Exercise, Cardiovascular Health, and Risk Factors for Atherosclerosis: A Narrative Review on These Complex Relationships and Caveats of Literature

Oxidative stress and vascular dysfunction: Potential therapeutic targets and therapies in peripheral artery disease

Peripheral artery disease (PAD) is the manifestation of atherosclerosis characterized by the accumulation of plaques in the arteries of the lower limbs. Interestingly, growing evidence suggests that the pathology of PAD is multifaceted and encompasses both vascular and skeletal muscle dysfunctions, which contributes to blunted physical capabilities and diminished quality of life. Importantly, it has been suggested that many of these pathological impairments may stem from blunted reduction-oxidation (redox) handling. Of note, in those with PAD, excessive production of reactive oxygen species (ROS) outweighs antioxidant capabilities resulting in oxidative damage, which may have systemic consequences. It has been suggested that antioxidant supplementation may be able to assist in handling ROS. However, the activation of various ROS production sites makes it difficult to determine the efficacy of these antioxidant supplements. Therefore, this review focuses on the common cellular mechanisms that facilitate ROS production and discusses how excessive ROS may impair vascular and skeletal muscle function in PAD. Furthermore, we provide insight for current and potential antioxidant therapies, specifically highlighting activation of the Kelch-like ECH-associated protein 1 (Keap1) - Nuclear Factor Erythroid 2-related factor 2 (Nrf2) pathway as a potential pharmacological therapy to combat ROS accumulation and aid in vascular function, and physical performance in patients with PAD. Altogether, this review provides a better understanding of excessive ROS in the pathophysiology of PAD and enhances our perception of potential therapeutic targets that may improve vascular function, skeletal muscle function, walking capacity, and quality of life in patients with PAD.

High-density lipoprotein dysfunction in carotid artery stenosis

Background: High density lipoprotein (HDL) is well established to have an athero-protective role under normal conditions; however, pro-inflammatory alteration of HDL proteins may transform the HDL particle into a dysfunctional molecule. Our aim was to investigate HDL dysfunction by measuring enzyme-based markers in carotid artery stenosis (CAS). Patients and methods: All participants underwent duplex ultrasound and 52 subjects diagnosed with CAS and 51 subjects who had no significant stenosis (as controls) were enrolled in this study. Serum lipid profiles and serum parameters associated with dysfunctional HDL including myeloperoxidase (MPO), paraoxonase 1 (PON1), arylesterase (ARE) activity, and lipid hydroperoxide (LOOH) levels were measured. Results: It was found that the patients with CAS had increased levels of MPO and LOOH while PON1 activity was decreased. There was no significant difference between the CAS and non-CAS groups in terms of HDL levels. MPO/PON1, MPO/ARE, and LOOH/PON1 ratios were significantly increased in the CAS group. MPO/PON1 and MPO/ARE ratios both demonstrated significant correlations with degree of stenosis (%). Conclusions: The MPO/PON1 and MPO/ARE ratios may be potential serum markers that can enable the monitoring of HDL functionality and the assessment of atherosclerotic disease risks. Additionally, monitoring the oxidative balance of lipids on HDL molecules by LOOH/PON1 ratio may have value in the early detection of pro-atherosclerotic transformation of the HDL particle.

Aerobic Exercise versus Electronic Cigarette in Vascular Aging Process: First Histological Insight

Smoking is related to vascular aging. However, the hazardous effect of e-cigarette is often debatable, with limited studies available. In contrast, moderate-intensity aerobic exercise is well known to decrease aortic stiffness. We provide novel research to determine the effect of e-cigarette and aerobic moderate-intensity exercise on the aortic structure of Wistar rats. A total of 26 male Wistar rats (Rattus norvegicus) 8 weeks aged, 200-250 g b.w., were randomly divided into 4 groups, namely, K0 (normal rats), K1 (rats were given moderate-intensity aerobic exercise by animal treadmill 20 m/30 min), K2 (rats were given e-cigarette with 6 mg nicotine, 40% propylene glycol, and 60% vegetable glycerine 30 min for 5 days/week), and K3 (rats were given e-cigarette and moderate-intensity aerobic exercise). After exposure for 6 weeks, all animals were sacrificed to isolate the aorta for histopathological analysis with hematoxylin-eosin stain to evaluate the elastic fiber layer and intimal-medial thickness. The Verhoeff-Van Gieson staining was done for quantification elastic lamina fragmentation. Our study found that the e-cigarette group had the highest elastic lamina fragmentation among groups (8.14 ± 2.85). The exercise only group showed the lowest elastic lamina fragmentation (2.50 ± 1.87). Fragmentation in the e-cigarette and exercise group was higher than in the exercise only group (5.83 ± 0.753 vs. 2.50 ± 1.87, p = 0.002). There is a significant difference of NO serum between four groups. The result of post hoc analysis using LSD showed that there is a significant difference of NO serum between K0 and K2, K0 and K3, K1 and K2, and K1 and K3. Therefore, our research demonstrated that the most injury of aorta elastic lamina was in the group that was exposed to e-cigarette that leads to vascular aging while exercise is not yet proven to reverse this effect.

ERRα Attenuates Vascular Inflammation via Enhanced NFκB Degradation Pathway

We have previously reported that β-aminoisobutyric acid (BAIBA), a muscle-derived exercise mimetic, had anti-inflammatory and reactive oxygen species (ROS) scavenging effects in vascular endothelial cells through the enhanced expression of peroxisome proliferator-activated receptor gamma coactivator-1β (PGC-1β). Although BAIBA also increased the expression of estrogen-related receptor α (ERRα), the roles of ERRα in vascular endothelial cells have yet to be fully elucidated. Here, we found that human aortic endothelial cells (HAECs) infected with ERRα-expressing adenovirus had significantly decreased mRNA levels of tumor necrosis factor α-stimulated proinflammatory molecules. However, ERRα overexpression had little effect on the mRNA levels of PGC-1β, peroxisome proliferator-activated receptors, and almost all ROS scavenging molecules, except for superoxide dismutase 2. ERRα expression significantly decreased NFκB reporter activities in a dose-dependent manner with unaltered IκBα phosphorylation levels but with a significant increase in the mRNA levels of PDZ and LIM domain protein 2 (PDLIM2) and copper metabolism gene MURR1 domain-containing protein (COMMD1), which enhance the ubiquitination and degradation of NFκB. Also, PDLIM2 and COMMD1 mRNA levels were upregulated in BAIBA-treated HAECs. Finally, we identified the ERRα-response element in the COMMD1 promoter region (-283 to -29 bp). These results indicated that ERRα exerted anti-inflammatory effects in vascular endothelial cells through COMMD1-mediated attenuation of NFκB activity, which could be an atheroprotective mechanism of physical exercise.

Endothelial Function Assessment by Flow-Mediated Dilation Method: A Valuable Tool in the Evaluation of the Cardiovascular System

Cardiovascular diseases (CVDs) in the course of atherosclerosis are one of the most critical public health problems in the world. Endothelial cells synthesize numerous biologically active substances involved in regulating the functions of the cardiovascular system. Endothelial dysfunction is an essential element in the pathogenesis of atherosclerosis. Thus, the assessment of endothelial function in people without overt CVD allows for a more accurate estimate of the risk of developing CVD and cardiovascular events. The assessment of endothelial function is primarily used in scientific research, and to a lesser extent in clinical practice. Among the tools for assessing endothelial function, we can distinguish biochemical and physical methods, while physical methods can be divided into invasive and non-invasive methods. Flow-mediated dilation (FMD) is based on the ultrasound assessment of changes in the diameter of the brachial artery as a result of increased blood flow. FMD is a non-invasive, safe, and repeatable test, but it must be performed by qualified and experienced medical staff. The purpose of this paper is to present the literature review results on the assessment of endothelial function using the FMD method, including its methodology, applications in clinical practice and research, limitations, and future perspectives.

Effects of aerobic, resistance, and combined training on endothelial function and arterial stiffness in older adults: study protocol for a systematic review and meta-analysis

INTRODUCTION

Aging is an independent risk factor for cardiovascular events. It promotes vascular dysfunction which is associated with risk factors for cardiovascular diseases (CVDs). Exercise can modulate vascular function parameters, but little is known about the effects of different modalities of training (aerobic, resistance, and combined) on endothelial function and arterial stiffness in older adults.

METHODS

This systematic review study will include randomized controlled trials (RCTs) selected from the electronic databases MEDLINE (PubMed), Cochrane, LILACS, EMBASE, and Web of Science. We will follow the PRISMA guidelines and PICOS framework. Studies involving both male and female older adults (≥60 years old) with or without comorbidities undergoing aerobic, resistance, and/or combined training compared to a control group (no exercise) will be eligible. We will use the Cochrane Risk of Bias 2 (RoB 2) tool to evaluate the quality of individual studies and GRADE to assess the strength of evidence. Statistical analyses will be conducted with RStudio for Windows (v1.3.959) using R package meta.

DISCUSSION

A systematic review and meta-analysis involving data from studies of older adults would deepen our understanding of vascular adaptations to exercise training in this population. It could provide new insights into how health providers can improve patient management and prevention of cardiovascular events in older adults.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 42021275451.

Recruitment methods and yield rates in a clinical trial of physical exercise for older adults with hypertension-HAEL Study: a study within a trial

Background

Although the prevalence of hypertension is high in older adults, clinical trial recruitment is a challenge. Our main aim was to describe the HAEL Study recruitment methods and yield rates. The secondary objectives were to explore the reasons for exclusion and to describe the characteristics of the enrolled participants.

Methods

This is a descriptive study within a trial. The HAEL Study was a Brazilian randomized two-center, parallel trial with an estimated sample of 184 participants. The recruitment strategy was based on four methods: electronic health records, word of mouth, print and electronic flyer, and press media. The yield rate was the ratio of the number of participants who underwent randomization to the total number of volunteers screened, calculated for overall, per recruitment method, by study center and by age group and sex. Additionally, we described the reasons for exclusion in the screening phase, as well as the demographic characteristics of those enrolled. The data are presented in absolute/relative frequencies and mean ± standard deviation.

Results

A total of 717 individuals were screened, and 168 were randomized over 32 months. The yield rate was higher for word of mouth (30.1%) in the overall sample. However, press media contributed the most (39.9%) to the absolute number of participants randomized in the trial. The coordinating center and participating center differed in methods with the highest yield ratios and absolute numbers of randomized participants. The main reason for exclusion in the screening phase was due to the physically active status in those intending to participate in the study (61.5%). Out of 220 participants included, 52 were excluded mainly because they did not meet the eligibility criteria (26.9%). Most of the screened volunteers were women (60.2%) age 60–69 years (59.5%), and most of the randomized participants were Caucasian/white (78.0%).

Conclusions

Multiple recruitment methods constituted effective strategies. We observed that approximately one of every four individuals screened was allocated to an intervention group. Even so, there were limitations in obtaining a representative sample of older Brazilian adults with hypertension. Data show an underrepresentation of race and age groups.

Trial registration

This SWAT was not registered.

Association between vascular endothelial dysfunction and the inflammatory marker neopterin in patients with classic congenital adrenal hyperplasia

BACKGROUND AND AIMS

Patients with congenital adrenal hyperplasia (CAH) are at increased risk of cardiometabolic abnormalities. We aimed to evaluate vascular endothelial dysfunction and its association with serum neopterin (NP) levels in CAH patients.

METHODS

The study included 40 patients, with a mean age of 14.8 ± 2.6 years; 28 (70%) subjects were females. They were compared with 40 healthy controls matched in anthropometric evaluation and measurement of fasting lipids, glucose, insulin, homeostasis model assessment for insulin resistance [HOMA-IR], and serum NP levels (nmol/L). Vascular ultrasound was used to measure brachial artery flow-mediated dilation (FMD%) and carotid intima-media thickness (CA-IMT). According to the degree of control on medical treatment, patients were classified into poor (n = 12) and good (n = 28) control groups.

RESULTS

Compared to controls, CAH patients had lower brachial FMD% (4.60 ± 2.13 versus 9.31 ± 2.29, p = 0.001), similar CA-IMT (0.44 ± 0.08 versus 0.44 ± 0.06, p = nonsignificant) and higher NP (42.6 ± 11.6 versus 9.2 ± 3.8, p = 0.001). However, differences between poor and good control CAH patients were significant regarding FMD%, CA-IMT, and NP measurements. FMD% correlated significantly with NP (r = -0.54, p = 0.001), high-sensitivity CRP (r = -0.53, p = 0.001), HOMA-IR (r = -0.31, p = 0.01), CA-IMT (r = -0.22, p < 0.05), diastolic blood pressure (r = 0.32, p = 0.01) and systolic blood pressure (r = -0.022, p < 0.05). NP was the most significant independent predictor of FMD%, as determined by linear regression analysis (p = 0.001).

CONCLUSIONS

Our study showed that CAH patients had endothelial dysfunction, which is an early process of vascular affection. This was significantly associated with NP levels, suggesting a crucial role of inflammation in the pathogenesis of vascular damage. Further studies are needed to confirm our findings and to investigate the exact role of NP, as either protective or proatherothrombotic.

Oxidized LDL Causes Endothelial Apoptosis by Inhibiting Mitochondrial Fusion and Mitochondria Autophagy

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial dysfunction is an initial step toward atherosclerosis development. Mitochondria damage correlates with ox-LDL-induced endothelial injury through an undefined mechanism. We explored the role of optic atrophy 1 (Opa1)-related mitochondrial fusion and mitophagy in ox-LDL-treated endothelial cells, focusing on mitochondrial damage and cell apoptosis. Oxidized low-density lipoprotein treatment reduced endothelial cell viability by increasing apoptosis. Endothelial cell proliferation and migration were also impaired by ox-LDL. At the molecular level, mitochondrial dysfunction was induced by ox-LDL, as demonstrated by decreased mitochondrial membrane potential, increased mitochondrial reactive oxygen species production, augmented mitochondrial permeability transition pore openings, and elevated caspase-3/9 activity. Mitophagy and mitochondrial fusion were also impaired by ox-LDL. Opa1 overexpression reversed this effect by increasing endothelial cell viability and decreasing apoptosis. Interestingly, inhibition of mitophagy or mitochondrial fusion through transfection of siRNAs against Atg5 or Mfn2, respectively, abolished the protective effects of Opa1. Our results illustrate the role of Opa1-related mitochondrial fusion and mitophagy in sustaining endothelial cell viability and mitochondrial homeostasis under ox-LDL stress.