were enhanced and shortened, respectively, in blood samples of polypathological patients with sarcopenia and/or frailty. Both were associated to decreased survival. They could be useful in the clinical practice to assess vulnerable populations with multimorbidity and of potential interest as therapeutic targets.

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

Aim: Both oxidative stress and inflammation are involved in the pathogenesis of cardiovascular disease (CVD). The serum level of derivatives of reactive oxygen metabolites (d-ROMs) is a measure of the total amount of hydroperoxides serving as a marker of oxidative stress. We investigated whether d-ROMs could predict the clinical outcomes in hemodialysis patients and whether the associations of d-ROMs with the outcomes are independent of a marker of inflammation, C-reactive protein (CRP).

Methods: This was a prospective cohort study in hemodialysis patients. The key exposures were the serum levels of d-ROMs and CRP. The outcome measures were all-cause mortality and new CVD events.

Results: A total of 517 patients were analyzed. d-ROMs correlated positively with CRP. During follow-up for 5 years, 107 patients died, and 190 patients experienced new CVD events. In the Kaplan–Meier analyses, both higher d-ROMs and higher CRP levels predicted higher risks for mortality and CVD events. By Cox proportional-hazard regression analysis adjusted for potential confounders excluding CRP, d-ROMs exhibited a significant association with all-cause mortality, but this association was no longer significant after further adjustment for CRP. Using the same model, CRP exhibited a significant association with all-cause mortality, but this association was no longer significant after further adjustment for d-ROMs. When we analyzed new CVD events as the outcome, CRP was a significant predictor, whereas the level of d-ROMs was not.

Conclusions: Although d-ROMs predicted mortality and CVD events in unadjusted models, the associations of d-ROMs with these outcomes were not independent of CRP. Oxidative stress and inflammation appear to share common causal pathways.

Dimethyl fumarate protects cardiomyocytes against oxygen-glucose deprivation/reperfusion (OGD/R)-induced inflammatory response and damages via inhibition of Egr-1

Acute myocardial infarction (AMI) is associated with high rates of morbidity and mortality. Atherosclerosis is among the leading causes of AMI. The rupture or erosion of atherosclerotic plaques can obstruct coronary arteries, thereby leading to an acute inflammatory reaction to ischemic injury and cardiomyocyte apoptosis. Dimethyl fumarate (DMF) is a fumaric acid diester which is used for the treatment of psoriasis and multiple sclerosis. DMF is most well-known for its modulatory actions on the Nrf2 and NF-κB cellular signaling pathways. In the present study, we employed an oxygen-glucose deprivation/reoxygenation (OGD/R) model of myocardial ischemia/reperfusion injury using H9c2 cardiomyocytes to assess the potential protective effects of DMF. We found that DMF significantly improved cell viability and reduced the expression of pro-inflammatory cytokines and chemokines, including IL-6, IL-8, and MCP-1. We further demonstrated an antioxidant effect of DMF via reduced production of ROS, which was mediated through NOX4 inhibition. Tissue factor and ICAM-1 play a major role in left ventricular remodeling. DMF inhibited the expression of TF and ICAM-1 induced by OGD/R, which we demonstrated to be mediated through the Egr-1 signaling pathway, as silencing of Egr-1 suppressed the expression of TF and ICAM-1. Together, these findings demonstrate a potential role for DMF in the treatment of myocardial infarction.

Objectives, design and main findings until 2020 from the Rotterdam Study

The Rotterdam Study is an ongoing prospective cohort study that started in 1990 in the city of Rotterdam, The Netherlands. The study aims to unravel etiology, preclinical course, natural history and potential targets for intervention for chronic diseases in mid-life and late-life. The study focuses on cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1700 research articles and reports. This article provides an update on the rationale and design of the study. It also presents a summary of the major findings from the preceding 3 years and outlines developments for the coming period.

Association of combined genetic variations in SOD3, GPX3, PON1, and GSTT1 with hypertension and severity of coronary artery disease

Oxidative stress plays a critical role in the pathophysiology of hypertension (HT) and the progression of atherosclerotic coronary artery disease (CAD). Genetic variations in superoxide dismutase (SOD), glutathione peroxidase 3 (GPX3), paraoxonase 1 (PON1) and glutathione S-transferase theta 1 (GSTT1) may modulate their gene functions, affecting protein functions. These changes could have an impact on the pathogenesis of HT and progression of CAD. The present study investigated the associations of individual and combined antioxidant-related gene polymorphisms with the incidence of HT and severity of CAD. Two study populations were enrolled. The HT-associated study comprised 735 control and 735 hypertensive subjects (mean age 59.3 ± 9.0 years), matched for age and sex. The CAD study, hospital-based subjects (mean age 62.1 ± 9.5 years), included 279 CAD patients and 165 non-CAD subjects. Gene polymorphisms were identified in genomic DNA using polymerase chain reaction (PCR)-based technique. Genetic variations were assessed for their associations with HT and severity of CAD. Antioxidant gene variants, SOD3 rs2536512-GG, GPX3 rs3828599-GG, PON1 rs705379-TT, and GSTT1^{-/- and +/-}, were independently associated with the incidence of HT. A combination of four HT-associated genotypes, as a genetic risk score (GRS), revealed an association of GRS 5 and GRS ≥ 6 with increased susceptibility to HT and CAD, and further with multivessel coronary atherosclerosis (multivessel CAD) compared with GRS 0-2 [respective ORs(95% CI) for GRS ≥ 6 = 2.37 (1.46-3.85), 3.26 (1.29-8.25), and 4.36 (1.36-14.0)]. Combined polymorphisms in these four antioxidant-related genes were associated with the incidences of HT and CAD, and with the severity of coronary atherosclerosis.

N-Oleoyl-Phosphatidyl-Ethanolamine and Epigallo Catechin-3-Gallate Mitigate Oxidative Stress in Overweight and Class I Obese People on a Low-Calorie Diet

Oxidative stress and lipid peroxidation are considered key factors linking obesity with its associated complications. Epigallo catechin-3-gallate (EGCG) and oleoylethanolamide, together with its phospholipid precursor N-oleoyl-phosphatidylethanolamine (NOPE), are nutritional compounds that might improve the oxidative stress status of obese people. Unfortunately, the bioavailability of these compounds is low; however, the coadministration of NOPE with EGCG has been shown to ameliorate both the plasma availability of EGCG and the intestinal levels of NOPE in rats. This double-blind placebo-controlled study investigated the effects of 2 months' supplementation with EGCG complexed with NOPE, combined with moderate energy restriction, on plasma oxidative status of overweight and class I obese subjects. A total of 138 subjects (body mass index: 25-35 kg/m²) were recruited and randomized into two groups: the first (n = 67) received caps of placebo and the second (n = 71) caps of an oily dispersion of EGCG complexed with NOPE for 2 months. Subjects' supplementation was combined with moderate energy restriction (-800 kcal/day). Plasma oxidative status was determined by measuring the levels of oxidized low-density lipoprotein (Ox-LDL), malondialdehyde and reactive oxygen metabolites, and by calculating the lag time and the slope of Cu-induced lipid peroxidation kinetics. In total 116 subjects (27 M/89 F) completed the supplementation period, 49 in the placebo group and 67 in the treated group. Treatment induced a similar significant weight reduction in the two groups. Moreover, we found the mean changes of Ox-LDL significantly lower and the mean changes of antioxidant capacity (lag time) significantly higher in NOPE-EGCG group than in placebo group (treatment effect mean difference: -3.15 UL, P < .044 and +5.37 min, P < .0347, respectively). EGCG plasma levels were detectable only after 2 months of NOPE-EGCG diet. The NOPE-EGCG integration to a low-energy diet seems, therefore, useful for ameliorating oxidative stress-related markers, which are concomitant causes of obesity-induced disorders.

Silencing of TXNIP Alleviated Oxidative Stress Injury by Regulating MAPK-Nrf2 Axis in Ischemic Stroke

Ischemic stroke is a life-threatening cerebrovascular thrombotic disease, oxidative stress is considered to be a critical factor to stroke pathophysiology. This study aimed to investigate the underlying molecular mechanism and propose the potential therapeutic strategy for ischemic stroke. Bioinformatics analysis based on a public microarray profile (GSE 61616) of ischemic stroke rats was performed as a pilot research. Oxidative stress was enriched as a significantly gene ontology item, and thioredoxin-interacting protein (TXNIP) and MAPK signaling were identified as the hub gene and pathway, respectively. The experiments in middle cerebral artery occlusion rats demonstrated that ischemia induced the activation of oxidative stress. The expressions of TXNIP, p-p38, p-JNK, p-ERK were significantly increased while Nrf2 and HO-1 expressions were decreased after stroke. Rescue assays were conducted in primary cultured neurons to explore the accurate interrelations among these factors. The results indicated that MAPK specific inhibitor and siRNA-TXNIP significantly alleviated the oxidative stress injury induced by oxygen-glucose deprivation. In addition, knocking down of TXNIP inhibited the activation of MAPK pathway and promoted Nrf2 pathway. Taken together, these findings indicated that TXNIP aggravated the oxidative stress injury by regulating MAPK-Nrf2 axis in ischemic stroke. Silencing of TXNIP seems a promising therapeutic strategy to alleviate ischemic stroke.

Association of Serum Markers of Oxidative Stress With Incident Major Cardiovascular Events, Cancer Incidence, and All-Cause Mortality in Type 2 Diabetes Patients: Pooled Results From Two Cohort Studies

OBJECTIVE

Oxidative stress plays an important role in the pathophysiology of type 2 diabetes mellitus (T2DM). However, associations of biomarkers of oxidative stress with diabetes complications have not yet been addressed in large cohort studies.

RESEARCH DESIGN AND METHODS

Derivatives of reactive oxygen metabolites (d-ROMs) levels, a proxy for the reactive oxygen species burden, and total thiol levels (TTLs), a proxy for the reductive capacity, were measured in 2,125 patients with T2DM from two German cohort studies of almost equal size at baseline and 3-4 years later. Multivariable adjusted Cox proportional hazards models with time-dependent modeled d-ROMs levels and TTLs were used to assess the associations with incident major cardiovascular events (MCE), cancer incidence, and all-cause mortality.

RESULTS

In total, 205, 179, and 394 MCE, cancer, and all-cause mortality cases were observed during 6-7 years of follow-up, respectively. Both oxidative stress biomarkers and the d-ROMs-to-TTL ratio were statistically significantly associated with all-cause mortality in both cohorts, and the pooled hazard ratios (HRs) and 95% CIs for top versus bottom tertiles were 2.10 (95% CI 1.43, 3.09) for d-ROMs levels, 0.59 (0.40, 0.87) for TTLs, and 2.50 (1.86, 3.36) for d-ROMs-to-TTL ratio. The d-ROMs-to-TTL ratio was also statistically significantly associated with incident MCE for top versus bottom tertile (1.65 [1.07, 2.54]), but this association did not persist after additional adjustment for chronic diseases. No associations with cancer were detected.

CONCLUSIONS

The observed strong associations of both biomarkers with mortality suggest an important contribution of an imbalanced redox system to the premature mortality of patients with diabetes.