Protective Effect of Statins on Pulmonary Hypertension in Chronic Obstructive Pulmonary Disease Patients: A Nationwide Retrospective, Matched Cohort Study

Extrapulmonary Comorbidities Associated with Chronic Obstructive Pulmonary Disease: A Review

Most patients with chronic obstructive pulmonary disease (COPD) suffer from at least one additional, clinically relevant chronic disease. To a degree, the high global prevalence and mortality rate of COPD is closely related to its extrapulmonary effects. Moreover, the various of comorbidities of COPD and itself interact with each other, resulting in diverse clinical manifestations and individual differences, and thus further influencing the prognosis as well as healthcare burden of COPD patients. This is closely related to the common risk factors of chronic diseases (aging, smoking, inactivity, etc.). Additionally, some pathophysiological mechanisms caused by COPD, including the systemic inflammatory response, hypoxia, oxidative stress, and others, also have an impact on other systems. But comprehensive management and medical interventions have not yet been established. The clinicians should improve their knowledge and skills in diagnosing as well as treating the comorbidities of COPD, and then aim to develop more individualized, efficient diagnostic and therapeutic strategies for different patients to achieve greater clinical benefits. In this article, we will review the risk factors, mechanisms, and treatment strategies for extrapulmonary comorbidities in chronic obstructive pulmonary disease, including cardiovascular diseases, diabetes, anemia, osteoporosis, emotional disorders, and gastroesophageal reflux disease.

Cardiovascular Diseases in COPD: From Diagnosis and Prevalence to Therapy

Chronic obstructive pulmonary disease (COPD) is considered one of the leading causes of mortality. Cardiovascular comorbidities are diagnosed often in COPD patients, not only because of the common risk factors these two diseases share, but also because of the systemic inflammation which characterizes COPD and has deleterious effects in the cardiovascular system. The comorbid cardiovascular diseases in COPD result in several difficulties in the holistic treatment of these patients and affect outcomes such as morbidity and mortality. Several studies have reported that mortality from cardiovascular causes is common among COPD patients, while the risk for acute cardiovascular events increases during COPD exacerbations and remains high for a long time even after recovery. In this review, we focus on the prevalence of cardiovascular comorbidities in COPD patients, presenting the evidence regarding the interaction of the pathophysiological pathways which characterize each disease. Furthermore, we summarize information regarding the effects of cardiovascular treatment on COPD outcomes and vice versa. Finally, we present the current evidence regarding the impact of cardiovascular comorbidities on exacerbations, quality of life and survival of COPD patients.

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.

Identifying Patients with Group 3 Pulmonary Hypertension Associated with COPD or ILD Using an Administrative Claims Database

BACKGROUND

Group 3 pulmonary hypertension (PH) describes a subpopulation of patients with PH due to chronic lung disease and/or hypoxia, with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) being two large subgroups. Claims database studies provide insights into the real-world treatment patterns and outcomes among these patients. However, claims data do not provide sufficient detail to assign the clinical subtype of PH required for identifying these patients.

METHODS

A panel of PH clinical experts and researchers was convened to discuss methodologies to identify patients with Group 3 PH associated with COPD or ILD in retrospective claims databases. To inform the discussion, a literature review was conducted to identify claims-based studies of Group 3 PH associated with COPD or ILD published from 2010 through June 2020.

RESULTS

Targeted title and abstract review identified 11 claims-based studies and two conference abstracts (eight based in the United States [US] and five conducted outside the US) that met search criteria. Based on insights from the panel and literature review, the following components were detailed across studies in the identification of Group 3 PH associated with COPD and ILD: (a) COPD or ILD identification, (b) PH identification, (c) defining the sequence between COPD/ILD and PH, and (d) other PH Group and Group 3 PH exclusions.

CONCLUSION

This article provides recommended approaches and considerations for identifying and studying patients with Group 3 PH associated with COPD or ILD using administrative claims data that provide the foundation for future validation studies.

Progress of Statin Therapy in the Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease (ILD) characterized by the proliferation of fibroblasts and aberrant accumulation of extracellular matrix. These changes are accompanied by structural destruction of the lung tissue and the progressive decline of pulmonary function. In the past few decades, researchers have investigated the pathogenesis of IPF and sought a therapeutic approach for its treatment. Some studies have shown that the occurrence of IPF is related to pulmonary inflammatory injury; however, its specific etiology and pathogenesis remain unknown, and no effective treatment, with the exception of lung transplantation, has been identified yet. Several basic science and clinical studies in recent years have shown that statins, the traditional lipid-lowering drugs, exert significant antifibrotic effects, which can delay the progression of IPF and impairment of pulmonary function. This article is aimed at summarizing the current understanding of the pathogenesis of IPF, the progress of research on the use of statins in IPF models and clinical trials, and its main molecular targets.

Chinese Herbs and Repurposing Old Drugs as Therapeutic Agents in the Regulation of Oxidative Stress and Inflammation in Pulmonary Diseases

Several pro-inflammatory factors and proteins have been characterized that are involved in the pathogenesis of inflammatory diseases, including acute respiratory distress syndrome, chronic obstructive pulmonary disease, and asthma, induced by oxidative stress, cytokines, bacterial toxins, and viruses. Reactive oxygen species (ROS) act as secondary messengers and are products of normal cellular metabolism. Under physiological conditions, ROS protect cells against oxidative stress through the maintenance of cellular redox homeostasis, which is important for proliferation, viability, cell activation, and organ function. However, overproduction of ROS is most frequently due to excessive stimulation of either the mitochondrial electron transport chain and xanthine oxidase or reduced nicotinamide adenine dinucleotide phosphate (NADPH) by pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor α. NADPH oxidase activation and ROS overproduction could further induce numerous inflammatory target proteins that are potentially mediated via Nox/ROS-related transcription factors triggered by various intracellular signaling pathways. Thus, oxidative stress is considered important in pulmonary inflammatory processes. Previous studies have demonstrated that redox signals can induce pulmonary inflammatory diseases. Thus, therapeutic strategies directly targeting oxidative stress may be effective for pulmonary inflammatory diseases. Therefore, drugs with anti-inflammatory and anti-oxidative properties may be beneficial to these diseases. Recent studies have suggested that traditional Chinese medicines, statins, and peroxisome proliferation-activated receptor agonists could modulate inflammation-related signaling processes and may be beneficial for pulmonary inflammatory diseases. In particular, several herbal medicines have attracted attention for the management of pulmonary inflammatory diseases. Therefore, we reviewed the pharmacological effects of these drugs to dissect how they induce host defense mechanisms against oxidative injury to combat pulmonary inflammation. Moreover, the cytotoxicity of oxidative stress and apoptotic cell death can be protected via the induction of HO-1 by these drugs. The main objective of this review is to focus on Chinese herbs and old drugs to develop anti-inflammatory drugs able to induce HO-1 expression for the management of pulmonary inflammatory diseases.

Statins for the Treatment of Pulmonary Hypertension in Patients with Chronic Obstructive Pulmonary Disease

Background: Patients with chronic obstructive pulmonary disease (COPD) are at risk for pulmonary hypertension (PH). The aim of our study was to investigate the benefit of statins for PH in patients with COPD.

Methods: The study enrolled 23 million individuals from Taiwan’s population database from January 1, 2002, to December 31, 2017. COPD patients who met the inclusion criteria were enrolled, and patients with lung cancer, less than one year of observation, specific drug therapy for PH and lung transplantation were excluded.

Results: A total of 643,131 COPD patients were included in the study, and only 12,308 patients developed PH during follow-up. Based on the inclusion and exclusion criteria, 8,577 PH patients were included in the cohort of patients with PH related to COPD for analysis. According to the definition of statin exposure, the final study population had 1,487 statin users and 7,090 statin non-users. The statin user group had a lower mortality related to PH than the non-user group (3.87 vs. 5.55 per 100 person-years, p < 0.001). The mortality rate for PH in the multivariate analysis (aHR = 0.78, 95% CI = 0.62–0.98, p = 0.046) was significantly lower for statin users than for non-users.

Conclusion: Statins seem to benefit patients with PH and COPD.

The roles of endothelin and its receptors in cigarette smoke-associated pulmonary hypertension with chronic lung disease

Chronic exposure to cigarette smoke is the major risk factor for the development of pulmonary hypertension (PH) with chronic lung disease (i.e. PH group III). The pathogenesis of smoke-associated PH group III in chronic obstructive pulmonary disease (COPD) involves cigarette smoke exposure-induced damage to lung tissue and dysfunction of pulmonary system with increased synthesis and release of endothelin-1 (ET-1), hypoxia, inflammation, pulmonary vascular remodeling. Many studies have demonstrated that cigarette smoke exposure induces activation of mitogen-activated protein kinase (MAPK) signal pathway that leads to up-regulation of ET-1 and its receptors with the receptor-mediated enhanced contraction, proliferation of pulmonary vascular smooth muscle cells, pulmonary vascular remodeling, elevated pulmonary arterial pressure and finally PH group III. This mini-review article aims to summarize the current state of understanding on the roles of cigarette smoke-induced up-regulation of ET-1 and its receptors in the development of PH group III. Understanding the underlying molecular mechanisms that cigarette smoke exposure leads to PH group III may provide a novel strategy for the treatment.