Systemic oxidative stress associates with new-onset hypertension in the general population

Effect of lifestyle intervention on systemic oxidative stress in kidney transplant recipients: A post-hoc analysis of the Active Care after Transplantation (ACT) randomized controlled trial

BACKGROUND

Oxidative stress is associated with adverse outcomes in kidney transplant recipients (KTR), including graft failure, morbidity, and mortality. Since both exercise training and dietary modifications have the potential to improve redox status, we aimed to investigate the potential mitigating effects of exercise or exercise plus diet intervention on circulating levels of free thiols (R-SH) as marker of systemic redox status in KTR.

METHODS

We conducted a post-hoc analysis of the Active Care after Transplantation (ACT) study, a randomized controlled lifestyle intervention trial which proved to enhance physical functioning of KTR. Systemic R-SH levels were quantified at baseline, 3-months, and 15-months (end of study) using a colorimetric detection method. Estimated marginal means (EMM) were reported using general linear mixed models.

RESULTS

KTR were randomized to usual care (n = 40), exercise intervention (n = 54), or exercise plus diet intervention (n = 55). At 3 months post-baseline, systemic R-SH concentrations decreased significantly in the control group, while the intervention groups showed a less pronounced decrease, although the difference compared to control nearly reached statistical significance in either the exercise intervention group (EMM +20.2 μM (95%CI -1.4, +41.9), P = 0.067) or the exercise plus diet intervention group (EMM +18.9 μM (95%CI -2.7, +40.4), P = 0.086). At 15 months post-baseline, R-SH concentrations further decreased in the exercise intervention group, resulting in a difference compared to control of +9.0 μM (95%CI -14.4, +32.3; P = 0.45), whereas R-SH concentrations increased to above baseline in the exercise plus diet intervention group, with a statistically significant difference compared to control of +32.8 μM (95%CI +9.4, +56.2; P = 0.006).

CONCLUSIONS

Lifestyle changes involving exercise and diet positively impacted systemic R-SH, suggesting that reducing oxidative stress through lifestyle interventions could potentially contribute to clinical benefits in KTR.

SERCA2a dysfunction in the pathophysiology of heart failure with preserved ejection fraction: a direct role is yet to be established

With rising incidence, mortality and limited therapeutic options, heart failure with preserved ejection fraction (HFpEF) remains one of the most important topics in cardiovascular medicine today. Characterised by left ventricular diastolic dysfunction partially due to impaired Ca2+ homeostasis, one ion channel in particular, SarcoEndoplasmic Reticulum Ca2+-ATPase (SERCA2a), may play a significant role in its pathophysiology. A better understanding of the complex mechanisms interplaying to contribute to SERCA2a dysfunction will help develop treatments targeting it and thus address the growing clinical challenge HFpEF poses. This review examines the conflicting evidence present for changes in SERCA2a expression and activity in HFpEF, explores potential underlying mechanisms, and finally evaluates the drug and gene therapy trials targeting SERCA2a in heart failure. Recent positive results from trials involving widely used anti-diabetic agents such as sodium-glucose co-transporter protein 2 inhibitors (SGLT2i) and glucagon-like peptide-1 (GLP-1) agonists offer advancement in HFpEF management. The potential interplay between these agents and SERCA2a regulation presents a novel angle that could open new avenues for modulating diastolic function; however, the mechanistic research in this emerging field is limited. Overall, the direct role of SERCA2a dysfunction in HFpEF remains undetermined, highlighting the need for well-designed pre-clinical studies and robust clinical trials.

Synergistic Efficacy of Policosanol (Raydel®) and Banaba Leaf Extract to Treat Hyperglycemia and Dyslipidemia in Streptozotocin-Induced Diabetic and Hyperlipidemic Zebrafish (Danio rerio): Protection of Liver and Kidney with Enhanced Tissue Regeneration

Background: The efficacy of banaba leaf extract was tested against carboxymethyllysine (CML)-induced toxicity in embryos and adult zebrafish. Additionally, the individual and combined effects of banaba (BNB) and policosanol (PCO) were analyzed to alleviate dyslipidemia, hyperglycemia, and associated effects in streptozotocin (STZ)-induced hyperlipidemic diabetic zebrafish. Methodology: The high cholesterol diet (HCD, final 4%, w/w)-fed zebrafish were injected with STZ to develop diabetes and were subsequently fed with either HCD or HCD+BNB (final 0.1% w/w) or HCD+PCO (final 0.1% w/w) or HCD+BNB+PCO (each final 0.1%, w/w) each for 14 days. The zebrafish tail fin was amputated to assess tissue regeneration, while the organs and blood were collected for histological and biochemical analysis. Results: Severely compromised embryo survivability and developmental defects were noticed in the CML-injected group that significantly improved following BNB exposure. Similarly, CML-induced acute paralysis and mortality of adult zebrafish were effectively mitigated by the treatment with BNB. In the hyperlipidemic diabetic zebrafish, both BNB and PCO supplementation displayed the hypoglycemic effect; however, a remarkable reduction (p < 0.05) in blood glucose levels was observed in the BNB+PCO group, around 14% and 16% less than the BNB group and PCO group, respectively. Likewise, higher tail fin regeneration was noticed in response to BNB+PCO supplementation. Both BNB and PCO have a substantial counter-effect against HCD+STZ-induced dyslipidemia. However, the combined supplementation (BNB+PCO) displayed a significantly better effect than that of BNB and PCO alone to alleviate total cholesterol (TC), triglycerides (TGs), and low-density lipoprotein cholesterol (LDL-C). The most impressive impact of BNB+PCO was noticed in the elevation of high-density lipoprotein cholesterol (HDL-C), which was ~1.5 times higher than the HDL-C level in response to BNB and PCO. Also, BNB+PCO effectively reduced the malondialdehyde (MDA) and elevated the plasma sulfhydryl content, paraoxonase (PON), and ferric ion reduction (FRA) activity. Histological analyses revealed a significant effect of BNB+PCO in preventing inflammatory infiltration, fatty liver changes, and interleukin-6 production. Similarly, a notably better effect of BNB+PCO compared to their individual effect was noticed in preventing kidney damage and mitigation of ROS generation, apoptosis, and cellular senescence. Conclusions: The finding establishes the substantial effect of BNB and PCO in countering hyperglycemia, dyslipidemia, and associated disorders, which synergistically improved following the combined supplementation with BNB+PCO.

Endothelial Dysfunction: Redox Imbalance, NLRP3 Inflammasome, and Inflammatory Responses in Cardiovascular Diseases

Endothelial dysfunction (ED) is characterized by an imbalance between vasodilatory and vasoconstrictive factors, leading to impaired vascular tone, thrombosis, and inflammation. These processes are critical in the development of cardiovascular diseases (CVDs) such as atherosclerosis, hypertension and ischemia/reperfusion injury (IRI). Reduced nitric oxide (NO) production and increased oxidative stress are key contributors to ED. Aging further exacerbates ED through mitochondrial dysfunction and increased oxidative/nitrosative stress, heightening CVD risk. Antioxidant systems like superoxide-dismutase (SOD), glutathione-peroxidase (GPx), and thioredoxin/thioredoxin-reductase (Trx/TXNRD) pathways protect against oxidative stress. However, their reduced activity promotes ED, atherosclerosis, and vulnerability to IRI. Metabolic syndrome, comprising insulin resistance, obesity, and hypertension, is often accompanied by ED. Specifically, hyperglycemia worsens endothelial damage by promoting oxidative stress and inflammation. Obesity leads to chronic inflammation and changes in perivascular adipose tissue, while hypertension is associated with an increase in oxidative stress. The NLRP3 inflammasome plays a significant role in ED, being triggered by factors such as reactive oxygen and nitrogen species, ischemia, and high glucose, which contribute to inflammation, endothelial injury, and exacerbation of IRI. Treatments, such as N-acetyl-L-cysteine, SGLT2 or NLRP3 inhibitors, show promise in improving endothelial function. Yet the complexity of ED suggests that multi-targeted therapies addressing oxidative stress, inflammation, and metabolic disturbances are essential for managing CVDs associated with metabolic syndrome.

A Comparative Effect of 12-Week Dietary Intervention of Policosanol (Raydel®) and Red Yeast Rice (RYR, Kobayashi) in Managing Dyslipidemia and Organ Damage in Hyperlipidemic Zebrafish

BACKGROUND

A comparative 12-week dietary intervention of red yeast rice (RYR, Beni-koji, Kobayashi, Japan) and Cuban policosanol (PCO, Raydel®, Thornleigh, Australia) was assessed for dyslipidemia, antioxidant status, and vital organ functionality in hyperlipidemic zebrafish.

METHODS

Hyperlipidemic zebrafish were supplemented with a high-cholesterol diet (HC, final 4%, w/w) infused with either a powdered RYR tablet (final 1.0%, w/w), a PCO tablet (final 1.0%, w/w), or a combination of 0.5% (w/w) each of RYR and PCO powder for 12 weeks. Subsequently, blood and organs were collected and processed for biochemical and histological examination.

RESULTS

RYR and PCO consumption showed a substantial effect against HC-induced hyperlipidemia by reducing the total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C). Exclusively, PCO supplementation revealed a significant elevation in the HC-diminished high-density lipoprotein cholesterol (HDL-C). In addition, PCO supplementation showed a significant elevation in plasma ferric ion-reducing ability (FRA) and sulfhydryl content, as well as alleviating the blood glucose level of hyperlipidemic zebrafish. The most noteworthy impact, with a significant two-fold (p < 0.001) augmentation of HC-diminished plasma paraoxonase (PON) activity, was observed in response to PCO. In contrast, the RYR supplementation failed to establish curative effects against HC-disturbed plasma antioxidant variables and blood glucose levels. The histological outcome revealed a severe toxicological impact of the RYR on the liver, reflected by fatty liver changes and three-fold heightened IL-6 production compared to HC control. Contrastingly, PCO exhibited significant hepatoprotection and effectively neutralized the hepatic toxicity triggered by HC and RYR. Also, RYR showed kidney atrophy, intense ROS generation, apoptosis, and senescence. Conversely, the PCO supplementation protected the kidney from HC- and RYR-induced toxicity. Likewise, PCO supplementation notably alleviated histological alterations and oxidative stress in the brain, ovary, and testis of hyperlipidemic zebrafish.

CONCLUSIONS

This comparative study establishes PCO's therapeutic effect against the challenges posed by HC, while RYR emerged with serious toxicological concerns towards the liver, kidney, and other organs of hyperlipidemic zebrafish.

Urinary neonicotinoid exposure and its association with hypertension and dyslipidemia among the elderly: A cross-sectional study in Shenzhen, China

In recent years, neonicotinoids (NEOs) as a new type of insecticide have been increasingly used worldwide, causing significant impacts on human health. This study collected urine samples from 1147 elderly individuals (including 714 in the control group and 433 in the hypertension group) in Shenzhen, China, and detected the concentrations of six types of NEOs and four metabolites of NEOs (mNEOs). The aim of this study is to investigate the association between NEOs exposure and hypertension and dyslipidemia. After measurement, we find that the lowest detection rate (DR) among NEOs is imidacloprid (IMI), at only 39.3%. The NEO with the highest urine median concentration is dinotefuran (DIN) (1.31 μg/L), while the mNEO with the highest median concentration is DM-ACE (2.74 μg/L). Through univariate analysis, we found that DM-THM may promote the development of hypertension, while logistic regression indicated that IMI-OF could be a risk factor for hypertension. As prototypes of these two metabolites, thiamethoxam (THM) and IMI may also be risk factors for hypertension. Linear regression analysis revealed a negative correlation between the concentration of thiamethoxam (THD) and low-density lipoprotein (LDL) level, while DIN was positively correlated with triglyceride (TG) level and negatively correlated with high-density lipoprotein (HDL) level. Mediation effect analysis showed that THD may influence the risk of hypertension in the elderly by affecting LDL level. Based on this study, we believe that exposure to NEOs may increase the risk of hypertension in the elderly population.

Reactive oxygen species in hypertension

Hypertension is a leading risk factor for stroke, heart disease and chronic kidney disease. Multiple interacting factors and organ systems increase blood pressure and cause target-organ damage. Among the many molecular elements involved in the development of hypertension are reactive oxygen species (ROS), which influence cellular processes in systems that contribute to blood pressure elevation (such as the cardiovascular, renal, immune and central nervous systems, or the renin-angiotensin-aldosterone system). Dysregulated ROS production (oxidative stress) is a hallmark of hypertension in humans and experimental models. Of the many ROS-generating enzymes, NADPH oxidases are the most important in the development of hypertension. At the cellular level, ROS influence signalling pathways that define cell fate and function. Oxidative stress promotes aberrant redox signalling and cell injury, causing endothelial dysfunction, vascular damage, cardiovascular remodelling, inflammation and renal injury, which are all important in both the causes and consequences of hypertension. ROS scavengers reduce blood pressure in almost all experimental models of hypertension; however, clinical trials of antioxidants have yielded mixed results. In this Review, we highlight the latest advances in the understanding of the role and the clinical implications of ROS in hypertension. We focus on cellular sources of ROS, molecular mechanisms of oxidative stress and alterations in redox signalling in organ systems, and their contributions to hypertension.

Beeswax Alcohol (BWA, Raydel®) Improved Blood Oxidative Variables and Ameliorated Severe Damage of Zebrafish Kidneys, Testes, and Ovaries Impaired by 24-Week Consumption of a High-Cholesterol and High-Galactose Diet: A Comparative Analysis with Coenzyme Q10

OBJECTIVES

The present study describes the comparative effect of 24-week supplementation of beeswax alcohol (BWA, Raydel®, 0.5% and 1.0%, wt/wt) and coenzyme Q10 (CoQ10, 0.5% and 1.0%, wt/wt) on plasma oxidative variables and the prevention of organ injury in adult zebrafish subjected to a high-cholesterol (HC, 4%, wt/wt) and -D-galactose (Gal, 30%, wt/wt) diet.

METHODS

Adult zebrafish were fed various HC+Gal diets enriched with either BWA or CoQ10. After 24 weeks of dietary intervention, blood and organs were harvested for subsequent biochemical and histological evaluations.

RESULTS

The HC+Gal-elevated plasma oxidative variables were reverted by the consumption of BWA, marked by the lowest plasma malondialdehyde (MDA) level and highest sulfhydryl content. The HC+Gal-impaired zebrafish swimming ability (staggering movement) was substantially recovered by BWA, manifested by a ~three-fold (p < 0.001) enhancement in swimming distance and speed. Also, the intake of BWA affected the morphology of HC+Gal-compromised kidney and induced histological changes by mitigating reactive oxygen species (ROS) production and cellular senescence, which was markedly more effective than the results seen in the CoQ10 group. Likewise, BWA proved effective in preventing HC+Gal-induced testis damage, apparent in the 48.3% (p < 0.05) higher spermatozoa and 26.3% (p < 0.01) reduced interstitial space between the seminiferous tubules. BWA substantially prevented HC+Gal-induced ovary damage by suppressing oxidative stress, lipid deposition and senescence, leading to the restoration of mature vitellogenic oocyte counts.

CONCLUSION

BWA demonstrated a greater ability than CoQ10 to enhance plasma antioxidant status, suppress ROS generation, delay organ aging and alleviate HC+Gal-induced adversity in zebrafish.

Plasma Calprotectin and New-onset Type 2 Diabetes in the General Population: A Prospective Cohort Study

CONTEXT

Systemic inflammation plays a pivotal role in the development of type 2 diabetes (T2D).

OBJECTIVE

We hypothesized that circulating levels of calprotectin, a myeloid cell-derived biomarker of inflammation, is associated with the development of new-onset T2D in the general population.

METHODS

A total of 4815 initially nondiabetic participants of the Prevention of Renal and Vascular End-stage Disease (PREVEND), a prospective population-based cohort study, were assessed for plasma levels of calprotectin at baseline. Circulating levels of calprotectin were investigated for potential associations with the risk of new-onset T2D, defined as a fasting plasma glucose level of 7.0 mmol/L or greater, a random plasma glucose level of 11.1 mmol/L or greater, a self-reported physician-based diagnosis of T2D, the use of glucose-lowering drugs, or any combinations thereof.

RESULTS

Median plasma calprotectin levels were 0.49 (0.35-0.69) mg/L. Plasma calprotectin levels were significantly associated with the risk of new-onset T2D (hazard ratio [HR] per doubling 1.42 [95% CI, 1.22-1.66]; P < .001). The association remained independent of adjustment for age and sex (HR 1.34 [95% CI, 1.14-1.57]; P < .001), but not after further adjustment for potentially confounding factors (HR 1.11 [95% CI, 0.90-1.37]; P = .326), with adjustment for hyperlipidemia and high-sensitivity C-reactive protein explaining the loss of significance. Stratified analyses showed significant effect modification by hypertension, history of cardiovascular disease (CVD), the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) (Pinteraction ≤ .001 for each), and the use of lipid-lowering drugs (Pinteraction ≤ .05), with higher HRs in individuals without hypertension, without history of CVD, with below-median HOMA-IR, and in those not using lipid-lowering drugs.

CONCLUSION

Elevated plasma levels of calprotectin are associated with a higher risk of developing T2D in the general population and may represent a moveable inflammatory biomarker. This association, however, does not represent a direct effect, and seems dependent on hyperlipidemia and systemic inflammation.

Renal Inflammation, Oxidative Stress, and Metabolic Abnormalities During the Initial Stages of Hypertension in Spontaneously Hypertensive Rats

Background: Hypertension is a major cause of mortality worldwide. The kidneys play a crucial role in regulating blood pressure and fluid volume. The relationship between the kidneys and hypertension is complex, involving factors such as the renin-angiotensin system, oxidative stress, and inflammation. This study aims to assess the levels of inflammatory markers, oxidative stress, and metabolic factors in the kidneys, focusing on their potential role in early renal damage and their association with the development of hypertension. Methods: This study was designed to compare the levels of selected inflammatory markers, e.g., interleukins, tumor necrosis factor-α (TNF-α), transforming growth factor, and serine/threonine-protein (mTOR); oxidative stress markers such as malondialdehyde, sulfhydryl group, and glucose (GLC); and metabolic markers among other enzymes, such as alanine transaminase (ALT), aspartate transaminase (AST), hexokinase II (HK-II), and hypoxia-inducible factor-1α (HIF-1α), as well as creatinine in the kidneys of spontaneously hypertensive rats (SHR/NCrl, n = 12) and Wistar Kyoto rats (WKY/NCrl, n = 12). Both juvenile (5 weeks old) and maturing (10 weeks old) specimens were examined using spectrophotometric methods, e.g., ELISA. Results: Juvenile SHRs exhibited reduced renal levels of all studied cytokines and chemokines, with lower oxidative stress and deficits in the mTOR and HK-II levels compared to the age-matched WKYs. Maturing SHRs showed increased renal levels of interleukin-1β (IL-1β), IL-6, IL-18, and TNF-α, alongside elevated carbonyl stress and increased HIF-1α as opposed to their control peers. The levels of all other studied markers were normalized in these animals, except for ALT (increased), ALP, and GLC (both reduced). Conclusions: This study underscores the significant impact of inflammatory, oxidative stress, and metabolic marker changes on renal function. Juvenile SHRs display lower marker levels, indicating an immature immune response and potential subclinical kidney damage that may contribute to hypertension development. In contrast, mature SHRs exhibit chronic inflammation, oxidative dysregulation, and metabolic disturbances, suggesting cellular damage. These changes create a feedback loop that worsens kidney function and accelerates hypertension progression, highlighting the kidneys' crucial role in both initiating and exacerbating this condition.

Phenotypes of Polish primary care patients using hierarchical clustering: Exploring the risk of mortality in the LIPIDOGEN2015 study cohort

BACKGROUND

Comorbidities in primary care do not occur in isolation but tend to cluster together causing various clinically complex phenotypes. This study aimed to distinguish phenotype clusters and identify the risks of all-cause mortality in primary care.

METHODS

The baseline cohort of the LIPIDOGEN2015 sub-study involved 1779 patients recruited by 438 primary care physicians. To identify different phenotype clusters, we used hierarchical clustering and investigated differences between clinical characteristics and mortality between clusters. We then performed causal analyses using causal mediation analysis to explore potential mediators between different clusters and all-cause mortality.

RESULTS

A total of 1756 patients were included (mean age 51.2, SD 13.0; 60.3% female), with a median follow-up of 5.7 years. Three clusters were identified: Cluster 1 (n = 543) was characterised by overweight/obesity (body mass index ≥ 25 kg/m2), older (age ≥ 65 years), more comorbidities; Cluster 2 (n = 459) was characterised by non-overweight/obesity, younger, fewer comorbidities; Cluster 3 (n = 754) was characterised by overweight/obesity, younger, fewer comorbidities. Adjusted Cox regression showed that compared with Cluster 2, Cluster 1 had a significantly higher risk of all-cause mortality (HR 3.87, 95% CI: 1.24-15.91), whereas this was insignificantly different for Cluster 3. Causal mediation analyses showed that decreased protein thiol groups mediated the hazard effect of all-cause mortality in Cluster 1 compared with Cluster 2, but not between Clusters 1 and 3.

CONCLUSION

Overweight/obesity older patients with more comorbidities had the highest risk of long-term all-cause mortality, and in the young group population overweight/obesity insignificantly increased the risk in the long-term follow-up, providing a basis for stratified phenotypic risk management.

Redox Homeostasis and Molecular Biomarkers in Precision Therapy for Cardiovascular Diseases

Precision medicine is envisioned as the future of cardiovascular healthcare, offering a more tailored and effective method for managing cardiovascular diseases compared to the traditional one-size-fits-all approaches. The complex role of oxidative stress in chronic diseases within the framework of precision medicine was carefully explored, delving into the cellular redox status and its critical involvement in the pathophysiological complexity of cardiovascular diseases (CVDs). The review outlines the mechanisms of reactive oxygen species generation and the function of antioxidants in maintaining redox balance. It emphasizes the elevated reactive oxygen species concentrations observed in heart failure and their detrimental impact on cardiovascular health. Various sources of ROS within the cardiovascular system are examined, including mitochondrial dysfunction, which contributes to oxidative stress and mitochondrial DNA degradation. The article also addresses oxidative stress's role in myocardial remodeling, a process pivotal to the progression of heart diseases. By integrating these aspects, the review underscores the importance of redox homeostasis and identifies molecular biomarkers that can enhance precision therapy for CVDs. The insights provided aim to pave the way for targeted therapeutic strategies that mitigate oxidative stress, thereby improving patient outcomes in cardiovascular medicine.

Ultrasmall CuMn-His Nanozymes with Multienzyme Activity at Neutral pH: Construction of a Colorimetric Sensing Array for Biothiol Detection and Disease Identification

Biothiol assays offer vital insights into health assessment and facilitate the early detection of potential health issues, thereby enabling timely and effective interventions. In this study, we developed ultrasmall CuMn-Histidine (His) nanozymes with multiple enzymatic activities. CuMn-His enhanced peroxidase (POD)-like activity at neutral pH was achieved through hydrogen bonding and electrostatic effects. In addition, CuMn-His possesses laccase (LAC)-like and superoxide dismutase (SOD)-like activities at neutral pH. Based on three different enzyme mimetic activities of CuMn-His at neutral pH, the colorimetric sensing array without changing the buffer solution was successfully constructed. The array was successfully used for the identification of three biothiols, glutathione (GSH), cysteine (Cys), and homocysteine (Hcy). Subsequently, excellent application results were shown in complex serum and cellular level analyses. This study provides an innovative strategy for the development of ultrasmall bimetallic nanozymes with multiple enzymatic activities and the construction of colorimetric sensing arrays.

A Prospective Study of the Association Between Plasma Calprotectin Levels and New-Onset CKD in the General Population

Introduction

Systemic inflammation has been associated with chronic kidney disease (CKD). In this study, we aimed to investigate a potential association between the plasma biomarker of inflammation calprotectin and new-onset CKD in a population-based cohort study.

Methods

Individuals without CKD at baseline (n = 4662) who participated in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) prospective population-based cohort study in the Netherlands were included. Baseline plasma calprotectin levels were assessed in samples that had been stored at -80 °C. Occurrence of new-onset CKD was defined as a composite outcome of an estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2, urinary albumin excretion (UAE) >30 mg/24h, or both.

Results

Baseline median (interquartile range) plasma calprotectin levels were 0.49 (0.35-0.68) mg/l and baseline median eGFR was 95.9 (interquartile range: 85.0-105.7) ml/min per 1.73 m2. After median follow-up of 8.3 (7.8-8.9) years, 467 participants developed new-onset CKD. Baseline plasma calprotectin levels were significantly associated with an increased risk of new-onset CKD (hazard ratio [HR] per doubling 1.28 [95% confidence interval, CI: 1.14-1.44], P < 0.001), independent of potentially confounding factors (HR 1.14 [95% CI: 1.01-1.29], P = 0.034), except for baseline high-sensitive C-reactive protein (hs-CRP) (HR 1.05 [0.91-1.21], P = 0.494). In secondary analyses, the association between plasma calprotectin and occurrence of UAE >30 mg/24h remained significant (HR 1.17 [1.02-1.34], P = 0.027), but not significantly so for the incidence of eGFR <60 ml/min per 1.73 m2 as individual outcome (HR 1.15 [0.92-1.43], P = 0.218).

Conclusion

Higher plasma calprotectin levels are associated with an increased risk of developing CKD in the general population. This association is mitigated after adjustment for hs-CRP, and more pronounced with new-onset CKD defined by UAE.

Systemic Oxidative Stress in Severe Early-Onset Fetal Growth Restriction Associates with Concomitant Pre-Eclampsia, Not with Severity of Fetal Growth Restriction

BACKGROUND

Placental insufficiency is an important mechanism underlying early-onset fetal growth restriction (eoFGR). Reduced placental function causes impaired metabolic and gaseous exchange. This unfavorable placental environment is among other processes characterized by increased oxidative stress. Systemic free thiols (FT) are known for their reactive oxygen species scavenging capacity, and higher plasma levels of FT are associated with a better outcome in a multitude of ischemic and inflammatory diseases. We aimed to investigate the relationships between systemic FT levels and maternal and perinatal clinical characteristics and outcomes.

STUDY DESIGN

In a post hoc analysis of the Dutch Strider study, a cohort of women with eoFGR, we investigated the association between the maternal redox status (FT) levels at study inclusion, placental biomarkers, and maternal and neonatal outcomes in 108 patients.

RESULTS

FT were significantly lower in pregnancies complicated with eoFGR with concurrent maternal hypertensive disorders (pregnancy-induced hypertension; ρ = -0.281 p = 0.004, pre-eclampsia; ρ = -0.505 p = 0.000). In addition, lower FT levels were significantly associated with higher systolic (ρ = -0.348 p = 0.001) and diastolic blood pressure (ρ = -0.266 p = 0.014), but not with the severity of eoFGR. FT levels were inversely associated with sFlt (ρ = -0.366, p < 0.001). A strong relation between systemic FT levels and PlGF levels was observed in women with pre-eclampsia at delivery (ρ = 0.452, p = 0.002), which was not found in women without hypertensive disorders (ρ = 0.008, p = 0.958).

CONCLUSIONS

In women with pregnancies complicated with eoFGR, FT levels reflect the severity of maternal disease related to the underlying placental insufficiency rather than the severity of the placental dysfunction as reflected in eoFGR or perinatal outcomes.

Selenium and coenzyme Q10 improve the systemic redox status while reducing cardiovascular mortality in elderly population-based individuals

BACKGROUND

Serum sulfhydryl groups (R-SH, free thiols) reflect the systemic redox status in health and disease, and may be amenable to therapeutic modulation. Since R-SH are readily oxidized by reactive species, oxidative stress is characterized by reduced serum R-SH levels. Selenium and coenzyme Q₁₀ supplementation may improve the systemic redox status. This study aimed to evaluate the effect of supplementation with selenium and coenzyme Q₁₀ on serum free thiols and to study associations with the risk of cardiovascular mortality in elderly community-dwelling individuals.

METHODS

In this randomized, double-blind, placebo-controlled trial, serum R-SH were measured colorimetrically and adjusted for albumin in 434 individuals at baseline and after 48 months of intervention. Selenium yeast (200 μg/day) and coenzyme Q₁₀ (200 mg/day) or placebo were provided as dietary supplements.

RESULTS

After 48 months of intervention, participants receiving combined selenium and coenzyme Q₁₀ supplementation demonstrated increased levels of serum R-SH compared to placebo (P = 0.002). In prospective association analysis, the highest rate of cardiovascular mortality after a median follow-up of 10 years (IQR: 6.8-10.5) was observed in the lowest quartile (Q1) of R-SH levels. Baseline albumin-adjusted serum R-SH were significantly associated with the risk of cardiovascular mortality, even after adjustment for potential confounding factors (hazard ratio [HR] 1.98 per SD, 95% CI: 1.34-2.91, P < 0.001).

CONCLUSION

Supplementation with selenium and coenzyme Q₁₀ to an elderly community-dwelling population low on the two substances, significantly improved serum R-SH levels, supporting a reduction in systemic oxidative stress. Low serum R-SH levels were significantly associated with an increased risk of cardiovascular mortality in elderly individuals.

A Sex-Specific Comparative Analysis of Oxidative Stress Biomarkers Predicting the Risk of Cardiovascular Events and All-Cause Mortality in the General Population: A Prospective Cohort Study

Oxidative stress plays a pivotal role in cardiovascular (CV) disease, but current biomarkers used to predict CV events are still insufficient. In this study, we comparatively assessed the utility of redox-related biomarkers in predicting the risk of CV events and all-cause mortality in male and female subjects from the general population. Subjects (n = 5955) of the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) population-based cohort study were included. Blood homocysteine, gamma-GT, HDL cholesterol, bilirubin and protein-adjusted free thiol (R-SH, sulfhydryl groups) levels were quantified at baseline and were prospectively analyzed in association with the risk of CV events and all-cause mortality. After adjustment for potentially confounding factors, protein-adjusted R-SH and homocysteine levels were significantly associated with the risk of CV events in men (HR 0.63 [0.40–0.99], p = 0.045 and HR 1.58 [1.20–2.08], p = 0.001, respectively). Protein-adjusted R-SH and HDL cholesterol levels were significantly associated with the risk of all-cause mortality in men (HR 0.52 [0.32–0.85], p = 0.009 and HR 0.90 [0.85–0.94], p < 0.001, respectively), while the same was observed for bilirubin and homocysteine levels in women (HR 0.68 [0.48–0.98], p = 0.040 and HR 2.30 [1.14–3.76], p < 0.001, respectively). Lower levels of protein-adjusted R-SH were robustly associated with an increased risk of CV events and all-cause mortality in men. Our results highlight the value of R-SH levels in cardiovascular risk assessment and their potential significance as being amenable to therapeutic intervention, while reaffirming the importance of other oxidative stress-related biomarkers, such as homocysteine, HDL cholesterol and bilirubin.

Serum free thiols in recently diagnosed patients with schizophrenia spectrum disorder: A potentially useful biomarker of oxidative stress

Schizophrenia spectrum disorders (SSD) have been linked to oxidative stress (OS). Recent findings from our group show that serum free thiols (R-SH, sulfhydryl groups) can function as an accurate biomarker of systemic OS, since they are readily oxidized by reactive species (ROS), thereby serving as potent antioxidants. The aim of this study is to investigate if reduced R-SH levels can be demonstrated in recently diagnosed patients with SSD compared to healthy controls (HC). In this study, 102 patients with recently diagnosed SSD (< three years), and 42 HC were included. Levels of R-SH were quantified and studied for correlations with age, C-reactive protein (CRP) as proxy of inflammation as well as body mass index (BMI) and total cholesterol as indices of metabolic health. R-SH levels were significantly lower in patients when compared to HC. When correcting for age the difference was borderline significant (p=0.05). Moreover, R-SH correlated significantly with age (r = -0.29) and CRP (r = -0.29) in patients with SSD, but not in the HC. R-SH levels are reduced in SSD as compared to HC and correlate negatively with CRP and age in SSD. Future studies are required to further investigate R-SH and its role in SSD.

Plasma Neutrophil Gelatinase-Associated Lipocalin Associates with New-Onset Chronic Kidney Disease in the General Population

Circulating levels of neutrophil gelatinase-associated lipocalin (NGAL) have been associated with acute kidney injury and the severity and progression of chronic kidney disease (CKD). This study investigated its potential utility as a biomarker for the risk of new-onset CKD in a population-based cohort study. Individuals without CKD at baseline (n = 4660) who participated in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) prospective population-based cohort study in the Netherlands were included. Baseline plasma NGAL concentrations were investigated for their associations with new-onset CKD, defined as a composite outcome of an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m², urinary albumin excretion (UAE) > 30 mg/24-h, or both. Mean (±SD) plasma NGAL concentrations were 104.0 (±34.7) μg/L and median eGFR was 96 [IQR: 85.3-105.8] mL/min/1.73 m². After median follow-up of 8.3 [IQR: 7.8-8.9] years, 467 participants developed new-onset CKD. Plasma NGAL concentrations were significantly associated with an increased risk of new-onset CKD (hazard ratio [HR] per doubling 1.35 [95% CI: 1.11-1.63], p = 0.002), even after adjustment for potentially confounding factors (1.37 [1.09-1.73], p = 0.007) except baseline eGFR (1.09 [0.86-1.37], p = 0.490). In secondary analyses, plasma NGAL concentrations were significantly associated with new-onset CKD as defined by eGFR < 60 mL/min/1.73 m² alone (adjusted HR per doubling 2.54 [1.69-3.80], p < 0.001), which was abrogated after adjustment for eGFR (1.05 [0.69-1.59], p = 0.828), also when UAE > 30 mg/24-h was set as individual outcome (1.05 [0.82-1.35], p = 0.705). Higher plasma NGAL concentrations are associated with an increased risk of developing CKD in the general population. This association is dependent on renal function, and mainly driven by new-onset CKD as defined by renal function decline.