Circulating endothelial and progenitor cells: Evidence from acute and long-term exercise effects

The effect of exercise on flow-mediated dilation in people with type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

Introduction

An increasing number of studies have investigated the effect of exercise on flow-mediated dilation (FMD) in people with type 2 diabetes mellitus (T2DM), while the findings were controversial. The primary aim of this systematic review and meta-analysis was to investigate the effect of exercise on FMD in T2DM patients, and the secondary aim was to investigate the optimal type, frequency, session duration, and weekly time of exercise for T2DM patients.

Methods

Searches were conducted in PubMed, Cochrane Library, Scopus, Web of Science, Embase and EBSCO databases. The Cochrane risk of bias tool (RoB2) in randomized trial and Physiotherapy Evidence Database (PEDro) scale were used to assess the methodological quality of the included studies.

Results

From the 3636 search records initially retrieved, 13 studies met the inclusion criteria. Our meta-analysis revealed that exercise had a significant effect on improving FMD in T2DM patients [WMD, 2.18 (95% CI, 1.78-2.58), p < 0.00001, I2 = 38%], with high-intensity interval training (HIIT) being the most effective intervention type [HIIT, 2.62 (1.42-3.82); p < 0.0001; aerobic exercise, 2.20 (1.29-3.11), p < 0.00001; resistance exercise, 1.91 (0.01-3.82), p = 0.05; multicomponent training, 1.49 (0.15-2.83), p = 0.03]. In addition, a higher frequency [> 3 times, 3.06 (1.94-4.19), p < 0.00001; ≤ 3 times, 2.02 (1.59-2.45), p < 0.00001], a shorter session duration [< 60 min, 3.39 (2.07-4.71), p < 0.00001; ≥ 60 min, 1.86 (1.32-2.40), p < 0.00001], and a shorter weekly time [≤ 180 min, 2.40 (1.63-3.17), p < 0.00001; > 180 min, 2.11 (0.82-3.40), p = 0.001] were associated with larger improvements in FMD.

Conclusion

This meta-analysis provides clinicians with evidence to recommended that T2DM patients participate in exercise, especially HIIT, more than 3 times per week for less than 60 min, with a target of 180 min per week being reached by increasing the frequency of exercise.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023466575.

Treatable Traits in Systemic Sclerosis

Systemic sclerosis (SSc) is a chronic systemic disease within the spectrum of connective tissue diseases, specifically characterized by vascular abnormalities and inflammatory and fibrotic involvement of the skin and internal organs resulting in high morbidity and mortality. The clinical phenotype of SSc is heterogeneous, and serum autoantibodies together with the extent of skin involvement have a predictive value in the risk stratification. Current recommendations include an organ-based management according to the predominant involvement with only limited individual factors included in the treatment algorithm. Similar to what has been proposed for other chronic diseases, we hypothesize that a "treatable trait" approach based on relevant phenotypes and endotypes could address the unmet needs in SSc stratification and treatment to maximize the outcomes. We provide herein a comprehensive review and a critical discussion of the literature regarding potential treatable traits in SSc, focusing on established and candidate biomarkers, with the purpose of setting the bases for a precision medicine-based approach. The discussion, structured based on the organ involvement, allows to conjugate the pathogenetic mechanisms of tissue injury with the proposed predictors, particularly autoantibodies and other serum biomarkers. Ultimately, we are convinced that precision medicine is the ideal guide to manage a complex condition such as SSc for which available treatments are largely unsatisfactory.

Effects of Exercise Training on Circulating Biomarkers of Endothelial Function in Pulmonary Arterial Hypertension

INTRODUCTION

In stable patients with pulmonary arterial hypertension (PAH), pulmonary rehabilitation (PR) is an effective, safe and cost-effective non-pharmacological treatment. However, the effects of PR on vascular function have been poorly explored. This study aimed to compare the amounts of circulating progenitor cells (PCs) and endothelial microvesicles (EMVs) in patients with PAH before and after 8 weeks of endurance exercise training as markers of vascular competence.

METHODS

A prospective study of 10 consecutive patients with PAH that successfully finished a PR program (8 weeks) was carried out before and after this intervention. Levels of circulating PCs defined as CD34+CD45low progenitor cells and levels of EMVs (CD31+ CD42b-) were measured by flow cytometry. The ratio of PCs to EMVs was taken as a measure of the balance between endothelial damage and repair capacity.

RESULTS

All patients showed training-induced increases in endurance time (mean change 287 s). After PR, the number of PCs (CD34+CD45low/total lymphocytes) was increased (p < 0.05). In contrast, after training, the level of EMVs (CD31+ CD42b-/total EMVs) was reduced. The ratio of PCs to EMVs was significantly higher after training (p < 0.05).

CONCLUSION

Our study shows, for the first time, that endurance exercise training in patients with stable PAH has a positive effect, promoting potential mechanisms of damage/repair in favor of repair. This effect could contribute to a positive hemodynamic and clinical response.

Effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in type 2 diabetes: A systematic review

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a chronic metabolic syndrome characterized by insulin resistance and hyperglycemia that may lead to endothelial dysfunction, reduced functional capacity and exercise intolerance. Regular aerobic exercise has been promoted as the most beneficial non-pharmacological treatment of cardiovascular diseases. High intensity interval training (HIIT) seems to be superior than moderate-intensity continuous training (MICT) in cardiovascular diseases by improving brachial artery flow-mediated dilation (FMD) and cardiorespiratory fitness to a greater extent. However, the beneficial effects of HIIT in patients with T2DM still remain under investigation and number of studies is limited.

AIM

To evaluate the effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in patients with T2DM.

METHODS

We performed a search on PubMed, PEDro and CINAHL databases, selecting papers published between December 2012 and December 2022 and identified published randomized controlled trials (RCTs) in the English language that included community or outpatient exercise training programs in patients with T2DM. RCTs were assessed for methodological rigor and risk of bias via the Physiotherapy Evidence Database (PEDro). The primary outcome was peak VO₂ and the secondary outcome was endothelial function assessed either by FMD or other indices of microcirculation.

RESULTS

Twelve studies were included in our systematic review. The 12 RCTs resulted in 661 participants in total. HIIT was performed in 310 patients (46.8%), MICT to 271 and the rest 80 belonged to the control group. Peak VO₂ increased in 10 out of 12 studies after HIIT. Ten studies compared HIIT with other exercise regimens (MICT or strength endurance) and 4 of them demonstrated additional beneficial effects of HIIT over MICT or other exercise regimens. Moreover, 4 studies explored the effects of HIIT on endothelial function and FMD in T2DM patients. In 2 of them, HIIT further improved endothelial function compared to MICT and/or the control group while in the rest 2 studies no differences between HIIT and MICT were observed.

CONCLUSION

Regular aerobic exercise training has beneficial effects on cardiorespiratory fitness and endothelial function in T2DM patients. HIIT may be superior by improving these parameters to a greater extent than MICT.

Effect of continuous aerobic exercise on endothelial function: A systematic review and meta-analysis of randomized controlled trials

Background: Current research suggests that continuous aerobic exercise can be effective in improving vascular endothelial function, while the effect between different intensities and durations of exercise is unclear. The aim of this study was to explore the effect of different durations and intensities of aerobic exercise on vascular endothelial function in different populations. Methods: Searches were performed in PubMed, Web of Science, and EBSCO databases. We included studies that satisfied the following criteria: 1) randomized controlled trials (RCTs); 2) including both an intervention and control group; 3) using flow-mediated dilation (FMD) as the outcome measure; and 4) testing FMD on the brachial artery. Results: From 3,368 search records initially identified, 41 studies were eligible for meta-analysis. There was a significant effect of continuous aerobic exercise on improving flow-mediated dilation (FMD) [weighted mean difference (WMD), 2.55, (95% CI, 1.93-3.16), p < 0.001]. Specifically, moderate-intensity [2.92 (2.02-3.825), p < 0.001] and vigorous-intensity exercise [2.58 (1.64-3.53), p < 0.001] significantly increased FMD. In addition, a longer duration [<12 weeks, 2.25 (1.54-2.95), p < 0.001; ≥12 weeks, 2.74 (1.95-3.54), p < 0.001], an older age [age <45, 2.09 (0.78-3.40), p = 0.002; 45 ≤ age <60, 2.25 (1.49-3.01), p < 0.001; age ≥60, 2.62 (1.31-3.94), p < 0.001], a larger basal body mass index (BMI) [20 < BMI < 25, 1.43 (0.98-1.88), p < 0.001; 25 ≤ BMI < 30, 2.49 (1.07-3.90), p < 0.001; BMI ≥ 30, 3.05 (1.69-4.42), p < 0.001], and a worse basal FMD [FMD < 4, 2.71 (0.92-4.49), p = 0.003; 4 ≤ FMD < 7, 2.63 (2.03-3.23), p < 0.001] were associated with larger improvements in FMD. Conclusion: Continuous aerobic exercise, especially moderate-intensity and vigorous-intensity aerobic exercise, contributed to improving FMD. The effect of continuous aerobic exercise on improving FMD was associated with duration and participant's characteristics. Specifically, a longer duration, an older age, a larger basal BMI, and a worse basal FMD contributed to more significant improvements in FMD. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=341442], identifier [CRD42022341442].

Effects and Optimal Dose of Exercise on Endothelial Function in Patients with Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Exercise-based cardiac rehabilitation (CR) is considered an effective treatment for enhancing endothelial function in patients with heart failure (HF). However, recent studies have been published and the optimal "dose" of exercise required to increase the benefits of exercise-based CR programmes on endothelial function is still unknown.

OBJECTIVES

(a) To estimate the effect of exercise-based CR on endothelial function, assessed by flow-mediated dilation (FMD), in patients with HF; (b) to determine whether high-intensity interval training (HIIT) is better than moderate-intensity training (MIT) for improving FMD; and (c) to investigate the influence of exercise modality (i.e. resistance exercise vs. aerobic exercise and combined exercise vs. aerobic exercise) on the improvement of endothelial function.

METHODS

Electronic searches were carried out in PubMed, Embase, and Scopus up to February 2022. Random-effects models of between-group mean differences were estimated. Heterogeneity analyses were performed by means of the chi-square test and I² index. Subgroup analyses and meta-regressions were used to test the influence of potential moderator variables on the effect of exercise.

RESULTS

We found a FMD increase of 3.09% (95% confidence interval [CI] = 2.01, 4.17) in favour of aerobic-based CR programmes compared with control groups in patients with HF and reduced ejection fraction (HFrEF). However, the results of included studies were inconsistent (p < .001; I² = 95.2%). Higher FMD improvement was found in studies which were randomised, reported radial FMD, or performed higher number of training sessions a week. Moreover, HIIT enhanced FMD to a greater extent than MIT (2.35% [95% CI = 0.49, 4.22]) in patients with HFrEF. Insufficient data prevented pooled analyses for the effect of exercise in patients with HF and preserved ejection fraction and the influence of exercise modality on the improvement of endothelial function.

CONCLUSION

Aerobic-based CR is a non-pharmacological treatment for enhancing endothelial function in patients with HFrEF. However, higher training frequency and HIIT induce greater adaptation of endothelial function in these patients, which should betaken into consideration when designing exercise-based CR programmes. Trial registration The protocol was prospectively registered on the PROSPERO database (CRD42022304687).

High-intensity interval training improves the vascular endothelial function comparing moderate-intensity interval training in overweight or obese adults: A meta-analysis

OBJECTIVE

Obesity is associated with endothelial dysfunction and cardiovascular diseases. Moderate-intensity continuous training (MICT) is a common method to improve endothelial function and the cardiovascular risk profile in obesity. However, in recent times, high-intensity interval training (HIIT) has become a popular alternative for MICT primarily because of its time efficiency. Therefore, we hypothesized that HIIT is superior to MICT in improving vascular function. We aimed to evaluate this hypothesis by conducting a meta-analysis and quantifying the effect of HIIT on flow-mediated dilation (FMD) in overweight/obese adults.

METHODS

Databases (Scopus, Web of Science, and PubMed) were searched up to January 2022 for HIIT vs. moderate-intensity interval training (MICT) and HIIT vs. control (CON) studies on endothelial function assessed by flow-mediated dilation (FMD) in overweight and obese adults. From the included studies, standardized mean difference (SMD) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

8 studies with 208 participants were included in this meta-analysis. According to the 6 studies, HIIT improved the FMD with an overall change of %2.6 [(95% CI: 0.82 to 4.377), p = 0.004] compared to the MICT in overweight and obese adults. Moreover, based on the 5 studies that compared HIIT and CON, the results showed HIIT significantly increased FMD by 1.83% [(95% CI: 0.478 to 3.187), p = 0.008].

CONCLUSIONS

These results showed that exercise training, particularly HIIT, could improve endothelial function in overweight and obese adults.

Associations between Objectively Measured Patterns of Sedentary Behavior and Arterial Stiffness in Chinese Community-Dwelling Older Women

AIMS

Arterial stiffness is an important risk factor of arteriosclerosis and cardiovascular events. Sedentary behavior (SB) is associated with increased risk for chronic cardiovascular diseases and poor health outcomes. This study aims to investigate the associations of objectively measured patterns of SB with arterial stiffness in Chinese community-dwelling older women.

METHODS AND RESULTS

Cross-sectional data were derived from the baseline survey of the Physical Activity and Health in Older Women Study (PAHIOWS). Arterial stiffness was evaluated through cardio-ankle vascular index (CAVI), CAVI ≥ 9 was defined as cutoff point. SB patterns including sedentary time in SB bouts of ≥10, 30 and 60 min, number of SB bouts ≥ 10, 30 and 60 min, were measured via tri-axial accelerometers. Multivariate logistic regression was used to investigate associations of different SB patterns with arterial stiffness. Of the total 1125 women aged 60-70, the prevalence of CAVI ≥ 9 was 25.8%. After adjustment for confounding factors, only sedentary time in SB bout ≥ 30 min and 60 min, number of SB bouts ≥ 60 min were associated with arterial stiffness, with an adjusted odds ratio (95% confidence interval) of 1.06 (1.00-1.12) and 1.11 (1.03-1.20) per 30 min increase per day, 1.35 (1.05-1.74) per bout per day, respectively.

CONCLUSIONS

Longer duration of prolonged SB periods was associated with higher level of arterial stiffness. Shortening and interrupting accumulated periods of SB may be an achievable strategy to reduce risk of cardiovascular disease in self-care and cardiovascular nursing.

Protective cardiovascular benefits of exercise training as measured by circulating endothelial cells and high-density lipoprotein in adults

Objective

This study aims to determine the protective cardiovascular effect of aerobic exercise training by measuring cluster of differentiation 146 (CD146), circulating endothelial cell (CEC), and high-density lipoprotein-cholesterol (HDL-C) levels in adults.

Methods

This study was an experimental pre-post-test without a control group. Forty-five participants were divided into three groups based on aerobic exercise training intensity: low, moderate, and high. Whole blood samples were measured for HDL-C levels. In addition, CEC was isolated from Peripheral Blood Mononuclear Cells (PBMC) samples, then identified by CD146 marker using flow cytometry.

Results

CEC percentage and HDL-C increase after aerobic exercise training. There was a significant difference in CEC percentage between the intensity groups. However, there was no difference in HDL-C levels.

Conclusion

Aerobic exercise training can protect cardiovascular health by stimulating CEC mobilization, identified by CD146. In addition, an HDL-C level increase also contributes to cardiovascular protection by decreasing inflammation levels, inhibiting low-density lipoprotein-cholesterol oxidation, improving endothelial regeneration capabilities, and lowering blood glucose.

Cardiac Rehabilitation Improves Endothelial Function in Coronary Artery Disease Patients

Exercise-based cardiac rehabilitation may be an effective non-pharmacological intervention for improving endothelial function in coronary artery disease patients. Therefore, this systematic review with meta-analysis aimed to (a) estimate the training-induced effect on endothelial and vascular smooth muscle function, assessed by flow-mediated dilation and nitroglycerin-mediated dilation, respectively, in coronary artery disease patients; and to (b) study the influence of potential trial-level variables (i. e. study and intervention characteristics) on the training-induced effect on endothelial and vascular smooth muscle function. Electronic searches were performed in Pubmed, Scopus, and Embase up to February 2021. Random-effects models of standardised mean change were estimated. Heterogeneity analyses were performed by using the Chi ² test and I ² index. Our results showed that exercise-based cardiac rehabilitation significantly enhanced flow-mediated dilation (1.04 [95% confidence interval=0.76 to 1.31]) but did not significantly change nitroglycerin-mediated dilation (0.05 [95% confidence interval=-0.03 to 0.13]). Heterogeneity testing reached statistical significance (p<.001) with high inconsistency for flow-mediated dilation (I ² =92%). Nevertheless, none of the analysed variables influenced the training-induced effect on flow-mediated dilation. Exercise-based cardiac rehabilitation seems to be an effective therapeutic strategy for improving endothelial-dependent dilation in coronary artery disease patients, which may aid in the prevention of cardiovascular events.

Endothelial Progenitor Cell Response to Acute Multicomponent Exercise Sessions with Different Durations

It is widely accepted that exercise training has beneficial effects on vascular health. Although a dose-dependent relation has been suggested, little is known about the effects of different exercise durations on endothelial markers. This study aimed to assess the effect of single exercise sessions with different durations in the circulating levels of endothelial progenitor cells (EPCs) and endothelial cells (CECs) among adults with cardiovascular risk factors. Ten participants performed two multicomponent exercise sessions, one week apart, lasting 30 and 45 min (main exercise phase). Before and after each exercise session, blood samples were collected to quantify EPCs and CECs by flow cytometry. The change in EPCs was significantly different between sessions by 3.0% (95% CI: 1.3 to 4.7), being increased by 1.8 ± 1.7% (p = 0.009) in the 30 min session vs. −1.2 ± 2.0% (p > 0.05) in the 45 min session. No significant change was observed in CECs [−2.0%, 95%CI: (−4.1 to 0.2)] between the sessions. In conclusion, a multicomponent exercise session of 30 min promotes an acute increase in the circulating levels of EPCs without increasing endothelial damage (measured by the levels of CECs) among adults with cardiovascular risk factors.

The impact of different forms of exercise on circulating endothelial progenitor cells in cardiovascular and metabolic disease

Circulating endothelial progenitor cells (EPCs) contribute to vascular repair and their monitoring could have prognostic clinical value. Exercise is often prescribed for the management of cardiometabolic diseases, however, it is not fully understood how it regulates EPCs.

OBJECTIVES

to systematically examine the acute and chronic effects of different exercise modalities on circulating EPCs in patients with cardiovascular and metabolic disease.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

six electronic databases and reference lists of eligible studies were searched to April 2021. Thirty-six trials met the inclusion criteria including 1731 participants. Acute trials: in chronic heart failure (CHF), EPC mobilisation was acutely increased after high intensity interval or moderate intensity continuous exercise training, while findings were inconclusive after a cardiopulmonary cycling exercise test. Maximal exercise tests acutely increased EPCs in ischaemic or revascularized coronary artery disease (CAD) patients. In peripheral arterial disease (PAD), EPC levels increased up to 24 h post-exercise. In patients with compromised metabolic health, EPC mobilisation was blunted after a single exercise session. Chronic trials: in CHF and acute coronary syndrome, moderate intensity continuous protocols, with or without resistance exercise or calisthenics, increased EPCs irrespective of EPC identification phenotype. Findings were equivocal in CAD regardless of exercise mode, while in severe PAD disease EPCs increased. High intensity interval training increased EPCs in hypertensive metabolic syndrome and heart failure reduced ejection fraction.

CONCLUSION

the clinical condition and exercise modality influence the degree of EPC mobilisation and magnitude of EPC increases in the long term.

The impact of different forms of exercise on endothelial progenitor cells in healthy populations

Circulating endothelial progenitor cells (EPCs) contribute to vascular healing and neovascularisation, while exercise is an effective means to mobilise EPCs into the circulation.

OBJECTIVES

to systematically examine the acute and chronic effects of different forms of exercise on circulating EPCs in healthy populations.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

thirty-one articles met the inclusion criteria including 747 participants aged 19 to 76 years. All included trials used flow cytometry for identification of circulating EPCs. Eight and five different EPC phenotypes were identified in the acute and chronic trials, respectively. In the acute trials, moderate intensity continuous (MICON), maximal, prolonged endurance, resistance and high intensity interval training (HIIT) exercise protocols were utilised. Prolonged endurance and resistance exercise had the most profound effect on circulating EPCs followed by maximal exercise. In the chronic trials, MICON exercise, HIIT, HIIT compared to MICON and MICON compared to exergame (exercise modality based on an interactive video game) were identified. MICON exercise had a positive effect on circulating EPCs in older sedentary individuals which was accompanied by improvements in endothelial function and arterial stiffness. Long-stage HIIT (4 min bouts) appears to be an effective means and superior than MICON exercise in mobilising circulating EPCs. In conclusion, both in acute and chronic trials the degree of exercise-induced EPC mobilisation depends upon the exercise regime applied. In future, more research is warranted to examine the dose-response relationship of different exercise forms on circulating EPCs using standardised methodology and EPC phenotype.

Effects of Different Intensities and Durations of Aerobic Exercise on Vascular Endothelial Function in Middle-Aged and Elderly People: A Meta-analysis

Background

Previous studies have found that aerobic exercise was more effective in improving vascular endothelial function than resistance training, high-intensity interval training (HIIT), and other types of exercise, while the effects between different intensities and durations of aerobic exercise were unclear. Therefore, we performed this meta-analysis to investigate the effects of different intensities and durations of aerobic exercise on the vascular endothelial function of middle-aged and elderly people.

Methods:

Databases were searched up to April 2021 for studies evaluating the influences of different intensities and durations of aerobic exercise on endothelial function assessed by flow-mediated dilation (FMD) among healthy middle-aged and elderly people. Data were pooled using random-effects models to obtain the weighted mean difference (WMD) and 95% confidence intervals (CIs).

Results

A total of 9 studies involving 221 participants fulfilled the inclusion criteria. Aerobic exercise improved the overall FMD of healthy middle-aged and elderly people [WMD, 1.33 (95% CI, 0.37–2.28), P < 0.05]. Specifically, vigorous-intensity exercise increased FMD significantly in healthy middle-aged and elderly people [WMD, 1.10 (95% CI, 0.27–1.93), P < 0.05], while moderate-intensity exercise had no significant association with FMD [WMD, 1.49 (95% CI, −0.62 to 3.60), P = 0.17]. In addition, long-term (8 weeks or above) aerobic exercise increased the FMD in healthy middle-aged and elderly people [WMD, 1.63 (95% CI, 0.61–2.66), P < 0.05], while one-time acute aerobic exercise had no significant association with FMD of healthy middle-aged and elderly people [WMD, 0.89 (95% CI, −1.47 to 3.24), P = 0.46]. Specifically, 8 weeks or above of vigorous-intensity exercise increased FMD significantly in healthy middle-aged and elderly people [WMD, 1.48 (95% CI, 1.06–1.90), P < 0.01], while 8 weeks or above of moderate aerobic exercise had no significant association with FMD [WMD, 1.49 (95% CI, −0.62 to 3.60), P = 0.17].

Conclusion

Aerobic exercise, especially 8 weeks or above of vigorous-intensity aerobic exercise, improved the endothelial function in healthy middle-aged and elderly people.

The impact of different forms of exercise on circulating endothelial progenitor cells in cardiovascular and metabolic disease

Circulating endothelial progenitor cells (EPCs) contribute to vascular repair and their monitoring could have prognostic clinical value. Exercise is often prescribed for the management of cardiometabolic diseases, however, it is not fully understood how it regulates EPCs.

OBJECTIVES

to systematically examine the acute and chronic effects of different exercise modalities on circulating EPCs in patients with cardiovascular and metabolic disease.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

six electronic databases and reference lists of eligible studies were searched to April 2021. Thirty-six trials met the inclusion criteria including 1731 participants. Acute trials: in chronic heart failure (CHF), EPC mobilisation was acutely increased after high intensity interval or moderate intensity continuous exercise training, while findings were inconclusive after a cardiopulmonary cycling exercise test. Maximal exercise tests acutely increased EPCs in ischaemic or revascularized coronary artery disease (CAD) patients. In peripheral arterial disease (PAD), EPC levels increased up to 24 h post-exercise. In patients with compromised metabolic health, EPC mobilisation was blunted after a single exercise session. Chronic trials: in CHF and acute coronary syndrome, moderate intensity continuous protocols, with or without resistance exercise or calisthenics, increased EPCs irrespective of EPC identification phenotype. Findings were equivocal in CAD regardless of exercise mode, while in severe PAD disease EPCs increased. High intensity interval training increased EPCs in hypertensive metabolic syndrome and heart failure reduced ejection fraction.

CONCLUSION

the clinical condition and exercise modality influence the degree of EPC mobilisation and magnitude of EPC increases in the long term.

MOTS-c and Exercise Restore Cardiac Function by Activating of NRG1-ErbB Signaling in Diabetic Rats

Pathologic cardiac remodeling and dysfunction are the most common complications of type 2 diabetes. Physical exercise is important in inhibiting myocardial pathologic remodeling and restoring cardiac function in diabetes. The mitochondrial-derived peptide MOTS-c has exercise-like effects by improving insulin resistance, combatting hyperglycemia, and reducing lipid accumulation. We investigated the effects and transcriptomic profiling of MOTS-c and aerobic exercise on cardiac properties in a rat model of type 2 diabetes which was induced by feeding a high fat high sugar diet combined with an injection of a low dose of streptozotocin. Both aerobic exercise and MOTS-c treatment reduced abnormalities in cardiac structure and function. Transcriptomic function enrichment analysis revealed that MOTS-c had exercise-like effects on inflammation, myocardial apoptosis, angiogenesis and endothelial cell proliferation and migration, and showed that the NRG1-ErbB4 pathway might be an important component in both MOTS-c and exercise induced attenuation of cardiac dysfunction in diabetes. Moreover, our findings suggest that MOTS-c activates NRG1-ErbB4 signaling and mimics exercise-induced cardio-protection in diabetes.

Exercise training in heart transplantation

Heart transplantation remains the gold standard in the treatment of end-stage heart failure (HF). Heart transplantation patients present lower exercise capacity due to cardiovascular and musculoskeletal alterations leading thus to poor quality of life and reduction in the ability of daily self-service. Impaired vascular function and diastolic dysfunction cause lower cardiac output while decreased skeletal muscle oxidative fibers, enzymes and capillarity cause arteriovenous oxygen difference, leading thus to decreased peak oxygen uptake in heart transplant recipients. Exercise training improves exercise capacity, cardiac and vascular endothelial function in heart transplant recipients. Pre-rehabilitation regular aerobic or combined exercise is beneficial for patients with end-stage HF awaiting heart transplantation in order to maintain a higher fitness level and reduce complications afterwards like intensive care unit acquired weakness or cardiac cachexia. All hospitalized patients after heart transplantation should be referred to early mobilization of skeletal muscles through kinesiotherapy of the upper and lower limbs and respiratory physiotherapy in order to prevent infections of the respiratory system prior to hospital discharge. Moreover, all heart transplant recipients after hospital discharge who have not already participated in an early cardiac rehabilitation program should be referred to a rehabilitation center by their health care provider. Although high intensity interval training seems to have more benefits than moderate intensity continuous training, especially in stable transplant patients, individualized training based on the abilities and needs of each patient still remains the most appropriate approach. Cardiac rehabilitation appears to be safe in heart transplant patients. However, long-term follow-up data is incomplete and, therefore, further high quality and adequately-powered studies are needed to demonstrate the long-term benefits of exercise training in this population.

Pulmonary Endothelial Dysfunction and Thrombotic Complications in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new strain of a Coronaviridae virus that presents 79% genetic similarity to the severe acute respiratory syndrome coronavirus, has been recently recognized as the cause of a global pandemic by the World Health Organization, implying a major threat to world public health. SARS-CoV-2 infects host human cells by binding through the viral spike proteins to the ACE-2 (angiotensin-converting enzyme 2) receptor, fuses with the cell membrane, enters, and starts its replication process to multiply its viral load. Coronavirus disease (COVID-19) was initially considered a respiratory infection that could cause pneumonia. However, in severe cases, it extends beyond the respiratory system and becomes a multiorgan disease. This transition from localized respiratory infection to multiorgan disease is due to two main complications of COVID-19. On the one hand, it is due to the so-called cytokine storm: an uncontrolled inflammatory reaction of the immune system in which defensive molecules become aggressive for the body itself. On the other hand, it is due to the formation of a large number of thrombi that can cause myocardial infarction, stroke, and pulmonary embolism. The pulmonary endothelium actively participates in these two processes, becoming the last barrier before the virus spreads throughout the body. In this review, we examine the role of the pulmonary endothelium in response to COVID-19, the existence of potential biomarkers, and the development of novel therapies to restore vascular homeostasis and to protect and/or treat coagulation, thrombosis patients. In addition, we review the thrombotic complications recently observed in patients with COVID-19 and its potential threatening sequelae.

Systemic Inflammation, Vascular Function, and Endothelial Progenitor Cells after an Exercise Training Intervention in COPD

BACKGROUND

Exercise training is a cornerstone of the treatment of chronic obstructive pulmonary disease (COPD) in all disease stages. Data about the training effects with supplemental oxygen in nonhypoxemic patients remains inconclusive. In this study we set out to investigate the training and oxygen effects on inflammatory markers, vascular function, and endothelial progenitor cells in this population of increased cardiovascular risk.

METHODS

In this prospective, randomized, double-blind, crossover study, 29 patients with nonhypoxemic COPD performed combined endurance and strength training 3 times a week while breathing medical air or supplemental oxygen for the first 6-week period, and were then reallocated to the opposite gas for the following 6 weeks. Exercise capacity, inflammatory biomarkers, endothelial function (peripheral arterial tone analysis), and endothelial progenitor cells were assessed. Data were also analyzed for a subgroup with endothelial dysfunction (reactive hyperemia index <1.67).

RESULTS

Following 12 weeks of exercise training, patients demonstrated a significant improvement of peak work rate and an associated decrease of blood fibrinogen and leptin. Eosinophils were found significantly reduced after exercise training in patients with endothelial dysfunction. In this subgroup, peripheral arterial tone analysis revealed a significant improvement of reactive hyperemia index. Generally, late endothelial progenitor cells were found significantly reduced after the exercise training intervention. Supplemental oxygen during training positively influenced the effect on exercise capacity without impact on inflammation and endothelial function.

CONCLUSIONS

This is the first randomized controlled trial in patients with COPD to show beneficial effects of exercise training not only on exercise capacity, but also on systemic/eosinophilic inflammation and endothelial dysfunction.

Changes in Circulating Stem and Progenitor Cell Numbers Following Acute Exercise in Healthy Human Subjects: a Systematic Review and Meta-analysis

Despite of the increasing number of investigations on the effects of acute exercise on circulating stem and progenitor cell (SC) numbers, and in particular on respective subgroups, i.e. endothelial (ESC), hematopoietic (HSC), and mesenchymal (MSC) stem and progenitor cells, a consensus regarding mechanisms and extent of these effects is still missing. The aim of this meta-analysis was to systematically evaluate the overall-effects of acute exercise on the different SC-subgroups and investigate possible subject- and intervention-dependent factors affecting the extent of SC-mobilization in healthy humans. Trials assessing SC numbers before and at least one timepoint after acute exercise, were identified in a systematic computerized search. Compared to baseline, numbers were significantly increased for early and non-specified SCs (enSCs) until up to 0.5 h after exercise (0–5 min: +0.64 [Standardized difference in means], p < 0.001; 6–20 min: +0.42, p < 0.001; 0.5 h: +0.29, p = 0.049), for ESCs until 12–48 h after exercise (0–5 min: +0.66, p < 0.001; 6–20 min: +0.43 p < 0.001; 0.5 h: +0.43, p = 0.002; 1 h: +0.58, p = 0.001; 2 h: +0.50, p = 0.002; 3–8 h: +0.70, p < 0.001; 12–48 h: +0.38, p = 0.003) and for HSCs at 0–5 min (+ 0.47, p < 0.001) and at 3 h after exercise (+ 0.68, p < 0.001). Sex, intensity and duration of the intervention had generally no influence. The extent and kinetics of the exercise-induced mobilization of SCs differ between SC-subpopulations. However, also definitions of SC-subpopulations are non-uniform. Therefore, finding a consensus with a clear definition of cell surface markers defining ESCs, HSCs and MSCs is a first prerequisite for understanding this important topic.

Endothelial progenitor cells mobilization after maximal exercise according to heart failure severity

BACKGROUND

Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Patients with CHF are characterized by impaired vasodilation and inflammation of the vascular endothelium. They also have low levels of endothelial progenitor cells (EPCs). EPCs are bone marrow derived cells involved in endothelium regeneration, homeostasis, and neovascularization. Exercise has been shown to improve vasodilation and stimulate the mobilization of EPCs in healthy people and patients with cardiovascular comorbidities. However, the effects of exercise on EPCs in different stages of CHF remain under investigation.

AIM

To evaluate the effect of a symptom-limited maximal cardiopulmonary exercise testing (CPET) on EPCs in CHF patients of different severity.

METHODS

Forty-nine consecutive patients (41 males) with stable CHF [mean age (years): 56 ± 10, ejection fraction (EF, %): 32 ± 8, peak oxygen uptake (VO₂, mL/kg/min): 18.1 ± 4.4] underwent a CPET on a cycle ergometer. Venous blood was sampled before and after CPET. Five circulating endothelial populations were quantified by flow cytometry: Three subgroups of EPCs [CD34⁺/CD45^-/CD133⁺, CD34⁺/CD45^-/CD133⁺/VEGFR₂ and CD34⁺/CD133⁺/vascular endothelial growth factor receptor 2 (VEGFR₂)] and two subgroups of circulating endothelial cells (CD34⁺/CD45^-/CD133^- and CD34⁺/CD45^-/CD133^-/VEGFR₂). Patients were divided in two groups of severity according to the median value of peak VO₂ (18.0 mL/kg/min), predicted peak VO₂ (65.5%), ventilation/carbon dioxide output slope (32.5) and EF (reduced and mid-ranged EF). EPCs values are expressed as median (25th-75th percentiles) in cells/10⁶ enucleated cells.

RESULTS

Patients with lower peak VO₂ increased the mobilization of CD34⁺/CD45^-/CD133⁺ [pre CPET: 60 (25-76) vs post CPET: 90 (70-103) cells/10⁶ enucleated cells, P < 0.001], CD34⁺/CD45^-/CD133⁺/VEGFR₂ [pre CPET: 1 (1-4) vs post CPET: 5 (3-8) cells/10⁶ enucleated cells, P < 0.001], CD34⁺/CD45^-/CD133^- [pre CPET: 186 (141-361) vs post CPET: 488 (247-658) cells/10⁶ enucleated cells, P < 0.001] and CD34⁺/CD45^-/CD133^-/VEGFR₂ [pre CPET: 2 (1-2) vs post CPET: 3 (2-5) cells/10⁶ enucleated cells, P < 0.001], while patients with higher VO₂ increased the mobilization of CD34⁺/CD45^-/CD133⁺ [pre CPET: 42 (19-73) vs post CPET: 90 (39-118) cells/10⁶ enucleated cells, P < 0.001], CD34⁺/CD45^-/CD133⁺/VEGFR₂ [pre CPET: 2 (1-3) vs post CPET: 6 (3-9) cells/10⁶ enucleated cells, P < 0.001], CD34⁺/CD133⁺/VEGFR₂ [pre CPET: 10 (7-18) vs post CPET: 14 (10-19) cells/10⁶ enucleated cells, P < 0.01], CD34⁺/CD45^-/CD133^- [pre CPET: 218 (158-247) vs post CPET: 311 (254-569) cells/10⁶ enucleated cells, P < 0.001] and CD34⁺/CD45^-/CD133^-/VEGFR₂ [pre CPET: 1 (1-2) vs post CPET: 4 (2-6) cells/10⁶ enucleated cells, P < 0.001]. A similar increase in the mobilization of at least four out of five cellular populations was observed after maximal exercise within each severity group regarding predicted peak, ventilation/carbon dioxide output slope and EF as well (P < 0.05). However, there were no statistically significant differences in the mobilization of endothelial cellular populations between severity groups in each comparison (P > 0.05).

CONCLUSION

Our study has shown an increased EPCs and circulating endothelial cells mobilization after maximal exercise in CHF patients, but this increase was not associated with syndrome severity. Further investigation, however, is needed.

Acute Exercise-Induced Oxidative Stress Does Not Affect Immediate or Delayed Precursor Cell Mobilization in Healthy Young Males

Exercise is known to acutely and transiently mobilize precursor cells to the peripheral blood. To date, the underlying mechanisms have not yet been fully elucidated and we hypothesized that exercise-induced oxidative stress could be a mobilizing agent, either directly or via circulating apoptotic cells as mediators. The aim of the study was to assess the effect of acute exercise-induced oxidative stress on numbers of circulating angiogenic precursor cells (CACs), circulating non-angiogenic precursor cells (nCACs), mesenchymal precursor cells (MPCs), mature endothelial cells (ECs), and mononuclear cells (MNCs), as well as their apoptotic subsets. Healthy, young males (n = 18, age: 24.2 ± 3.5 years) completed two identical, standardized incremental cycling tests. The first, un-supplemented control test was followed by a 7-day-long supplementation of vitamin C (1,000 mg/day) and E (400 I.U./day), immediately preceding the second test. Blood samples were collected before, directly after, 30, 90, 180, and 270 min after exercise, and aforementioned circulating cell numbers were determined by flow cytometry and a hematology analyzer. Additionally, total oxidative capacity (TOC) and total antioxidative capacity (TAC) were measured in serum at all timepoints. Antioxidative supplementation abolished the exercise-induced increase in the oxidative stress index (TOC/TAC), and reduced baseline concentrations of TOC and TOC/TAC. However, it did not have any effect on CACs, nCACs, and MPC numbers or the increase in apoptotic MNCs following exercise. Our results indicate that exercise-induced oxidative stress is neither a main driver of lymphocyte and monocyte apoptosis, nor one of the mechanisms involved in the immediate or delayed mobilization of precursor cells.

Association of the Amount and Pattern of Physical Activity With Arterial Stiffness: The Maastricht Study

Background Arterial stiffness is an independent risk factor for cardiovascular disease and can be beneficially influenced by physical activity. However, it is not clear how an individual's physical activity pattern over a week is associated with arterial stiffness. Therefore, we examined the associations of the amount and pattern of higher intensity physical activity with arterial stiffness. Methods and Results Data from the Maastricht Study (n=1699; mean age: 60±8 years, 49.4% women, 26.9% type 2 diabetes mellitus) were used. Arterial stiffness was assessed by carotid-to-femoral pulse wave velocity and carotid distensibility. The amount (continuous variable as h/wk) and pattern (categorical variable) of higher intensity physical activity were assessed with the activPAL3. Activity groups were: inactive (<75 min/wk), insufficiently active (75-150 min/wk), weekend warrior (>150 min/wk in ≤2 sessions), and regularly active (>150 min/wk in ≥3 sessions). In the fully adjusted model (adjusted for demographic, lifestyle, and cardiovascular risk factors), higher intensity physical activity was associated with lower carotid-to-femoral pulse wave velocity (amount: β = -0.05, 95% CI, -0.09 to -0.01; insufficiently active: β = -0.33, 95% CI, -0.55 to -0.11; weekend warrior: β = -0.38, 95% CI, -0.64 to -0.12; and regularly active: β = -0.46, 95% CI, -0.71 to -0.21 [reference: inactive]). These associations were stronger in those with type 2 diabetes mellitus. There was no statistically significant association between higher intensity physical activity with carotid distensibility. Conclusions Participating in higher intensity physical activity was associated with lower carotid-to-femoral pulse wave velocity, but there was no difference between the regularly actives and the weekend warriors. From the perspective of arterial stiffness, engaging higher intensity physical activity, regardless of the weekly pattern, may be an important strategy to reduce the risk of cardiovascular disease, particularly in individuals with type 2 diabetes mellitus.

Does High Volume of Exercise Training Increase Aseptic Vascular Inflammation in Male Athletes?

Aseptic vascular inflammation can be caused by high levels of various inflammatory and apoptotic factors such as tumor necrosis factor (TNFα), nitric oxide (NO), 3-nitrotyrosine (3-Nitro), and free and oxidized low-density lipoproteins (oxLDL) generated during intense exercise. Endothelial dysfunction resulting from enhanced inflammation has been implicated in cardiovascular disease (CVD). The purpose of the study was to observe the effects of high volume of exercise training on inflammatory mediators and their interaction with conventional CVD risk factors.

Blood samples were collected from highly-trained men (n = 16, 21.8 ± 4.0 years) as well as from nonactive men (n = 20, 21.1 ± 1.1 years). NO concentration did not differ between groups while TNFα, 3-Nitro, oxLDL, and CRP levels were significantly higher in athletes compared to nonathletes. TNFα reached even 7-fold higher level in athletes and was highly correlated with CVD risk factor such as TG, lipoproteins LDL and HDL as well as CRP. Approximately 50% of physically active men demonstrated a 20% increase in non-HDL caused by high levels of TC and LDL.

These findings suggest that athletes with a high exercise volume demonstrate increased levels of circulating biomarkers of vascular inflammation and may be more likely to have CVD.

Physical activity intervention improved the number and functionality of endothelial progenitor cells in low birth weight children

BACKGROUND AND AIMS

The purpose of this study was to investigate whether an intervention with physical activity (PA) would promote positive effects on the angiogenic factors, mobilization, and functionality of circulating endothelial progenitor cells (EPCs) in children with low birth weight (LBW).

METHODS AND RESULTS

Thirty-five children participated in a 10-week PA program (intensity: 75-85% of heart rate reserve, frequency: four times/week, and duration: 45 min). Before and after the PA program, we evaluated anthropometric parameters, blood pressure levels, biochemical profile, number of EPCs, number of EPC colony forming units, and plasma levels of vascular endothelial growth factor-A (VEGF-A), nitric oxide (NO), and matrix metalloproteinases (MMPs) 2 and 9. We found a significant main effect of the PA program on waist circumference (η_p² = 0.489), cardiorespiratory fitness (η_p² = 0.463), and MMP-9 (η_p² = 0.582). Birth weight or the PA program produced significant independent effects on systolic blood pressure (birth weight: η_p² = 0.431; PA program: η_p² = 0.615) and EPC colony forming units (birth weight: η_p² = 0.541; PA program: η_p² = 0.698) with no significant interactions. The combination of birth weight and the PA program produced a significant interaction effect on the number of circulating EPCs (η_p² = 0.123), NO (η_p² = 0.258), and VEGF-A (η_p² = 0.175). The variation in the number of EPCs from baseline to 10 weeks of the PA program correlated positively with the change in NO (P = 0.002) and VEGF-A (P = 0.004).

CONCLUSIONS

A 10-week PA program attenuates the adverse effect of LBW on the number and functionality of EPCs; this effect occurs through an improvement in circulating levels of NO and VEGF-A. CLINICAL TRIALS: https://www.clinicaltrials.gov. Unique Identifier: NCT02982967. Date: December/2016.

Id-1 Promotes Reendothelialization In The Early Phase After Vascular Injury Through Activation Of NFkB/survivin Signaling Pathway

BACKGROUND

Percutaneous coronary intervention (PCI) treatment can benefit patients, but also cause irreversible mechanical damage to the vascular endothelium, ultimately leading to restenosis of the target vessel. Thus, achieving rapid re-endothelialization and restoring the integrity of the vascular endothelium and function plays an important role in inhibiting neointimal hyperplasia and preventing restenosis. Id1 (inhibitor of DNA binding/differentiation factor 1) plays an important role in promoting cell proliferation and angiogenesis.

STUDY OBJECTIVE

This study aims to investigate the relationship between Id1 and NFκB/survivin signaling pathways and their role in injured vascular repair by establishing a rat carotid balloon injury model.

METHODS

The carotid artery model of rat balloon injury was established. The injured common carotid artery was obtained at different time points after vascular injury. RNA and protein were extracted and the mRNA and protein expression levels of Id1, NFκB and survivin were detected in vascular injury. The NFκB blocker BAY 11-7082 and survivin blocker YM155 were used and the effects of Id1, NFκB, survivin mRNA and protein expression, revascularization of blood vessels and neointimal responsiveness after vascular injury were observed in the vascular tissues of Ad-Id1 transfected balloon injury.

RESULTS

Id1, NFκB and survivin were expressed in injured rat carotid arteries. Overexpression of Id1 promoted re-endothelialization of injured vessels through NFκB/survivin signaling pathway, inhibited early vascular endometrial reactive hyperplasia; blocked NFκB the/survivin signaling pathway attenuates the re-endothelialization of Ad-Id1 and the early endothelium of Ad-Id1. Blocking the NFκB/survivin signaling pathway attenuates the re-endothelialization and early reactive hyperplasia of vascular intima of Ad-Id1.

CONCLUSION

NF-kappa B/survivin signaling pathway may play an important role in Id1 promoting vascular re-endothelialization, inhibiting neointimal hyperplasia and preventing vascular restenosis.

Elevated levels of circulating microvesicles in coronary artery disease patients with type 2 diabetes and albuminuria: Effects of exercise training

OBJECTIVE

Circulating microvesicles, released from activated/apoptotic cells, are involved in vascular complications and may be looked upon as biomarkers. Albuminuria is characteristic of disease progression in type 2 diabetes mellitus. We aimed to investigate quantitative and qualitative differences of circulating microvesicles in type 2 diabetes mellitus with and without albuminuria and whether 12-month exercise training influenced expression of circulating microvesicles.

METHODS

Coronary artery disease patients with type 2 diabetes mellitus (n = 75), of which 25 had albuminuria, were included. Annexin V⁺ (AV⁺) circulating microvesicles were analysed by flow cytometry in citrated plasma. The exercise volume was 150 min per week.

RESULTS

In albuminuria patients, circulating microvesicles from endothelial-(CD146⁺/CD62E⁺/AV⁺) and endothelial-progenitor-(CD309⁺/CD34⁺/AV⁺) cells were significantly higher compared to those without (p ⩽ 0.01, both). Receiver operating characteristic curve analysis of the endothelial circulating microvesicles shows an area under the curve of 0.704 (95% confidence interval: 0.57-0.84; p = 0.004). Albuminuria patients had more circulating microvesicles derived from activated leukocytes and monocytes and monocytes carrying tissue factor (CD11b⁺/AV⁺, CD11b⁺/CD14⁺/AV⁺, CD142⁺/CD14⁺/AV⁺, respectively, p ⩽ 0.05, all) and higher number of circulating microvesicles from activated platelets (CD62P⁺/AV⁺). Within exercising patients, circulating microvesicles from progenitor cells increased (p = 0.023), however, not significantly different from controls.

CONCLUSION

Coronary artery disease patients with type 2 diabetes mellitus and albuminuria had elevated number of circulating microvesicles from activated blood and vascular cells, rendering them as potential predictors of disease severity. The circulating microvesicles were limitedly affected by long-term exercise training in our population.

Progenitor cell mobilisation and recruitment in pulmonary arteries in chronic obstructive pulmonary disease

Background

Pulmonary vascular abnormalities are a characteristic feature of chronic obstructive pulmonary disease (COPD). Cigarette smoking is the most important risk factor for COPD. It is believed that its constant exposure triggers endothelial cell damage and vascular remodelling. Under pathological conditions, progenitor cells (PCs) are mobilized from the bone marrow and recruited to sites of vascular injury. The aim of the study was to investigate whether in COPD the number of circulating PCs is related to the presence of bone marrow-derived cells in pulmonary arteries and the association of these phenomena to both systemic and pulmonary endothelial dysfunction.

Methods

Thirty-nine subjects, 25 with COPD, undergoing pulmonary resection because of a localized carcinoma, were included. The number of circulating PCs was assessed by flow cytometry using a triple combination of antibodies against CD45, CD133 and CD34. Infiltrating CD45⁺ cells were identified by immunohistochemistry in pulmonary arteries. Endothelial function in systemic and pulmonary arteries was measured by flow-mediated dilation and adenosine diphosphate-induced vasodilation, respectively.

Results

COPD patients had reduced numbers of circulating PCs (p < 0.05) and increased numbers of CD45⁺ cells (< 0.05) in the pulmonary arterial wall than non-COPD subjects, being both findings inversely correlated (r = − 0.35, p < 0.05). In pulmonary arteries, the number of CD45⁺ cells correlated with the severity of vascular remodelling (r = 0.4, p = 0.01) and the endothelium-dependent vasodilation (r = − 0.3, p = 0.05). Systemic endothelial function was unrelated to the number of circulating PCs and changes in pulmonary vessels.

Conclusion

In COPD, the decrease of circulating PCs is associated with their recruitment in pulmonary arteries, which in turn is associated with endothelial dysfunction and vessel remodelling, suggesting a mechanistic link between these phenomena. Our findings are consistent with the notion of an imbalance between endothelial damage and repair capacity in the pathogenesis of pulmonary vascular abnormalities in COPD.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1024-z) contains supplementary material, which is available to authorized users.

Exercise training and endothelial function in patients with type 2 diabetes: a meta-analysis

BACKGROUND AND AIMS

Exercise training is considered a cornerstone in the management of type 2 diabetes, which is associated with impaired endothelial function. However, the association of exercise training with endothelial function in type 2 diabetes patients has not been fully understood. This meta-analysis aimed to investigate their associations with focus on exercise types.

METHODS

Databases were searched up to January 2018 for studies evaluating the influences of exercise training with durations ≥ 8 weeks on endothelial function assessed by flow-mediated dilation (FMD) among type 2 diabetes patients or between type 2 diabetics and non-diabetics. Data were pooled using random-effects models to obtain the weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RESULTS

Sixteen databases were included. Exercise training resulted in an overall improvement in FMD by 1.77% (95% CI 0.94-2.59%) in type 2 diabetes patients. Specifically, both aerobic and combined aerobic and resistance exercise increased FMD by 1.21% (95% CI 0.23-2.19%) and 2.49% (95% CI 1.17-3.81%), respectively; but resistance exercise only showed a trend. High-intensity interval aerobic exercise did not significantly improve FMD over moderate-intensity continuous exercise. Notably, the improvement in FMD among type 2 diabetes patients was smaller compared with non-diabetics in response to exercise training (WMD - 0.72%, 95% CI - 1.36 to - 0.08%) or specifically to aerobic exercise (WMD - 0.65%, 95% CI - 1.31 to 0.01%).

CONCLUSIONS

Exercise training, in particular aerobic and combined exercise, improves endothelial function in type 2 diabetes patients, but such an improvement appears to be weakened compared with non-diabetics. Trial registration PROSPERO CRD42018087376.

Aerobic exercise prevents rarefaction of pial collaterals and increased stroke severity that occur with aging

Variation in extent of the brain's collateral circulation is an important determinant of variation in the severity of stroke and efficacy of revascularization therapies. However, the number and diameter of pial collateral "arterioles" decrease with aging in associated with reduced eNOS and increased oxidative stress. We tested whether exercise reduces this aging-induced rarefaction. Twelve-month-old mice were randomized to sedentary or voluntary wheel-running. At 26 months' age, permanent MCA occlusion was followed 72 h later by determination of infarct volume and vascular casting after maximal dilation. The decline in collateral number and diameter and 2.4-fold increase in infarct volume evident in 26-versus 3-month-old sedentary mice were prevented by exercise-training. In contrast, number and diameter of the posterior communicating collateral "arteries" were unaffected by aging or exercise. Interestingly, diameter of the primary intracranial arteries increased with aging. Mechanistically, genetic overexpression of eNOS inhibited age-induced collateral rarefaction, and exercise increased eNOS and SOD2 and decreased the inflammatory marker NFkB assessed in hindlimb arteries. In conclusion, exercise prevented age-induced rarefaction of pial collaterals and reduced infarct volume. Aging also promoted outward remodeling of intracranial arteries. These effects were associated with increased eNOS and reduced markers of inflammation and aging in the vascular wall.

Effects of Chronic Exercise on Endothelial Progenitor Cells and Microparticles in Professional Runners

Background

The effects of chronic exposure to exercise training on vascular biomarkers have been poorly explored.

Objective

Our study aimed to compare the amounts of endothelial progenitor cells (EPCs), and endothelial (EMP) and platelet (PMP) microparticles between professional runners and healthy controls.

Methods

Twenty-five half-marathon runners and 24 age- and gender-matched healthy controls were included in the study. EPCs (CD34+/KDR+, CD133+/KDR+, and CD34+/CD133+), EMP (CD51+) and PMP (CD42+/CD31+) were quantified by flow-cytometry. All blood samples were obtained after 12 h of fasting and the athletes were encouraged to perform their routine exercises on the day before.

Results

As compared with controls, the CD34+/KDR+ EPCs (p=0.038) and CD133+/KDR+ EPCs (p=0.018) were increased, whereas CD34+/CD133+ EPCs were not different (p=0.51) in athletes. In addition, there was no difference in MPs levels between the groups.

Conclusion

Chronic exposure to exercise in professional runners was associated with higher percentage of EPCs. Taking into account the similar number of MPs in athletes and controls, the study suggests a favorable effect of exercise on these vascular biomarkers.

Exercise training with dietary restriction enhances circulating irisin level associated with increasing endothelial progenitor cell number in obese adults: an intervention study

Objective

Circulating endothelial progenitor cells (EPCs) correlate negatively with obesity. Previous studies have shown that exercise significantly restores circulating EPC levels in obese people; however, the underlying mechanisms have not been elucidated. Recently, irisin has been reported to have a critical role in the regulation of EPCs. This exercise-induced myokine has been demonstrated to play a therapeutic role in obesity. In this study, we hypothesized that the increase in circulating irisin may form a link with increasing EPC levels in obese people after exercise.

Methods

Seventeen obese adults completed an 8-week program of combined exercise and dietary intervention. Clinical characteristics, blood biochemistry, and circulating irisin levels of subjects were measured before and after eight weeks of training. EPC levels were evaluated via flow cytometry, and EPC migratory and adhesive functions were also determined.

Results

Circulating irisin levels significantly increased following the 8-week training program (P < 0.05). We furthermore observed an improvement in EPC numbers (P < 0.05), and EPC migratory and adhesive functions (P < 0.001 and P < 0.05, respectively) after the intervention. Additionally, we detected a positive correlation between changes in irisin and changes in EPC number (r = 0.52, P < 0.05).

Discussion

For the first time, a positive correlation between increasing irisin levels and increasing EPC levels has been reported after an 8-week program, consisting of exercise and dietary intervention. This result suggests a novel effect of irisin on the regulation of EPC mobilization, which might contribute to improvement of endothelial function in obese people.

Assessing the evidence: Exploring the effects of exercise on diabetic microcirculation

Diabetes mellitus (DM) is associated with cardiovascular complications. Impairment of glycemic control induces noxious glycations, an increase in oxydative stress and dearangement of various metabolic pathways. DM leads to dysfunction of micro- and macrovessels, connected to metabolic, endothelial and autonomic nervous system. Thus, assessing vascular reactivity might be one of the clinical tools to evaluate the impact of harmful effects of DM and potential benefit of treatment; skin and skeletal muscle microcirculation have usually been tested. Physical exercise improves vascular dysfunction through various mechanisms, and is regarded as an additional effective treatment strategy of DM as it positively impacts glycemic control, improves insulin sensitivity and glucose uptake in the target tissues, thus affecting glucose and lipid metabolism, and increases the endothelium dependent vasodilation. Yet, not all patients respond in the same way so titrating the exercise type individualy would be desirable. Resistance training has, apart from aerobic one, been shown to positively correlate to glycemic control, and improve vascular reactivity. It has been prescribed in various forms or in combination with aerobic training. This review would assess the impact of different modes of exercise, the mechanisms involved, and its potential positive and negative effects on treating patients with Type I and Type II DM, focusing on the recent literature.

Exercise Training and Epigenetic Regulation: Multilevel Modification and Regulation of Gene Expression

Exercise training elicits acute and adaptive long term changes in human physiology that mediate the improvement of performance and health state. The responses are integrative and orchestrated by several mechanisms, as gene expression. Gene expression is essential to construct the adaptation of the biological system to exercise training, since there are molecular processes mediating oxidative and non-oxidative metabolism, angiogenesis, cardiac and skeletal myofiber hypertrophy, and other processes that leads to a greater physiological status. Epigenetic is the field that studies about gene expression changes heritable by meiosis and mitosis, by changes in chromatin and DNA conformation, but not in DNA sequence, that studies the regulation on gene expression that is independent of genotype. The field approaches mechanisms of DNA and chromatin conformational changes that inhibit or increase gene expression and determine tissue specific pattern. The three major studied epigenetic mechanisms are DNA methylation, Histone modification, and regulation of noncoding RNA-associated genes. This review elucidates these mechanisms, focusing on the relationship between them and their relationship with exercise training, physical performance and the enhancement of health status. On this chapter, we clarified the relationship of epigenetic modulations and their intimal relationship with acute and chronic effect of exercise training, concentrating our effort on skeletal muscle, heart and vascular responses, that are the most responsive systems against to exercise training and play crucial role on physical performance and improvement of health state.

Mitochondria-specific antioxidant supplementation does not influence endurance exercise training-induced adaptations in circulating angiogenic cells, skeletal muscle oxidative capacity or maximal oxygen uptake

KEY POINTS

Reducing excessive oxidative stress, through chronic exercise or antioxidants, can decrease the negative effects induced by excessive amounts of oxidative stress. Transient increases in oxidative stress produced during acute exercise facilitate beneficial vascular training adaptations, but the effects of non-specific antioxidants on exercise training-induced vascular adaptations remain elusive. Circulating angiogenic cells (CACs) are an exercise-inducible subset of white blood cells that maintain vascular integrity. We investigated whether mitochondria-specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training in CACs, muscle mitochondrial capacity and maximal oxygen uptake in young healthy men. We show that endurance exercise training increases multiple CAC types, an adaptation that is not altered by MitoQ supplementation. Additionally, MitoQ does not affect skeletal muscle or whole-body aerobic adaptations to exercise training. These results indicate that MitoQ supplementation neither enhances nor attenuates endurance training adaptations in young healthy men.

ABSTRACT

Antioxidants have been shown to improve endothelial function and cardiovascular outcomes. However, the effects of antioxidants on exercise training-induced vascular adaptations remain elusive. General acting antioxidants combined with exercise have not impacted circulating angiogenic cells (CACs). We investigated whether mitochondria-specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training on CD3+ , CD3+ /CD31+ , CD14+ /CD31+ , CD31+ , CD34+ /VEGFR2+ and CD62E+ peripheral blood mononuclear cells (PBMCs), muscle mitochondrial capacity, and maximal oxygen uptake (VO2 max ) in healthy men aged 22.1 ± 0.7 years, with a body mass index of 26.9 ± 0.9 kg m-2 , and 24.8 ± 1.3% body fat. Analysis of main effects revealed that training induced 33, 105 and 285% increases in CD14+ /CD31+ , CD62E+ and CD34+ /VEGFR2+ CACs, respectively, and reduced CD3+ /CD31- PBMCs by 14%. There was no effect of MitoQ on CAC levels. Also independent of MitoQ supplementation, exercise training significantly increased quadriceps muscle mitochondrial capacity by 24% and VO2 max by roughly 7%. In conclusion, endurance exercise training induced increases in multiple CAC types, and this adaptation is not modified by MitoQ supplementation. Furthermore, we demonstrate that a mitochondrial-targeted antioxidant does not influence skeletal muscle or whole-body aerobic adaptations to exercise training.

Effect of targeted therapy on circulating progenitor cells in precapillary pulmonary hypertension

BACKGROUND

Endothelial dysfunction is key in the development of pulmonary hypertension (PH) and is associated with reduced number of circulating progenitor cells. Studies to date evaluating levels of circulating progenitor cells in PH have provided conflicting results. Current treatment of pulmonary arterial hypertension (PAH) and medical treatment of chronic thromboembolic pulmonary hypertension (CTEPH) targets endothelium dependent signalling pathways. The effect of PAH-targeted therapy on circulating progenitor cells has not been clearly established.

OBJECTIVES

To investigate whether levels of circulating progenitor cells in treatment-naïve patients with PAH or CTEPH differ from healthy subjects and to assess the effect of PAH-targeted therapy on the circulating levels of these progenitors.

METHODS

Thirty controls, 33 PAH and 11 CTEPH treatment-naïve patients were studied. Eighteen patients with PAH and 9 with CTEPH were re-evaluated 6-12months after starting PAH-targeted therapy. Levels of progenitors were measured by flow cytometry as CD45⁺CD34⁺ and CD45⁺CD34⁺CD133⁺ cells.

RESULTS

Compared with controls, the number of circulating progenitor cells was reduced in PAH but not in CTEPH. After 6-12months of treatment, levels of circulating progenitors increased in PAH and remained unchanged in CTEPH. Patients with lower exercise tolerance presented lower levels of circulating progenitors. No other relation was found between levels of progenitors and clinical or hemodynamic parameters.

CONCLUSIONS

Patients with PAH, but not those with CTEPH, present reduced levels of circulating progenitor cells. PAH-targeted therapy increases levels of progenitors in PAH but not in CTEPH, suggesting different involvement of progenitor cells in the pathobiology of these pulmonary hypertensive disorders.

The Beneficial Effects of Cardiac Rehabilitation on the Function and Levels of Endothelial Progenitor Cells

Cardiac rehabilitation (CR) is a comprehensive program, which mainly focusses on exercise training, disease evaluation, cardiovascular risk factors control, medication therapy, psychosocial intervention, and patient education. Although the beneficial properties of CR have been widely evidenced, its mechanism is still not completely clarified. To date, endothelial progenitor cells (EPCs) have been explored by emerging studies, and evidence has suggested that CR, especially exercise training, significantly increases the function and levels of EPCs, which is likely to elucidate the profiting mechanism of CR. Thus, this review summarises the potential relationship between CR and EPCs with an aim of providing novel directions for future CR research.

The effect of moderate-intensity acute aerobic exercise duration on the percentage of circulating CD31⁺ cells in lymphocyte population

Background: The increasing number of circulating CD31+ endothelial progenitor cells is one of the important factors for maintaining vascular homeostasis. Exercise will effectively increase the number of circulating CD31+ endothelial progenitor cells. This study aims to determine the effect of moderate-intensity acute aerobic exercise duration on the percentage of circulating CD31+ cells in untrained healthy young adult subjects.Methods: This study was an experimental study. Untrained healthy volunteers (n=20) performed ergocycle at moderate-intensity (64–74% maximum heart rate) for 10 minutes or 30 minutes. Immediately before and 10 minutes after exercise, venous blood samples were drawn. The percentage of CD31+ cells in peripheral blood was analyzed using flow cytometry. Data was statistically analyzed using student t-test.Results: There were no significant differences in the mean percentage of circulating CD31+ cells before and after exercise for 10 minutes and 30 minutes (p>0.05). However, there was a different trend in the percentage of circulating CD31+ cells after exercise for 10 minutes and 30 minutes. In the 10 minutes duration, 50% of subjects showed increase. Whereas in the 30 minutes duration, 80% of subjects showed increase.Conclusion: The percentage of circulating CD31+ cells before and after exercise for 10 minutes was not different compared to 30 minutes. However, data analysis shows that majority of subjects (80%) had increased in the percentage of circulating CD31+ cells after 30 minutes exercise.

Short-term exercise training improves flow-mediated dilation and circulating angiogenic cell number in older sedentary adults

Cardiovascular disease risk increases with age due, in part, to impaired endothelial function and decreased circulating angiogenic cell (CAC) number and function. We sought to determine if 10 days of aerobic exercise training improves endothelial function, CAC number, and intracellular redox balance in older sedentary adults. Eleven healthy subjects (4 men, 7 women), 61 ± 2 years of age participated in 60 min of aerobic exercise at 70% maximal oxygen consumption for 10 consecutive days while maintaining body weight. Before and after training, endothelial function was measured as flow-mediated dilation of the brachial artery and fasting blood was drawn to enumerate 3 CAC subtypes. Intracellular reactive oxygen species (ROS) and nitric oxide (NO) in CD34+ CACs were measured using fluorescent probes and reinforced via real-time quantitative polymerase chain reaction. Flow-mediated dilation improved significantly following training (10% ± 1.3% before vs. 16% ± 1.4% after training; P < 0.05). Likewise, CD34+/KDR+ number increased 104% and KDR+ number increased 151% (P < 0.05 for both), although CD34+ number was not significantly altered (P > 0.05). Intracellular NO and ROS levels in CD34+ CACs were not different after training (P > 0.05 for both). Messenger RNA expression of SOD1, endothelial nitric oxide synthase, and NADPH oxidase 2 and neutrophil cytosolic factor 1 in CD34+ CACs was not significantly altered with training (P > 0.05). In conclusion, 10 consecutive days of aerobic exercise increased flow-mediated dilation and CAC number in older, previously sedentary adults, but did not affect intracellular redox balance in CD34+ CACs. Overall, these data indicate that even short-term aerobic exercise training can have a significant impact on cardiovascular disease risk factors.

Flow cytometric analysis of circulating endothelial cells and endothelial progenitors for clinical purposes in oncology: A critical evaluation

Malignant tumors are characterized by uncontrolled cell growth and metastatic spread, with a pivotal importance of the phenomenon of angiogenesis. For this reason, research has focused on the development of agents targeting the vascular component of the tumor microenvironment and regulating the angiogenic switch. As a result, the therapeutic inhibition of angiogenesis has become an important component of anticancer treatment, however, its utility is partly limited by the lack of an established methodology to assess its efficacy in vivo. Circulating endothelial cells (CECs), which are rare in healthy subjects and significantly increased in different tumor types, represent a promising tool for monitoring the tumor clinical outcome and the treatment response. A cell population circulating into the blood also able to form endothelial colonies in vitro and to promote vasculogenesis is represented by endothelial progenitor cells (EPCs). The number of both of these cell types is extremely low and they cannot be identified using a single marker, therefore, in absence of a definite consensus on their phenotype, require discrimination using combinations of antigens. Multiparameter flow cytometry (FCM) is ideal for rapid processing of high numbers of cells per second and is commonly utilized to quantify CECs and EPCs, however, remains technically challenging since there is as yet no standardized protocol for the identification and enumeration of these rare events. Methodology in studies on CECs and/or EPCs as clinical biomarkers in oncology is heterogeneous and data have been obtained from different studies leading to conflicting conclusions. The present review presented a critical review of the issues that limit the comparability of results of the most significant studies employing FCM for CEC and/or EPC detection in patients with cancer.

The influence of hypoxic physical activity on cfDNA as a new marker of vascular inflammation

The phenomenon of circulating cell-free DNA (cfDNA) is important for many biomedical disciplines including the field of exercise biochemistry and physiology. It is likely that cfDNA is released into the plasma by apoptosis of endothelial cells and circulating endothelial progenitor cells (EPCs), and/or by NETosis of immune cells induced by strenuous exercise. Increases of cfDNA are described to be a potential hallmark for the overtraining syndrome, and might be related to aseptic vascular inflammation in athletes. Yet, the relevance of systemic inflammation and cfDNA with endothelial dysfunction in athletes still remains unclear. In this review article, we provide a current overview of exercise-induced cfDNA release to the circulation with special emphasis on its relationship with apoptosis and NETosis and the effect of hypoxic physical activity on vascular inflammation in athletes.

Circulating endothelial cells and their subpopulations: role as predictive biomarkers in antiangiogenic therapy for colorectal cancer

Several anticancer therapies have been developed to block angiogenesis, a key mechanism in tumor growth and metastasis. The predominantly cytostatic action of these compounds makes an assessment of their clinical activities inadequate if based only on the reduction of the tumor dimensions, as this may not reflect their true biologic efficacy. Thus, it is crucial to identify biomarkers that permit the recognition of potentially responsive subjects and to spare toxicity in those who are unlikely to benefit from treatment. Circulating endothelial cells (CECs) have been recently indicated as potential surrogate biomarkers of angiogenesis in several types of cancer. The possibility of rapidly quantifying these cells represents a promising tool for monitoring the clinical outcome of tumors with the potential to assess response to various treatments. However, the identification and quantification of CECs is technically difficult and not well standardized. A variety of methods to detect CECs in patients with solid tumors have been used; these are based on different technical approaches, combinations of surface markers, sample handling, and staining protocols. With an expanding interest in the field of potential clinical applications for CECs in oncology, the development of standardized protocols for analysis is mandatory. The aim of this review was to critically summarize the available data concerning the clinical value of CECs and their subpopulations as biomarkers of antiangiogenic therapy in patients with metastatic colorectal cancer.

Combined intermittent hypobaric hypoxia and muscle electro-stimulation: a method to increase circulating progenitor cell concentration?

BACKGROUND

Our goal was to test whether short-term intermittent hypobaric hypoxia (IHH) at a level well tolerated by healthy humans could, in combination with muscle electro-stimulation (ME), mobilize circulating progenitor cells (CPC) and increase their concentration in peripheral circulation.

METHODS

Nine healthy male subjects were subjected, as the active group (HME), to a protocol involving IHH plus ME. IHH exposure consisted of four, three-hour sessions at a barometric pressure of 540 hPa (equivalent to an altitude of 5000 m). These sessions took place on four consecutive days. ME was applied in two separate 20-minute periods during each IHH session. Blood samples were obtained from an antecubital vein on three consecutive days immediately before the experiment, and then 24 h, 48 h, 4 days, 7 days and 14 days after the last day of hypoxic exposure. Four months later a control study was carried out involving seven of the original subjects (CG), who underwent the same protocol of blood samples but without receiving any special stimulus.

RESULTS

In comparison with the CG the HME group showed only a non-significant increase in the number of CPC CD34+ cells on the fourth day after the combined IHH and ME treatment.

CONCLUSION

CPC levels oscillated across the study period and provide no firm evidence to support an increased CPC count after IHH plus ME, although it is not possible to know if this slight increase observed is physiologically relevant. Further studies are required to understand CPC dynamics and the physiology and physiopathology of the hypoxic stimulus.

Endothelial progenitor cells and pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease characterised by lung endothelial cell dysfunction and vascular remodelling. A number of studies now suggest that endothelial progenitor cells (EPCs) may induce neovascularisation and could be a promising approach for cell based therapy for PAH. On the contrary EPCs may contribute to pulmonary vascular remodelling, particularly in end-stage pulmonary disease. This review article will provide a brief summary of the relationship between PAH and EPCs, the application of the EPCs to PAH and highlight the potential clinical application of the EPCs cell therapy to PAH.

Activity of daily living is associated with circulating CD34+/KDR+ cells and granulocyte colony-stimulating factor levels in patients after myocardial infarction

The study aimed to investigate whether the extent of activities of daily living (ADL) of patients after myocardial infarction affect numbers of circulating CD34+/KDR+ and CD45+/CD34+ cells, which are supposed to protect structural and functional endothelial integrity. In a cross-sectional study, 34 male coronary artery disease patients with a history of myocardial infarction were assessed for times spent per week for specific physical ADL, including basic activities (instrumental ADL), leisure time activities, and sport activities, using a validated questionnaire. Individual specific activity times were multiplied with respective specific metabolic equivalent scores to obtain levels of specific activities. Numbers of circulating CD34+/KDR+ and CD45+/CD34+ cells were analyzed by flow cytometry. Furthermore, the colony-forming capacity of CD34+ cells and the level of granulocyte colony-stimulating factor (G-CSF) in serum were measured. Analysis revealed that the extent of total activities and basic activities, as well as total activity time, were positively correlated with numbers of circulating CD34+/KDR+ cells ( r = 0.60, 0.56, and 0.55, P < 0.05). Higher levels of total activity were also associated with increased colony-forming capacity of CD34+ cells ( r = 0.54, P < 0.05) and with higher systemic levels of G-CSF ( r = 0.44, P < 0.05). These findings indicate that even ADL-related activities of coronary artery disease patients after myocardial infarction exert stimulating effects on CD34+/KDR+ cell mobilization, potentially mediated by increased G-CSF levels. This, in turn, potentially contributes to the beneficial effects of exercise on the diseased cardiovascular system.

Androgens modulate endothelial function and endothelial progenitor cells in erectile physiology

The incidence of erectile dysfunction (ED) increases with age and cardiovascular disease risk factors, such as hypertension, hyperlipidemia, insulin resistance, obesity, and diabetes. These risk factors are thought to contribute to endothelial dysfunction and atherosclerosis, thus contributing to the pathophysiology of ED. The role of the endothelium in regulating erectile physiology is well established. However, the role of androgens in modulating endothelial function and endothelial repair mechanisms subsequent to vascular injury in erectile tissue remains a subject of intensive research. The clinical and preclinical evidence discussed in this review suggests that androgens regulate endothelial function and also play an important role in the development and maturation of endothelial progenitor cells (EPCs), which are thought to play a critical role in repair of endothelial injury in vascular beds. In this review, we discuss the data available on the effects of androgens on endothelial function and EPCs in the repair of vascular injury. Indeed, more research is needed to fully understand the molecular and cellular basis of androgen action in regulating the development, differentiation, maturation, migration, and homing of EPCs to the site of injury. A better understanding of these processes will be critical to the development of new therapeutic approaches to the treatment of vascular ED.

Decreased circulating endothelial progenitor cell levels in patients with heart failure with preserved ejection fraction

OBJECTIVES

The purpose of this study was to explore the relationship between endothelial progenitor cell (EPC) levels, heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF).

METHODS

A total of 44 HFpEF patients, 40 HFrEF patients and 69 age-, gender- and comorbidity-matched controls were enrolled after evaluating their clinical manifestations and echocardiography findings. Flow cytometry with quantification of three EPC markers in peripheral blood samples was used to assess the number of circulating EPCs.

RESULTS

HFpEF and HFrEF patients had significantly decreased circulating EPC levels compared to controls. Among heart failure patients, patients with New York Heart Association functional class (FC) IV had fewer circulating EPCs compared to those with FC II and FC III (p = 0.053). A simple linear regression analysis of data showed that high sensitivity C-reactive protein, left ventricular ejection fraction, left atrium diameter and the ratio of medial early filling to early diastolic mitral annular velocity all correlated with the EPC count. In multivariate Cox regression analyses, both HFpEF and HFrEF were found to be independent predictors of a decreased EPC number.

CONCLUSIONS

HFpEF and HFrEF patients have decreased circulating EPC numbers, which is an indication of impaired endothelial turnover.