Endothelial dysfunction in COPD: a systematic review and meta-analysis of studies using different functional assessment methods

Smoking and Respiratory Diseases in Patients with Coronary Microvascular Dysfunction

BACKGROUND

Coronary microvascular disease (CMD) is common in patients with and without obstructive coronary artery disease, and is associated with adverse clinical outcomes. Respiratory-related variables are associated with pulmonary and systemic microvascular dysfunction, while evidence about their relationship with CMD is limited. We aim to evaluate respiratory-related variables as risk factors of CMD.

METHODS

This is an observational, single-center study enrolling consecutive patients undergoing invasive evaluation of coronary microvascular function in the catheterization laboratory. Patients with evidence of obstructive coronary artery disease or with missing data were excluded. Associations between respiratory-related variables and indices of CMD were assessed using univariate and multivariate regression models.

RESULTS

Overall, 266 patients (mean age 67 ± 11 years, 59% females) were included in the current analysis. Of those, 155 (58%) had evidence of CMD. Among the respiratory variables, independent predictors of CMD were current smoking (adjusted odds ratio [AOR] 2.5; 95% confidence interval [CI], 1.2-5; P = .01) and obstructive sleep apnea (AOR 5.7; 95% CI, 1.2-26; P = .03), while chronic obstructive pulmonary disease was not. Among ever-smokers, higher smoking pack-years was an independent risk factor for CMD (median 35 vs 25 pack-years, AOR 1.09; 95% CI, 1.04-1.13; P < .01), and was associated with higher rates of pathologic index of microcirculatory resistance and resistive reserve ratio.

CONCLUSION

In patients undergoing invasive coronary microvascular evaluation, current smoking and obstructive sleep apnea are independently associated with CMD. Among smokers, higher pack-years is a strong predictor for CMD. Our findings should raise awareness for prevention and possible treatment options.

Vascular Endothelial Damage in COPD: Where Are We Now, Where Will We Go?

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has higher rates among the general population, so early identification and prevention is the goal. The mechanisms of COPD development have not been completely established, although it has been demonstrated that endothelial dysfunction plays an important role. However, to date, the measurement of endothelial dysfunction is still invasive or not fully established. Nailfold video capillaroscopy (NVC) is a safe, non-invasive diagnostic tool that can be used to easily evaluate the microcirculation and can show any possible endothelial dysfunctions early on. The aim of this review is to evaluate if nailfold microcirculation abnormalities can reflect altered pulmonary vasculature and can predict the risk of cardiovascular comorbidities in COPD patients.

METHODS

A systematic literature search concerning COPD was performed in electronic databases (PUBMED, UpToDate, Google Scholar, ResearchGate), supplemented with manual research. We searched in these databases for articles published until March 2024. The following search words were searched in the databases in all possible combinations: chronic obstructive pulmonary disease (COPD), endothelial damage, vascular impairment, functional evaluation, capillaroscopy, video capillaroscopy, nailfold video capillaroscopy. Only manuscripts written in English were considered for this review. Papers were included only if they were able to define a relationship between COPD and endothelium dysfunction.

RESULTS

The search selected 10 articles, and among these, only three previous reviews were available. Retinal vessel imaging, flow-mediated dilation (FMD), and skin autofluorescence (AF) are reported as the most valuable methods for assessing endothelial dysfunction in COPD patients.

CONCLUSIONS

It has been assumed that decreased nitric oxide (NO) levels leads to microvascular damage in COPD patients. This finding allows us to assume NVC's potential effectiveness in COPD patients. However, this potential link is based on assumption; further investigations are needed to confirm this hypothesis.

The Role of Nutrition in the Development and Management of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a prevalent lung condition associated with significant morbidity and mortality. The management of COPD classically involves pulmonary rehabilitation, bronchodilators, and corticosteroids. An aspect of COPD management that is currently lacking in the literature is nutritional management, despite the prevalence of inadequate nutritional status in patients with COPD. In addition, certain nutritional imbalances have been reported to increase the risk of COPD development. This review summarizes the current literature on the role diet and nutrients may play in the risk and management of COPD development.

Integrative assessment of cerebral blood regulation in COPD patients

Cerebrovascular responses were compared between COPD and non-COPD participants. The association between COPD severity and cognitive function was also investigated. Cerebral blood velocity in the middle cerebral artery, blood pressure, and end-tidal CO2 were recorded at rest, followed by a brain activation paradigm, and an inhaled gas mixture (5% CO2) to assess cerebral autoregulation (CA), neurovascular coupling (NVC) and cerebrovascular reactivity to carbon dioxide (CVRCO2), respectively. Pulmonary function, blood gas analysis (COPD) and cognitive function (MoCA test) were also performed. No difference in baseline (systemic and cerebral parameters) and CA was found between 20 severe COPD and 21 non-COPD. Reduced NVC and CVRCO2 test were found in the COPD group. Lower pulmonary function was positively correlated with CA, NVC and CVRCO2 in COPD patients. Cognitive impairment (MoCA<26) was associated with lower NVC responses (COPD and non-COPD) and lower pulmonary function (COPD). Both mechanisms, CVRCO2 and NVC, were lower in COPD patients. Moreover, disease severity and cognitive impaired were associated with worse cerebrovascular regulation.

Elevated Blood Pressure Occurs without Endothelial Dysfunction in a Rat Model of Pulmonary Emphysema

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease involving airway closure and parenchyma destruction (emphysema). Cardiovascular diseases are the main causes of morbi-mortality in COPD and, in particular, hypertension and heart failure with preserved ejection fraction (HFpEF). However, no mechanistic link has currently been established between the onset of COPD, elevated blood pressure (BP) and systemic vascular impairment (endothelial dysfunction). Thus, we aimed to characterize BP and vascular function and remodeling in a rat model of exacerbated emphysema focusing on the role of sympathetic hyperactivity. Emphysema was induced in male Wistar rats by four weekly pulmonary instillations of elastase (4UI) and exacerbation by a single dose of lipopolysaccharides (LPS). Five weeks following the last instillation, in vivo and ex vivo cardiac and vascular functions were investigated. Exacerbated emphysema induced cardiac dysfunction (HFpEF) and a BP increase in this COPD model. We observed vasomotor changes and hypotrophic remodeling of the aorta without endothelial dysfunction. Indeed, changes in contractile and vasorelaxant properties, though endothelium-dependent, were pro-relaxant and NO-independent. A β1-receptor antagonist (bisoprolol) prevented HFpEF and vascular adaptations, while the effect on BP increase was partial. Endothelial dysfunction would not trigger hypertension and HFpEF in COPD. Vascular changes appeared as an adaptation to the increased BP. The preventing effect of bisoprolol revealed a pivotal role of sympathetic hyperactivation in BP elevation. The mechanistic link between HFpEF, cardiac sympathetic activation and BP deserves further studies in this exacerbated-emphysema model, as well as in COPD patients.

Alterations of Macular Structure in Non-Glaucomatous Subjects With Obstructive Pulmonary Function

Purpose

The purpose of this study was to identify possible associations between obstructive pulmonary function and macular structure parameters on optical coherence tomography (OCT) and angiography in subjects without glaucomatous optic neuropathy.

Methods

A total of 70 patients were prospectively enrolled from June to December 2021 as a part of All About Life Yongin-Pulmonary/Psychiatry, Rehabilitation, Eye (AALY PRE) cohort in Yongin Severance Hospital. Patients underwent intraocular pressure (IOP), visual acuity measurements, cirrus OCT, OCT angiography, and pulmonary function testing (PFT) on the same day. Subjects with glaucomatous optic nerve damage were excluded. Those whose first second of forced expiration (FEV1) to forced vital capacity (FVC) ratio was below 70% were diagnosed with obstructive pulmonary function. Vessel densities (VDs) of retinal superficial vascular plexus were compared.

Results

Patients with obstructive function (n = 30) were significantly older than those with normal pulmonary function (n = 40, P < 0.001). After adjusting for age, IOP, and average ganglion cell-inner plexiform layer (GCIPL) thickness, macular VD was significantly decreased in all sectors except for the nasal sector in subjects with obstructive pulmonary function in comparison to those with normal function (P = 0.006). Multivariate regression analysis demonstrated that macular VD was linearly associated with FEV1/FVC (β = 0.102, P = 0.031). In subjects with obstructive function, the severity of pulmonary obstruction, FEV1, was linearly associated with GCIPLT (β = 0.302, P = 0.017).

Conclusions

Obstructive pulmonary function is associated with reduced macular VD in subjects without glaucoma. Among subjects with obstructive pulmonary function, the severity of pulmonary obstruction is associated with GCIPL thickness in the macular region. Further studies are needed on the relationship between pulmonary function and macular disease.

Inhibition of oxidative stress by apocynin attenuated chronic obstructive pulmonary disease progression and vascular injury by cigarette smoke exposure

BACKGROUND AND PURPOSE

Cardiovascular disease affects up to half of the patients with chronic obstructive pulmonary disease (COPD), exerting deleterious impact on health outcomes and survivability. Vascular endothelial dysfunction marks the onset of cardiovascular disease. The present study examined the effect of a potent NADPH Oxidase (NOX) inhibitor and free-radical scavenger, apocynin, on COPD-related cardiovascular disease.

EXPERIMENTAL APPROACH

Male BALB/c mice were exposed to either room air (Sham) or cigarette smoke (CS) generated from 9 cigarettes·day-1 , 5 days a week for up to 24 weeks with or without apocynin treatment (5 mg·kg-1 ·day-1 , intraperitoneal injection).

KEY RESULTS

Eight-weeks of apocynin treatment reduced airway neutrophil infiltration (by 42%) and completely preserved endothelial function and endothelial nitric oxide synthase (eNOS) availability against the oxidative insults of cigarette smoke exposure. These preservative effects were maintained up until the 24-week time point. 24-week of apocynin treatment markedly reduced airway inflammation (reduced infiltration of macrophage, neutrophil and lymphocyte), lung function decline (hyperinflation) and prevented airway collagen deposition by cigarette smoke exposure.

CONCLUSION AND IMPLICATIONS

Limiting NOX activity may slow COPD progression and lower cardiovascular disease risk, particularly when signs of oxidative stress become evident.

The matricellular protein CCN3 supports lung endothelial homeostasis and function

Aberrant vascular remodeling contributes to the progression of many aging-associated diseases, including idiopathic pulmonary fibrosis (IPF), where heterogeneous capillary density, endothelial transcriptional alterations, and increased vascular permeability correlate with poor disease outcomes. Thus, identifying disease-driving mechanisms in the pulmonary vasculature may be a promising strategy to limit IPF progression. Here, we identified Ccn3 as an endothelial-derived factor that is upregulated in resolving but not in persistent lung fibrosis in mice, and whose function is critical for vascular homeostasis and repair. Loss and gain of function experiments were carried out to test the role of CCN3 in lung microvascular endothelial function in vitro through RNAi and the addition of recombinant human CCN3 protein, respectively. Endothelial migration, permeability, proliferation, and in vitro angiogenesis were tested in cultured human lung microvascular endothelial cells (ECs). Loss of CCN3 in lung ECs resulted in transcriptional alterations along with impaired wound-healing responses, in vitro angiogenesis, barrier integrity as well as an increased profibrotic activity through paracrine signals, whereas the addition of recombinant CCN3 augmented endothelial function. Altogether, our results demonstrate that the matricellular protein CCN3 plays an important role in lung endothelial function and could serve as a promising therapeutic target to facilitate vascular repair and promote lung fibrosis resolution.

Endothelial function in patients with COPD: an updated systematic review of studies using flow-mediated dilatation

INTRODUCTION

Cardiovascular disease is a significant cause of morbidity and mortality in COPD. Endothelial dysfunction is suggested to be involved in cardiovascular disease pathogenesis, and multiple studies report endothelial dysfunction in COPD. This article summarized the current knowledge on endothelial function in COPD patients.

AREAS COVERED

Databases were screened until November 2022 for studies using ultrasound-based flow-mediated dilation in patients with stable COPD. Pooled effect sizes were calculated using random effects model. Meta-regression analyses assessed the effects of demographic and clinical variables.

EXPERT OPINION

34 studies were identified (1365 COPD patients; 617 controls). Pooled analysis demonstrated an impaired endothelial-dependent (-2.33%; 95%CI -3.30/-1.35; p < 0.001) and endothelial-independent dilation (-3.11%; 95%CI -5.14/-1.08; p = 0.003) in COPD patients when compared to non-COPD controls. Meta-regression identified that higher age, worse severity of airflow obstruction, and current smoking were significantly associated with impaired endothelial function. Studies evaluating the effects of pharmacological and non-pharmacological interventions on endothelial function in COPD patients demonstrated conflicting results.

Analysis of pathogenesis and drug treatment of chronic obstructive pulmonary disease complicated with cardiovascular disease

Chronic obstructive pulmonary disease (COPD) is a disease characterized by persistent airflow limitation, and is associated with abnormal inflammatory responses in the lungs to cigarette smoke and toxic and harmful gases. Due to the existence of common risk factors, COPD is prone to multiple complications, among which cardiovascular disease (CVD) is the most common. It is currently established that cardiovascular comorbidities increase the risk of exacerbations and mortality from COPD. COPD is also an independent risk factor for CVD, and its specific mechanism is still unclear, which may be related to chronic systemic inflammation, oxidative stress, and vascular dysfunction. There is evidence that chronic inflammation of the airways can lead to destruction of the lung parenchyma and decreased lung function. Inflammatory cells in the airways also generate reactive oxygen species in the lungs, and reactive oxygen species further promote lung inflammation through signal transduction and other pathways. Inflammatory mediators circulate from the lungs to the whole body, causing intravascular dysfunction, promoting the formation and rupture of atherosclerotic plaques, and ultimately leading to the occurrence and development of CVD. This article reviews the pathophysiological mechanisms of COPD complicated by CVD and the effects of common cardiovascular drugs on COPD.

Blood CDC42 overexpression is associated with an increased risk of acute exacerbation, inflammation and disease severity in patients with chronic obstructive pulmonary disease

It has been previously reported that cell division control 42 (CDC42) protein can regulate macrophage recruitment, T cell-associated inflammation and lung injury. However, its role in chronic obstructive pulmonary disease (COPD) remain poorly understood. Therefore, the present study aimed to investigate the possible association among CDC42 expression, the risk of acute exacerbation and disease features in patients with COPD. Peripheral blood mononuclear cells (PBMCs) and serum samples were collected from 60 patients with acute exacerbation COPD (AE-COPD), 60 patients with stable COPD (S-COPD) and 60 healthy control (HCs) individuals. The mRNA expression levels of CDC42 in PBMCs were then measured using reverse transcription-quantitative PCR. The serum levels of TNF-α, IL-1β, IL-6 and IL-17 were measured using ELISA. The results showed that the expression of CDC42 was dysregulated among patients with AE-COPD and S-COPD compared with that in HCs. Specifically, the expression level of CDC42 was the highest in patients with AE-COPD, followed by those with S-COPD and the lowest in HCs (P<0.001). Furthermore, receiver operating characteristic curve analysis demonstrated that CDC42 expression was associated with an increased risk of acute exacerbation in COPD with an area under curve of 0.690 (95% confidence interval=0.595-0.785). CDC42 was found to be positively associated with Global Initiative for Chronic Obstructive Lung Disease staging in patients with AE-COPD (P<0.01) and S-COPD (P<0.05). Additionally, CDC42 expression associated positively with the serum levels of TNF-α, IL-1β, IL-6 and IL-17 in patients with AE-COPD (all P<0.05). However, this association was weaker in patients with S-COPD and became negligible in HCs. In conclusion, data from the present study suggest that CDC42 is associated with an increased risk of acute exacerbation, inflammation and disease severity in patients with COPD, implicating its application as a potential biomarker for COPD.

Peripheral endothelial and microvascular damage in liver cirrhosis: a systematic review and meta-analysis

OBJECTIVE

This is the first systematic review and meta-analysis of studies using any available functional method to examine differences in peripheral endothelial function between cirrhotic and non-cirrhotic individuals.

METHODS

Literature search involved PubMed, Web-of-Science and Scopus databases, as well as grey literature sources. We included studies in adult subjects evaluating endothelial function with any semi-invasive or non-invasive functional method in patients with and without liver cirrhosis.

RESULTS

From 3378 records initially retrieved, 15 studies with a total of 570 participants were included in the final quantitative meta-analysis. In 6 studies examining endothelial function with flow-mediated-dilatation no differences between patients with cirrhosis and controls were evident (WMD: 1.33, 95%CI [-2.87, 5.53], I² =97%, p<0.00001). Among studies assessing differences in endothelial-dependent or endothelial-independent vasodilation with venous-occlusion-plethysmography, there were no significant differences between the two groups. When pooling all studies together, regardless of the technique used, no significant difference in endothelial function between cirrhotic patients and controls was observed(SMD: 0.79, 95%CI[-0.04, 1.63], I2=94%, p<0.00001).

CONCLUSIONS

No differences in peripheral endothelial function assessed with semi-invasive or non-invasive functional methods exist between cirrhotic and non-cirrhotic subjects. The increasing co-existence of cardiovascular risk factors leading to impaired vascular reactivity in cirrhotic patients may partly explain these findings.