The aim of this study was to examine the association between chronic mucus hypersecretion, and FEV1 decline, and subsequent hospitalization from chronic obstructive pulmonary disease (COPD). We used data from The Copenhagen City Heart Study on 5,354 women and 4,081 men 30 to 79 yr of age with assessment of smoking habits, respiratory symptoms, and spirometry at two surveys 5 yr apart. Information on COPD hospitalization during 8 to 10 yr of subsequent follow-up was obtained from a nationwide register. Chronic mucus hypersecretion was significantly associated with FEV1 decline; the effect was most prominent among men, where chronic mucus hypersecretion at both surveys was associated with an excess FEV1 decline of 22.8 ml/yr (95% confidence interval, 8.2 to 37.4) compared with men without mucus hypersecretion, after adjusting for age, height, weight change, and smoking; in women, the excess decline was 12.6 ml/yr (0.7-24.6). Chronic mucus hypersecretion was associated with subsequent hospitalization due to COPD after adjusting for age and smoking; relative risk was 5.3 (2.9 to 9.6) among men and 5.1 (2.5 to 10.3) among women. After further adjusting for FEV1 at the second survey, the relative risk was reduced to 2.4 (1.3 to 4.5) for men and 2.6 (1.2 to 5.3) for women. Chronic mucus hypersecretion was significantly and consistently associated with both an excess FEV1 decline and an increased risk of subsequent hospitalization because of COPD.
A common statement from exsmokers is that symptoms of asthma develop shortly after smoking cessation. This study, therefore, investigated the relationship between smoking cessation and development of asthma in a large cohort from the Copenhagen City Heart Study (CCHS). The CCHS is a longitudinal, epidemiological study of the general population from the capital of Denmark, conducted between 1976 and 1994. The study population involved the 10,200 subjects who provided information on self-reported asthma and smoking habits from the first two examinations (baseline and 5-yr follow-up), and the 6,814 subjects who also attended the third and last examination (10-yr follow-up). The point-prevalence of smoking cessation as well as the asthma incidence between examinations was estimated, and a multivariate logistic regression model was used to examine the relationship between changes in smoking habits and development of asthma. During the study period, asthma incidence increased from 1.2-4.2%. Between examinations 1,316 subjects quit smoking. Smoking cessation between examinations was significantly related to reported asthma at follow-up. With never-smokers as the reference group and following adjustment for sex, age, chronic bronchitis, level of forced expiratory volume in one second and pack-yrs of smoking, the odds ratio (OR) for developing asthma when quitting smoking between examinations was 3.9 (95% confidence interval (CI) 1.8-8.2) from baseline to first follow-up and 3.1 (95% CI 1.9-5.1) from first to second follow-up. Continuing smoking also increased the risk of asthma significantly (OR 2.6 and 2.0, respectively). The results indicate that exsmokers have a higher incidence of self-reported asthma than never-smokers. It is likely that subjects perceive chronic obstructive pulmonary disease as asthma, hence the relationship between smoking cessation and asthma might be due to misclassification rather than causality.
We analysed data from the Copenhagen City Heart Study to study the prevalence, possible risk factors for, and inter-relations between bronchial hypersecretion (BH) and chronic airflow limitation. The study sample consisted of 12,698 subjects between 20 years and 90 years of age, randomly selected from the population of the city of Copenhagen. The age-adjusted overall prevalence of BH in the population of Copenhagen was estimated to be 10.1%; 12.5% in men and 8.2% in women. The overall prevalence of clinically relevant chronic airflow limitation (forced expiratory volume in 1 s less than 60% of that predicted) was 3.7% and not significantly different between sexes. Both airflow limitation and BH increased with age, smoking, alcohol consumption, short education, and low income. However, the association of airflow limitation with alcohol consumption, education and income was much weaker than the association with smoking. Regardless of smoking habits, the majority of subjects with airflow limitation did not report symptoms of bronchial hypersecretion.
Cigarette smoking is a well-know health hazard, probably not least for patients suffering from asthma. This review gives a short overview concerning the effects of passive and active smoking on the inception and outcome with regard to longitudinal changes in lung function and mortality for patients with asthma. Substantial evidence suggests that smoking affects asthma adversely. Exposure to environmental tobacco smoke in children, especially maternal smoking, may be a significant risk factor for asthma. Environmental tobacco exposure in patients with established asthma is not only associated with more severe symptoms, but also with lower quality of life, reduced lung function, and increased health care utilisation for asthma, including hospital admissions. Active smoking appears not to be a significant risk factor for asthma, but it is associated with worse outcome with regard to both longitudinal changes in lung function and asthma-related mortality. Based on the current knowledge, it therefore seems of utmost importance to encourage patients with asthma not to smoke. In line with this, patients with asthma should be given full support in their right to a smoke-free environment.
Cystic fibrosis is the most common fatal autosomal recessive disease affecting Caucasian populations. It remains a puzzle how this disease is maintained at such a remarkably high incidence, however, it could be due to a reproductive advantage in cystic fibrosis heterozygotes. We tested this hypothesis. An adult Danish general population sample of 9141 individuals was screened for cystic fibrosis DeltaF508 heterozygotes; 250 carriers of this mutation were identified (2.7%). In the total sample DeltaF508 heterozygotes did not have more children than noncarriers; however, smoking interacted with genotype in predicting number of children (ANOVA: P
To investigate the annual decline of lung function in subjects with self-reported asthma, we analyzed data from a longitudinal epidemiologic study. The Copenhagen City Heart Study. The study sample consisted of 10,952 subjects (4,824 men), 20 to 90 yr of age, randomly selected from the city of Copenhagen followed over a 5-yr period. The overall prevalence of asthma was 3.7% (n = 177) in men and 3.6% (n = 219) in women. Subjects who reported asthma at the first examination had, in general, lower values for lung function than did nonasthmatic subjects, which was also the case for subjects who developed asthma during follow-up (new asthma). The annual loss of FEV1 increased with age among both asthmatics and nonasthmatics. Multiple regression analysis showed a higher decline of FEV1 in subjects with new asthma. The excess decline was, on average, 39 ml/yr in men (p = 0.002) and 11 ml/yr in women (NS), respectively, compared with that in nonasthmatic subjects. In subjects with chronic asthma, the decline was not increased compared with that in nonasthmatic subjects. Separate analyses of lifelong nonsmokers revealed that the excess decline of FEV1 in subjects with new asthma was, on average, 33 ml/yr, whereas it was not significantly increased in subjects with chronic asthma. In conclusion, this study of a large sample from the general population showed that the rate of decline of FEV1 is increased in subjects with new asthma, whereas in subjects with chronic asthma the decline of FEV1 did not differ significantly from the decline in the nonasthmatic subjects.
In order to illustrate whether there is a connection between smoking and the degree of wrinkles on the face, the authors investigated an age-stratified random sample of 4,485 women and 2,485 men aged 40-69 years. The degree of wrinkles lateral to the canthus of the right eye was described without the investigator being aware of the smoking habits of the individual concerned. For both sexes, the prevalence of deep wrinkles increased with increasing age and with decreasing household income but no significant association with body mass index was demonstrated. In men, a significant association was demonstrated between the cumulated cigarette consumption and the degree of deep wrinkles while this was not the case in women. No definite explanation of this difference between the sexes could be found but a difference in exposure to sunlight and use of face cream may be the reasons.
The aim of this study was to examine the effects of cigarette smoking and changes in smoking habits on the decline of forced expiratory volume in the first second of expiration (FEV1). We studied 7,764 men and women for 5 yrs. The subjects were grouped according to self-reported smoking habits during the observation period. We found that persistent cigarette smoking, in particular heavy smoking, accelerated the decline in FEV1. In 310 subjects who quitted smoking during the observation period, the decline of FEV1 was less pronounced than the decline observed in persistent smokers. In subjects younger than 55 yrs of age, smoking reduction was associated with a less pronounced FEV1 decline, while in the elderly subjects smoking reduction had no effect on the FEV1 decline. An increase in the number of cigarettes smoked was generally associated with a more rapid decline of FEV1, while the beginning of smoking during the 5 yrs of observation did not seem to influence the decline of FEV1. We conclude that smoking cessation or reduction may lead to a demonstrable beneficial effect on the FEV1 decline within a few years.
We tested whether increased concentrations of the acute-phase reactant fibrinogen correlate with pulmonary function and rate of chronic obstructive pulmonary disease (COPD) hospitalization. We measured plasma fibrinogen and forced expiratory volume in 1 s (FEV(1)), and assessed prospectively COPD hospitalizations in 8,955 adults from the Danish general population. Smokers with plasma fibrinogen in the upper and middle tertile (> 3.3 and 2.7-3.3 g/L) had 7% (95% confidence interval [CI]: 5-8%) and 2% (0-3%) lower percentage predicted FEV(1) than smokers with fibrinogen in the lower tertile (