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

Effects of switching from dipeptidyl peptidase 4 inhibitors to oral semaglutide on oxidative stress and glycemic variability in patients with type 2 diabetes: an open-label, prospective, randomized, multicenter, parallel-group comparison study

BACKGROUND

To compare the effects of switching from dipeptidyl peptidase 4 (DPP-4) inhibitors to oral semaglutide on oxidative stress and glucose variability assessed by continuous glucose monitoring in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was an open-label, prospective, randomized, multicenter, parallel-group comparison study conducted over 24 weeks. Patients with T2DM who had been taking regular doses of DPP-4 inhibitors for at least 12 weeks were enrolled. They were randomly assigned to either continue on DPP-4 inhibitors (DPP-4 inhibitor group) or switch to oral semaglutide at 3 mg/day, with a dose increase to 7 mg/day after 4 weeks (semaglutide group). The primary endpoint was the change in the diacron-reactive oxygen metabolites test, an oxidative stress marker. Secondary endpoints included changes in glucose variability assessed using continuous glucose monitoring, metabolic indices, physical assessments, and Diabetes Treatment Satisfaction Questionnaire scores.

RESULTS

Fifty-eight patients with T2DM were randomized to the semaglutide group (n = 30) and the DPP-4 inhibitor group (n = 28). Six patients in the semaglutide group and one patient in the DPP-4 inhibitor group dropped out during the study. Ultimately, data from 24 patients in the semaglutide group and 27 patients in the DPP-4 inhibitor group were included for analysis. Switching to oral semaglutide therapy for 24 weeks significantly reduced oxidative stress, glucose variability, and hemoglobin A1c levels compared to continuous treatment with DPP-4 inhibitors. However, there was no significant difference in Diabetes Treatment Satisfaction Questionnaire scores between the two groups.

(II) CONCLUSIONS

Our study demonstrated that switching to oral semaglutide therapy from DPP-4 inhibitors significantly improved oxidative stress and glycemic parameters, including glucose variability, in patients with T2DM.

TRIAL REGISTRATION

jRCT1031210620.

Improving 10-year cardiovascular risk prediction in patients with type 2 diabetes with metabolomics

BACKGROUND

Existing cardiovascular risk prediction models still have room for improvement in patients with type 2 diabetes who represent a high-risk population. This study evaluated whether adding metabolomic biomarkers could enhance the 10-year prediction of major adverse cardiovascular events (MACE) in these patients.

METHODS

Data from 10,257 to 1,039 patients with type 2 diabetes from the UK Biobank (UKB) and the German ESTHER cohort, respectively, were used for model derivation, internal and external validation. A total of 249 metabolites were measured with nuclear magnetic resonance (NMR) spectroscopy. Sex-specific LASSO regression with bootstrapping identified significant metabolites. The enhanced model's predictive performance was evaluated using Harrell's C-index.

RESULTS

Seven metabolomic biomarkers were selected by LASSO regression for enhanced MACE risk prediction (three for both sexes, three male- and one female-specific metabolite(s)). Especially albumin and the omega-3-fatty-acids-to-total-fatty-acids-percentage among males and lactate among females improved the C-index. In internal validation with 30% of the UKB, adding the selected metabolites to the SCORE2-Diabetes model increased the C-index statistically significantly (P = 0.037) from 0.660 to 0.678 in the total sample. In external validation with ESTHER, the C-index increase was higher (+ 0.043) and remained statistically significant (P = 0.011).

CONCLUSIONS

Incorporating seven metabolomic biomarkers in the SCORE2-Diabetes model enhanced its ability to predict MACE in patients with type 2 diabetes. Given the latest cost reduction and standardization efforts, NMR metabolomics has the potential for translation into the clinical routine.

Novel type 2 diabetes prediction score based on traditional risk factors and circulating metabolites: model derivation and validation in two large cohort studies

Background

We aimed to evaluate the incremental predictive value of metabolomic biomarkers for assessing the 10-year risk of type 2 diabetes when added to the clinical Cambridge Diabetes Risk Score (CDRS).

Methods

We utilized 86,232 UK Biobank (UKB) participants (recruited between 13 March 2006 and 1 October 2010) for model derivation and internal validation. Additionally, we included 4383 participants from the German ESTHER cohort (recruited between 1 July 2000 and 30 June 2002 for external validation). Participants were followed up for 10 years to assess the incidence of type 2 diabetes. A total of 249 NMR-derived metabolites were quantified using nuclear magnetic resonance (NMR) spectroscopy. Metabolites were selected with LASSO regression and model performance was evaluated with Harrell's C-index.

Findings

11 metabolomic biomarkers, including glycolysis related metabolites, ketone bodies, amino acids, and lipids, were selected. In internal validation within the UKB, adding these metabolites significantly increased the C-index (95% confidence interval (95% CI)) of the clinical CDRS from 0.815 (0.800, 0.829) to 0.834 (0.820, 0.847) and the continuous net reclassification index (NRI) with 95% CI was 39.8% (34.6%, 45.0%). External validation in the ESTHER cohort showed a comparable statistically significant C-index increase from 0.770 (0.750, 0.791) to 0.798 (0.779, 0.817) and a continuous NRI of 33.8% (26.4%, 41.2%). A concise model with 4 instead of 11 metabolites yielded similar results.

Interpretation

Adding 11 metabolites to the clinical CDRS led to a novel type 2 diabetes prediction model, we called UK Biobank Diabetes Risk Score (UKB-DRS), substantially outperformed the clinical CDRS. The concise version with 4 metabolites performed comparably. As only very few clinical information and a blood sample are needed for the UKB-DRS, and as high-throughput NMR metabolomics are becoming increasingly available at low costs, these models have considerable potential for routine clinical application in diabetes risk assessment.

Funding

The ESTHER study was funded by grants from the Baden-Württemberg state Ministry of Science, Research and Arts (Stuttgart, Germany), the Federal Ministry of Education and Research (Berlin, Germany), the Federal Ministry of Family Affairs, Senior Citizens, Women and Youth (Berlin, Germany), and the Saarland State Ministry of Health, Social Affairs, Women and the Family (Saarbrücken, Germany). The UK Biobank project was established through collaboration between various entities including the Wellcome Trust, the Medical Research Council, Department of Health, Scottish Government, and the Northwest Regional Development Agency. Additional funding was provided by the Welsh Assembly Government, British Heart Foundation, Cancer Research UK, and Diabetes UK, with support from the National Health Service (NHS). The German Diabetes Center is funded by the German Federal Ministry of Health (Berlin, Germany) and the Ministry of Culture and Science of the state North Rhine-Westphalia (Düsseldorf, Germany) and receives additional funding from the German Federal Ministry of Education and Research (BMBF) through the German Center for Diabetes Research (DZD e.V.).

New insights of DsbA-L in the pathogenesis of metabolic diseases

Metabolic diseases, such as obesity, diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD), are abnormal conditions that result from disturbances of metabolism. With the improvement of living conditions, the morbidity and mortality rates of metabolic diseases are steadily rising, posing a significant threat to human health worldwide. Therefore, identifying novel effective targets for metabolic diseases is crucial. Accumulating evidence has indicated that disulfide bond A oxidoreductase-like protein (DsbA-L) delays the development of metabolic diseases. However, the underlying mechanisms of DsbA-L in metabolic diseases remain unclear. In this review, we will discuss the roles of DsbA-L in the pathogenesis of metabolic diseases, including obesity, diabetes mellitus, and NAFLD, and highlight the potential mechanisms. These findings suggest that DsbA-L might provide a novel therapeutic strategy for metabolic diseases.

Efficacy of Oral Nanoparticle-Encapsulated Insulin in Reducing Oxidative Stress and Enhancing Tissue Integrity in a Diabetic Rat Model

Introduction

Diabetes mellitus, a chronic metabolic disorder, leads to systemic organ damage characterized by oxidative stress and structural alterations, contributing to increased morbidity and mortality. Traditional subcutaneous insulin therapy, while managing hyperglycemia, often falls short in addressing the oxidative damage and preventing organ-specific complications. This study evaluates the therapeutic efficacy of a novel oral nanoparticle-mediated insulin (nCOF/Insulin) against these diabetes-induced changes, comparing it with traditional subcutaneous insulin in a streptozotocin (STZ)-induced diabetic rat model.

Methods

We induced diabetes in Wistar rats, dividing them into four groups: standard control, diabetic control, diabetic treated with subcutaneous insulin, and diabetic treated with oral nanoparticle-mediated insulin (nCOF/Insulin). Assessments included organ and body weights, histopathological examinations, and oxidative stress markers (MDA and PCOs) across various organs, including the brain, muscle, intestine, spleen, heart, liver, kidney, and adrenal glands. Additionally, we evaluated antioxidant parameters (GSH and catalase) and conducted immunohistochemical analysis of E-cadherin to assess intestinal integrity.

Results

Our findings reveal that STZ-induced diabetes significantly impacts organ health, with subcutaneous insulin providing limited mitigation and, in some cases, exacerbating oxidative stress. Conversely, oral nCOF/Insulin treatment effectively restored organ and body weights, reduced oxidative stress markers, and mitigated histological damage. This suggests that oral nCOF/Insulin not only offers superior glycemic control but also addresses the underlying oxidative stress.

Conclusion

nCOF/Insulin emerges as a promising treatment for diabetes, with the potential to improve patient quality of life by ameliorating oxidative stress and preventing organ-specific complications. This study underscores the need for further investigation into the long-term effects and mechanisms of action of oral nCOF/Insulin, aiming to revolutionize diabetes management and treatment strategies.

Association between the oxidative balance score and all-cause and cardiovascular mortality in patients with diabetes and prediabetes

BACKGROUND

Few studies have examined the link between systemic oxidative stress and mortality risk in diabetes and prediabetes patients. The Oxidative Balance Score (OBS) is a novel measure of systemic oxidative stress, with higher scores indicating greater antioxidant exposure. This study investigates the relationship between OBS and all-cause and cardiovascular mortality in these patients.

METHODS

This study analyzed 10,591 diabetes and prediabetes patients from the 1999-2018 National Health and Nutrition Examination Survey (NHANES). The endpoints were all-cause and cardiovascular mortality, determined from the National Death Index (NDI). OBS was calculated using 20 dietary and lifestyle factors. Kaplan-Meier survival analysis, multivariable Cox regression models, restricted cubic splines (RCS), and subgroup analyses were used to assess the relationship between OBS and mortality risks.

RESULTS

Over an average follow-up of 99.8 months, 2900 (26.4 %) participants died, including 765 (8.9 %) from cardiovascular diseases. Kaplan-Meier analysis showed the lowest all-cause and cardiovascular mortality in the highest OBS quartile (Q4) and the highest mortality in the lowest quartile (Q1) (p < 0.001). In the fully adjusted model, multivariable Cox regression revealed that each unit increase in OBS was linked to a 1.8 % decrease in all-cause mortality risk (HR 0.982, 95 % CI 0.976-0.987, p < 0.0001) and a 4 % decrease in cardiovascular mortality risk (HR 0.960, 95 % CI 0.949-0.970, p < 0.0001). Compared to Q1, those in Q4 had significantly lower all-cause mortality (HR 0.719, 95 % CI 0.643-0.804, p < 0.0001, p for trend <0.0001) and cardiovascular mortality (HR 0.567, 95 % CI 0.455-0.705, p < 0.0001, p for trend <0.0001). These findings were consistent across subgroups. RCS curves showed a negative correlation between OBS and both mortality types.

CONCLUSION

Higher OBS is linked to reduced all-cause and cardiovascular mortality in diabetes and prediabetes patients.

Serum lipid peroxidation potential as a biomarker for risk-stratification of coronary artery disease in patients with type 2 diabetes mellitus

AIM

We examined the serum lipid peroxidation potential as an estimate of systemic oxidative stress levels in people with type 2 diabetes (T2D) for coronary artery disease (CAD) risk stratification.

METHODS

We prospectively recruited patients and categorized them into four subgroups based on diabetes and severity of CAD [Gensini score <20, non-significant CAD; Gensini score >20, significant CAD]: non-diabetics with non-significant CAD, diabetics with non-significant CAD, non-diabetics with significant CAD and diabetics with significant CAD. Lipid profile, HbA1c, fasting blood glucose, and oxidized LDL were assessed. A newly developed assay estimated serum lipid peroxidation potential.

RESULTS

Circulatory oxidized LDL levels were significantly higher in patients with severe CAD compared to non-diabetics with non-significant CAD, however no significant differences were observed across the four subgroups. Diabetics with non-significant CAD demonstrated significantly elevated serum lipid peroxidation potential compared to non-diabetics with non-significant CAD. Intriguingly, serum lipid peroxidation potential was markedly elevated in diabetics with non-significant CAD compared to both diabetics and non-diabetics with significant CAD. Poor glycemic control and reduced blood total antioxidant capacity were the primary factors contributing to increased serum lipid peroxidation potential in diabetics with non-significant CAD group.

CONCLUSIONS

We found that people with T2D who are associated with non-significant CAD are more vulnerable to oxidative stress than those with significant CAD. The study demonstrates the application of 'serum lipid peroxidation potential' assay for risk-stratification of CAD in people with T2D.

The Impact of Flavonoid Supplementation on Serum Oxidative Stress Levels Measured via D-ROMs Test in the General Population: The PREVES-FLAVON Retrospective Observational Study

BACKGROUND

Oxidative stress has emerged as a key contributor to numerous NCDs (non-communicable diseases), including cardiovascular diseases, cancer, and diabetes. This study aims to explore the potential of targeted interventions to mitigate oxidative stress as part of a primary prevention strategy.

METHODS

The study included 32 healthy participants (11 men, 21 women) aged 45-65 who completed both the initial and follow-up assessments of the Healthy Days Initiative, a community-based wellness program organized by the non-profit Associazione O.R.A. ETS. Through blood analysis, vital sign assessment, lifestyle questionnaires, and individualized recommendations, participants received guidance on improving their health and reducing disease risk. The initiative also offered the opportunity for participants to consume a flavonoid supplement containing quercitrin, rutin, and hesperidin, with the goal of reducing oxidative stress. Participants who opted for supplementation were instructed to take 1-2 tablets daily for two weeks. Data collected included demographic information, anthropometric measurements, vital signs, dietary and lifestyle habits, medical history, WHO-5 Well-Being Index scores, and blood parameters.

RESULTS

Significant reductions were observed in glucose levels (from 82 to 74.5 mg/dL), reactive oxygen metabolites (d-ROMs) (from 394.5 to 365.5 U.CARR), and systolic blood pressure (from 133 to 122 mmHg) after the two-week flavonoid intervention. Most participants (26/31) reported no side effects, and the majority (30/31) expressed a willingness to continue using a product combination of quercitrin, rutin, and hesperidin or a similar product long-term.

CONCLUSIONS

While limited in scope and duration, the PREVES-FLAVON study contributes valuable insights to the growing body of evidence suggesting that flavonoid supplementation may play a significant role in reducing risk factors associated with NCDs in primary prevention settings. By targeting novel risk factors such as oxidative stress, this intervention holds promise for mitigating the global burden of NCDs and promoting healthy aging.

Magainin-AM2 inhibits sucrose-induced hyperglycaemia, oxidative stress, and cognitive dysfunction in Drosophila melanogaster

Hyperglycaemia-induced oxidative stress plays significant roles in the development of type 2 diabetes and its complications. This study investigates effects of magainin-AM2 on high-sucrose diet induced redox imbalance and cognitive impairment in Drosophila melanogaster. Effects of various concentrations of sucrose, magainin-AM2 or a combination of both agents on mortality, eclosion rate, generation of reactive oxygen and nitrogen species, activities of antioxidant enzymes, thiol system, and markers of cognitive functions in control and treated flies were examined. Results showed that the exposure of flies to high sucrose (30 %-60 % w/w) diet increased mortality rate (38-67 %, P < 0.001) and levels of glucose (1.8-1.9-fold, P < 0.001), hydrogen peroxide (1.4-1.5-fold, P < 0.01) and nitrite/nitrate (1.2-fold, P < 0.01). Decreased levels of total thiol (53-59 %, P < 0.01), non-protein thiols (59-63 %, P < 0.01), catalase activities (39-47 %, P < 0.01-0.05) and glutathione-s-transferase activities (31-43 %, P < 0.01-0.05) were also observed. Magainin-AM2 (0-10 μM/kg diet) did not affect fly mortality rate, levels of hydrogen peroxide and nitrite/nitrate, and activities of catalase and glutathione-s-transferase. However, the peptide produced a dose-dependent increase in total thiol 1.2-1.6-fold, P < 0.001-0.01)and increases non-protein thiol levels at 10 μM/kg diet (2.0-fold, P < 0.01). Magainin-AM2 inhibited sucrose-induced elevation of glucose (55-70 %, P < 0.001), hydrogen peroxide (11-12 %, P < 0.01) and nitrite/nitrate (20-34 %, P < 0.01-0.05). The peptide prevented sucrose-induced reduction in total and non-protein thiols (1.9-2.0-fold, P < 0.05) levels and activities of catalase (2.3-3.1-fold, P < 0.001) and glutathione-s-transferase (1.8-2.8-fold, P < 0.001-0.05). Magainin-AM2 inhibited sucrose-induced reduction in acetylcholinesterase activities (3.6-4.0-fold, P < 0.001), eclosion rate (18 %, P < 0.001) and negative geotaxis (1.3-14-fold, P < 0.001). These results indicate that beneficial actions of magainin-AM2 may also involve the prevention of hyperglycaemia-induced oxidative damage and encourage its further development as an anti-diabetic agent.

Risk factors for pre-clinical atherosclerosis in adolescents with type 1 diabetes

AIMS

To assess whether, besides "traditional" risk factors, overall oxidative stress, oxidized lipoproteins, and glycemic variability are associated with early macro-vascular damage in type 1 diabetes (T1D).

METHODS

In 267 children/adolescents with T1D (130 girls, age 9.1-23.0 years) we evaluated: derivatives of reactive oxygen metabolites [d-ROMs], serum total antioxidant capacity [TAC] and oxidized LDL-cholesterol [oxLDL]; markers of early vascular damage (Lipoprotein-associated phospholipase A2 [Lp-PLA2], z-score of carotid intima-media thickness [z-cIMT] and carotid-femoral pulse wave velocity [z-PWV]); CGM metrics of four weeks preceding the visit, central systolic/diastolic blood pressures (cSBP/cDBP), and HbA1c, z-score of BP (z-SBP/z-DBP) and circulating lipids longitudinally collected since T1D onset.. Three general linear models were built with z-cIMT, z-PWV adjusted for current cDBP, and Lp-PLA2 as independent variables.

RESULTS

The z-cIMT was associated with male gender (B = 0.491, η² = 0.029, p = 0.005), cSBP (B = 0.023, η² = 0.026, p = 0.008) and oxLDL (B = 0.022, η² = 0.022, p = 0.014). The z-PWV was associated with diabetes duration (B = 0.054, η² = 0.024, p = 0.016), daily insulin dose (B = 0.52, η² = 0.018, p = 0.045), longitudinal z-SBP (B = 0.18, η² = 0.018, p = 0.045) and dROMs (B = 0.003, η² = 0.037, p = 0.004). Lp-PLA2 was associated with age (B = 0.221, η² = 0.079, p = 3*10^-6), oxLDL (B = 0.081, η² = 0.050, p = 2*10^-4), longitudinal LDL-cholesterol (B = 0.031, η² = 0.043, p = 0.001) and male gender (B = -1.62, η² = 0.10, p = 1.3*10⁷).

CONCLUSIONS

Oxidative stress, male gender, insulin dose, diabetes duration and longitudinal lipids and blood pressure, contributed to the variance of early vascular damage in young patients with T1D.

Lifestyle-based oxidative balance score and its association with cardiometabolic health of the community-dwelling elderly: A cross-sectional secondary analysis

Background

Cardiometabolic diseases, the main disease burden in older adults, are largely caused by oxidative stress resulting from lifestyle factors. This study investigated the relationship between lifestyle-based oxidative balance scores and cardiometabolic health among the community-dwelling elderly.

Methods

This work conducted a secondary analysis of previous cross-sectional research data and constructed a lifestyle-based oxidative balance score (LOBS) including 4 components (higher scores were considered more antioxidant). Linear regression models and logistic regression models were used to evaluate the associations with cardiometabolic biomarkers and the number of cardiometabolic risk factors. Besides, we investigated whether these associations differed by covariates.

Results

A total of 710 individuals (60.99% female, median age 70.0 years) were recruited. The inverse associations of LOBS with SBP and TG and the positive association with HDLC were statistically significant in both linear and logistic regression models. In contrast, an inverse association of LOBS with DBP was significant only in the linear regression model (all P < 0.05). The associations of LOBS with TG and HDLC were not affected by age, gender, or socioeconomic level. A significant inverse association was observed between LOBS and the number of cardiometabolic risk factors. Compared with the lowest LOBS, the ORs for more cardiometabolic risk factors in the second and third intervals were 0.577 (0.422, 0.788) and 0.460 (0.301, 0.703) (both P < 0.001).

Conclusion

In summary, this study shows that antioxidant-predominant lifestyle exposure yields a better cardiometabolic health status. We recommend that general practitioners should offer comprehensive healthy lifestyle management to community-dwelling elderly.

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.

Interleukins and redox impairment in type 2 diabetes mellitus: mini-review and pilot study

BACKGROUND

Type 2 diabetes mellitus (T2DM) represents a leading cause of morbidity and premature mortality, low-grade inflammation being acknowledged as a key contributor to its development and progression. A tailored therapeutic approach, based on sensitive and specific biomarkers, could allow a more accurate analysis of disease susceptibility/prognostic and of the response to treatment.

OBJECTIVES

This mini-review and pilot study had two main goals: (1) reviewing the most recent literature encompassing the use of interleukins as inflammatory markers influenced by the redox imbalances in T2DM and (2) assessing parameters that conjunctly evaluate the redox impairment and inflammatory burden of T2DM patients, taking into consideration smoking status, as such group-specific biomarkers are scarcely reported in literature.

METHODS

Firstly, PubMed database was surveyed to select and review the relevant studies employing interleukins as T2DM biomarkers and to assess if studies using combined inflammatory-redox indices were reported. Then, routine biochemical parameters were assessed in a pilot study -T2DM patients with 3 subgroups: non-smokers, smokers and ex-smokers, were compared to a control group of non-diabetic, apparently healthy non-smokers. Protein (AOPPs, AGEs), lipid/HDL (Amplex Red-based method) oxidative damage and inflammatory status (CRP, IL-1β, IL-6, IL-10) biomarkers were assessed. Cytokine ratios and 2 oxidative-inflammatory status indices were developed (IH1 and IH2) and evaluated.

RESULTS

We observed significant differences in terms of serum redox and inflammatory status (AOPPs, AGEs, CRP, CRP/HDL, CRP/IL-6, IL-10/IL-6, IH1) between T2DM patients compared to control and, moreover, between the subgroups formed considering smoking status (CRP, CRP/HDL, IH1). Glycemic control strongly influenced inflammatory status biomarkers: glycemia was positively correlated with the inflammatory parameters (CRP/IL-10) and inversely with the anti-inflammatory ones (IL-10, IL-10/IL-1β ratio).

CONCLUSIONS

Several of the assessed parameters may possess prognostic value for diabetics, especially when comparing subgroups with a different smoking history and could prove useful in clinical practice for assessing disease progress and therapeutic efficacy.

Do low molecular weight antioxidants contribute to the Protection against oxidative damage? The interrelation between oxidative stress and low molecular weight antioxidants based on data from the MARK-AGE study

A redox steady state is important in maintaining vital cellular functions and is therefore homeostatically controlled by a number of antioxidative agents, the most important of which are enzymes. Oxidative Stress (OS) is associated with (or/and caused by) excessive production of damaging reactive oxygen and/or nitrogen species (ROS, RNS), which play a role in many pathologies. Because OS is a risk factor for many diseases, much effort (and money) is devoted to early diagnosis and treatment of OS. The desired benefit of the "identify (OS) and treat (by low molecular weight antioxidants, LMWA)" approach is to enable selective treatment of patients under OS. The present work aims at gaining understanding of the benefit of the antioxidants based on interrelationship between the concentration of different OS biomarkers and LMWA. Both the concentrations of a variety of biomarkers and of LMWA were previously determined and some analyses have been published by the MARK-AGE team. For the sake of simplicity, we assume that the concentration of an OS biomarker is a linear function of the concentration of a LMWA (if the association is due to causal relationship). A negative slope of this dependence (and sign of the correlation coefficient) can be intuitively expected for an antioxidant, a positive slope indicates that the LMWA is pro-oxidative, whereas extrapolation of the OS biomarker to [LMWA] = 0 is an approximation of the concentration of the OS biomarker in the absence of the LMWA. Using this strategy, we studied the effects of 12 LMWA (including tocopherols, carotenoids and ascorbic acid) on the OS status, as observed with 8 biomarkers of oxidative damage (including malondialdehyde, protein carbonyls, 3-nitrotyrosine). The results of this communication show that in a cross-sectional study the LMWA contribute little to the redox state and that different "antioxidants" are very different, so that single LMWA treatment of OS is not scientifically justified assuming our simple model. In view of the difficulty of quantitating the OS and the very different effects of various LMWA, the use of the "identify and treat" approach is questionable.

Development and Validation of Risk Prediction Model for New-Onset Diabetes After Percutaneous Coronary Intervention (NODAP): A Study Protocol for a Retrospective, Multicenter Analysis

Background: Type 2 Diabetes mellitus (T2DM) is a major risk factor for cardiovascular diseases and increase mortality. Clinical outcomes of patients after percutaneous coronary intervention (PCI) were worse in T2DM patients than those without T2DM. New-onset diabetes after PCI (NODAP) is often observed during long-term follow-up and this further aggravates cardiovascular diseases. Several studies had focused on patients after PCI with known T2DM. Previous studies showed that impaired glucose tolerance and aging are risk factors that promote NODAP. Considering the unique characteristics of patients after PCI, we will further study relevant risk factors. We sought to investigate the potential predictors of acute coronary syndrome patients with NODAP by a multicenter retrospective cohort study.

Methods: This is a multicenter retrospective cohort study including patients after PCI. Clinical medical records of these patients were collected from four hospitals in different areas in China, from 2010 to 2021. Patients' demographic information, medical history, diagnostic testing, PCI-related information, medication situation will be summarized using descriptive statistics, and correlation analysis was performed on the development of new-onset diabetes. Variation will be described and evaluated using χ² test or Kreskas-Wallis test. The prediction model will be verified by a validation set.

Discussion: A novel diabetes prediction model for patients after PCI is established, and this study can achieve advanced intervention for the occurrence of NODAP. Owing to its retrospective nature, this study has some limitations, but it will be further studied through supplement data collection or prospective study. The study has been registered for clinical trials by the Chinese Clinical Trial Registry (ChiCTR2100047241).

Malondialdehyde-modified HDL particles elicit a specific IgG response in abdominal aortic aneurysm

High Density Lipoprotein (HDL) plays a protective role in abdominal aortic aneurysm (AAA); however, recent findings suggest that oxidative modifications could lead to dysfunctional HDL in AAA. This study aimed at testing the effect of oxidized HDL on aortic lesions and humoral immune responses in a mouse model of AAA induced by elastase, and evaluating whether antibodies against modified HDL can be found in AAA patients. HDL particles were oxidized with malondialdehyde (HDL-MDA) and the changes were studied by biochemical and proteomics approaches. Experimental AAA was induced in mice by elastase perfusion and then mice were treated with HDL-MDA, HDL or vehicle for 14 days. Aortic lesions were studied by histomorphometric analysis. Levels of anti-HDL-MDA IgG antibodies were measured by an in-house immunoassay in the mouse model, in human tissue-supernatants and in plasma samples from the VIVA cohort. HDL oxidation with MDA was confirmed by enhanced susceptibility to diene formation. Proteomics demonstrated the presence of MDA adducts on Lysine residues of HDL proteins, mainly ApoA-I. MDA-modification of HDL abrogated the protective effect of HDL on cultured endothelial cells as well as on AAA dilation in mice. Exposure to HDL-MDA elicited an anti-HDL-MDA IgG response in mice. Anti-HDL-MDA were also detected in tissue-conditioned media from AAA patients, mainly in intraluminal thrombus. Higher plasma levels of anti-HDL-MDA IgG antibodies were found in AAA patients compared to controls. Anti-HDL-MDA levels were associated with smoking and were independent predictors of overall mortality in AAA patients. Overall, MDA-oxidized HDL trigger a specific humoral immune response in mice. Besides, antibodies against HDL-MDA can be detected in tissue and plasma of AAA patients, suggesting its potential use as surrogate stable biomarkers of oxidative stress in AAA.

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.

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.

Relationship of Physical Activity at Older Age with Biomarkers of Oxidative Stress: A Large, Population-based Cohort Study

BACKGROUND

No population-based cohort study on the associations of physical activity with biomarkers of oxidative stress has been performed so far.

METHODS

The total thiol groups of serum proteins (TTP), which can be considered as a proxy biomarker for the antioxidant defense capacity of cells and the derivatives of reactive oxygen metabolites (D-ROM) serum concentration, which is mainly a biomarker of lipid peroxidation, were measured in 2,572 participants of a population-based cohort study of older adults (age range: 57-83 years) of whom 2,068 had repeated measurements 3 years later. Physical activity was assessed by a questionnaire specifically designed for the elderly.

RESULTS

In multivariable linear regression models, total physical activity was statistically significantly, inversely associated with both D-ROM concentrations measured at baseline and with their 3-year-change. With respect to TTP, a non-significant, positive association with total physical activity was observed in the cross-sectional analysis, which was statistically significant in obese study participants and a statistically significant interaction between physical activity and obesity was detected. However, no longitudinal association between total physical activity and changes in TTP levels was observed. The type of physical activity (sports, leisure time, or household activity) did not have a strong impact on the results.

CONCLUSION

This first population-based cohort study suggests that regular physical activity at older age could reduce oxidative stress. With the multifold potential adverse health consequences of chronically increased, systemic oxidative stress in mind, physical activity should be intensively promoted for all older adults as a measure to prevent age-related diseases.

Can Blood-Circulating Factors Unveil and Delay Your Biological Aging?

According to the World Health Organization, the population of over 60 will double in the next 30 years in the developed countries, which will enforce a further raise of the retirement age and increase the burden on the healthcare system. Therefore, there is an acute issue of maintaining health and prolonging active working longevity, as well as implementation of early monitoring and prevention of premature aging and age-related disorders to avoid early disability. Traditional indicators of biological age are not always informative and often require extensive and expensive analysis. The study of blood factors is a simple and easily accessible way to assess individual health and supplement the traditional indicators of a person's biological age with new objective criteria. With age, the processes of growth and development, tissue regeneration and repair decline; they are gradually replaced by enhanced catabolism, inflammatory cell activity, and insulin resistance. The number of senescent cells supporting the inflammatory loop rises; cellular clearance by autophagy and mitophagy slows down, resulting in mitochondrial and cellular damage and dysfunction. Monitoring of circulated blood factors not only reflects these processes, but also allows suggesting medical intervention to prevent or decelerate the development of age-related diseases. We review the age-related blood factors discussed in recent publications, as well as approaches to slowing aging for healthy and active longevity.

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.

Vitamin D Status, Fiber Intake, and Type 2 Diabetes in U.S. Adults

Vitamin D and fiber intake are nutritional factors that could affect the development of type 2 diabetes (T2D), potentially by reducing insulin resistance. Therefore, we hypothesized that the influence of vitamin D on T2D might depend on fiber intake. This study investigated the association between vitamin D status and T2D according to fiber intake. The present study analyzed data from 9,656 American adults (≥20 years old) who participated in the National Health and Nutrition Examination Survey (NHANES) 2007-2010. The serum concentration of 25-hydroxyvitamin D [25(OH)D] was used as a biomarker for vitamin D status. The T2D classification was based on two criteria: T2D^a was identified using only self-reported questionnaire data and T2D^b was identified based on both survey and laboratory data. The deficient vitamin D status (<50 nmol/L) was used as the reference group. After controlling for sociodemographic, behavioral, and dietary factors, the odds ratios (ORs) were 0.72 (95% confidence interval [CI]: 0.58, 0.90) for T2D^a and 0.60 (0.50, 0.80) for T2D^b in the sufficient vitamin D status (≥75 nmol/L). Furthermore, the total vitamin D concentration exhibited dose-dependent associations with lower OR values for T2D^a (P for trend = .005) and T2D^b (P for trend <.001). Among participants with high-fiber intake, the OR values for T2D^b were 0.60 (95% CI: 0.42, 0.90) at suboptimal vitamin D status and 0.49 (95% CI: 0.31, 0.77) at sufficient vitamin D status. Moreover, the significant dose-dependent association persisted in the high-fiber-intake subgroup (P for trend = .004). Therefore, combining vitamin D plus high-fiber intake would help reduce the prevalence of diabetes, although the interaction analysis results were not statistically significant.

Blood markers of oxidative stress are strongly associated with poorer prognosis in colorectal cancer patients

Oxidative stress has been implicated in the initiation of several cancers, including colorectal cancer (CRC). Whether it also plays a role in CRC prognosis is unclear. We assessed the associations of two oxidative stress biomarkers (Diacron's reactive oxygen metabolites [d-ROMs] and total thiol level [TTL]) with CRC prognosis. CRC patients who were diagnosed in 2003 to 2012 and recruited into a population-based study in Germany (n = 3361) were followed for up to 6 years. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the associations of d-ROMs and TTL (measured from blood samples collected shortly after CRC diagnosis) with overall survival (OS) and disease-specific survival (DSS) were estimated using multivariable Cox regression. Particularly pronounced associations of higher d-ROMs with lower survival were observed in stage IV patients, with patients in the highest (vs lowest) tertile having much lower OS (HR = 1.52, 95% CI = 1.14-2.04) and DSS (HR = 1.61, 95% CI = 1.20-2.17). For TTL, strong inverse associations of TTL with mortality were observed within all stages. In patients of all stages, those in the highest (vs lowest) quintile had substantially higher OS (HR = 0.48, 95% CI = 0.38-0.62) and DSS (HR = 0.52, 95% CI = 0.39-0.69). The addition of these biomarkers to models that included age, sex, tumor stage and subsite significantly improved the prediction of CRC prognosis. The observed strong associations of higher d-ROMs and lower TTL levels with poorer prognosis even in stage IV patients suggest that oxidative stress contributes significantly to premature mortality in CRC patients and demonstrate a large potential of these biomarkers in enhancing the prediction of CRC prognosis beyond tumor stage.

Association of Hemoglobin A1c, 1,5-Anhydro-D-Glucitol and Glycated Albumin with Oxidative Stress in Type 2 Diabetes Mellitus Patients: A Cross-Sectional Study

INTRODUCTION

Oxidative stress plays a central role in the development and progression of vascular complications in patients with type 2 diabetes mellitus (T2DM). We have previously shown that markers of glucose variability evaluated by continuous glucose monitoring (CGM) are positively associated with oxidative stress in patients with T2DM. However, the evaluation of the glycemic variability by CGM remains a time- and money-consuming procedure. Therefore, this study investigated the independent correlates of oxidative stress among various other clinical markers routinely measured in primary care.

METHODS

This was a retrospective cross-sectional study with 234 T2DM patients to examine which clinical variables, including 1,5-anhydro-D-glucitol (1,5-AG) and glycated albumin (GA), were independently associated with oxidative stress. Oxidative stress was measured using the diacron-reactive oxygen metabolites (d-ROMs) test. The relationships between d-ROMs and clinical factors, such as blood glucose, glycated hemoglobin (HbA1c), 1,5-AG, GA, lipid parameters, and blood pressure, were examined.

RESULTS

Multiple stepwise regression analysis revealed that 1,5-AG (inversely), GA, triglycerides, use of metformin and being female were independently associated with d-ROMs. When patients with T2DM were stratified into two groups with HbA1c < 8.0% and HbA1c ≥ 8.0%, 1,5-AG (inversely), HbA1c, use of metformin and being female were independently associated with d-ROMs in diabetes patients with HbA1c < 8.0%, whereas GA, fasting plasma glucose and being female were independently associated with d-ROMs in patients with HbA1c ≥ 8.0%.

CONCLUSION

Our present study suggests that 1,5-AG and GA are the strongest correlates of oxidative stress in patients with well and poorly controlled T2DM, respectively.

Mitochondrial 8-hydroxy-2'-deoxyguanosine and coronary artery disease in patients with type 2 diabetes mellitus

Background

Little is known about whether mitochondria 8-hydroxy-2′-deoxyguanosine (8-OHdG), a biomarker of mitochondrial DNA (mtDNA) oxidative damage, contributes to the development of coronary artery disease (CAD) in diabetic patients. Here, we explored the associations of mtDNA 8-OHdG in leukocytes with obstructive CAD, coronary stenosis severity, cardiovascular biomarkers, and 1-year adverse outcomes after coronary revascularization in patients with type 2 diabetes mellitus (T2DM).

Methods

In a total of 1920 consecutive patients with T2DM who underwent coronary angiography due to symptoms of angina or angina equivalents, the presence of obstructive CAD, the number of diseased vessels with ≥ 50% stenosis, and modified Gensini score were cross-sectionally evaluated; the level of mtDNA 8-OHdG was quantified by quantitative PCR. Then, 701 of 1920 diabetic patients who further received coronary revascularization completed 1-year prospective follow-up to document major adverse cardiovascular and cerebral events (MACCEs). In vitro experiments were also performed to observe the effects of mtDNA oxidative damage in high glucose-cultured human umbilical vein endothelial cells (HUVECs).

Results

Cross-sectionally, greater mtDNA 8-OHdG was associated with increased odds of obstructive CAD (odds ratio [OR] 1.38, 95% CI confidence interval 1.24–1.52), higher degree of coronary stenosis (number of diseased vessels: OR 1.29, 95% CI 1.19–1.41; modified Gensini scores: OR 1.28, 95% CI 1.18–1.39), and higher levels of C-reactive protein (β 0.18, 95% CI 0.06–0.31) after adjusting for confounders. Sensitivity analyses using propensity score matching yielded similar results. Stratification by smoking status showed that the association between mtDNA 8-OHdG and obstructive CAD was most evident in current smokers (P_interation < 0.01). Prospectively, the adjusted hazards ratio per 1-SD increase in mtDNA 8-OHdG was 1.59 (95% CI 1.33–1.90) for predicting 1-year MACCEs after revascularization. In HUVECs, exposure to antimycin A, an inducer for mtDNA oxidative damage, led to adverse alterations in markers of mitochondrial and endothelia function.

Conclusion

Greater mtDNA 8-OHdG in leukocytes may serve as an independent risk factor for CAD in patients with T2DM.

Factors associated with high oxidative stress in patients with type 2 diabetes: a meta-analysis of two cohort studies

OBJECTIVE

Our objective is to identify the potential factors associated with serum Diacron's reactive oxygen metabolites test (D-ROM) levels of patients with type 2 diabetes mellitus (T2DM) by conducting cross-sectional and longitudinal analyses in two large cohorts and further strengthening these results by performing a meta-analysis.

METHODS

Serum D-ROM concentrations were measured in 1045 and 1101 patients with T2DM from two independent cohort studies from Germany at baseline and repeatedly 3-4 years later. The cross-sectional and longitudinal associations of various potential determinants with D-ROM levels were assessed with a backwards selection algorithm in multivariable adjusted models.

RESULTS

In the meta-analysis of the cross-sectional analysis, female sex, low education, obesity, smoking, high total cholesterol, hemoglobin A_1c ≥7%, no diabetes medication, a history of myocardial infarction, heart failure, a history of cancer and C reactive protein levels (CRP) >3 mg/L were statistically significantly associated with increased D-ROM levels in patients with T2DM. The meta-analysis of the longitudinal analysis revealed that old age, female sex, obesity, smoking, physical inactivity, high alcohol consumption, ≥5 years since diabetes diagnosis and CRP levels between 3 mg/L and 10 mg/L were statistically significantly associated with D-ROM levels measured 3-4 years later.

CONCLUSIONS VALIDITY, LIMITATIONS AND CLINICAL APPLICABILITY

This comprehensive analysis confirmed that several modifiable risk factors are being associated with oxidative stress in patients with T2DM within an observational study design. We discuss potential prevention measures against these risk factors that might help to reduce oxidative stress and to prevent some cases of premature mortality in patients with T2DM.