The influence of cigarette smoking on viral infections: translating bench science to impact COPD pathogenesis and acute exacerbations of COPD clinically

Associations of Self-Reported Cigarette Smoking with Chronic Obstructive Pulmonary Disease and Co-Morbid Chronic Conditions in the United States

BACKGROUND

The question of how smoking, COPD, and other chronic diseases are related remains unresolved. Therefore, we examined relationships between smoking, COPD, and 10 other chronic diseases and assessed the prevalence of co-morbid chronic conditions among people with COPD.

METHODS

We analyzed cross-sectional data from 405,856 US adults aged 18 years or older in the 2011 Behavioral Risk Factor Surveillance System. We used log-linear regression to estimate prevalence ratios (PRs) and their corresponding 95% confidence intervals (CIs) for these relationships adjusting for age, gender, race/ethnicity, marital status, educational attainment, annual household income, and health insurance coverage.

RESULTS

Overall, 17.5% reported being current cigarette smokers, 6.9% reported having COPD, and 71.2% reported another chronic condition. After age-adjustment, prevalence of COPD was 14.1% (adjusted PR = 3.9; 95% CI: 3.7, 4.1) among current smokers and 7.1% (adjusted PR = 2.5; 95% CI: 2.4, 2.7) among former smokers compared to 2.9% among never smokers. The most common chronic conditions among current smokers after age-adjustment were high cholesterol (36.7%), high blood pressure (34.6%), arthritis (29.4%), depression (27.4%), and asthma (16.9%). In separate multivariable models, smoking and COPD were associated with each of the 10 other chronic conditions (p < 0.05), which also included cancer, coronary heart disease, diabetes, kidney disease, and stroke; COPD modified associations between smoking and co-morbidities, while smoking did not modify associations between COPD and co-morbidities.

CONCLUSIONS

Our findings confirm previous evidence and highlight the continuing importance of comprehensive care coordination for people with COPD and co-morbid chronic conditions and also tobacco prevention and control strategies.

Interrelated role of cigarette smoking, oxidative stress, and immune response in COPD and corresponding treatments

Cigarette smoking (CS) can impact the immune system and induce pulmonary disorders such as chronic obstructive pulmonary disease (COPD), which is currently the fourth leading cause of chronic morbidity and mortality worldwide. Accordingly, the most significant risk factor associated with COPD is exposure to cigarette smoke. The purpose of the present study is to provide an updated overview of the literature regarding the effect of CS on the immune system and lungs, the mechanism of CS-induced COPD and oxidative stress, as well as the available and potential treatment options for CS-induced COPD. An extensive literature search was conducted on the PubMed/Medline databases to review current COPD treatment research, available in the English language, dating from 1976 to 2014. Studies have investigated the mechanism by which CS elicits detrimental effects on the immune system and pulmonary function through the use of human and animal subjects. A strong relationship among continued tobacco use, oxidative stress, and exacerbation of COPD symptoms is frequently observed in COPD subjects. In addition, therapeutic approaches emphasizing smoking cessation have been developed, incorporating counseling and nicotine replacement therapy. However, the inability to reverse COPD progression establishes the need for improved preventative and therapeutic strategies, such as a combination of intensive smoking cessation treatment and pharmaceutical therapy, focusing on immune homeostasis and redox balance. CS initiates a complex interplay between oxidative stress and the immune response in COPD. Therefore, multiple approaches such as smoking cessation, counseling, and pharmaceutical therapies targeting inflammation and oxidative stress are recommended for COPD treatment.

Animal models of chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a leading global cause of mortality and chronic morbidity. Inhalation of cigarette smoke is the principal risk factor for development of this disease. COPD is a progressive disease that is typically characterised by chronic pulmonary inflammation, mucus hypersecretion, airway remodelling and emphysema that collectively reduce lung function. There are currently no therapies that effectively halt or reverse disease progression. It is hoped that the development of animal models that develop the hallmark features of COPD, in a short time frame, will aid in the identifying and testing of new therapeutic approaches.

AREAS COVERED

The authors review the recent developments in mouse models of chronic cigarette smoke-induced COPD as well as the principal findings. Furthermore, the authors discuss the use of mouse models to understand the pathogenesis and the contribution of infectious exacerbations. They also discuss the investigations of the systemic co-morbidities of COPD (pulmonary hypertension, cachexia and osteoporosis).

EXPERT OPINION

Recent advances in the field mark a point where animal models recapitulate the pathologies of COPD patients in a short time frame. They also reveal novel insights into the pathogenesis and potential treatment of this debilitating disease.