Childhood smoking is an independent risk factor for obstructive airways disease in women

Childhood Cigarette Smoking and Risk of Chronic Obstructive Pulmonary Disease in Older U.S. Adults

Rationale: It is not certain the extent to which childhood smoking adds chronic obstructive pulmonary disease (COPD) risk independent of lifetime cigarette exposure. Objectives: We examined the association between age started smoking cigarettes regularly, current smoking status, smoking history, and risk of COPD. Methods: Cross-sectional survey of U.S. adults ⩾40 years old in the 2020 National Health Interview Survey. Respondents who were ever cigarette smokers were asked when they began smoking regularly. Multivariable analysis assessed self-report of COPD diagnosis as a function of age started smoking (<15 yr vs. ⩾15 yr) adjusting for current smoking, cigarette pack-years, and covariates. Measurements and Main Results: Overall, 7.1% reported that they had COPD, 2.6% for never-smokers compared with 23.1% and 11.6% for smoking onset <15 and ⩾15 years, respectively. Persons who began smoking regularly at <15 years of age had higher pack-years of smoking (median, 29 vs. 15, respectively), and higher smoking intensity (median, 20 cigarettes/d for <15 yr vs. 10 cigarettes/d for ⩾15 yr for current smokers). In the multivariable analysis, the relative risk for COPD among childhood smokers was 1.41 (95% confidence interval, 1.22-1.63) compared with later-onset smokers. Substituting smoking duration for pack-years confounded the association between current smoking and COPD but did not change the childhood smoking estimate. In a stratified analysis, higher risk for childhood smoking was found at all current smoking intensity levels. Conclusions: Among adults aged ⩾40 years, one-fifth of childhood smokers have COPD. Lifetime cigarette smoking explained some but not all of the higher risk. If replicated, this suggests a lung development window of enhanced vulnerability to cigarette smoking.

Evidence-based core information for health communication of tobacco control: The effect of smoking on risks of female disease

Objective

Cigarettes have become the the biggest killer of contemporary female's health and beauty. What kind of health information is suitable for the general public is an important issue to be discussed globally. The purpose of this study is to generate systematic, rigorous, public-demand-oriented and appropriate core information relevant to tobacco control based on the best available evidence, combined with audience preferences and pre-dissemination content review from multidisciplinary expertise in order to improve the effectiveness of health communication of tobacco control.

Methods

Relevant systematic reviews meta-analysis that reported smoking on risks of female disease were identified by searching PubMed, Embase, the Cochrane Library, Web of Science, Clinical Trials.gov, and the International Clinical Trial Registry Platform. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was applied to assess the evidence in order to make rigorous core information. The audience prevalence survey was conducted to ensure that core information was targeted and tailored. Finally, the expert assessment was used for a pre-dissemination content review and to evaluate whether the core information was appropriate or not.

Results

The final core information consisted of eight parts concerning the effects of smoking and female cardiovascular disease, diabetes, rheumatoid arthritis, respiratory disease, digestive system disease, mental disease, non-pregnant female reproductive system disease, as well as pregnant women and their fetuses. A total of 35 items of core information suitable for dissemination was included and the quality of evidence, the degree of public demand and the outcome of pre-dissemination content review were reported.

Conclusion

The core information related to female cardiovascular system diseases, as well as liver cancer and upper gastrointestinal cancer is the preferred content for health communication of tobacco control. The quality of evidence for core information related to pregnant women and their infants, as well as diseases of reproductive system, respiratory system, and diabetes needs to be improved to meet high public demand. The core information related to mental disease is more suitable for dissemination to patients with mental illness than to the general public. Besides, dissemination of core information should be individualized. Evidence-based Core Information for Health Communication of Tobacco Control would be helpful to provide evidence support for health communication related to tobacco control and enhance public health literacy for international communities that have high smoking prevalence and related disease burden.

The effect of β-carotene on the mortality of male smokers is modified by smoking and by vitamins C and E: evidence against a uniform effect of nutrient

A previous analysis of the Alpha-Tocopherol Beta-Carotene (ATBC) Study on male smokers found that β-carotene supplementation increased the risk of pneumonia 4-fold in those who started smoking at the age of ≥21 years and smoked ≥21 cigarettes/d (a subgroup of 7 % of the study population). The present study hypothesised that β-carotene increases mortality in the same subgroup. The ATBC Study (1985–1993) recruited 29 133 Finnish male smokers (≥5 cigarettes/d) aged 50–69 years. Cox regression models were constructed to estimate the effect of β-carotene supplementation in subgroups. β-Carotene increased mortality (risk ratio 1·56; 95 % CI 1·06, 2·3) in those who started to smoke at ≥21 years and smoked ≥21 cigarettes/d. Within this subgroup, there was strong evidence of further heterogeneity. The effect of β-carotene supplementation was further modified by dietary vitamin C intake, fruit and vegetable intake (P = 0·0004), and by vitamin E supplementation (P = 0·011). Thus, harm from β-carotene was not uniform within the study population. Interactions between β-carotene and vitamins C and E were seen only within a subgroup of 7 % of the ATBC participants, and therefore should not be extrapolated to the general population. Heterogeneity of the β-carotene effect on mortality challenges the validity of previous meta-analyses that have pooled many diverse antioxidants for one single estimate of effect using the assumption that a single estimate equally applies to all antioxidants and all people. Trial registration: ClinicalTrials.gov NCT00342992.

Implementation of guideline-based therapy for chronic obstructive pulmonary disease: Differences between men and women veterans

Chronic obstructive pulmonary disease (COPD) is common among both men and women, and guidelines recommend the same therapy for both sexes. While previous studies have identified gender differences in other chronic disease management, few studies have examined how implementation of COPD guidelines differs between men and women. We performed a cross-sectional study of veterans admitted to Veterans Affairs (VA) hospitals for COPD during October 1, 2008, to September 30, 2011. We collected information on baseline COPD medications during the 6 months prior to hospitalization and categorized therapies as “appropriate” or “inappropriate” based on current guidelines. We used multivariable logistic regression to examine the differences in COPD medications between men and women, after controlling for baseline patient characteristics. We also examined the differences in hospital outcomes, including length of stay and hospital readmission. We identified 33,558 veterans, including 1149 women and 32,409 men who were admitted to 130 VA hospitals. Women were significantly less likely to have received inhaler therapies prior to admission, with lower rates of short-acting beta agonists, short-acting muscarinic antagonists, long-acting beta agonists, and long-acting muscarinic antagonists compared to men. Women also received fewer appropriate inhaler combinations (odds ratio [OR] = 0.83, 95% confidence interval [CI] 0.74–0.93) and more inappropriate combinations (OR = 1.33, 95% CI 1.17–1.51). Women and men were prescribed similar rates of inhaled steroid and oral steroids. Hospital outcomes were also similar between the two groups. These findings highlight a potential gender disparity in appropriate outpatient COPD therapy. Improving the quality of care for patients with COPD should include equitable implementation of guideline-based COPD management.

Call to action: improving primary care for women with COPD

In this perspective-based article, which is based on findings from a comprehensive literature search, we discuss the significant and growing burden of chronic obstructive pulmonary disease in women worldwide. Chronic obstructive pulmonary disease now affects both men and women almost equally. Despite this, there remains an outdated perception of chronic obstructive pulmonary disease as a male-dominated disease. Primary care physicians play a central role in overseeing the multidisciplinary care of women with chronic obstructive pulmonary disease. Many women with chronic obstructive pulmonary disease delay seeking medical assistance, due to fear of stigmatization or dismissing symptoms as a 'smoker's cough'. Improving awareness is important to encourage women with symptoms to seek advice earlier. Once women do seek help, primary care physicians need to have knowledge of the nuances of female chronic obstructive pulmonary disease disease presentation to avoid mis- or delayed diagnosis, both of which are more common in women with chronic obstructive pulmonary disease than men. Subsequent management should consider gender-specific issues, such as differential incidences of comorbid conditions, potentially higher symptom burden, and a higher risk of exacerbations. Chronic obstructive pulmonary disease treatment and smoking cessation management should be specifically tailored to the individual woman and reviewed regularly to optimize patient outcomes. Finally, education should be an integral part of managing chronic obstructive pulmonary disease in women as it will help to empower them to take control of their disease.

Smoking Cessation Failure Among Korean Adolescents

The aim of this study was to identify smoking cessation failure subgroups among Korean adolescents. Participants were 379 smoking adolescents who joined a smoking cessation program. A questionnaire and a cotinine urine test were administered before the program began. Three months after the program ended, the cotinine urine test was repeated. A decision-tree model identified seven subgroups with low or high smoking cessation rates. The predictors of smoking cessation were intention to stop smoking, initiation of smoking, amount of cigarette use, self-efficacy, and paternal smoking status. The subgroup with the lowest smoking cessation rate included adolescents who did not have any intention to stop smoking and who had started smoking after eighth grade, and none of the participants in this group stopped smoking. The results of this study provide crucial information for tailored smoking cessation programs.

From Childhood Asthma to Chronic Obstructive Pulmonary Disease: Evidence Supporting a Disease Continuum

In this review, we analyze the available evidence showing a link between asthma and chronic obstructive pulmonary disease (COPD). Many features (epidemiologic, physiologic, and histologic) overlap between these two conditions. Both environmental cigarette smoke exposure and early lung development are risk factors for the development of asthma and COPD. However, recent studies suggest that up to 25% of COPD cases were nonsmokers. Asthma during early childhood, independent of smoking history, may be an independent risk factor for the later development of COPD. One explanation for this phenomenon suggests that early small airway dysfunction (including chronic airway inflammation and airway remodeling) can lead to permanent impairment in lung physiology. Several reasons why control of airway inflammation is difficult in some patients are explored. Finally, we examine the available evidence suggesting overlapping histologic features in both asthma and COPD.

Secondhand smoke exposure causes bronchial hyperreactivity via transcriptionally upregulated endothelin and 5-hydroxytryptamine 2A receptors

BACKGROUND

Cigarette smoke exposure is strongly associated with airway hyperreactivity (AHR) which is the main characteristic seen in asthma. The intracellular MAPK signaling pathways are suggested to be associated with the airway damage to the AHR. In the present study, we hypothesize that secondhand cigarette smoke (SHS) exposure upregulates the bronchial contractile receptors via activation of the Raf/ERK/MAPK pathway.

METHODOLOGY/PRINCIPAL FINDINGS

Rats were exposed to SHS for 3 h daily for up to 8 weeks. The receptor agonists-induced bronchial contractile reactivity was analyzed with a sensitive myograph system. The mRNA transcription and protein translation of the target receptors and the kinases in Raf/ERK/MAPK pathway were investigated by real-time PCR, Western blotting and immunofluorescence, respectively. Compared with exposure to fresh air, SHS induced enhanced bronchial contractile responses mediated by the 5-hydroxytryptamine 2A (5-HT(2A)) receptors as well as the endothelin type B (ET(B)) and type A (ET(A)) receptors. The response curves were shifted toward the left with an increased maximal contraction (E(max)) demonstrating that SHS induced AHR. Additionally, the mRNA and protein levels of the 5-HT(2A), ET(B) and ET(A) receptors were increased. Furthermore, SHS exposure increased the phosphorylation of Raf-1 and ERK1/2, but it did not alter p38 or JNK. A Raf-1 inhibitor (GW5074) suppressed the SHS-induced increase in the expression of 5-HT(2A) and ET(A) receptors and the receptor-mediated AHR.

CONCLUSIONS/SIGNIFICANCE

Our findings show that SHS exposure induces transcriptional upregulation of the 5-HT(2A), ET(B) and ET(A) receptors in rat bronchial smooth muscle cells, which mediates AHR. The Raf/ERK/MAPK pathway is involved in SHS-associated receptor upregulation and AHR.

Reconsidering sex-based stereotypes of COPD

Chronic obstructive pulmonary disease (COPD) has historically been considered a disease of older, white, male smokers, as illustrated in Frank Netter's classic images of the 'pink puffer' and 'blue bloater'. However, women may be more susceptible to COPD than men, and the disease course may be reflective of that increased susceptibility. From a review of epidemiological data of COPD, we found differences in the way men and women present with COPD symptoms, a bias in the way COPD symptoms are treated in men and women, and differences in susceptibility to airway obstruction based on age, sex, and smoking history. These data show that classic stereotypes of COPD - including male predominance - should be abandoned, and that there are not two but multiple COPD phenotypes, which are characterised by differences between women and men in susceptibility, symptoms, and disease progression. These differences impact on physician perception. Although further research into this concept is needed, the differences we found should prompt, in the short term, changes in the way (and in whom) COPD is evaluated, diagnosed, and treated; in the long term, these differences should prompt research into the prognosis of COPD based on sex differences.

Systematic review with meta-analysis of the epidemiological evidence relating smoking to COPD, chronic bronchitis and emphysema

BACKGROUND

Smoking is a known cause of the outcomes COPD, chronic bronchitis (CB) and emphysema, but no previous systematic review exists. We summarize evidence for various smoking indices.

METHODS

Based on MEDLINE searches and other sources we obtained papers published to 2006 describing epidemiological studies relating incidence or prevalence of these outcomes to smoking. Studies in children or adolescents, or in populations at high respiratory disease risk or with co-existing diseases were excluded. Study-specific data were extracted on design, exposures and outcomes considered, and confounder adjustment. For each outcome RRs/ORs and 95% CIs were extracted for ever, current and ex smoking and various dose response indices, and meta-analyses and meta-regressions conducted to determine how relationships were modified by various study and RR characteristics.

RESULTS

Of 218 studies identified, 133 provide data for COPD, 101 for CB and 28 for emphysema. RR estimates are markedly heterogeneous. Based on random-effects meta-analyses of most-adjusted RR/ORs, estimates are elevated for ever smoking (COPD 2.89, CI 2.63-3.17, n = 129 RRs; CB 2.69, 2.50-2.90, n = 114; emphysema 4.51, 3.38-6.02, n = 28), current smoking (COPD 3.51, 3.08-3.99; CB 3.41, 3.13-3.72; emphysema 4.87, 2.83-8.41) and ex smoking (COPD 2.35, 2.11-2.63; CB 1.63, 1.50-1.78; emphysema 3.52, 2.51-4.94). For COPD, RRs are higher for males, for studies conducted in North America, for cigarette smoking rather than any product smoking, and where the unexposed base is never smoking any product, and are markedly lower when asthma is included in the COPD definition. Variations by sex, continent, smoking product and unexposed group are in the same direction for CB, but less clearly demonstrated. For all outcomes RRs are higher when based on mortality, and for COPD are markedly lower when based on lung function. For all outcomes, risk increases with amount smoked and pack-years. Limited data show risk decreases with increasing starting age for COPD and CB and with increasing quitting duration for COPD. No clear relationship is seen with duration of smoking.

CONCLUSIONS

The results confirm and quantify the causal relationships with smoking.

Effects of atorvastatin on smoking-induced alveolar injury in rat lungs

BACKGROUND

Smoking is one of the most serious health care issues worldwide, as one third to one half of all people who smoke eventually use tobacco habitually. Chronic smoke exposure causes airway and lung parenchymal inflammation and the destruction of alveolar cell walls. Statins may have anti-inflammatory effects that would play a role in preventing the cellular damage associated with smoking.

OBJECTIVE

The aim of this study was to investigate whether atorvastatin protects against smoking-induced inflammation in alveolar epithelial type I (ATI) and type II (ATII) cells in the lungs of rats.

METHODS

Adult male albino Wistar rats (200-250 g) were randomly divided into 3 groups and exposed to cigarette smoke 8 hours per day for 15 days. During that 15-day period, the 2 treatment groups received atorvastatin 0.5 or 1.0 mg/kg/d in 2 mL of methyl cellulose solution and the control group received 2 mL of methyl cellulose solution alone, all via nasogastric catheter. After the 15 days, the lungs were excised and the tissues were examined by transmission electron microscopy.

RESULTS

Thirty rats were divided into 3 groups of 10 rats each. All rats survived the 15 days. In the atorvastatin 0.5-mg group, no changes were found in the ATI cells or in the blood-air barrier. In the atorvastatin 1.0-mg group, we observed hyperplasia in the common basal membranes. Hypertrophy, mitochondrial crystolysis (MC), and intracytoplasmic edema (ICE) were detected in the ATI cells in the 1.0-mg group, while chromatin condensation, atrophic appearance, cell shrinkage, and cyto-plasmic vacuolization were observed in the ATII cells. The rough endoplasmic reticulum (rER) tubules of the ATII cells appeared spiral-shaped. In the control group, minimal ICE was detected in the ATI cells. However, microvillus deformation, pseu-dopod formation, edema, mitochondrial swelling, and MC were observed in the ATII cells. We also observed MC, several pinocytic vesicles, and normal rER tubules in the endothelial cells of the control group.

CONCLUSIONS

The administration of atorvastatin 0.5 mg/kg/d was associated with some attenuation of lung injury caused by smoke inhalation in these rat lungs. However, atorvastatin 1.0 mg/kg/d was associated with lung damage. Future studies are needed to evaluate the dose-response relationship of atorvastatin to smoking-induced alveolar damage.

The effects of tobacco smoke exposure on respiratory health in school-aged children

The effects of tobacco smoke exposure on the respiratory health of school-aged children relate to persisting effects of exposure to tobacco smoke during pregnancy and early infancy, passive exposure to environmental tobacco smoke in the home and elsewhere, and active smoking during later childhood. Much of the current evidence comes from cross-sectional and longitudinal observational studies and suggests that, for asthma and pulmonary function outcomes, the strongest associations are with smoke exposure in pregnancy and early childhood, although independent effects of later exposure are reported. Exposure in later childhood to environmental tobacco smoke is associated with increased respiratory symptoms, although for some of these, the effect appears to diminish with increasing age of the child. There is currently a paucity of evidence on the long-term adverse respiratory consequences of active smoking by children and adolescents, but such evidence there is suggests that these may be substantial.

Cigarette smoking and acne in adolescents: results from a cross-sectional study

BACKGROUND

Previous studies on the association between smoking and acne have reported conflicting results.

OBJECTIVE

To investigate the association between smoking and acne among school-going adolescents.

METHODS

A cross-sectional study was conducted. Smoking was defined as smoking > 3 cigarettes daily for 6 months or more. We defined acne as having > 20 retentional and/or inflammatory facial acne lesions. Multivariate (proportional) logistic regression models were used to adjust for confounding variables.

RESULTS

Of the 594 participants, 36.2% had acne. Acne sufferers were less likely to smoke (18.1 vs. 23.7%, P = 0.10). In girls, smoking was significantly associated with lower prevalence of acne (adjusted OR = 0.41, 95% CI = 0.13, 0.82). Smoking, daily cigarette consumption and duration of smoking appeared to be protective in the development of inflammatory acne in girls. No significant associations between acne and smoking variables were detected among boys.

LIMITATIONS

although this study suggests a significant negative association between smoking and inflammatory acne in girls, it does not prove causality. This association did show a trend for linear relationship. Because of the unexpected differences between boys and girls, sample size may have affected our results.

CONCLUSION

The anti-inflammatory effects of smoking may inhibit the development of papulopustular acne in girls more than in boys. However, smoking should not be considered a therapeutic option for acne. Additional studies that consider possible differences across age, gender and type of acne are needed to clarify the association between smoking and acne.

Survival and future need of long-term oxygen therapy for chronic obstructive pulmonary disease—gender differences

We aimed to study trends in gender-related differences in incidence, and prevalence for long-term oxygen therapy due to chronic obstructive pulmonary disease. Another aim was to study survival after onset of oxygen therapy. Prospectively followed were 5689 Swedish patients, who were prescribed oxygen therapy because of chronic obstructive pulmonary disease from 1987 to 2000. The annual incidence of women starting oxygen therapy increased more rapidly than that in men. In 2000, 7.6 per 100,000 women started treatment compared with 7.1 in men. The frequency of ever smoking in Sweden in the age group receiving oxygen, i.e. age 65-84 years, was 36.4% in women and 65.0% in men, indicating that women ran a higher risk of developing an oxygen-requiring chronic hypoxaemia. An increase in women requiring oxygen therapy is predicted due to the increase in smoking frequency in young and middle-aged women and it is estimated that about 70% of Swedish patients on oxygen in 2026 will be women, with an estimated prevalence of 61 per 100,000. In conclusion, the incidence and prevalence for long-term oxygen therapy increases more rapidly among women than in men. This is probably due to the increased frequency of smoking in women compared with men and a higher susceptibility to develop severe hypoxaemia in women. The survival is better in women with long-term oxygen therapy than in men.

Mechanism of relaxation induced by nicotine in normal and ovalbumin-sensitized guinea-pig trachea

Nicotine is an irritant molecule in the cigarette that contributes airway hyper-reactivity. The aim of this study was to investigate the mechanism of these effects and effects of nicotine on the isolated trachea preparations from control and ovalbumin-sensitized guinea-pigs. Nicotine (3x10(-5) to 3x10(-4) M) produced concentration-dependent relaxation on isolated trachea preparations precontracted by carbachol (10(-6) M) in both groups. We found that the relaxant effect of nicotine decreased in the presence of N(w)-nitro L-arginine methyl ester (L-NAME) (10(-6) M), and hexamethonium (10(-2) M) but not in the presence of alpha-bungarotoxin (10(-3) M), and tetrodotoxin (3.1x10(-6) M) in isolated trachea preparations in both groups. The relaxant effect of nicotine was less significant in isolated trachea preparations from ovalbumin-sensitized guinea-pigs than from control guinea-pigs (P<0.05). The contractions elicited by carbachol (10(-6) M) were not significantly different in the ovalbumin-sensitized group than in the control group. Nicotine (10(-4) M) significantly increased the cGMP levels in trachea preparations compared with the control preparations.(P<0.05). These results suggest that nicotine-induced relaxation response in normal and ovalbumin sensitized guinea-pigs trachea is at least in part mediated by nitric oxide (NO) since it was significantly reduced in the presence of L-NAME. The decreased relaxation response to nicotine in ovalbumin sensitized guinea-pigs trachea may be due to impaired production and/or liberation of NO.

Incidence and determinants of moderate COPD (GOLD II) in male smokers aged 40-65 years: 5-year follow up

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a major health problem with an estimated prevalence of 10-15% among smokers. The incidence of moderate COPD, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), is largely unknown.

AIM

To determine the cumulative incidence of moderate COPD (forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC] <0.7 and FEV1 <80% predicted) and its association with patient characteristics in a cohort of male smokers.

DESIGN

Prospective cohort study.

SETTING

The city of IJsselstein, a small town in the Netherlands.

METHOD

Smokers aged 40-65 years who were registered with local GPs, participated in a study to identify undetected COPD. Baseline measurements were taken in 1998 of 399 smokers with normal spirometry (n = 292) or mild COPD (FEV1/FVC <0.7 and FEV1 >or=80% predicted, n = 107) and follow-up measurements were conducted in 2003.

RESULTS

After a mean follow-up of 5.2 years, 33 participants developed moderate COPD (GOLD II). This showed an estimated cumulative incidence of 8.3% (95% CI = 5.8 to 11.4) and a mean annual incidence of 1.6%. No participant developed severe airflow obstruction. The risk of developing moderate COPD in smokers with baseline mild COPD (GOLD I) was five times higher than in those with baseline normal spirometry (one in five versus one in 25).

CONCLUSIONS

In a cohort of middle-aged male smokers, the estimated cumulative incidence of moderate COPD (GOLD II) over 5 years was relatively high (8.3%). Age, childhood smoking, cough, and one or more GP contacts for lower respiratory tract problems were independently associated with incident moderate COPD.

Polymorphic light eruption may be associated with cigarette smoking and alcohol consumption

BACKGROUND

Although the genetic influence on polymorphic light eruption (PLE) is well established, the role of lifestyle factors is less well defined.

METHODS

A retrospective case-control study was conducted that included 74 PLE patients and 102 controls. Each participant was interviewed about demographic, disease and lifestyle characteristics such as smoking, alcohol consumption and use of medications. Multivariate logistic regression models were used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Compared with the controls, patients with PLE were significantly more likely to be younger females (P<0.05). Univariate analysis did not show a significant association between any of the smoking-related questions and PLE. However, after adjusting for gender and drinking alcohol, patients with PLE were significantly more likely to smoke 15 cigarettes or more daily [adjusted OR=4.06 (95% CI=1.19, 13.80) compared with 0 daily cigarettes] than controls. Participants who consumed six or more drinks a week were less likely to have PLE [adjusted OR=0.24 (95% CI=0.07, 0.80)]. In contrast, women who used oral anticonceptives for a longer period were four-fold more likely to have PLE [adjusted OR=4.74 (95% CI=1.33, 16.86)].

CONCLUSION

Several lifestyle factors may be associated with PLE, but further studies are warranted to confirm these retrospective findings.

Female smokers beyond the perimenopausal period are at increased risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Recent reports indicate that over the next decade rates of chronic obstructive pulmonary disease (COPD) in women will exceed those in men in the western world, though in most jurisdictions, women continue to smoke less compared with men. Whether female adult smokers are biologically more susceptible to COPD is unknown. This study reviewed the available evidence to determine whether female adult smokers have a faster decline in forced expiratory volume in one second (FEV1) compared with male adult smokers and whether age modifies the relationship between cigarette smoke and lung function decline.

METHODS

A systematic review and a meta-analysis was performed of population-based cohort studies that had a follow-up period of at least 3 years, measured FEV1 on at least two different time points, and presented FEV1 data stratified by gender and smoking status in adults.

RESULTS

Of the 646 potentially relevant articles, 11 studies met these criteria and were included in the analyses (N = 55,709 participants). There was heterogeneity in gender-related results across the studies. However, on average current smokers had a faster annual decline rate in FEV1% predicted compared with never and former smokers. Female current smokers had with increasing age a significantly faster annual decline in FEV1% predicted than male current smokers (linear regression analysis, R2 = 0.56; p = 0.008). Age did not materially affect the rate of decline in FEV1% predicted in male and female former and never smokers (p = 0.775 and p = 0.326, respectively).

CONCLUSION

As female smokers age, they appear to experience an accelerated decline in FEV1% predicted compared with male smokers. Future research powered specifically on gender-related changes in lung function is needed to confirm these early findings.

Smoking particles enhance endothelin A and endothelin B receptor-mediated contractions by enhancing translation in rat bronchi

Background

Smoking is known to cause chronic inflammatory changes in the bronchi and to contribute to airway hyper-reactivity, such as in bronchial asthma. To study the effect of smoking on the endothelin system in rat airways, bronchial segments were exposed to DMSO-soluble smoking particles (DSP) from cigarette smoke, to nicotine and to DMSO, respectively.

Methods

Isolated rat bronchial segments were cultured for 24 hours in the presence or absence of DSP, nicotine or DMSO alone. Contractile responses to sarafotoxin 6c (a selective agonist for ET_B receptors) and endothelin-1 (an ET_A and ET_B receptor agonist) were studied by use of a sensitive myograph. Before ET-1 was introduced, the ET_B receptors were desensitized by use of S6c. The remaining contractility observed was considered to be the result of selective activation of the ET_A receptors. ET_A and ET_B receptor mRNA expression was analyzed using real-time quantitative PCR. The location and concentration of ET_A and ET_B receptors were studied by means of immunohistochemistry together with confocal microscopy after overnight incubation with selective antibodies.

Results

After being cultured together with DSP for 24 hours the bronchial segments showed an increased contractility mediated by ET_A and ET_B receptors, whereas culturing them together with nicotine did not affect their contractility. The up-regulation of their contractility was blunted by cycloheximide treatment, a translational inhibitor. No significant change in the expression of ET_A and ET_B receptor mRNA through exposure to DMSO or to nicotine exposure alone occurred, although immunohistochemistry revealed a clear increase in ET_A and ET_B receptors in the smooth muscle after incubation in the presence of DSP. Taken as a whole, this is seen as the presence of a translation mechanism.

Conclusion

The increased contractility of rat bronchi when exposed to DSP appears to be due to a translation mechanism.