The Effects of Passive Smoking on the Six-Minute Walk Test in Obese Pediatric Cases

Objective: The aim of this study was to evaluate whether exposure to second-hand smoke affected the six-minute walk test (6MWT) of obese non-asthmatic pediatric cases.Methods: Obese pediatric patients (body mass index >95th p) with no existing co-morbidities were included in the study. Smoke exposure was assessed with a self-reported questionnaire completed by the parents. The subjects were divided into two groups: Group 1 consisting of obese children exposed to passive smoking and Group 2 of obese children not exposed to passive smoking. In addition to 6MWT, spirometric flow and volume, including forced expiratory volume in 1 s and peak expiratory flow rate, were also measured in all subjects. The results of the 6MWT were assessed to determine any association with passive smoking.Results: The study included 75 obese pediatric cases (40 male, 35 female) with a mean age of 9.06±0.97 years. The 6MWT results in Group 1 was 501.88±62.12 meters and in Group 2 559.63±72.93 meters. The difference was statistically significant (p=0.001).Conclusions: Passive smoking may negatively affect the respiratory and cardiovascular capacity in obese children, who are already at risk of lower cardiopulmonary function. The evaluation of 6MWT in these pediatric patients may be useful for monitoring and families should be warned about potential problems due to smoking.     

Effects of Active Smoking on Airway and Systemic Inflammation Profiles in Patients With Chronic Obstructive Pulmonary Disease

BackgroundThe markers that characterize local and systemic inflammation in chronic obstructive pulmonary disease (COPD) remain unclear, as do their correlations with smoking status and presence of disease. The aim of this study was to assess markers of inflammation in the peripheral blood and airways of current smokers without COPD, of current smokers with COPD and of ex-smokers with COPD.MethodsIn this study, 17 current smokers with COPD (mean age: 58.2 ± 9.6 years; mean forced expiratory volume in 1 second [FEV₁]: 56.1 ± 15.9%), 35 ex-smokers with COPD (mean age: 66.3 ± 7.3 years; mean FEV₁: 47.9 ± 17.2%) and 20 current smokers without COPD (mean age: 49.1 ± 6.2 years; mean FEV₁: 106.5 ± 15.8%) were evaluated. Spirometry findings, body composition and serum/induced sputum concentrations of tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-8 and IL-10, together with serum C-reactive protein (CRP) levels, were assessed.ResultsSerum TNF-α concentration was higher in all current smokers than in ex-smokers with COPD. In current smokers without COPD, serum CRP level was lower than in ex-smokers with COPD and significantly lower than in current smokers with COPD. Sputum TNF-α concentration was higher in current and ex-smokers with COPD than in current smokers without COPD. Multiple regression analyses showed that serum TNF-α was associated with active smoking, and serum CRP and sputum TNF-α were associated with COPD diagnosis.ConclusionsSmoking is associated with higher systemic inflammation in patients with COPD. Current findings also support the hypothesis that smoking and COPD have different effects on the regulation of airway and systemic inflammatory processes.     

Passive Smoking Among Children with Chronic Respiratory Disease

The purpose of this study was to determine the prevalence and source of passive smoke exposure among children with chronic respiratory diseases and compare these to both a well child and nonrespiratory chronic illness child population. Rates and source of passive smoke exposure were compared among four child groups: asthma, cystic fibrosis, rheumatoid arthritis, and well children using a questionnaire mailed to the parents of the selected children. Twenty percent of respondents reported current smoking with a significantly higher rate among the cystic fibrosis and rheumatoid arthritis groups. One-third of all children surveyed were exposed to passive smoke at home and/or day care on a daily basis. Over 80% of the asthma and cystic fibrosis respondents reported a change in smoking behavior (i.e., smoking outside the home or smoking fewer cigarettes) after the diagnosis of their child's illness as compared with only 40% of the nonrespiratory groups. Health care providers need to inquire about potential sources of passive smoke exposure in their patients, particularly children with chronic respiratory disease.     

Heart Disease From Passive Smoking in the Workplace

Objectives. This review sought to determine whether passive smoking in the workplace has roughly the same association with heart disease as passive smoking at home and to update a previous 1994 review on the effects of home-based passive exposure on the heart.Background. To predict the effects of passive smoking at work on heart disease, public agencies have had to assume that workplace exposure to tobacco smoke was equivalent to home exposure. With the availability of more workplace exposure data, it is now possible to make a direct comparison.Methods. The odds ratios and relative risks (RRs) of the eight studies that contained data on workplace exposure (1,699 cases) were arranged in what was believed to be the order of the quality of their tobacco smoke exposure measurements. A meta-analysis was performed to obtain combined RRs. Data from seven new studies on largely home-based exposure and heart disease that were not included in the 1994 review were also evaluated.Results. The combined RR for the three top-rated workplace studies was 1.50 (95% confidence interval [CI] 1.12 to 2.01). Adding four lower rated studies reduced the RR to 1.35 (95% CI 1.09 to 1.67). Adding the largest study but the one with questionable exposure history reduced the combined RR to 1.18 (95% CI 1.04 to 1.34). Adding the seven new, largely home-based studies increased the home-based morbidity RR to 1.49 (95% CI 1.29 to 1.72) compared with 1.42 in 1994 while leaving the mortality RR unchanged at 1.23 (95% CI 1.14 to 1.32).Conclusions. The RRs for heart disease from passive smoking at work are roughly equal to those from home-based exposure.     

Long-Term Effects of Breastfeeding,Maternal Smoking During Pregnancy,and Recurrent Lower Respiratory Tract Infections on Asthma in Children

The effect of breastfeeding on asthma is controversial, which may be explained by related and interacting early childhood risk factors. We assessed the joint effects of a risk-triad consisting of maternal smoking during pregnancy, breastfeeding for less than 3 months, and recurrent lower respiratory tract infections (RLRTI) on physician-diagnosed childhood asthma. The association was assessed in the Isle of Wight birth cohort study (1989–1990) using a repeated measurement approach with data collection at birth, and at ages 1, 2, 4, and 10 years. The population consists of 1,456 children recruited between January 1989 and February 1990. Prenatal smoking, breastfeeding for less than 3 months, and recurrent lower respiratory infections (RLRTI) were combined into eight risk-triads. Relative risks (RR) and 95% confidence intervals were estimated with a log-linear model. The risk-triad involving RLRTI in infancy, maternal smoking during pregnancy, and breastfeeding for less than 3 months showed a stronger association with asthma at ages 4 and 10 compared to other risk-triads (RR of 5.79 for any asthma at ages 1, 2, 4, and 10; and 3.1 for asthma at ages 4 and 10). Of the three individual risk factors, RLRTI appeared to be the major driver of the combined effects in the risk-triads. The effect of RLRTI on asthma was modified by breastfeeding. Breastfeeding for ≥ 3 months also attenuated the effect of prenatal smoking on asthma in children without RLRTI. A high proportion of asthma cases in childhood can be prevented by promoting breastfeeding, by preventing smoking during pregnancy, and by avoidance of recurrent lower respiratory tract infections in early childhood.     

不同孕期大鼠被动吸烟对胎鼠的发育及脑组织c-fos基因表达的影响

目的目的：被动吸烟对胎鼠的发育及脑组织c—fos基因的表达是否与孕期有关。方法利用妊娠大鼠构建不同孕期被动吸烟模型,运用HE染色及逆转录多聚酶链反应检测不同孕期胎鼠的脑组织的病理变化及海马中c-fos幕因的表达。结果A组（2—7灭吸烟组）的吸收胎及死胎与其他组相比差异有显著性;B组（8—13天吸烟组）IUGR发生率最高,其胎鼠脑组织病理改变及脑组织c-fos基因的表达与其它组相比有统计学意义。结论被动吸烟对胎鼠的发育及脯组织c—fos基因的表达与孕期有关。     

Frequent Ear Infections in Infancy and the Risk of Asthma in Mexican American Children

Objectives. This study examined the associations of history of ear infections in infancy with doctor-diagnosed asthma in a large sample of Mexican American children. Methods. In this population-based cross-sectional study, parents of 2023 children completed a questionnaire that collected data on doctor-diagnosed asthma, doctor-diagnosed ear infections, as well as antibiotics use in infancy, and other potential confounding variables. Results. Children with a history of ear infections in infancy were more likely to have asthma compared with those who had no history of ear infections in infancy; the adjusted odds ratios (ORs) were 2.52 (95% confidence interval [CI]: 1.35–4.69) and 1.27 (95% CI: 0.79–2.04) in children who had ≥3 and 1–2 (versus none) ear infections in infancy, respectively, p for trend = .0074. These associations were independent of antibiotics use, acetaminophen consumption, and history of various infections (other than ear infections) in the first year of life. In stratified analyses, the increased risk of asthma in children with recurrent ear infections in infancy persisted among children whose parents reported no lifetime history of rhinitis but not in children who had a history of rhinitis. Conclusions. This study demonstrated significant associations of asthma with history of ear infections in infancy, with a significant dose-response effect of repeated ear infections on the odds of asthma. These findings add to the growing body of literature linking early childhood infections with the risk of asthma and highlight the need for more research to identify the mechanisms through which ear infections may be associated with asthma.     

Case-Control Study of Passive Smoking at Home and Risk of Acute Myocardial Infarction

Objectives. We sought to study the relation between passive smoking at home and the risk of acute myocardial infarction (AMI).Background. Previous epidemiologic studies have linked environmental tobacco smoke to an increased risk of coronary heart disease, but the evidence to support this view is not strong enough. To study this issue further, we analyzed the data from a case-control study conducted in Argentina between 1991 and 1994.Methods. Case patients included 336 never-smokers with AMI. Control patients were 446 never-smokers admitted to the same network of hospitals with a wide spectrum of acute disorders unrelated to smoking or to known or suspected risk factors for AMI. Data on the smoking habits of the participants’ close relatives (spouse and children) were collected by trained interviewers using a structured questionnaire.Results. Compared with subjects whose relatives had never smoked, the multivariate odds ratios for passive smokers, according to the smoking status of their relatives, were 1.68 (95% confidence interval [CI] 1.20 to 2.37) for one or more relatives who smoked; 1.59 (95% CI 0.85 to 2.96) for a spouse who smoked; 1.24 (95% CI 0.61 to 2.52) for a spouse who smoked 1 to 20 cigarettes/day; 4.03 (95% CI 0.99 to 16.32) for a spouse who smoked >20 cigarettes/day; and 1.80 (95% CI 1.20 to 2.68) for one or more children who smoked. There was a significant interaction between passive smoking and hypercholesterolemia (≥240 mg/dl), hypertension, diabetes and family history of MI.Conclusions. In never-smokers, passive smoking at home appeared to be associated with the risk of AMI, and ∼14% of cases in men and 18% of cases in women in this Argentinian cohort are attributable to passive smoking.     

Cardiovascular Effects of Smoking

Coronary heart disease (CHD) increases with smoking and this factor interacts with hypercholesterolemia and hypertension in raising the incidence of this condition in a greater than linear fashion. This can be explained by the adverse effect of smoking on plasma fibrogen, platelet turnover and lipid profile. It may also be accounted for, however, by the acute bradycardia, increase in blood pressure and generalized vasoconstriction accompanying smoking, due to a nicotine-dependent activation of the sympathetic nervous system. These effects (which in heavy smokers can raise blood pressure permanently) are only partly offset by beta-blockers and can only be abolished by opposing the cardiac and vascular sympathetic influences by alpha and beta-blockade combined.     

Potentiating Effect of Passive Cigarette Smoking on Gastrointestinal Damage Induced by Indomethacin in Rats

Cigarette smoking and nonsteroidalantiinflammatory drugs (NSAIDs) have been associatedwith gastroduodenal ulcers. The present study aimed toclarify the ulcerogenic mechanisms of passive cigarettesmoking on gastrointestinal damage induced byindomethacin in fasted or in fasted and refed rats. Ratswere exposed to cigarette smoke (0%, 1%, 2%, or 4%, v/v)before and/or after indomethacin administration.Cigarette smoke dose-dependently potentiatedindomethacin-induced gastric mucosal lesions in thefasted animals and further lowered gastric blood flow.The gastric myeloperoxidase activity (a marker enzymefor neutrophils) was also potentiated. In addition, passivecigarette smoking increased the mortality and aggravatedduodenal ulceration and also the reduction of duodenalblood flow in the fasted and refed rats afterindomethacin treatment. The results indicated that thepotentiating effect of passive cigarette smoking onindomethacin-induced gastroduodenal lesions is probablydue to the depression of blood flow in thegastroduodenal mucosa and to the aggravation of neutrophilinfiltration in the gastric mucosa.     

The Effects of Smoking on the Lungs

The literature relating to tobacco smoking has been reviewed and is discussed under a number of headings. The smoking habits of Australians and people of other countries, the constituents of tobacco smoke and the different types of tobacco are discussed. The effects of tobacco smoke on lung defences and function are outlined and the evidence relating cigarette smoking to lung cancer in Australia, the UK and the USA is reviewed. The relationship between cigarette smoking and diseases with chronic air flow obstruction is outlined. Differences in smoking-related diseases in males and females and the effects of stopping smoking are included in the discussion.     

Active Vitamin D and Acute Respiratory Infections in Dialysis Patients

Summary

Background and objectives

Vitamin D has gained attention for its pleiotropic effects in areas other than bone metabolism, and the effects of vitamin D in preventing respiratory infections have been reported as one of its immunomodulating properties. This study assessed the preventive effect of vitamin D receptor activator (VDRA) on respiratory infections in dialysis patients.

Design, setting, participants, & measurements

Maintained Japanese hemodialysis patients (n = 508) were observed for 5 years, and the incidence of hospitalization during this period because of acute respiratory infection (ARI) was recorded.

Results:

Of the 508 patients, 212 had taken oral VDRA at the start of the study, whereas 296 patients had not received it. During the 5-year follow-up period, 57 patients were hospitalized because of ARIs. Kaplan–Meier analysis revealed that the incidence of hospitalization because of respiratory infection was significantly lower in patients who had been treated with VDRA compared with patients who had not (log rank test; P = 0.02). The multivariate Cox proportional hazards model demonstrated that the patients who had taken oral VDRA were at a significantly lower risk of hospitalization because of respiratory disease (hazard ratio 0.47, 95% confidence interval 0.25 to 0.90).

Conclusions:

The findings of this study suggest that the administration of oral VDRA has a preventive effect on the incidence of ARIs in dialysis patients.     

Intravenous Nicotine Simulation of Passive Smoking to Estimate Dosage to Exposed Non-Smokers

To estimate nicotine intake from passive smoking, six subjects received slow intravenous infusions of known doses of nicotine at a steady rate over one hour. The plasma and urinary nicotine concentrations produced by the infusions were compared with those found in previous studies of non-smokers exposed to tobacco smoke, in non-smokers in the general population, and in smokers during and after smoking their first cigarette of the day. It was estimated that the average rate of nicotine absorption was 0.23 mg/hr in a group of non-smokers exposed in a poorly ventilated public house, 0.36 mg/hr in non-smokers exposed to more extreme conditions in a smoke-filled unventilated room, and that the average daily-life exposure of a sample of 188 urban non-smokers was 0.014 mg nicotine per hour. In contrast, the dose absorbed by three smokers from their first cigarette of the day averaged 1.4 mg nicotine. The results indicate that when passive exposure of non-smokers results in carbon monoxide intake equivalent to the active smoking of one cigarette, the amount of nicotine absorbed is much less - equivalent to about one third of a cigarette dose. In view of the small samples and various assumptions in deriving these estimates, they can only be viewed as approximate.     

Effects of the Wars on Smoking Among Veterans

BACKGROUND

Educating medical students about health disparities may be one step in diminishing the disparities in health among different populations. According to adult learning theory, learners’ opinions are vital to the development of future curricula.

DESIGN

Qualitative research using focus group methodology.

OBJECTIVES

Our objectives were to explore the content that learners value in a health disparities curriculum and how they would want such a curriculum to be taught.

PARTICIPANTS

Study participants were first year medical students with an interest in health disparities (n?=?17).

APPROACH

Semi-structured interviews consisting of 12 predetermined questions, with follow-up and clarifying questions arising from the discussion. Using grounded theory, codes were initially developed by the team of investigators, applied, and validated through an iterative process.

MAIN RESULTS

The students perceived negative attitudes towards health disparities education as a potential barrier towards the development of a health disparities curriculum and proposed possible solutions. These solutions centered around the learning environment and skill building to combat health disparities.

CONCLUSIONS

While many of the students’ opinions were corroborated in the literature, the most striking differences were their opinions on how to develop good attitudes among the student body. Given the impact of the provider on health disparities, how to develop such attitudes is an important area for further research.