Ventilatory lung function in young cigarette smokers: a study of susceptibility

The objective of this study was to estimate the effect of cigarette smoking on ventilatory lung function among young adults with special emphasis on the recognition of susceptible subgroups. In a cross-sectional study of 1,044 adults aged 15-40 yrs, a statistically significant linear relationship between quantity of smoking in cigarette-years and level of forced expiratory volume in one second (FEV1) was found. Among current cigarette smokers, FEV1 level was on average 35 ml lower for each 100 cigarette-years of exposure (corresponding to smoking of ten cigarettes per day for 10 yrs) compared to lifelong nonsmokers in a linear regression adjusted for confounding. Potentially susceptible subgroups were studied by introducing interaction terms between quantitative smoking and gender, wheezing, atopy, asthma, childhood respiratory illness and exposure to environmental tobacco smoke during the growth period, to the additive linear regression model explaining the FEV1 level. Wheezing was found to modify the effect of smoking significantly: the FEV1 level was on average 68 ml lower for each 100 cigarette-years due to interaction between smoking and wheezing. An introduction of the interaction term eliminated the independent effect of smoking. The results suggest that the detrimental effect of smoking on FEV1 in young adults may be limited to individuals with wheezing. Thus, the presence of wheezing among smokers indicates a higher risk for low level of ventilatory lung function compared to smokers who do not wheeze.     

Respiratory symptoms and occupational bronchitis in chromite ore miners, Sudan

Prevalence of respiratory symptoms and chronic bronchitis was determined in a group of 122 subjects (77 exposed miners, 18 partially exposed, 27 controls) working at chromite ore mines in Sudan. The mean ages (+/- s.d.) of the three groups were 36.4 (+/- 7.8), 35.2 (+/- 6.8) and 34.6 (+/- 7.5) years respectively. Methods included a respiratory symptoms questionnaire based on the British Medical Research Council (MRC 1976) questionnaire on respiratory symptoms, determination of FEV1, FVC and FEV1/FVC%. The majority (66%) of the exposed subjects were non-smokers (NS) and 20 (77%) of the 'ever-smokers' (current and ex-smokers) were smokers of less than 15 cigarettes day-1. Respiratory symptoms (cough, phlegm, dyspnoea) were more frequent among the miners and so was chronic bronchitis. The prevalence of the latter was 26% among the miners compared to 11% and 7% among the partially exposed and the controls respectively. These differences could not be accounted for by cigarette smoking. Sixty-five per cent of the miners diagnosed as having asthma, chronic bronchitis or both were non-smokers. Although the values for the FEV1/FVC% remained normal or near the lower limits of the normal range, the mean value was significantly lower among the miners. It was concluded that the mine dust was the prime cause of the respiratory symptoms and chronic bronchitis among the miners.     

Chronic respiratory effect of narguileh smoking compared with cigarette smoking in women from the East Mediterranean region

Narguileh is a water pipe. Narguileh smoking is a traditional pattern of smoking among Eastern Mediterranean women, publicly considered as a harmless entertainment. We performed a survey aimed at tracking chronic respiratory symptoms and alteration in respiratory functions in 77 female narguileh smokers, 77 cigarette smokers, and controls. A questionnaire about respiratory symptoms, quantity, and duration of smoking was completed by each woman, and a flow-volume loop was performed with all women. Women were then categorized in subgroups according to a cumulative smoking duration of over 5 years, and cumulative quantity of 50 kilograms smoked. We obtained 8 subgroups for quantity and 10 for duration. Results showed a higher proportion of chronic bronchitis in narguileh smokers compared with cigarette smokers for both quantity and duration (p value < 0.001), as well as quasi-permanent alteration in maximum mid-expiratory flow (MMEF 25%–75%) in narguileh smokers compared with cigarette smokers (p value < 0.001). Forced expired volume in one second was more altered in cigarette smokers than in narguileh smokers (p value > 0.001). These results will help to raise health authority awareness that narguileh smoking is also dangerous for women.     

Effects of randomized assignment to a smoking cessation intervention and changes in smoking habits on respiratory symptoms in smokers with early chronic obstructive pulmonary disease: the Lung Health Study

PURPOSE: To evaluate the effects of randomly assigning smokers who have early chronic obstructive pulmonary disease (COPD) to a smoking-cessation intervention on the symptoms of chronic cough, chronic phlegm production, wheezing and shortness of breath, and to determine the effects of quitting smoking on these symptoms. SUBJECTS AND METHODS: A total of 5,887 male and female smokers 35 to 60 years of age with early COPD [defined as a forced expiratory volume in the first second (FEV1) of 55% to 90% of predicted and FEV1/forced vital capacity (FVC) <0.70] were enrolled in a 5-year clinical trial. Two-thirds of participants were randomly assigned to smoking-intervention groups and one-third to a usual-care group. The intervention groups attended 12 intensive smoking-cessation sessions that included behavior modification techniques and the use of nicotine chewing gum. One intervention group was treated with ipratropium bromide by inhaler; the other intervention group received placebo inhalers. The usual-care group was advised to stop smoking. All participants were followed annually. Smoking status was biochemically validated by salivary cotinine measurements or exhaled carbon monoxide values. RESULTS: Validated 5-year sustained smoking cessation occurred in 22% of participants in the intervention compared with only 5% of participants in the usual-care group. At the end of the study, the prevalence of each of the four symptoms in the two intervention groups was significantly less than in the usual-care group (P <0.0001). For example, among participants who did not report cough at baseline, 15% of those in the intervention groups had cough at least 3 months during the year, compared with 23% of those in usual care. Sustained quitters had the lowest prevalence of all four symptoms, whereas continuous smokers had the greatest prevalence of these symptoms. Changes in symptoms occurred primarily in the first year after smoking cessation. Respiratory symptoms were associated with greater declines in FEV1 during the study (P <0.001). Ipratropium bromide had no long-term effects on respiratory symptoms. CONCLUSIONS: In this prospective randomized trial using an intention-to-treat analysis, smokers with early COPD who were assigned to a smoking-cessation intervention had fewer respiratory symptoms after 5 years of follow-up.     

Smoking cessation--but not smoking reduction--improves the annual decline in FEV1 in occupationally exposed workers

INTRODUCTION: Individuals exposed both to cigarette smoke and respiratory pollutants at work incur a greater risk of development of airway hyperresponsiveness (AHR) and accelerated decline in forced expiratory volume in 1 s (FEV1) than that incurred by subjects undergoing each exposure separately. We examined whether smoking cessation or smoking reduction improves AHR and thereby slows down the decline in FEV1 in occupationally exposed workers. METHODS: We examined 165 workers (137 males and 28 females) participating in a smoking cessation programme. Nicotine tablets were used for smoking cessation or smoking reduction. Respiratory symptoms were assessed by questionnaire, FEV1 by spirometry and AHR by methacholine challenge test. At 1 year, subjects were classified into quitters, reducers, or continuing smokers. RESULTS: Sixty-seven subjects completed the study (32 quitters; 17 reducers; 18 continuing smokers). Respiratory symptoms improved markedly in quitters (P<0.001 for all comparisons) and less so in reducers (P values between 0.163 and 0.027). At 1 year, FEV1 had slightly but significantly improved in quitters (P=0.006 vs. smokers; P=0.038 vs. reducers) and markedly deteriorated in reducers and continuing smokers. Concurrent, 1-year change in AHR did not differ significantly among the groups. CONCLUSION: In occupationally exposed workers, stopping smoking markedly improved respiratory symptoms and, in males, slowed the annual decline in FEV1. Smoking reduction resulted in smaller improvements in symptoms but deterioration in FEV1. These findings were independent of AHR. While smoking cessation should remain the ultimate goal in workplace cessation programmes more studies are necessary to better ascertain the benefits of smoking reduction.     

Comparative analysis of the effects of hubble-bubble (Sheesha) and cigarette smoking on respiratory and metabolic parameters in hubble-bubble and cigarette smokers

OBJECTIVES AND BACKGROUND: Hazard of smoking tobacco is believed to be minimized by smoking hubble-bubble (HB) instead of cigarettes. Our aims were to (i) develop an assay for estimating nicotine and cotinine; and (ii) evaluate the effect of smoking on respiratory and metabolic parameters in cigarette and HB smokers. METHODS: Urine samples were collected from 152 volunteer smokers (75 cigarette and 77 HB) as well as from 16 healthy controls. We optimized an HPLC method for the determination of nicotine and cotinine. Subjects were asked to complete a chronic respiratory symptoms questionnaire and to undergo spirometry. Fasting blood samples were collected for the determination of their lipid profile. RESULTS: The intra-assay coefficients of variation for nicotine and cotinine were 16.6% and 6.6%, respectively. The mean of cotinine in cigarette smokers (1321.4 ng/mL) was significantly (P = 0.008) higher than the mean cotinine (677.6 ng/mL) in HB smokers. The mean nicotine level in cigarette smokers (1487.3 ng/mL) was significantly (P < 0.0001) higher than the mean nicotine (440.5 ng/mL) in HB smoker. The urinary cotinine and nicotine levels of the control subjects were lower than the detection levels of the assay. The mean high-density lipoprotein cholesterol was lower in cigarette smokers (0.99 mmol/L) compared with HB smoker smokers (1.02 mmol/L) but this was not significant (P = 0.28). Spirometric values were comparable among the three groups but the chronic respiratory symptoms in the smoking groups appeared at an earlier age in the HB smokers compared with the cigarettes smokers (P < 0.05). CONCLUSION: Smoking HB does not reduce the risk of tobacco exposure and it's potentially harmful metabolites on health.     

Respiratory consequences of light and moderate smoking in young adults in Chile.

OBJECTIVE: To assess the association between smoking and respiratory symptoms, lung function and bronchial hyperresponsiveness (BHR) in young adults in Chile. SETTING: Selected sample of 1232 subjects aged 22-28 years. DESIGN: In this cross-sectional study, the outcome measures were: respiratory symptoms, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% (FEF25-75), FEV1/FVC and BHR. RESULTS: Among the 1232 subjects, 67.7% of the men and 49.4% of the women were smokers; the median cigarettes smoked per day was four for men and three for women. Smoking was associated with wheezing, waking up with a cough, breathlessness following exercise and persistent cough, with odds ratios (OR) between 1.94 (95% CI 1.41-2.66) and 3.12 (95% CI 2.21-4.40) among those smoking > or = 5 cigarettes per day, compared to non-smokers. Smoking < 5 cigarettes was significantly associated with wheezing and waking up with a cough. Smokers had a lower FEV1/FVC than non-smokers by approximately 0.8%. Smoking was not associated with FEV1, FEF25-75 or BHR status. CONCLUSIONS: This study highlights the early effects of smoking on respiratory symptoms. It could help governments in Latin America take vigorous action to deter young people from starting smoking.     

Smoking, respiratory symptoms, and diseases : a comparative study between northern Sweden and northern Finland: report from the FinEsS study

STUDY OBJECTIVES: The influences of different smoking categories on the prevalence of respiratory symptoms, asthma, and chronic bronchitis have been examined in the most northern province of Sweden, Norrbotten, and in Lapland, Finland. The two areas have similar geographic and demographic conditions. METHODS AND STUDY POPULATION: The study is a part of the FinEsS studies, which are epidemiologic respiratory surveys in progress in Sweden, Finland, and Estonia. A random sample of 20- to 69-years-olds were invited to answer a postal questionnaire about respiratory symptoms, smoking habits, and occupation. In Norrbotten, 8,333 subjects were invited and 7,104 responded (85%). In Lapland, 8,005 were invited and 6,633 responded (83%). RESULTS: The participation by age and sex was similar in both countries. The prevalence of smokers in Lapland was 32% vs 26% in Norrbotten. Significantly more women than men in Norrbotten were smokers, while the opposite was true for Lapland. Sputum production was the most prevalent symptom in both areas, 25% in Lapland vs 19% in Norrbotten. The prevalence of chronic productive cough was 11% in Lapland and 7% in Norrbotten. Bronchitic symptoms were more prevalent in Lapland among both smokers and nonsmokers. A positive family history of chronic obstructive airway disease together with increased number of consumed cigarettes showed an additive effect for both chronic productive cough and wheezing. The odds ratio (OR) for wheezing during the last 12 months was 3.8 for subjects without a family history of obstructive airway disease who consumed > 14 cigarettes per day compared with nonsmokers, but if the subjects had a family history of obstructive airway disease, the risk for wheezing increased to OR 8.4. CONCLUSION: Bronchitic symptoms were more common in Finland. The difference remained also after correction for demographic variables including smoking habits, age and socioeconomic group, and family history of obstructive airway disease. Identical methods, sample composition, and the high participation rate contribute to the validity of the results. Air pollution, including environmental tobacco smoke, may contribute to the difference. To explain the difference, further analysis and investigations of social and environmental factors as well as genetic factors are needed.     

Correlates of FEV1 and prevalence of pulmonary conditions in Japanese-American men

Correlates of forced expiratory volume in one second (FEV1) and the prevalence of pulmonary disease and symptoms were examined in 6,346 Japanese-American men 45 to 68 yr of age. There was a significant inverse dose-response relationship between FEV1 and cigarette smoking measured as pack-years, number of cigarettes, or number of years smoked. Ex-smokers had FEV1 values that were intermediate to the higher values for nonsmokers and the lower values for current smokers. Among current smokers, inhaling and starting to smoke at a younger age were associated with lower values of FEV1, independent of pack-years. FEV1 was also correlated with a variety of other biologic and sociobehavioral variables, even after removing the effects of smoking. These variables included skinfold thickness, dynamometry, hematocrit, triglycerides, and systolic blood pressure. When compared with Caucasian populations, these Japanese-American men had low prevalence rates of airflow obstruction and pulmonary disease symptoms.     

Relations between respiratory symptoms and spirometric values in young adults: the European community respiratory health study

We aim to assess whether respiratory symptoms are associated with lung function in young adults, and whether any such relation is similar in those with asthma, in men and women, and in different countries. Study participants (aged 20-44 years) were randomly selected from the general population in 35 centres in 15 countries as part of the European Community Respiratory Health Study. In all, 12,541 subjects (47%) completed a respiratory symptoms questionnaire and spirometry, metacholine challenge and immunoglobulin E tests. Indicators of diagnosed asthma showed the largest association with airways obstruction (FEV1--maximal 1-s forced expiratory volume/forced vital capacity--FVC < 70%), followed by symptoms of wheezing or shortness of breath, in both genders. Among the 96% of subjects whose FEV1/FVC ratios were greater or equal to 70%, wheezing or shortness of breath was associated with lower FEV1 levels (-211 ml in men and -169 ml in women (P < 0.01)), independent of diagnosed asthma, smoking, atopy or bronchial responsiveness. This association was not explained by a lower FVC. Symptoms of chronic bronchial mucus hypersecretion (chronic phlegm) were unrelated to both airways obstruction and FEV1 levels. Findings were homogeneous across all centres. These results suggest that lung diseases that cause wheezing are generally associated with impaired lung function.     

Lung health in workers exposed to reed dust

We conducted a cross-sectional survey in a cellulose plant among 109 reed workers, exposed to reed dust and 78 unexposed office workers, to investigate respiratory health effects of reed dust exposure. Investigations included dust measurements, serum total IgE, skin prick test, pulmonary function testing and questionnaire on respiratory symptoms. Total dust level in the reed processing unit was higher than the office (9.7 and 0.02 mg/m3, respectively). Reed workers had a higher rate of current smoking (67% and 46%, respectively). After the adjustment for smoking status and age, reed dust exposure was significantly associated with wheezing, chronic cough, dyspnea, itching eyes and itching nose. Chest tightness and ODTS symptoms were only reported by reed workers (27.5% and 23.9%, respectively). After the adjustment for pack-years of smoking, percentage of predicted FEV1, FVC, FEV1/FVC and FEF25-75 in reed workers were significantly lower than office workers. Among reed workers, wheezing was associated with older age (>40 years) and ever smoking, and cross-shift decline in FVC and FEV1 with shorter duration of work. Reed dust exposure in the workplace could provoke respiratory symptoms, possibly due to an irritating effect. Health selection bias is likely, and could have underestimated the health effects of reed dust exposure.     

Bronchial reactivity to cigarette smoke; relation to lung function, respiratory symptoms, serum-immunoglobulin E and blood eosinophil and leukocyte counts

STUDY OBJECTIVES: The aim of the study was to investigate the relationship between the immediate bronchial response to inhaled cigarette smoke [cigarette smoke bronchial reactivity (CBR)] and lung function, respiratory symptoms and markers of allergy and inflammation. DESIGN, PARTICIPANTS AND MEASUREMENTS: This cross-sectional study included 98 smokers. Their lung function and reversibility to inhaled terbutaline was measured. Their clinical history was obtained, an allergological examination was done, and bronchial reactivity to methacholine and inhaled cigarette smoke was measured. Questionnaires about respiratory symptoms, smoking history and drug usage were completed and a blood sample was obtained. Participants were divided into three groups: with asthma, chronic bronchitis and persons without asthma or chronic bronchitis (the respiratory healthy). RESULTS: Forced expiratory volume in 1sec (FEV1) residuals were independently related to the % fall in FEV1 after 12 cigarette smoke inhalations (DFEV%) in all participants (P<001), in asthmatic smokers (P<0.01) and in smokers with chronic bronchitis (P<0.05). In smokers with asthma and chronic bronchitis FEV1 residuals explained 51% and 13% of the variation in DFEV%, respectively, but only 8% (P<0.05) and 1% (N.S.) of the variation in the methacholine bronchial reactivity. In the total population the presence of wheeze (P<0.01), attacks of breathlessness (P<0.05) and daily expectoration (P<0.001) were related to higher DFEV% readings. Serum immunonoglobulin (ES-IgE) was independently related to DFEV% in all participants (P<0.01), in smokers with chronic bronchitis (P<0.01) and in the respiratory healthy (0.05相似文献   

Relationships between pulmonary function and changes in chronic respiratory symptoms. Comparison of Tucson and Cracow longitudinal studies

Parallel analyses of data from two longitudinal studies, one in Poland and one in the United States, were performed to assess the relationships between pulmonary function and respiratory symptoms. Similar relationships were seen in the both cities using the same methods of analysis. The rate of FEV1 decline and its final level were related to the prior presence of attacks of breathlessness or to a syndrome that also included wheezing and diagnosed asthma. Initial FEV1 level was lower in subjects with dyspnea appearing during the follow-up than in the never-symptom group. These relationships were independent of smoking habits. The consistencies in the parallel analyses strengthen the relationships observed. In Tucson, Ariz, the FEV1 decline in smokers with persistent chronic cough was greater than that due to separate effects of the symptom and smoking. This suggests that chronic cough may be an indicator of an increased effect of tobacco smoke on pulmonary function.     

Difference in airflow obstruction between Hispanic and non-Hispanic White female smokers

Smoking-related respiratory diseases are a major cause of morbidity and mortality. However, the relationship between smoking and respiratory disease has not been well-studied among ethnic minorities in general and among women in particular. The objective of this cross-sectional study was to evaluate the risk of airflow obstruction and to assess lung function among Hispanic and non-Hispanic White (NHW) female smokers in a New Mexico cohort. Participants completed a questionnaire detailing smoking history and underwent spirometry testing. Outcomes studied included airflow obstruction, selected lung function parameters, and chronic mucus hyper-secretion. Chi square, logistic, and linear regression techniques were utilized. Of the 1,433 eligible women participants, 248 (17.3%) were Hispanic; and 319 had airflow obstruction (22.3%). Hispanic smokers were more likely to be current smokers, and report lower pack-years of smoking, compared to NHW smokers (p < 0.05 for all analyses). Further, Hispanic smokers were at a reduced risk of airflow obstruction compared to NHW smokers, with an O.R. of 0.51, 95% C.I. 0.34, 0.78 (p = 0.002) after adjustment for age, BMI, pack-years and duration of smoking, and current smoking status. Following adjustment for covariates, Hispanic smokers also had a higher mean absolute and percent predicted post-bronchodilator FEV(1)/FVC ratio, as well as higher mean percent predicted FEV(1) (p < 0.05 for all analyses). Hispanic female smokers in this New Mexico-based cohort had lower risk of airflow obstruction and better lung function than NHW female smokers. Further, smoking history did not completely explain these associations.     

Persistent cough and sputum: prevalence and clinical characteristics in south east England.

In order to measure the prevalence of chronic respiratory symptoms in the population and to identify subjects for a case-referent study of aetiologic factors, 10,000 persons registered with general practices in south east England were surveyed. Responses to an initial postal questionnaire were validated by telephone interview; clinical interviews and simple spirometry were subsequently carried out on a sample of persons aged 5-54 years, reporting persistent sputum production. Results indicated that the postal questionnaire was an effective and sensitive method of surveying respiratory symptoms in the population. Comparison with earlier surveys suggests that the prevalence of chronic cough and sputum in Great Britain has fallen in males but not in females. Of those adults reporting persistent sputum production, high proportions reported associated symptoms of wheezing (54%), breathlessness (45%) or upper respiratory tract symptoms (54%). Thirty percent recalled a serious respiratory infection in childhood and 52% were current cigarette smokers although 34% reported that they had never been regular smokers. Overall there was little evidence of serious airflow obstruction in this group.     

Harm reduction--a treatment approach for resistant smokers with tobacco-related symptoms

Smokers with chronic obstructive pulmonary disease (COPD) appear to represent a hard-core group, and this presents a dilemma for chest physicians. A reduction in cigarette smoking benefits health, and nicotine replacement therapy (NRT) can aid smoking reduction. Hence we studied the efficacy of nicotine gum in helping hard-core smokers with severe COPD to quit. Seventeen smokers with severe COPD (FEV(1) 38-47% of predicted normal) who smoked >30 cigarettes/day but were unable to quit were encouraged to reduce their smoking as much as possible by using 4-mg nicotine gum. Five gradually reduced their daily tobacco consumption and, 18 months after starting NRT, were smoking an average of 6 cigarettes/day while still using nicotine gum. Compared to baseline, their respiratory symptoms had improved, and both FEV(1) and FVC had increased. There was no improvement in pulmonary function in the group of smokers who did not reduce their cigarette consumption. No adverse events relating to nicotine occurred among the patients who used NRT to reduce their smoking. We propose that this reduction approach should be considered for patients with respiratory disease who are unable or unwilling to stop smoking.     

Smoking, respiratory symptoms, and pulmonary function among a population of Hispanic farmworkers.

We conducted a cross-sectional study in the agricultural Central Valley to evaluate the prevalence of respiratory symptoms, smoking status, and pulmonary function in Hispanic California farmworkers. Of 759 farmworkers completing questionnaires and spirometry, 747 were Hispanic. The prevalences of current, former, and never smokers (29, 17, and 54 percent, respectively) were comparable to rates in other studies of Hispanics, but daily cigarette consumption (median-five for men and three for women) was lower than in comparison populations. Prevalences of chronic cough, chronic phlegm, and persistent wheeze were low (1.6, 5.1, and 2.8 percent, respectively). Current smoking, increased age, female sex, and working greater than or equal to 8 months per year in agriculture were associated with increased prevalence of respiratory symptoms. Adjusted lung function was higher than for reference populations. Hispanic California farmworkers have a similar smoking prevalence to other Hispanic populations, but lower respiratory symptom prevalences and higher pulmonary function are consistent with lower daily cigarette consumption and the "healthy worker effect."     

Comparison of pulmonary function and respiratory symptoms in water pipe and cigarette smokers

Background and objective: A major type of smoking in Middle Eastern countries is water pipe (WP) smoking. In the present study, pulmonary function tests (PFT) and respiratory symptoms (RS) were compared in WP smokers and deep inspiration (S‐DI) or normal inspiration (S‐NI) cigarette smokers. Methods: Pulmonary function and RS were compared among WP smokers, deep or normal inspiration cigarette smokers, and non‐smokers. Results: All PFT values in WP smokers and S‐DI, but only some values in S‐NI, were lower than those of non‐smokers (P < 0.05 to P < 0.001). In addition, all PFT values in WP smokers and S‐DI were lower than the corresponding values in S‐NI, except for forced expiratory volume in 1 s and maximal expiratory flow at 25% of forced vital capacity (P < 0.05 to P < 0.001). The prevalence of RS, except for sputum production, was greater in all three groups of smokers than in non‐smokers (P < 0.05 to P < 0.001). However, the severity of most RS in WP smokers and S‐DI, but only the severity of wheezing in S‐NI, was greater than that in non‐smokers (P < 0.05 to P < 0.01). There were inverse correlations for PFT values and positive correlations for RS, with duration and total amount of smoking (P < 0.05 to P < 0.001). Conclusions: The results from this study showed that there was a profound effect of WP smoking on PFT values and RS, which were similar to the effects of deep inspiration cigarette smoking.     

Obstructive lung disease among the urban homeless

STUDY OBJECTIVES: Homelessness is a growing problem in the United States that may significantly impair physical health. The homeless have a high prevalence of cigarette smoking, poor nutrition, and adverse environmental exposures, which could contribute to obstructive lung disease (OLD). Despite this risk, the prevalence of OLD among the homeless remains unknown. We aimed to systematically assess the prevalence of OLD among the urban homeless. DESIGN, SETTING, AND PARTICIPANTS: We conducted a cross-sectional study of the prevalence of OLD among homeless individuals in San Francisco. By random sampling, we recruited 68 adults living in one homeless shelter to participate in a structured interview survey and spirometry assessment. We used a multifaceted approach to assess OLD, including respiratory symptoms, self-reported physician diagnosis of asthma, chronic bronchitis, emphysema, or COPD, and spirometry (defined as FEV1 < 80% predicted and FEV1/FVC ratio < 0.70). RESULTS: Sixty-eight adults completed the survey, and 67 adults completed the spirometry. Homeless adults were likely to be homeless < 1 year and homeless for the first time. There was a high prevalence of cigarette smoking (75% ever smokers, 68% current smokers). The prevalence of symptoms suggestive of OLD was high, including cough (29%), wheezing (40%), chronic bronchitis symptoms (21%), and dyspnea on exertion (29%). A substantial proportion of homeless subjects indicated a prior diagnosis of asthma (24%), chronic bronchitis (19%), and COPD (4%). Based on spirometry, the prevalence of OLD was 15% (95% confidence interval, 8 to 26%), which was more than double the expected prevalence in the general US population. CONCLUSIONS: As OLD is a leading cause of death in the United States, it is important to identify it early for treatment. Homeless individuals have a higher-than-expected prevalence of OLD. Public health interventions should target the homeless population for prevention and treatment of OLD.     

Passive smoking, gas cooking, and respiratory health of children living in six cities

As part of a longitudinal study of the respiratory health effects of indoor and outdoor air pollutants, pulmonary function, respiratory illness history, and symptom history were recorded at 2 successive annual examinations of 10,106 white children living in 6 cities in the United States. Parental education, illness history, and smoking habits also were recorded, along with the fuel used for cooking in the child's home. Maternal cigarette smoking was associated with increases of 20 to 35% in the rates of 8 respiratory illnesses and symptoms investigated, and paternal smoking was associated with smaller but still substantial increases. Illness and symptom rates were linearly related to the number of cigarettes smoked by the child's mother. Illness rates were higher for children of current smokers than for children of ex-smokers. The associations between maternal smoking status and childhood respiratory illnesses and symptoms were reduced but not eliminated by adjustment for parental illness history. Levels of forced expiratory volume in one second (FEV1) were significantly lower for children of current smokers than for children of nonsmokers at both examinations and highest for children of ex-smokers. Levels of forced vital capacity (FVC) were lower for children of nonsmokers than for children of current smokers at both examinations, but the difference was statistically significant only at the first examination. Both the increase in mean FVC and the decrease in mean FEV1 among children of current smokers were linearly related to daily cigarette consumption. None of the respiratory illnesses and symptoms studied was significantly associated with exposure to gas cooking in the child's home.(ABSTRACT TRUNCATED AT 250 WORDS)