Cigaret smoking and the lung

Clinical implication of pulmonary hospitalization in heart failure with preserved ejection fraction: from the TOPCAT

Aims

The aim of the study was to explore the risk factors and evaluate the prognostic implication of pulmonary hospitalization on heart failure (HF) with preserved ejection fraction (HFpEF).

Methods and results

We performed a secondary analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist Trial (TOPCAT). A total of 1714 patients with HFpEF were analysed in our study. In the multivariate Cox proportional hazards regression analysis, history of chronic obstructive pulmonary disease (COPD), smoking, bone fracture after the age of 45, and previous HF hospitalization were identified as independent risk factors for pulmonary hospitalization. To evaluate the prognostic significance of pulmonary hospitalization, patients were categorized into five groups according to the causes of their first hospitalization. The all‐cause and cardiovascular (CV) mortality risks in these five groups were compared using time‐varying Cox proportional hazards model. Compared with patients without hospitalization during follow‐up, those with pulmonary hospitalization were associated with a 204% increase [hazard ratio (HR) 3.04, 95% confidence interval (CI) 2.07–4.47, P < 0.001] and 164% increase (HR 2.64, 95% CI 1.60–4.36, P < 0.001) in risks of all‐cause and CV mortality, respectively, while the corresponding risk increases associated with HF hospitalization were 146% (HR 2.46, 95% CI 1.74–3.48, P < 0.001) for all‐cause mortality and 186% (HR 2.86, 95% CI 1.87–4.36, P < 0.001) for CV mortality.

Conclusions

Pulmonary hospitalization was associated with a significant increase in risks of all‐cause and CV mortality, which was comparable with that associated with HF hospitalization. The results suggested that pulmonary hospitalization could be another important clinical endpoint of HFpEF.

Smoking and interstitial lung diseases

For many years has been well known that smoking could cause lung damage. Chronic obstructive pulmonary disease and lung cancer have been the two most common smoking-related lung diseases. In the recent years, attention has also focused on the role of smoking in the development of interstitial lung diseases (ILDs). Indeed, there are three diseases, namely respiratory bronchiolitis-associated ILD, desquamative interstitial pneumonia and pulmonary Langerhans cell histiocytosis, that are currently considered aetiologically linked to smoking and a few others which are more likely to develop in smokers. Here, we aim to focus on the most recent findings regarding the role of smoking in the pathogenesis and clinical behaviour of ILDs.

Smoking is implicated in the pathogenesis and clinical behaviour of interstitial lung diseasehttp://ow.ly/PYLcT

Non-cigarette tobacco and the lung

Cigarette smoking is known to cause a wide range of damaging health outcomes; however, the effects of non-cigarette tobacco products are either unknown or perceived as less harmful than cigarettes. Smokeless tobacco, cigar smoking, and waterpipe smoking have increased in usage over the past few decades. Some experts believe that their use is reaching epidemic proportions. Factors such as a perception of harm reduction, targeted advertising, and unrecognized addiction may drive the increased consumption of non-cigarette tobacco products. In particular, the need for social acceptance, enjoyment of communal smoking activities, and exotic nature of waterpipe smoking fuels, in part, its popularity. The public is looking for "safer" alternatives to smoking cigarettes, and some groups advertise products such as smokeless tobacco and electronic cigarettes as the alternatives they seek. Though it is clear that cigar and waterpipe tobacco smoking are probably as dangerous to health as cigarette smoking, there is an opinion among users that the health risks are less compared to cigarette smoking. This is particularly true in younger age groups. In the cases of smokeless tobacco and electronic cigarettes, the risks to health are less clear and there may be evidence of a harm reduction compared to cigarettes. In this article, we discuss commonly used forms of non-cigarette tobacco products, their impacts on lung health, and relevant controversies surrounding their use.

Comparison of clinical features between non-smokers with COPD and smokers with COPD: a retrospective observational study

Background

Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD); however, the similarities and differences in clinical presentation between smokers and nonsmokers are not fully described in patients with COPD. This study was designed to address this issue in a general teaching hospital in the People’s Republic of China.

Methods

The medical records of patients hospitalized with a lung mass for further evaluation at Zhongshan Hospital, Fudan University, from January 2006 to December 2010 were reviewed and the data of interest were collected. The definition of COPD was according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) spirometric criteria. Participants who had a previous exacerbation within 4 weeks of admission, airflow limitation due to abnormalities in the large airways, or with other pulmonary diseases were excluded. Included subjects were divided into nonsmokers with COPD and smokers with COPD by a cutoff of a 5 pack-year smoking history.

Results

A total of 605 subjects were included in the final analysis. The average age was 64.8±8.5 years and 62.0% (375/605) were smokers. Eighty percent of the patients had mild to moderate disease (GOLD grade 1–2). Age and years with COPD were comparable between the two groups. Compared with smokers with COPD, nonsmokers with COPD were more likely to be female, reported less chronic cough and sputum, have less emphysema on radiologic examination, and higher measures of forced expiratory volume in the first second percent predicted (FEV₁), forced expiratory volume in one second/forced vital capacity (FEV₁/FVC%) percent predicted, maximal voluntary ventilation percent predicted, diffusing capacity of lung (DLCO) percent predicted, and DLCO/alveolar volume percent predicted, with lower levels of residual volume percent predicted and residual volume/total lung capacity percent predicted. There were no significant differences between the two groups with regard to distribution of disease severity, vital capacity percent predicted, total lung capacity percent predicted, PaO₂, PaCO₂, modified Medical Research Council dyspnea score, wheezing, airway reversibility, and comorbidities. Smoking amount (pack-years) was correlated negatively with FEV₁ percent predicted, FEV₁/FVC% percent predicted, inspiratory capacity percent predicted, inspiratory capacity/total lung capacity percent predicted, and DLCO percent predicted, and correlated positively with GOLD grade and symptoms.

Conclusion

Non-smokers with COPD had less impairment in airflow limitation and gas exchange, and a lower prevalence of emphysema, chronic cough, and sputum compared with their smoking counterparts. Tobacco cessation is warranted in smokers with COPD.

In utero tobacco smoke exposure alters pulmonary responses of newborn rats to ozone

Prenatal tobacco smoke (TS) exposure has been implicated in various adverse health outcomes in the offspring, including poor development of lung and immune system, which in turn can alter the response of neonates to environmental challenges. This study was performed to determine whether in utero exposure to TS influences the pulmonary response of newborn rat pups to ozone (O₃). Timed pregnant Sprague-Dawley (SD) rats were exposed to TS or air for 3 h/d from gestation d 7 through 21. The pulmonary response of pups was assessed following a single 3-h exposure to air or 0.6 ppm O₃ on d 13 after birth. In all, 4 exposure groups were evaluated: (1) Air/Air (in utero air and postnatal air), (2) Air/O₃ (in utero air and postnatal O₃), (3) TS/Air (in utero TS and postnatal air), and (4) TS/O₃ (in utero TS and postnatal O₃). Bronchoalveolar lavage (BAL) was performed, and BAL cells and fluid were analyzed. Data revealed a significant increase in polymorphonuclear leukocytes (PMN) and total BALF protein in the Air/O₃ group compared to the Air/Air control, reflecting the inflammatory and cytotoxic effects of O₃. However, in utero exposure to TS attenuated PMN infiltration into the air spaces for recovery in the BAL of TS/O₃ pups. Lung tissue myeloperoxidase activity significantly increased only in the TS/O₃ group but not in Air/O₃ pups, thus suggesting that PMN are sequestered in the lung tissue and that the in utero TS likely inhibits O₃-mediated influx of PMN into the air spaces. Lung tissue analyses further showed a significant rise in manganese superoxide dismutase (SOD) protein and a decrease in extracellular SOD protein in the Air/O₃ group, suggesting oxidative effects of O₃. Interestingly, in utero TS exposure again suppressed these effects in the TS/O₃ group. Overall, results suggest that in utero exposure to TS alone produced minimal acute pulmonary effects in newborn rats, but modulated adverse effects of postnatal O₃ exposure. The results are contrary to the interactive toxic responses predicted for sequential exposures to TS and O₃, and may represent the development of "cross-tolerance."

The impact of smoking in primary spontaneous pneumothorax

BACKGROUND

The crucial role of cigarette smoking in the development of pneumothorax is unclear because nonsmokers can also develop primary spontaneous pneumothorax. The purpose of this study was to clarify the pathophysiologic effects of cigarette smoking and its clinical correlations in primary spontaneous pneumothorax.

METHODS

Included were 115 specimens of lung tissue from patients with primary spontaneous pneumothorax who underwent video-assisted thoracoscopic surgery from January 2001 to December 2002. We reviewed the clinical features of 56 smokers and 59 nonsmokers with an average follow-up of 67 months. The pathologic findings of resected lung specimens were analyzed retrospectively.

RESULTS

There were no statistical differences in sex, age, body height, body weight, body mass index, or the presence of blebs/bullae on computed tomography scans of the lung or under thoracoscopy between the 2 groups. In the smoking group, patients had more extensive respiratory bronchiolitis (P < .001), a high prevalence of tobacco pigmentation (P < .001), and a higher recurrence rate without or after surgery than the nonsmoking group (57% vs 22%, P = .001 and 8.9% vs 1.7%, P = .02, respectively). Patients with extensive respiratory bronchiolitis had significantly higher nonoperative and postoperative recurrences than patients with nonextensive respiratory bronchiolitis (P = .004 and P < .001, respectively).

CONCLUSION

Cigarette smoking is associated with the pathophysiologic consequences of extensive respiratory bronchiolitis, which had a significant impact on the recurrence rates of primary spontaneous pneumothorax.

Smoking-related interstitial lung disease

Pulmonary diseases associated with tobacco smoking are a complex group of disorders ranging from chronic obstructive pulmonary disease (COPD) to lung cancer. Interstitial lung diseases (ILDs) have only recently been linked to smoking. The ILDs related to smoking include respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia, and pulmonary Langerhans cell histiocytosis. The relationship of smoking with each of these entities has been largely established on the weight of epidemiologic evidence. Although they have been retained as distinct and separate conditions in various classifications of interstitial lung diseases, these 3 entities share a number of clinical, radiologic, and pathologic features suggesting that they represent a spectrum of patterns of interstitial lung disease occurring in predisposed individuals who smoke. Evaluation of histologic features, particularly in surgical lung biopsy samples, is important in making the distinction between these disorders. However, even after tissue biopsy, it may sometimes be difficult to clearly separate these entities. The importance of making the distinction between them lies in the different clinical management strategies used. Further experimental evidence, including genetic information, may be important in improving our understanding of these diseases.

Cigarette smoke, inflammation, and lung injury: a mechanistic perspective

Inflammation is a common feature in the pathogenesis of cigarette smoke-associated diseases. The recruitment of inflammatory cells into the lung following cigarette smoke exposure presents a risk of tissue damage through the release of toxic mediators, including proteolytic enzymes and reactive oxygen species. This review represents a toxicological approach to investigation of cigarette smoke-induced lung injury, with a focus on laboratory studies and an emphasis on inflammatory mechanisms. The studies discussed in this review analyze the role of inflammation and inflammatory mediators in the development of injury. In cases where information relating to cigarette smoke is limited, examples are taken from other models of lung injury applicable to cigarette smoke. The primary aim of the review is to summarize published work so as to permit (1) an evaluation of chronic lung injury and inflammatory responses in animal models, (2) a discussion of inflammatory mediators in the development of chronic injury, and (3) identification of immunological mechanisms of injury. These studies discuss the currently understood roles of cytokines, cell adhesion molecules, and oxidative stress in inflammatory reactions and lung injury. A role for lipocortin 1 (annexin 1), a naturally occurring defense factor against inflammation, is discussed because of the possibility that impaired synthesis and degradation of lipocortin 1 will influence immune responses in animals exposed to cigarette smoke either by augmenting T helper cell Th1 response or by shifting Th1 to Th2 response. While Th1 augmentation will increase the risk for development of emphysema, Th1 to Th2 shift will favor development of asthma.

Cigarette Smoke Extract Suppresses Human Dendritic Cell Function Leading to Preferential Induction of Th-2 Priming

Dendritic cells (DC) are key regulators of immune responses. In the current study, we hypothesized that cigarette smoke-induced aberrance in DC function is an important mechanism by which smokers develop cancer, infection, and allergy--diseases common in smokers. We demonstrate that cigarette smoke extract (CSE) inhibits DC-mediated priming of T cells, specifically inhibiting the secretion of IFN-gamma whereas enhancing the production of IL-4 in the MLR. Conditioning with CSE did not effect cytokine (IL-10, IL-6, or IL-12) production from immature DCs, but significantly inhibited IL-12p70 release by LPS-matured DCs. In contrast, IL-10 secretion by LPS-activated CSE-conditioned DCs was enhanced when compared with control DCs. CSE also induced cyclooxygenase-2 protein levels in maturing DCs and significantly augmented endogenous PGE2 release. Conditioning of DCs with CSE also suppressed LPS-mediated induction of CD40, CD80, and CD86, and suppressed maturation-associated CCR7 expression. Although CSE has been reported to induce apoptosis of fibroblasts and epithelial cells, the immunomodulatory effects observed with CSE were not due to diminished DC viability. The effects of CSE on DC function were not exclusively mediated by nicotine, because equivalent, or even higher concentrations of nicotine than those found in CSE, failed to suppress DC-induced T cell priming. These data provide evidence that soluble components extracted from cigarette smoke suppress key DC functions and favor the development of Th-2 immunity.

Smoking-related interstitial lung diseases: a concise review

Interstitial lung diseases (also known as diffuse infiltrative lung diseases) are a heterogeneous group of parenchymal lung disorders of known or unknown cause. These disorders are usually associated with dyspnoea, diffuse lung infiltrates, and impaired gas exchange. The majority of interstitial lung diseases are of unknown cause. Known causes of interstitial lung disease include inhalation of organic and inorganic dusts as well as gases or fumes, drugs, radiation, and infections. This review summarizes the clinical, radiological, and histopathological features of four interstitial lung disorders that have been linked to smoking. These disorders include desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, pulmonary Langerhans' cell histiocytosis, and idiopathic pulmonary fibrosis. Available evidence suggests most cases of desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, and pulmonary Langerhans' cell histiocytosis are caused by cigarette smoking in susceptible individuals. Smoking cessation should be a main component in the initial therapeutic approach to smokers with these interstitial lung diseases. In addition, smoking appears to be a risk factor for the development of idiopathic pulmonary fibrosis.

Smoking and chronic obstructive pulmonary disease

Smoking is overwhelmingly the major cause of chronic bronchitis and emphysema worldwide. Additional risk factors for developing COPD are presented, along with the variables that govern cigarette smoke deposition in the lung. Major paradigms for the pathogenesis of COPD, including the protease-antiprotease and oxidant-antioxidant theories are described, and evidence for impaired reparative mechanisms in the causation of emphysema is noted. A description of the natural history of declining lung function in smokers and in the susceptible subset of smokers that ultimately develop smoking-induced COPD is accompanied by a discussion of the effects of smoking cessation on preservation of lung health. The disordered ventilation and gas-exchange physiology in the cigarette smoke-damaged lung is explained on the basis of the observed morphological changes.