Renin-angiotensin system blockade: a novel therapeutic approach in chronic obstructive pulmonary disease

Musculoskeletal crosstalk in chronic obstructive pulmonary disease and comorbidities: Emerging roles and therapeutic potentials

Chronic Obstructive Pulmonary Disease (COPD) is a multifaceted respiratory disorder characterized by progressive airflow limitation and systemic implications. It has become increasingly apparent that COPD exerts its influence far beyond the respiratory system, extending its impact to various organ systems. Among these, the musculoskeletal system emerges as a central player in both the pathogenesis and management of COPD and its associated comorbidities. Muscle dysfunction and osteoporosis are prevalent musculoskeletal disorders in COPD patients, leading to a substantial decline in exercise capacity and overall health. These manifestations are influenced by systemic inflammation, oxidative stress, and hormonal imbalances, all hallmarks of COPD. Recent research has uncovered an intricate interplay between COPD and musculoskeletal comorbidities, suggesting that muscle and bone tissues may cross-communicate through the release of signalling molecules, known as "myokines" and "osteokines". We explored this dynamic relationship, with a particular focus on the role of the immune system in mediating the cross-communication between muscle and bone in COPD. Moreover, we delved into existing and emerging therapeutic strategies for managing musculoskeletal disorders in COPD. It underscores the development of personalized treatment approaches that target both the respiratory and musculoskeletal aspects of COPD, offering the promise of improved well-being and quality of life for individuals grappling with this complex condition. This comprehensive review underscores the significance of recognizing the profound impact of COPD on the musculoskeletal system and its comorbidities. By unravelling the intricate connections between these systems and exploring innovative treatment avenues, we can aspire to enhance the overall care and outcomes for COPD patients, ultimately offering hope for improved health and well-being.

The tobacco-specific carcinogen NNK induces pulmonary tumorigenesis via nAChR/Src/STAT3-mediated activation of the renin-angiotensin system and IGF-1R signaling

The renin-angiotensin (RA) system has been implicated in lung tumorigenesis without detailed mechanistic elucidation. Here, we demonstrate that exposure to the representative tobacco-specific carcinogen nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) promotes lung tumorigenesis through deregulation of the pulmonary RA system. Mechanistically, NNK binding to the nicotinic acetylcholine receptor (nAChR) induces Src-mediated signal transducer and activator of transcription 3 (STAT3) activation, resulting in transcriptional upregulation of angiotensinogen (AGT) and subsequent induction of the angiotensin II (AngII) receptor type 1 (AGTR1) signaling pathway. In parallel, NNK concurrently increases insulin-like growth factor 2 (IGF2) production and activation of IGF-1R/insulin receptor (IR) signaling via a two-step pathway involving transcriptional upregulation of IGF2 through STAT3 activation and enhanced secretion from intracellular storage through AngII/AGTR1/PLC-intervened calcium release. NNK-mediated crosstalk between IGF-1R/IR and AGTR1 signaling promoted tumorigenic activity in lung epithelial and stromal cells. Lung tumorigenesis caused by NNK exposure or alveolar type 2 cell-specific Src activation was suppressed by heterozygous Agt knockout or clinically available inhibitors of the nAChR/Src or AngII/AGTR1 pathways. These results demonstrate that NNK-induced stimulation of the lung RA system leads to IGF2-mediated IGF-1R/IR signaling activation in lung epithelial and stromal cells, resulting in lung tumorigenesis in smokers.

Renin-angiotensin-system inhibitors and the risk of exacerbations in chronic obstructive pulmonary disease: a nationwide registry study

OBJECTIVE

The renin-angiotensin system (RAS) has been shown to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD) because of the inflammatory properties of the system. Many patients with COPD use RAS-inhibiting (RASi) treatment. The aim was to determine the association between treatment with RASi and the risk of acute exacerbations and mortality in patients with severe COPD.

METHODS

Active comparator analysis by propensity-score matching. Data were collected in Danish national registries, containing complete information on health data, prescriptions, hospital admissions and outpatient clinic visits. Patients with COPD (n=38 862) were matched by propensity score on known predictors of the outcome. One group was exposed to RASi treatment (cases) and the other was exposed to bendroflumethiazide as an active comparator in the primary analysis.

RESULTS

The use of RASi was associated with a reduced risk of exacerbations or death in the active comparator analysis at 12 months follow-up (HR 0.86, 95% CI 0.78 to 0.95). Similar results were evident in a sensitivity analysis of the propensity-score-matched population (HR 0.89, 95% CI 0.83 to 0.94) and in an adjusted Cox proportional hazards model (HR 0.93, 95% CI 0.89 to 0.98).

CONCLUSION

In the current study, we found that the use of RASi treatment was associated with a consistently lower risk of acute exacerbations and death in patients with COPD. Explanations to these findings include real effect, uncontrolled biases, and-less likely-chance findings.

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.

Optimal Management of Heart Failure and Chronic Obstructive Pulmonary Disease: Clinical Challenges

Heart failure (HF) and chronic obstructive pulmonary disease (COPD) are common causes of breathlessness which frequently co-exist; one potentially exacerbating the other. Distinguishing between the two can be challenging due to their similar symptomatology and overlapping risk factors, but a timely and correct diagnosis is potentially lifesaving. Modern treatment for HF can substantially improve symptoms and prognosis for many patients and may have beneficial effects for patients with COPD. Conversely, while many inhaled treatments for COPD can improve symptoms and reduce exacerbations, there is conflicting evidence regarding the safety of some inhaled treatments for COPD in patients with HF. Here we explore the overlap between HF and COPD, examine the effect of one condition on the other, and address the challenges of managing patients with both conditions.

The Association of Renin-Angiotensin System Blockades and Mortality in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease and Acute Respiratory Failure: A Retrospective Cohort Study

Background

Acute respiratory failure (ARF) is a common cause of admission to the intensive care unit (ICU) for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). There is still a lack of effective interventions and treatments. ACE inhibitors (ACEI)/ angiotensin II receptor blockers (ARB) were effective in COPD patients. We aimed to study the effect of ACEI/ARB use on AECOPD combined with ARF and evaluate the effect of in-hospital continuation of medication.

Methods

We included patients with AECOPD and ARF from the Medical Information Bank for Intensive Care (MIMIC-III) database. MIMIC III is a large cohort database from Boston, USA. Patients were divided into two groups according to the use of ACEI/ARB before admission. Propensity score matching (PSM) was used to reduce potential bias between the two groups. Cox regression and Kaplan-Meier curves compared 30-day mortality in ACEI/ARB users and non-users. We also defined and analyzed the use of in-hospital ACEI/ARB. Multiple models were used to ensure the robustness of the findings. Subgroup analysis was used to analyze the variability between groups.

Results

A total of 544 patients were included in the original study. After PSM, 256 patients were included in the matched cohort. Multivariate Cox regression showed 30-day mortality was significantly lower in ACEI/ARB users compared with controls (HR = 0.50, 95% CI: 0.29–0.86, p= 0.013). In PSM and inverse probability-weighted models, the results are stable Continued in-hospital use of ACEI/ARB remains effective (HR 0.40, 95% CI 0.22–0.74, p = 0.003). Kaplan-Meier showed a significant difference in survival between the two groups.

Conclusion

This study found that pre-hospital ACEI/ARB use was associated with reduced mortality in patients with AECOPD and ARF.

Effect of heated tobacco products and traditional cigarettes on pulmonary toxicity and SARS-CoV-2-induced lung injury

Cigarette smoke (CS) significantly contributes to the development of chronic obstructive pulmonary disease (COPD). Heated tobacco products (HTPs), newly developed cigarette products, have been proposed as an alternative for safe cigarette smoking. Although it is plausible to think that replacing traditional cigarettes with HTPs would lower the risks of COPD, this notion requires confirmation by further investigations from sources independent of the tobacco industry. COPD is characterized by an ongoing inflammatory process in the lungs, and the renin-angiotensin system (RAS) has been implicated in the pathogenesis of COPD. Angiotensin-converting enzyme-2 (ACE2) functions as a negative regulator of RAS and has been suggested as a cellular receptor for the causative agent of SARS-CoV-2. It has been shown that smoking is most likely associated with the negative progression and adverse outcomes of SARS-CoV-2. In this study, we found that cigarette smoke extracts from traditional cigarettes (CSE) caused higher cytotoxicity and higher oxidative stress levels than extracts from HTPs (HTPE) in two lung cell lines (Calu-3 and Beas-2B). CSE and HTPE induced RAS activation, MAPK activation, and NF-kB inflammatory pathway activation, resulting in the production of inflammatory cytokines. Furthermore, CSE and a high dose of HTPE reduced tight junction proteins, including claudin 1, E-cadherin, and ZO-1, and disrupted lung epidermal tight junctions at the air-liquid interface (ALI). Finally, CSE and HTPE enhanced the spike protein S1-induced lung injury response. Together, these results suggest that HTPE induced similar lung pathogenesis relevant to COPD and SARS-CoV-2-induced lung injury caused by CSE.

The Association Between Antihypertensive Drug Use and Hospitalization for Pneumonia in the General Population: A Case-Crossover Study Using the National Health Insurance Database of Korea

BACKGROUND

Previous studies have reported an association between pneumonia risk and the use of certain drugs. We investigated the relationship between antihypertensive drugs and pneumonia in the general population.

METHODS

This case-crossover study utilized the nationwide data of South Korea. We included participants who were hospitalized for pneumonia. A single case period was defined as 30 days before pneumonia onset, and two control periods were established (90-120 and 150-180 days before pneumonia onset). Further, we performed sensitivity and subgroup analyses (according to the presence of diabetes, documented disability, and whether participants were aged ≥ 70 years). We used conditional logistic regression models adjusted for covariates, such as angiotensin-converting-enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), other antihypertensives, statins, antipsychotics, benzodiazepine, and the number of outpatient visits.

RESULTS

In total, 15,463 subjects were included in this study. ACE inhibitors (adjusted odds ratio [aOR], 0.660; 95% confidence interval [CI], 0.558-0.781), ARBs (aOR, 0.702; 95% CI, 0.640-0.770), and other antihypertensive drugs (aOR, 0.737; 95% CI, 0.665-0.816) were significantly associated with reduced pneumonia risk. Subgroup analyses according to the presence of diabetes mellitus, documented disability, and whether participants were aged ≥ 70 years consistently showed the association of antihypertensives with a reduced risk of hospitalization for pneumonia.

CONCLUSION

All antihypertensive drug types were related to a lower risk of hospitalization for pneumonia in the general population. Our results implied that frequent medical service usage and protective immunity were primarily related to a reduced risk of pneumonia in the general population of South Korea.

Whey-Derived Peptides at the Heart of the COVID-19 Pandemic

The renin-angiotensin system (RAS) is a key regulator of blood pressure and hypertension. Angiotensin-converting enzyme 2 (ACE2) and angiotensin-converting enzyme I (ACE) are two main components of the RAS that play a major role in blood pressure homeostasis. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses ACE2 as a receptor to enter cells. Despite some controversies, numerous studies have reported a significant association between the use of ACE inhibitors and reduced risk of COVID-19. In our previous studies, we produced and identified peptide sequences present in whey hydrolysates exhibiting high ACE inhibitory activity. Therefore, the aim of this work is to obtain an improved understanding of the function of these natural peptides as RAS inhibitors and investigate their potential therapeutic role in the COVID-19 pandemic. The molecular interactions between peptides IPP, LIVTQ, IIAE, LVYPFP, and human ACE2 were assessed by employing a molecular docking approach. The results show that natural whey-derived peptides have a dual inhibitory action against both ACE and ACE2. This dual activity distinguishes these ACE inhibitory peptides from synthetic drugs, such as Captopril and Lisinopril which were not shown to inhibit ACE2 activity, and may represent a potential strategy in the treatment of COVID-19.

CD38 in the age of COVID-19: a medical perspective

This medical review addresses the hypothesis that CD38/NADase is at the center of a functional axis (i.e., intracellular Ca2+ mobilization/IFNγ response/reactive oxygen species burst) driven by severe acute respiratory syndrome coronavirus 2 infection, as already verified in respiratory syncytial virus pathology and CD38 activity in other cellular settings. Key features of the hypothesis are that 1) the substrates of CD38 (e.g., NAD+ and NADP+) are depleted by viral-induced metabolic changes; 2) the products of the enzymatic activity of CD38 [e.g., cyclic adenosine diphosphate-ribose (ADPR)/ADPR/nicotinic acid adenine dinucleotide phosphate] and related enzymes [e.g., poly(ADP-ribose)polymerase, Sirtuins, and ADP-ribosyl hydrolase] are involved in the anti‐viral and proinflammatory response that favors the onset of lung immunopathology (e.g., cytokine storm and organ fibrosis); and 3) the pathological changes induced by this kinetic mechanism may be reduced by distinct modulators of the CD38/NAD+ axis (e.g., CD38 blockers, NAD+ suppliers, among others). This view is supported by arrays of associative basic and applied research data that are herein discussed and integrated with conclusions reported by others in the field of inflammatory, immune, tumor, and viral diseases.

Emphysema Progression and Lung Function Decline Among Angiotensin Converting Enzyme Inhibitors and Angiotensin-Receptor Blockade Users in the COPDGene Cohort

BACKGROUND

Attenuation of transforming growth factor β by blocking angiotensin II has been shown to reduce emphysema in a murine model. General population studies have demonstrated that the use of angiotensin converting enzyme inhibitors (ACEis) and angiotensin-receptor blockers (ARBs) is associated with reduction of emphysema progression in former smokers and that the use of ACEis is associated with reduction of FEV₁ progression in current smokers.

RESEARCH QUESTION

Is use of ACEi and ARB associated with less progression of emphysema and FEV₁ decline among individuals with COPD or baseline emphysema?

METHODS

Former and current smokers from the Genetic Epidemiology of COPD Study who attended baseline and 5-year follow-up visits, did not change smoking status, and underwent chest CT imaging were included. Adjusted linear mixed models were used to evaluate progression of adjusted lung density (ALD), percent emphysema (%total lung volume <-950 Hounsfield units [HU]), 15th percentile of the attenuation histogram (attenuation [in HU] below which 15% of voxels are situated plus 1,000 HU), and lung function decline over 5 years between ACEi and ARB users and nonusers in those with spirometry-confirmed COPD, as well as all participants and those with baseline emphysema. Effect modification by smoking status also was investigated.

RESULTS

Over 5 years of follow-up, compared with nonusers, ACEi and ARB users with COPD showed slower ALD progression (adjusted mean difference [aMD], 1.6; 95% CI, 0.34-2.9). Slowed lung function decline was not observed based on phase 1 medication (aMD of FEV₁ % predicted, 0.83; 95% CI, -0.62 to 2.3), but was when analysis was limited to consistent ACEi and ARB users (aMD of FEV₁ % predicted, 1.9; 95% CI, 0.14-3.6). No effect modification by smoking status was found for radiographic outcomes, and the lung function effect was more pronounced in former smokers. Results were similar among participants with baseline emphysema.

INTERPRETATION

Among participants with spirometry-confirmed COPD or baseline emphysema, ACEi and ARB use was associated with slower progression of emphysema and lung function decline.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.

COVID-19 and pulmonary fibrosis: therapeutics in clinical trials, repurposing, and potential development

In 2019, an unprecedented disease named coronavirus disease 2019 (COVID-19) emerged and spread across the globe. Although the rapid transmission of COVID-19 has resulted in thousands of deaths and severe lung damage, conclusive treatment is not available. However, three COVID-19 vaccines have been authorized, and two more will be approved soon, according to a World Health Organization report on December 12, 2020. Many COVID-19 patients show symptoms of acute lung injury that eventually leads to pulmonary fibrosis. Our aim in this article is to present the relationship between pulmonary fibrosis and COVID-19, with a focus on angiotensin converting enzyme-2. We also evaluate the radiological imaging methods computed tomography (CT) and chest X-ray (CXR) for visualization of patient lung condition. Moreover, we review possible therapeutics for COVID-19 using four categories: treatments related and unrelated to lung disease and treatments that have and have not entered clinical trials. Although many treatments have started clinical trials, they have some drawbacks, such as short-term and small-group testing, that need to be addressed as soon as possible.

Scientific Hypothesis for Treatment of COVID-19's Lung Lesions by Adjusting ACE/ACE2 Imbalance

In March 2019 began the global pandemic COVID-19 caused by the new Coronavirus SARS-CoV-2. The first cases of SARS-CoV-2 infection occurred in November-19 in Wuhan, China. The preventive measures taken did not prevent the rapid spread of the virus to all countries around the world. To date, there are about 2.54 million deaths, effective vaccines are in clinical trials. SARS-CoV-2 uses the ACE-2 protein as an intracellular gateway. ACE-2 is a key component of the Renin Angiotensin (RAS) system, a key regulator of cardiovascular function. Considering the key role of ACE-2 in COVID-19 infection, both as an entry receptor and as a protective role, especially for the respiratory tract, and considering the variations of ACE-2 and ACE during the stages of viral infection, it is clear the important role that the pharmacological regulation of RAS and ACE-2 can assume. This biological knowledge suggests different pharmacological approaches to treat COVID-19 by modulating RAS, ACE-2 and the ACE/ACE2 balance that we describe in this article.

CD38 in the age of COVID-19: a medical perspective

This medical review addresses the hypothesis that CD38/NADase is at the center of a functional axis (i.e., intracellular Ca²⁺ mobilization/IFNγ response/reactive oxygen species burst) driven by severe acute respiratory syndrome coronavirus 2 infection, as already verified in respiratory syncytial virus pathology and CD38 activity in other cellular settings. Key features of the hypothesis are that 1) the substrates of CD38 (e.g., NAD⁺ and NADP⁺) are depleted by viral-induced metabolic changes; 2) the products of the enzymatic activity of CD38 [e.g., cyclic adenosine diphosphate-ribose (ADPR)/ADPR/nicotinic acid adenine dinucleotide phosphate] and related enzymes [e.g., poly(ADP-ribose)polymerase, Sirtuins, and ADP-ribosyl hydrolase] are involved in the anti‐viral and proinflammatory response that favors the onset of lung immunopathology (e.g., cytokine storm and organ fibrosis); and 3) the pathological changes induced by this kinetic mechanism may be reduced by distinct modulators of the CD38/NAD⁺ axis (e.g., CD38 blockers, NAD⁺ suppliers, among others). This view is supported by arrays of associative basic and applied research data that are herein discussed and integrated with conclusions reported by others in the field of inflammatory, immune, tumor, and viral diseases.

Effects of ACEI and ARB on COVID-19 patients: A meta-analysis

BACKGROUND

The clinical use of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin-receptor blockers (ARB) in patients with COVID-19 infection remains controversial. Therefore, we performed a meta-analysis on the effects of ACEI/ARB on disease symptoms and laboratory tests in hypertensive patients infected with COVID-19 virus and those who did not use ACEI/ARB.

METHODS

We systematically searched the relevant literatures from Pubmed, Embase, EuropePMC, CNKI, and other databases during the study period of 31 December 2019 (solstice, 15 March 2020), and analyzed the differences in symptoms and laboratory tests between patients with COVID-19 and hypertension who used ACEI/ARB drugs and those who did not. All statistical analyses were performed with REVMAN5.3.

RESULTS

We included a total of 1808 patients with hypertension diagnosed with COVID-19 in six studies. Analysis results show that ACEI/ARB drugs group D-dimer is lower (SMD = -0.22, 95%CI: -0.36 to -0.06), and the chances of getting fever is lower (OR = 0.74, 95%CI: 0.55 to 0.98). Meanwhile, laboratory data and symptoms were not statistical difference, but creatinine tends to rise (SMD = 0.22, 95% CI: 0.04 to 0.41).

CONCLUSION

We found that the administration of ACEI/ARB drugs had positive effect on reducing D-dimer and the number of people with fever. Meanwhile it had no significant effect on other laboratory tests (creatinine excepted) or symptoms in patients with COVID-19, while special attention was still needed in patients with renal insufficiency.

Potential Roles of the Renin-Angiotensin System in the Pathogenesis and Treatment of COVID-19

The spread of pathogenic severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) poses a global health emergency. Based on the symptomatic treatment and supporting therapy, prevention of complications is the major treatment option. Therefore, it is necessary to illustrate the potential mechanisms for the pathogenesis of COVID-19. Angiotensin-converting enzyme 2 (ACE2), the major receptor of SARS-CoV-2, is one of the major members of the renin-angiotensin system (RAS). In this review, we aimed to summarize the crucial roles of ACE2 in the pathogenesis of COVID-19, followed by illustrating potential treatment options relating to ACE2 and the RAS.

A hypothesis for pathobiology and treatment of COVID-19: The centrality of ACE1/ACE2 imbalance

Angiotensin Converting Enzyme2 is the cell surface binding site for the coronavirus SARS-CoV-2, which causes COVID-19. We propose that an imbalance in the action of ACE1- and ACE2-derived peptides, thereby enhancing angiotensin II (Ang II) signalling is primary driver of COVID-19 pathobiology. ACE1/ACE2 imbalance occurs due to the binding of SARS-CoV-2 to ACE2, reducing ACE2-mediated conversion of Ang II to Ang peptides that counteract pathophysiological effects of ACE1-generated ANG II. This hypothesis suggests several approaches to treat COVID-19 by restoring ACE1/ACE2 balance: (a) AT receptor antagonists; (b) ACE1 inhibitors (ACEIs); (iii) agonists of receptors activated by ACE2-derived peptides (e.g. Ang (1-7), which activates MAS1); (d) recombinant human ACE2 or ACE2 peptides as decoys for the virus. Reducing ACE1/ACE2 imbalance is predicted to blunt COVID-19-associated morbidity and mortality, especially in vulnerable patients. Importantly, approved AT antagonists and ACEIs can be rapidly repurposed to test their efficacy in treating COVID-19. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.

Candesartan could ameliorate the COVID-19 cytokine storm

BACKGROUND

Angiotensin receptor blockers (ARBs) reducing inflammation and protecting lung and brain function, could be of therapeutic efficacy in COVID-19 patients.

METHODS

Using GSEA, we compared our previous transcriptome analysis of neurons injured by glutamate and treated with the ARB Candesartan (GSE67036) with transcriptional signatures from SARS-CoV-2 infected primary human bronchial epithelial cells (NHBE) and lung postmortem (GSE147507), PBMC and BALF samples (CRA002390) from COVID-19 patients.

RESULTS

Hundreds of genes upregulated in SARS-CoV-2/COVID-19 transcriptomes were similarly upregulated by glutamate and normalized by Candesartan. Gene Ontology analysis revealed expression profiles with greatest significance and enrichment, including proinflammatory cytokine and chemokine activity, the NF-kappa B complex, alterations in innate and adaptive immunity, with many genes participating in the COVID-19 cytokine storm.

CONCLUSIONS

There are similar injury mechanisms in SARS-CoV-2 infection and neuronal injury, equally reduced by ARB treatment. This supports the hypothesis of a therapeutic role for ARBs, ameliorating the COVID-19 cytokine storm.

A hypothesis for pathobiology and treatment of COVID-19: The centrality of ACE1/ACE2 imbalance

Angiotensin Converting Enzyme2 is the cell surface binding site for the coronavirus SARS-CoV-2, which causes COVID-19. We propose that an imbalance in the action of ACE1- and ACE2-derived peptides, thereby enhancing angiotensin II (Ang II) signalling is primary driver of COVID-19 pathobiology. ACE1/ACE2 imbalance occurs due to the binding of SARS-CoV-2 to ACE2, reducing ACE2-mediated conversion of Ang II to Ang peptides that counteract pathophysiological effects of ACE1-generated ANG II. This hypothesis suggests several approaches to treat COVID-19 by restoring ACE1/ACE2 balance: (a) AT receptor antagonists; (b) ACE1 inhibitors (ACEIs); (iii) agonists of receptors activated by ACE2-derived peptides (e.g. Ang (1-7), which activates MAS1); (d) recombinant human ACE2 or ACE2 peptides as decoys for the virus. Reducing ACE1/ACE2 imbalance is predicted to blunt COVID-19-associated morbidity and mortality, especially in vulnerable patients. Importantly, approved AT antagonists and ACEIs can be rapidly repurposed to test their efficacy in treating COVID-19. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.

The Severity of Oxidative Stress in Comorbid Chronic Obstructive Pulmonary Disease (COPD) and Hypertension: Does it Depend On ACE and AGT Gene Polymorphisms?

There is an increasing number of studies suggesting the role of genetic factors in the development and progression of chronic obstructive pulmonary disease and hypertension. Therefore, our study aimed to establish the role of ACE and AGT gene polymorphisms in the mechanisms behind the development of oxidative stress in patients with concomitant chronic obstructive pulmonary disease and hypertension. The study group consisted of 96 patients: Group 1 (individuals with a chronic obstructive pulmonary disease), Group 2 (individuals with arterial hypertension), Group 3 (individuals with a chronic obstructive pulmonary disease and arterial hypertension). The control group consisted of 20 healthy subjects. ACE and AGT gene polymorphisms were determined by polymerase chain reaction amplification. Detection of intracellular reactive oxygen species levels was performed by EPICS XL cytometer (Beckman Coulter, USA) with dichlorodihydrofluorescein diacetate and dihydroethidium. Serum levels of 8-isoprostane were assayed with ELISA, Cayman Chemicals (USA). No significant correlations between ACE and AGT gene polymorphisms and parameters of oxidative stress in a setting of comorbid chronic obstructive pulmonary disease and hypertension were observed. However, the increase in oxidative stress parameters was observed to be the most significant in patients with chronic obstructive pulmonary disease + hypertension and with I/I genotype of the ACE gene, which was due to their lowest values in virtually healthy individuals. This suggests that I/I genotype may be associated with lower levels of reactive oxygen species production compared with other genotypes.

Arterial hypertension in adults. Clinical guidelines 2020

Arterial hypertension in adults. Clinical guidelines 2020

Aging Fits the Disease Criteria of the International Classification of Diseases

The disease criteria used by the World Health Organization (WHO) were applied to human biological aging in order to assess whether aging can be classified as a disease. These criteria were developed for the 11th revision of the International Classification of Diseases (ICD) and included disease diagnostics, mechanisms, course and outcomes, known interventions, and linkage to genetic and environmental factors. RESULTS: Biological aging can be diagnosed with frailty indices, functional, blood-based biomarkers. A number of major causal mechanisms of human aging involved in various organs have been described, such as inflammation, replicative cellular senescence, immune senescence, proteostasis failures, mitochondrial dysfunctions, fibrotic propensity, hormonal aging, body composition changes, etc. We identified a number of clinically proven interventions, as well as genetic and environmental factors of aging. Therefore, aging fits the ICD-11 criteria and can be considered a disease. Our proposal was submitted to the ICD-11 Joint Task force, and this led to the inclusion of the extension code for "Ageing-related" (XT9T) into the "Causality" section of the ICD-11. This might lead to greater focus on biological aging in global health policy and might provide for more opportunities for the new therapy developers.

Autonomic Cardiac Regulation in Experimental Comorbidity of Chronic Obstructive Pulmonary Disease and Acute Cerebral Ischemia

Autonomic regulation of the heart was examined in 5 groups of rats: intact, sham-operated, experimental chronic obstructive pulmonary disease, acute cerebral ischemia, and acute cerebral ischemia modeled against the background of chronic obstructive pulmonary disease. The latter was provoked by combination of inhaled papain and intraperitoneal bacterial LPS, whereas acute cerebral ischemia was modeled by single-stage bilateral occlusion of the common carotid arteries. Chronic obstructive pulmonary disease was verified by X-ray computed microtomography. The disturbances in autonomic control of the heart during comorbid pathologies were most prominent; they were manifested by overstrain and decompensation of the mechanisms implicated in the heart control and systolic-diastolic arterial hypotension. The correlations were established between blood oxygenation, respiration rate, and some parameters of autonomic cardiac regulation. The data attest to relevance and usefulness of the developed model of respiratory and cerebrovascular comorbidity in assessment of pathophysiological mechanisms underlying dysregulation of the heart and the development of personalized approaches for its pharmacological correction.

Cardiovascular Comorbidities in Chronic Obstructive Pulmonary Disease (COPD)-Current Considerations for Clinical Practice

In patients with chronic obstructive pulmonary disease (COPD), cardiovascular comorbidities are highly prevalent and associated with considerable morbidity and mortality. This coincidence is increasingly seen in context of a “cardiopulmonary continuum” rather than being simply attributed to shared risk factors such as cigarette smoking. Overlapping symptoms such as dyspnea or chest pain lead to a worse prognosis due to missed concomitant diagnoses. Moreover, medication is often withheld as a result of unfounded concerns about side effects. Despite the frequent coincidence, current guidelines are still mostly restricted to the management of the individual disease. Future diagnostic and therapeutic strategies should therefore be guided by an integrative perspective as well as a refined phenotyping of disease entities.

Angiotensin II Signal Transduction: An Update on Mechanisms of Physiology and Pathophysiology

The renin-angiotensin-aldosterone system plays crucial roles in cardiovascular physiology and pathophysiology. However, many of the signaling mechanisms have been unclear. The angiotensin II (ANG II) type 1 receptor (AT₁R) is believed to mediate most functions of ANG II in the system. AT₁R utilizes various signal transduction cascades causing hypertension, cardiovascular remodeling, and end organ damage. Moreover, functional cross-talk between AT₁R signaling pathways and other signaling pathways have been recognized. Accumulating evidence reveals the complexity of ANG II signal transduction in pathophysiology of the vasculature, heart, kidney, and brain, as well as several pathophysiological features, including inflammation, metabolic dysfunction, and aging. In this review, we provide a comprehensive update of the ANG II receptor signaling events and their functional significances for potential translation into therapeutic strategies. AT₁R remains central to the system in mediating physiological and pathophysiological functions of ANG II, and participation of specific signaling pathways becomes much clearer. There are still certain limitations and many controversies, and several noteworthy new concepts require further support. However, it is expected that rigorous translational research of the ANG II signaling pathways including those in large animals and humans will contribute to establishing effective new therapies against various diseases.

Cardiovascular disease and COPD: dangerous liaisons?

Chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD) frequently occur together and their coexistence is associated with worse outcomes than either condition alone. Pathophysiological links between COPD and CVD include lung hyperinflation, systemic inflammation and COPD exacerbations. COPD treatments may produce beneficial cardiovascular (CV) effects, such as long-acting bronchodilators, which are associated with improvements in arterial stiffness, pulmonary vasoconstriction, and cardiac function. However, data are limited regarding whether these translate into benefits in CV outcomes. Some studies have suggested that treatment with long-acting β₂-agonists and long-acting muscarinic antagonists leads to an increase in the risk of CV events, particularly at treatment initiation, although the safety profile of these agents with prolonged use appears reassuring. Some CV medications may have a beneficial impact on COPD outcomes, but there have been concerns about β-blocker use leading to bronchospasm in COPD, which may result in patients not receiving guideline-recommended treatment. However, there are few data suggesting harm with these agents and patients should not be denied β-blockers if required. Clearer recommendations are necessary regarding the identification and management of comorbid CVD in patients with COPD in order to facilitate early intervention and appropriate treatment.

ACE gene polymorphism is associated with COPD and COPD with pulmonary hypertension: a meta-analysis

Purpose

Angiotensin-converting enzyme (ACE) gene I/D polymorphism has been studied in relation to the susceptibility to COPD and COPD with pulmonary hypertension (PH) with inconclusive results. We performed the first comprehensive meta-analysis to evaluate accurately the association between the ACE gene polymorphism and the risk of COPD.

Methods

Data were analyzed using odds ratios (ORs) and the corresponding 95% CIs to measure the strength of the models. Subgroup analyses were conducted by ethnicity and complication which referred to PH.

Results

In total, 15 studies (2,635 participants) were included in our study, of which four studies (288 participants) were for PH subgroup. The overall analysis results indicated that the ACE gene polymorphism was not associated with COPD susceptibility in all gene models. However, the ethnic subgroup analysis results indicated that ACE gene polymorphism was associated with Asians’ susceptibility to COPD (DD+DI vs II, OR=1.47, P=0.019, 95% CI: 1.07–2.02). Further, the overall results of the present study detected no statistical significance between ACE gene polymorphism and the risk of COPD with PH, but the homozygote variant (DD) increased the risk of PH in Asian COPD patients (DD vs ID+II, OR=2.05, P=0.05, 95% CI: 1.00–4.19).

Conclusion

The current study suggests that ACE polymorphism, particularly the homozygote variant (DD), might contribute to the risk of COPD and COPD with PH among Asians. Further studies with larger sample size and more ethnicities are expected to be conducted in the future to validate the results.

Nicotine and the renin-angiotensin system

Cigarette smoking is the single most important risk factor for the development of cardiovascular and pulmonary diseases (CVPD). Although cigarette smoking has been in constant decline since the 1950s, the introduction of e-cigarettes or electronic nicotine delivery systems 10 yr ago has attracted former smokers as well as a new generation of consumers. Nicotine is a highly addictive substance, and it is currently unclear whether e-cigarettes are "safer" than regular cigarettes or whether they have the potential to reverse the health benefits, notably on the cardiopulmonary system, acquired with the decline of tobacco smoking. Of great concern, nicotine inhalation devices are becoming popular among young adults and youths, emphasizing the need for awareness and further study of the potential cardiopulmonary risks of nicotine and associated products. This review focuses on the interaction between nicotine and the renin-angiotensin system (RAS), one of the most important regulatory systems on autonomic, cardiovascular, and pulmonary functions in both health and disease. The literature presented in this review strongly suggests that nicotine alters the homeostasis of the RAS by upregulating the detrimental angiotensin-converting enzyme (ACE)/angiotensin (ANG)-II/ANG II type 1 receptor axis and downregulating the compensatory ACE2/ANG-(1-7)/Mas receptor axis, contributing to the development of CVPD.

Do outpatient statins and ACEIs/ARBs have synergistic effects in reducing the risk of pneumonia? A population-based case-control study

Whether statins and an angiotensin-converting enzyme inhibitors (ACEIs) / angiotensin receptor blockors (ARBs) are associated with reduced risks of infection events is still inconclusive. This study aimed to explore the risk of hospitalization for pneumonia among patients who had received treatment with ACEIs/ARBs and/or statins using a population-based dataset. This study included 19,281 patients as cases who were hospitalized for pneumonia and 19,281 controls. We used a logistic regression to compute the odds ratio (OR) and 95% confidence interval (CI) for having previously used statins or an ACEI/ ARB between patients who were hospitalized for pneumonia treatment and controls. We found there were significant associations between hospitalization for pneumonia and statin-only users (p<0.001), ACEI/ARB-only users (p<0.001), and statin and ACEI/ARB users (p<0.001). The logistic regression analysis suggested that statin-only users (adjusted OR = 0.38, 95% CI = 0.34~0.43), ACEI/ARB-only users (adjusted OR = 0.86, 95% CI = 0.82~0.91), and statin and ACEI/ARB users (adjusted OR = 0.47, 95% CI = 0.44~0.50) were all less likely to be hospitalized for pneumonia treatment than were non-users. Furthermore, we found that statin-only users (adjusted OR = 0.44, 95% CI = 0.40~0.50) and statin and ACEI/ARB users (adjusted OR = 0.55, 95% CI = 0.52~0.58) were less likely to be hospitalized for pneumonia treatment compared to ACEI-only users. However, combined statin and ACEI/ARB users (adjusted OR = 1.24, 95% CI = 1.10~1.40) were more likely to have been hospitalized for pneumonia treatment compared to statin-only users. Although we found use of both statins and ACEI/ARB were significantly associated with a lower risk of pneumonia, the combination of the two medications did not provide additional protection against pneumonia risk.

Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers: A Promising Medication for Chronic Obstructive Pulmonary Disease?

Chronic obstructive pulmonary disease (COPD) is a complex disorder that primarily affects the lungs and is characterized not only by local pulmonary, but also by systemic inflammation which promotes the development of extrapulmonary and cardiovascular co-morbidities. Angiotensin converting enzyme (ACE) inhibitors and ARBs (angiotensin receptor blockers) are widely used drugs in the treatment of cardiovascular diseases, with growing evidence suggesting potential benefits in COPD patients. The purpose of this review is to describe the correlation of renin-angiotensin system (RAS) with COPD pathophysiology and to present the latest data regarding the potential role of RAS blockers in COPD.

Targeting the renin-angiotensin system as novel therapeutic strategy for pulmonary diseases

The renin-angiotensin system (RAS) plays a major role in regulating electrolyte balance and blood pressure. RAS has also been implicated in the regulation of inflammation, proliferation and fibrosis in pulmonary diseases such as asthma, acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF) and pulmonary arterial hypertension (PAH). Current therapeutics suffer from some drawbacks like steroid resistance, limited efficacies and side effects. Novel intervention is definitely needed to offer optimal therapeutic strategy and clinical outcome. This review compiles and analyses recent investigations targeting RAS for the treatment of inflammatory lung diseases. Inhibition of the upstream angiotensin (Ang) I/Ang II/angiotensin receptor type 1 (AT₁R) pathway and activation of the downstream angiotensin-converting enzyme 2 (ACE2)/Ang (1-7)/Mas receptor pathway are two feasible strategies demonstrating efficacies in various pulmonary disease models. More recent studies favor the development of targeting the downstream ACE2/Ang (1-7)/Mas receptor pathway, in which diminazene aceturate, an ACE2 activator, GSK2586881, a recombinant ACE2, and AV0991, a Mas receptor agonist, showed much potential for further development. As the pathogenesis of pulmonary diseases is so complex that RAS modulation may be used alone or in combination with existing drugs like corticosteroids, pirfenidone/nintedanib or endothelin receptor antagonists for different pulmonary diseases. Personalized medicine through genetic screening and phenotyping for angiotensinogen or ACE would aid treatment especially for non-responsive patients. This review serves to provide an update on the latest development in the field of RAS targeting for pulmonary diseases, and offer some insights into future direction.

Angiotensin-Converting Enzyme Inhibition as an Adjunct to Pulmonary Rehabilitation in Chronic Obstructive Pulmonary Disease

RATIONALE

Epidemiological studies in older individuals have found an association between the use of angiotensin-converting enzyme (ACE) inhibition (ACE-I) therapy and preserved locomotor muscle mass, strength, and walking speed. ACE-I therapy might therefore have a role in the context of pulmonary rehabilitation (PR).

OBJECTIVES

To investigate the hypothesis that enalapril, an ACE inhibitor, would augment the improvement in exercise capacity seen during PR.

METHODS

We performed a double-blind, placebo-controlled, parallel-group randomized controlled trial. Patients with chronic obstructive pulmonary disease, who had at least moderate airflow obstruction and were taking part in PR, were randomized to either 10 weeks of therapy with an ACE inhibitor (10 mg enalapril) or placebo.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measurement was the change in peak power (assessed using cycle ergometry) from baseline. Eighty patients were enrolled, 78 were randomized (age 67 ± 8 years; FEV₁ 48 ± 21% predicted), and 65 completed the trial (34 on placebo, 31 on the ACE inhibitor). The ACE inhibitor-treated group demonstrated a significant reduction in systolic blood pressure (Δ, -16 mm Hg; 95% confidence interval [CI], -22 to -11) and serum ACE activity (Δ, -18 IU/L; 95% CI, -23 to -12) versus placebo (between-group differences, P < 0.0001). Peak power increased significantly more in the placebo group (placebo Δ, +9 W; 95% CI, 5 to 13 vs. ACE-I Δ, +1 W; 95% CI, -2 to 4; between-group difference, 8 W; 95% CI, 3 to 13; P = 0.001). There was no significant between-group difference in quadriceps strength or health-related quality of life.

CONCLUSIONS

Use of the ACE inhibitor enalapril, together with a program of PR, in patients without an established indication for ACE-I, reduced the peak work rate response to exercise training in patients with chronic obstructive pulmonary disease.

ACE and response to pulmonary rehabilitation in COPD: two observational studies

Introduction

Skeletal muscle impairment is an important feature of chronic obstructive pulmonary disease (COPD). Renin–angiotensin system activity influences muscle phenotype, so we wished to investigate whether it affects the response to pulmonary rehabilitation.

Methods

Two studies are described; in the first, the response of 168 COPD patients (mean forced expiratory volume in one second 51.9% predicted) to pulmonary rehabilitation was compared between different ACE insertion/deletion polymorphism genotypes. In a second, independent COPD cohort (n=373), baseline characteristics and response to pulmonary rehabilitation were compared between COPD patients who were or were not taking ACE inhibitors or angiotensin receptor antagonists (ARB).

Results

In study 1, the incremental shuttle walk distance improved to a similar extent in all three genotypes; DD/ID/II (n=48/91/29) 69(67)m, 61 (76)m and 78 (78)m, respectively, (p>0.05). In study 2, fat free mass index was higher in those on ACE-I/ARB (n=130) than those who were not (n=243), 17.8 (16.0, 19.8) kg m⁻² vs 16.5 (14.9, 18.4) kg/m² (p<0.001). However change in fat free mass, walking distance or quality of life in response to pulmonary rehabilitation did not differ between groups.

Conclusions

While these data support a positive association of ACE-I/ARB treatment and body composition in COPD, neither treatment to reduce ACE activity nor ACE (I/D) genotype influence response to pulmonary rehabilitation.

Role of B-Type Natriuretic Peptide in Predicting In-Hospital Outcomes in Acute Exacerbation of Chronic Obstructive Pulmonary Disease With Preserved Left Ventricular Function: A 5-Year Retrospective Analysis

BACKGROUND

The role of B-type natriuretic peptide (BNP) is less understood in the risk stratification of patients with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD), especially in patients with normal left ventricular ejection fraction (LVEF).

METHODS

This retrospective study from 2008 to 2012 evaluated all adult patients with AECOPD having BNP levels and available echocardiographic data demonstrating LVEF ≥40%. The patients were divided into groups 1, 2, and 3 with BNP ≤ 100, 101 to 500, and ≥501 pg/mL, respectively. A subgroup analysis was performed for patients without renal dysfunction. Outcomes included need for and duration of noninvasive ventilation (NIV) and mechanical ventilation (MV), NIV failure, reintubation at 48 hours, intensive care unit (ICU) and total length of stay (LOS), and in-hospital mortality. Two-tailed P < .05 was considered statistically significant.

RESULTS

Of the total 1145 patients, 550 (48.0%) met our inclusion criteria (age 65.1 ± 12.2 years; 271 [49.3%] males). Groups 1, 2, and 3 had 214, 216, and 120 patients each, respectively, with higher comorbidities and worse biventricular function in higher categories. Higher BNP values were associated with higher MV use, NIV failure, MV duration, and ICU and total LOS. On multivariate analysis, BNP was an independent predictor of higher NIV and MV use, NIV failure, NIV and MV duration, and total LOS in groups 2 and 3 compared to group 1. B-type natriuretic peptide continued to demonstrate positive correlation with NIV and MV duration and ICU and total LOS independent of renal function in a subgroup analysis.

CONCLUSION

Elevated admission BNP in patients with AECOPD and normal LVEF is associated with worse in-hospital outcomes and can be used to risk-stratify these patients.

The association of renin-angiotensin system blockades and pneumonia requiring admission in patients with COPD

BACKGROUND

The hallmark of COPD is chronic airway inflammation, which may be mediated by renin-angiotensin system. The renin-angiotensin system blockers such as angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARBs) have exhibited anti-inflammatory and immunomodulatory effects in patients with various diseases. We explored the effects of ACEi and ARBs on the risk of pneumonia in patients with COPD.

METHODS

A nested case-control study was performed on COPD patients recruited from January 2010 to August 2013 in two referral hospitals in Korea. A total of 130 COPD patients admitted with pneumonia were included, and 245 COPD patients without pneumonia were selected as controls from a total of 1,646 such patients. Controls were matched with test patients by age, sex, and severity of airflow limitation. The effects of ACEi/ARBs use on the odds ratio (OR) for the development of pneumonia were tested through conditional logistic regression.

RESULTS

Elderly patients (over 70 years of age) constituted ~30% of each group; most of the patients were male (85%). Of the COPD patients with pneumonia, 21.5% had taken ACEi/ARBs for a mean of 9.8 months (standard deviation ±3.5 months). The proportions of ACEi/ARBs users and the mean duration of such use did not differ when compared to those of the control patients (26.9%, P=0.25; 9.6±3.6 months, P=0.83). Univariate analyses indicated that the use of ACEi/ARBs was not associated with a decreased risk of pneumonia (OR =0.70, 95% confidence interval 0.41-1.23, P=0.21), whereas both a history of pulmonary tuberculosis (OR =1.85, 95% confidence interval 1.12-3.06, P=0.02) and exposure to systemic steroids (OR =2.33, 95% confidence interval 1.28-4.23, P=0.005) did show an association. After adjustment for a history of tuberculosis, comorbid chronic renal disease, and exposure to corticosteroids, ACEi/ARBs reduced the risk of pneumonia in COPD patients (OR =0.51, 95% confidence interval 0.27-0.98, P=0.04).

CONCLUSION

This study revealed that the use of ACEi/ARBs was associated with reducing the risk of pneumonia in patients with COPD. Further prospective studies are necessary to confirm the protective effect of ACEi/ARBs and elucidate the underlying mechanisms in COPD patients.

Influence of Left Ventricular Hypertrophy on In-Hospital Outcomes in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Left ventricular hypertrophy (LVH) is associated with worse outcomes in chronic obstructive pulmonary disease (COPD); however, its role in an acute exacerbation of COPD (AECOPD) has not been reported. This was a retrospective cohort study during 2008-2012 at an academic medical center. AECOPD patients >18 years with available echocardiographic data were included. LVH was defined as LV mass index (LVMI) >95 g/m² (women) and >115g/m² (men). Relative wall thickness was used to classify LVH as concentric (>0.42) or eccentric (<0.42). Outcomes included need for and duration of non-invasive ventilation (NIV) and mechanical ventilation (MV), NIV failure, intensive care unit (ICU) and total length of stay (LOS), and in-hospital mortality. Two-tailed p < 0.05 was considered statistically significant. Of 802 patients with AECOPD, 615 patients with 264 (42.9%) having LVH were included. The LVH cohort had higher LVMI (141.1 ± 39.4 g/m² vs. 79.7 ± 19.1 g/m²; p < 0.001) and lower LV ejection fraction (44.5±21.9% vs. 50.0±21.6%; p ≤ 0.001). The LVH cohort had statistically non-significant longer ICU LOS, and higher NIV and MV use and duration. Of the 264 LVH patients, concentric LVH (198; 75.0%) was predictive of greater NIV use [82 (41.4%) vs. 16 (24.2%), p = 0.01] and duration (1.0 ± 1.9 vs. 0.6 ± 1.4 days, p = 0.01) compared to eccentric LVH. Concentric LVH remained independently associated with NIV use and duration. In-hospital outcomes in patients with AECOPD were comparable in patients with and without LVH. Patients with concentric LVH had higher NIV need and duration in comparison to eccentric LVH.

Impact of I/D polymorphism of ACE gene on risk of development and course of chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) affects more than 10% of the world's population over 40 years of age. The main exogenous risk factor is cigarette smoking; however, only 20% of smokers develop COPD, indicating that some other factors, e.g. genetic, may play an important role in the disease pathogenesis. Recent research indicates that ACE (angiotensin-converting enzyme) may be a susceptibility gene for asthma or COPD. The aim of our study was to determine the influence of I/D (insertion/deletion) polymorphism of the ACE gene (AluYa5, rs4646994) on the risk and course of COPD.

MATERIAL AND METHODS

We investigated ACE I/D polymorphism in 206 COPD and 165 healthy Caucasian subjects.

RESULTS

In the generalized linear model (GLZ) analysis of the influence of selected factors on presence of COPD we found a significant independent effect for male sex (repeatedly increases the risk of COPD, OR = 7.7, p = 0.049), as well as smoking or lower body mass index, but only in combination with older age (OR = 0.96, p = 0.003 and OR = 1.005, p = 0.04 respectively). Interestingly, analysis of factors which may influence the risk of a higher number of exacerbations demonstrated that occurrence of DD genotype, but only in men, is associated with a lower risk (OR = 0.7, p = 0.03) of this complication.

CONCLUSIONS

We suggest that ACE may not be a susceptibility gene for the origin of COPD but a disease-modifying gene. Since the impact of I/D polymorphism of the ACE gene on COPD risk is moderate or negligible, other molecular changes, that will help predict the development of this disease, should still be sought.

Treatment options for moderate-to-very severe chronic obstructive pulmonary disease

INTRODUCTION

The appropriate drug management of COPD is still based on the use of bronchodilators, possibly associated with an anti-inflammatory agent. However, there are still fundamental questions that require clarification to optimise their use and major unmet clinical needs that must be addressed.

AREAS COVERED

The advances obtained with the pharmacological options currently consolidated and the different approaches that are often used in an attempt to respond to unmet therapeutic needs are reviewed Expert opinion: In view of the unsatisfactory status of current treatments for COPD, there is an urgent need for alternative and more effective therapeutic approaches that will help to relieve patient symptoms and affect the natural course of COPD, inhibiting chronic inflammation and reversing the disease process or preventing its progression. However, new pharmacologic options have proved difficult to develop. Therefore, it is mandatory to optimize the use of the treatment options at our disposal. However, there are still fundamental questions regarding their use, including the step-up and step-down pharmacological approach, that require clarification to optimise the use of these drugs. It is likely that phenotyping COPD patients would help in identifying the right treatment for each COPD patient and improve the effectiveness of therapies.

Airway Remodeling in Chronic Obstructive Pulmonary Disease and Asthma: the Role of Matrix Metalloproteinase-9

Chronic obstructive pulmonary disease (COPD) and asthma are both associated with airflow restriction and progressive remodeling, which affect the respiratory tract. Among various biological factors involved in the pathomechanisms of both diseases, proteolytic enzymes--matrix metalloproteinases (MMPs)--play an important role, especially MMP-9. In this review, the authors discuss the current topics of research concerning the possible role of MMP-9 in both mentioned diseases. They include the analysis of protein levels, nucleotide polymorphisms of MMP-9 gene and their possible correlation with asthma and COPD. Finally, the authors refer to the studies on MMP-9 inhibition as a new perspective for increasing the effectiveness of treatment in asthma and COPD.

Activation of the GLP-1 Receptor by Liraglutide Increases ACE2 Expression, Reversing Right Ventricle Hypertrophy, and Improving the Production of SP-A and SP-B in the Lungs of Type 1 Diabetes Rats

Diabetes alters microvascular function in the vascular beds of organs, including the lungs. Cardiovascular complications of pulmonary vascular affectation may be a consequence of the overactivation of the vasoconstrictive and proliferative components of the renin-angiotensin system. We previously reported that pulmonary physiology and surfactant production is improved by the glucagon-like peptide 1 receptor (GLP-1R) agonist liraglutide (LIR) in a rat model of lung hypoplasia. Because we hypothesized that streptozotocin-induced diabetes rats would show deficiencies in lung function, including surfactant proteins, and develop an imbalance of the renin-angiotensin system in the lungs. This effect would in turn be prevented by long-acting agonists of the GLP-1R, such as LIR. The induction of diabetes reduced the surfactant protein A and B in the lungs and caused the vasoconstrictor component of the renin-angiotensin system to predominate, which in turn increased angiotensin II levels, and ultimately being associated with right ventricle hypertrophy. LIR restored surfactant protein levels and reversed the imbalance in the renin-angiotensin system in this type 1 diabetes mellitus rat model. Moreover, LIR provoked a strong increase in angiotensin-converting enzyme 2 expression in the lungs of both diabetic and control rats, and in the circulating angiotensin(1-7) in diabetic animals. These effects prompted complete reversion of right ventricle hypertrophy. The consequences of LIR administration were independent of glycemic control and of glucocorticoids, and they involved NK2 homeobox 1 signaling. This study demonstrates by first time that GLP-1R agonists, such as LIR, might improve the cardiopulmonary complications associated with diabetes.

Therapeutic approaches of uncomplicated arterial hypertension in patients with COPD

The concomitant presence of systemic arterial hypertension and chronic obstructive pulmonary disease (COPD) is frequent. Indeed, arterial hypertension is the most common comorbid disease in COPD patients. Since many antihypertensive drugs can act on airway function the treatment of arterial hypertension in COPD patients appears complex. Moreover, in these patients, a combined therapy is required for the adequate control of blood pressure. Currently, available data are inconsistent and not always comparable. Therefore the aim of this review is to analyze how antihypertensive drugs can affect airway function in order to improve the clinical management of hypertensive patients with COPD. Thiazide diuretics and calcium channel blockers appear the first-choice pharmacological treatment for these patients.

Renin-angiotensin system: an old player with novel functions in skeletal muscle

Skeletal muscle is a tissue that shows the most plasticity in the body; it can change in response to physiological and pathological stimuli. Among the diseases that affect skeletal muscle are myopathy-associated fibrosis, insulin resistance, and muscle atrophy. A common factor in these pathologies is the participation of the renin-angiotensin system (RAS). This system can be functionally separated into the classical and nonclassical RAS axis. The main components of the classical RAS pathway are angiotensin-converting enzyme (ACE), angiotensin II (Ang-II), and Ang-II receptors (AT receptors), whereas the nonclassical axis is composed of ACE2, angiotensin 1-7 [Ang (1-7)], and the Mas receptor. Hyperactivity of the classical axis in skeletal muscle has been associated with insulin resistance, atrophy, and fibrosis. In contrast, current evidence supports the action of the nonclassical RAS as a counter-regulator axis of the classical RAS pathway in skeletal muscle. In this review, we describe the mechanisms involved in the pathological effects of the classical RAS, advances in the use of pharmacological molecules to inhibit this axis, and the beneficial effects of stimulation of the nonclassical RAS pathway on insulin resistance, atrophy, and fibrosis in skeletal muscle.

Angiotensin-Converting Enzyme 2/Angiotensin-(1-7)/Mas Receptor Axis

Experimental and clinical evidence supports an active role of the renin–angiotensin system (RAS) in the pathogenesis and progression of lung diseases. Angiotensin II (Ang II), a key vasoactive peptide of the RAS, has been implicated in pulmonary disorders such as pulmonary arterial hypertension, lung fibrosis, chronic obstructive pulmonary disease, and acute respiratory distress syndrome. Over the past few years, the classical concept of the RAS has undergone substantial changes to include several new active components. Among them, the identification of angiotensin-converting enzyme 2 (ACE2), its metabolic product angiotensin-(1-7) (Ang-(1-7)), and the Mas receptor has been of biological significance since these components form a counterregulatory axis (ACE2/Ang-(1-7)/Mas) that opposes the detrimental actions of Ang II. In this chapter, we will discuss the role of the ACE2/Ang-(1-7)/Mas axis in lung diseases and describe novel therapeutic approaches to activate this axis for the treatment of pulmonary disorders.

Effects of olmesartan therapy on the expression of lung adrenoceptors in rats with chronic heart failure

INTRODUCTION

Adrenergic receptors (AR) play important roles in regulating lung function. However, there are few reports concerning AR expression and the protective effect of angiotensin II receptor blockers (ARB) on the lung in chronic heart failure (CHF). In this study, we aimed to investigate the protective effects of the ARB olmesartan on the lung in CHF.

MATERIALS AND METHODS

Wistar rats were randomly divided into four groups: normal control, sham-operated rats, rats with CHF induced by ligating the left anterior descending coronary arteries, and rats with CHF treated with olmesartan (1 mg/kg) once daily for 8 weeks. Heart function, plasma renin activity (PRA) and angiotensin II (Ang II) levels, lung microscopic structure inspection and mRNA and protein expressions of α1A-, β1- and β2-AR in lung were tested.

RESULTS

Compared with the CHF group, PRA and Ang II levels were decreased while heart function and mRNA and protein expression of α1A-AR, β1-AR and β2-AR were up-regulated in the olmesartan group (p<0.05 or p<0.01). The inflammation and cell proliferation in CHF lung tissue were reduced in the olmesartan group.

CONCLUSION

Olmesartan may play a beneficial role in protecting lung in CHF by up-regulating AR and decreasing levels of PRA and Ang II.

In-hospital and one-year mortality and their predictors in patients hospitalized for first-ever chronic obstructive pulmonary disease exacerbations: a nationwide population-based study

Introduction

Natural history of chronic obstructive pulmonary disease (COPD) is punctuated by exacerbations; however, little is known about prognosis of the first-ever COPD exacerbation and variables predicting its outcomes.

Materials and Methods

A population-based cohort study among COPD patients with their first-ever exacerbations requiring hospitalizations was conducted. Main outcomes were in-hospital mortality and one-year mortality after discharge. Demographics, comorbidities, medications and in-hospital events were obtained to explore outcome predictors.

Results

The cohort comprised 4204 hospitalized COPD patients, of whom 175 (4%) died during the hospitalization. In-hospital mortality was related to higher age (odds ratio [OR]: 1.05 per year; 95% confidence interval [CI]: 1.03–1.06) and Charlson comorbidity index score (OR: 1.08 per point; 95% CI: 1.01–1.15); angiotensin II receptor blockers (OR: 0.61; 95% CI: 0.38–0.98) and β blockers (OR: 0.63; 95% CI: 0.41–0.95) conferred a survival benefit. At one year after discharge, 22% (871/4029) of hospital survivors were dead. On multivariate Cox regression analysis, age and Charlson comorbidity index remained independent predictors of one-year mortality. Longer hospital stay (hazard ratio [HR] 1.01 per day; 95% CI: 1.01–1.01) and ICU admission (HR: 1.33; 95% CI: 1.03–1.73) during the hospitalization were associated with higher mortality risks. Prescription of β blockers (HR: 0.79; 95% CI: 0.67–0.93) and statins (HR: 0.66; 95% CI: 0.47–0.91) on hospital discharge were protective against one-year mortality.

Conclusions

Even the first-ever severe COPD exacerbation signifies poor prognosis in COPD patients. Comorbidities play a crucial role in determining outcomes and should be carefully assessed. Angiotensin II receptor blockers, β blockers and statins may, in theory, have dual cardiopulmonary protective properties and probably alter prognosis of COPD patients. Nevertheless, the limitations inherent to a claims database study, such as the diagnostic accuracy of COPD and its exacerbation, should be born in mind.

A randomized controlled trial of angiotensin-converting enzyme inhibition for skeletal muscle dysfunction in COPD

BACKGROUND

Skeletal muscle impairment is a recognized complication of COPD, predicting mortality in severe disease. Increasing evidence implicates the renin-angiotensin system in control of muscle phenotype. We hypothesized that angiotensin-converting enzyme (ACE) inhibition would improve quadriceps function and exercise performance in COPD.

METHODS

This double-blind, randomized placebo-controlled trial investigated the effect of the ACE inhibitor, fosinopril, on quadriceps function in patients with COPD with quadriceps weakness. Primary outcomes were change in quadriceps endurance and atrophy signaling at 3 months. Quadriceps maximum voluntary contraction (QMVC), mid-thigh CT scan of the cross-sectional area (MTCSA), and incremental shuttle walk distance (ISWD) were secondary outcomes.

RESULTS

Eighty patients were enrolled (mean [SD], 65 [8] years, FEV1 43% [21%] predicted, 53% men). Sixty-seven patients (31 fosinopril, 36 placebo) completed the trial. The treatment group demonstrated a significant reduction in systolic BP (Δ-10.5 mm Hg; 95% CI, -19.9 to -1.1; P = .03) and serum ACE activity (Δ-20.4 IU/L; 95% CI, -31.0 to -9.8; P < .001) compared with placebo. No significant between-group differences were observed in the primary end points of quadriceps endurance half-time (Δ0.5 s; 95% CI, -13.3-14.3; P = .94) or atrogin-1 messenger RNA expression (Δ-0.03 arbitrary units; 95% CI, -0.32-0.26; P = .84). QMVC improved in both groups (fosinopril: Δ1.1 kg; 95% CI, 0.03-2.2; P = .045 vs placebo: Δ3.6 kg; 95% CI, 2.1-5.0; P < .0001) with a greater increase in the placebo arm (between-group, P = .009). No change was shown in the MTCSA (P = .09) or ISWD (P = .51).

CONCLUSIONS

This randomized controlled trial found that ACE inhibition, using fosinopril for 3 months, did not improve quadriceps function or exercise performance in patients with COPD with quadriceps weakness.

TRIAL REGISTRY

Current Controlled Trials; No.: ISRCTN05581879; URL: www.controlled-trials.com.

Anaemia in chronic obstructive pulmonary disease: an insight into its prevalence and pathophysiology

Chronic obstructive pulmonary disease (COPD) is a major health problem, with increasing morbidity and mortality. There is a growing literature regarding the extra-pulmonary manifestations of COPD, which can have a significant impact on symptom burden and disease progression. Anaemia is one of the more recently identified co-morbidities, with a prevalence that varies between 4.9% and 38% depending on patient characteristics and the diagnostic criteria used. Systemic inflammation seems to be an important factor for its establishment and repeated bursts of inflammatory mediators during COPD exacerbations could further inhibit erythropoiesis. However, renal impairment, malnutrition, low testosterone levels, growth hormone level abnormalities, oxygen supplementation, theophylline treatment, inhibition of angiotensin-converting enzyme and aging itself are additional factors that could be associated with the development of anaemia. The present review evaluates the published literature on the prevalence and significance of anaemia in COPD. Moreover, it attempts to elucidate the reasons for the high variability reported and investigates the complex pathophysiology underlying the development of anaemia in these patients.

Chronic kidney disease and premature ageing

Chronic kidney disease (CKD) shares many phenotypic similarities with other chronic diseases, including heart failure, chronic obstructive pulmonary disease, HIV infection and rheumatoid arthritis. The most apparent similarity is premature ageing, involving accelerated vascular disease and muscle wasting. We propose that in addition to a sedentary lifestyle and psychosocial and socioeconomic determinants, four major disease-induced mechanisms underlie premature ageing in CKD: an increase in allostatic load, activation of the 'stress resistance response', activation of age-promoting mechanisms and impairment of anti-ageing pathways. The most effective current interventions to modulate premature ageing-treatment of the underlying disease, optimal nutrition, correction of the internal environment and exercise training-reduce systemic inflammation and oxidative stress and induce muscle anabolism. Deeper mechanistic insight into the phenomena of premature ageing as well as early diagnosis of CKD might improve the application and efficacy of these interventions and provide novel leads to combat muscle wasting and vascular impairment in chronic diseases.