Emphysema detected by lung cancer screening with low-dose spiral CT: prevalence, and correlation with smoking habits and pulmonary function in Japanese male subjects

OBJECTIVE: Screening with low-dose spiral CT is a promising new tool for early lung cancer detection. A study was undertaken to assess the prevalence of emphysema detected by CT screening, and to assess the correlation between the extent of emphysema and the severity defined according to the recently published Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. METHODS: After informed consent, CT screening and pulmonary function tests were performed on 615 men between the ages of 40 and 69. Severity of emphysema was assessed visually. Only the pulmonary function data for male subjects were analysed because there were too few female subjects with emphysema. RESULTS: Emphysema was detected in 30.5% of current smokers, 14.1% of former smokers and 3.0% of non-smokers. In male current smokers, airflow obstruction (FEV(1)/FVC < 0.7) was seen in 18.1% of subjects with mild emphysema, and in 33.3% of subjects with moderate emphysema. FEV(1) values were less than 80% of the predicted normal in 8.5% of subjects with mild emphysema, and 28.6% of subjects with moderate emphysema. The percentage of male subjects with emphysema equivalent to GOLD stage 0 was 90.0% for subjects in their 40s, 82.5% for those in their 50s, and 68.2% for those in their 60s. CONCLUSION: A considerable percentage of the subjects with emphysema as detected by CT screening had GOLD stage 0. CT screening assists in detecting early-stage emphysema.     

Effects of cigarette smoking on pulmonary vasoreactivity]

The effects of cigarette smoking on hemodynamics and hypoxic pulmonary vasoconstriction were studied in intact rats, in isolated rat lungs and in humans. The results show that smoking increases the vascular tone of pulmonary arterioles and venules, and increases their reactivity to alveolar hypoxia; leukotrienes, prostaglandins and sympathetic nerve mediate the smoking--induced pulmonary vasoconstriction; and the augmentation of pulmonary vasoreactivity to hypoxia is mainly mediated by leukotrienes and sympathetic nerve, possibly by prostaglandins as well in humans.     

Effects of asthma on pulmonary function in children. A longitudinal population-based study.

Data from a longitudinal study of childhood factors influencing the development of chronic obstructive lung disease were used to assess the effects of asthma on lung function development in male and female children. A population-based cohort of 602 white children, initially aged 5 to 9 yr, was observed prospectively for 13 yr. Spirometry was performed and a standardized respiratory and illness questionnaire was administered by trained interviewers on a yearly basis. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and forced expiratory flow between 25 and 75% of vital capacity (FEF25-75) were used as measures of lung function. The total number of children reporting asthma over the course of the study was 67. Male asthmatic subjects (n = 42) had larger average percentage of predicted FVC than nonasthmatic males (n = 277). Female asthmatic subjects (n = 23) had a lower average percentage of predicted FEV1 than nonasthmatic females (n = 260). In a multivariate analysis of the individual lung function measures, adjusting for previous level of pulmonary function, age, height, change in height, and personal and maternal smoking, males reporting active asthma had a significantly larger FVC than males with no history of asthma. In contrast, females with active asthma had a significantly smaller FEV1 than females with no history of asthma. Both males and females with active asthma had decreased FEF25-75. From our analysis, we would predict that a female who develops asthma at age 7 would experience a 5% reduction in FEV1 by age 10 and a 7% deficit by age 15.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of ozone on pulmonary function in normal subjects. An environmental-chamber study.

Twenty healthy adults, 10 smokers and 10 nonsmokers, were exposed to 0.5 ppm of ozone for 6 hours in an environmental chamber. They engaged in two 15-min, medium-exercise stints on a bicycle ergometer during this period. The symptoms most commonly noted with exposure to ozone, dry cough and chest discomfort, were experienced by more nonsmokers than smokers. Subjects who experienced symptoms, in general, were those who developed objective evidence of decreased pulmonary function. Significant changes from control values for the group as a whole with exposure to ozone were observed for the following pulmonary function tests: specific airway conductance, pulmonary resistance, forced vital capacity, and 3-sec forced expiratory volume. No significant change was observed with respect to diffusing capacity for CO, static compliance, or the various tests derived from the N2 elimination rate. In addition, nonsmokers exhibited a significant decrease in dynamic compliance after exposure to ozone. When the smokers were considered as a separate group, no significant decrease in pulmonary function was observed, although some individual smokers showed adverse functional changes.     

Changes in smoking habits and risk of asthma: a longitudinal population based study.

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.     

Effects of inhaled aerosol of platelet activating factor on pulmonary function and airway responsiveness in normal subjects]

Platelet activating factor (PAF), which was given as an aerosol to normal subjects, caused immediate bronchoconstriction. After the first inhalation of PAF, percentage fall of VP30 was 43.2% +/- 7.1% at five minute. Subsequent inhalations of PAF, bronchoconstriction effect of PAF gradually attenuated. There was an increase in the airway responsiveness to methacholine following inhalation of PAF. The mean PC40 fell from 18.57 +/- 1.69 g.L-1 to 7.01 +/- 2.24g.L-1 (P < 0.01) on day three and returned to baseline in 1 to 2 weeks. DLCO decreased from 3.3 +/- 0.7ml.kPa-1/s to 2.9 +/- 0.4ml.kPa-1/s (P < 0.01) on day three. Chlorpheniramine partially inhibited the bronchoconstriction effect of PAF in a double blind, crossover study. These data suggest that PSF may contribute to the pathogenesis of airway hyperresponsiveness in asthma and the bronchoconstriction induced by inhaled PAF is mediated in part by histamine release.     

Effects of smoking and changes in smoking habits on the decline of FEV1

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.     

A comparison of smoking habits among medical and nursing students

OBJECTIVE: The approach and credibility of future physicians and nurses as treatment providers for smoking- and tobacco-related diseases may be influenced by their smoking habits. We compared smoking habits among medical and nursing students, and examined whether these habits changed during the course of education for each cohort. METHOD: Over 1,100 medical and nursing students from a university were surveyed in year 2000 using a questionnaire that included the Fagerstrom test for nicotine dependence (FTND). RESULTS: A total of 397 medical students and 126 nursing students completed the survey. Significantly fewer medical students (3.3%) smoked compared to nursing students (13.5%). Also, significantly more nursing students were former smokers (17.8%) than medical students (9.8%). The severity of nicotine dependence, as indicated by the total FTND score as well as scores on five of the six items on the FTND, was significantly lower among medical students compared to nursing students. Smoking or quit rates did not differ across class years in both groups; however, unlike nursing students, time since quitting significantly differed across class years for medical students. Although smoking habits appear to change little during the course of education for both medical and nursing students, many smokers may have quit just prior to entering medical school but not nursing school. CONCLUSIONS: The findings confirm the continuing decline in smoking among medical students in the United States; however, increased efforts to promote tobacco education and intervention among nursing students seem necessary. Nevertheless, both groups appear to have the potential to be credible advisors to patients and public regarding smoking cessation.     

Effects of pulmonary function of oral high frequency oscillation in normal and asthmatic subjects.

High frequency jet devices are not only used as 'internal percussors' to aid clearance of pulmonary secretions, but are also a mode of ventilatory support. As physical stimuli can cause bronchospasm in asthmatic individuals, we hypothesized that direct airway vibration may induce bronchospasm. To ascertain whether an airway vibration jet device could cause bronchoconstriction, we exposed eight asthmatic and six normal subjects to 5 min of jet-induced airway vibration or placebo treatment with cross-over at 3 h. Subjects breathed spontaneously for 5 min through an open mouthpiece into which either jet (10 Hz, 25 psi) or sham pulsations (same device, pressure vented to room at compressor) were delivered in a double-blind, random order. A constant-volume body plethysmography measured functional residual capacity and specific airway conductance (SGAW) and a water seal spirometer measured forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC). These pulmonary function measurements were taken before and at 5, 10, 20, 30, 60, 90 and 120 min after each exposure. In the normal subjects there was no significant change in any pulmonary function. There was not statistically significant change in the pulmonary function in the asthmatic patients. However, the oral high frequency oscillator induced a clinical asthmatic attack in one asthmatic patient. In this one patient, the FEV1 fell 35% from its initial value at 5 min following exposure to a maximum of 49% decline from initial value at 1 h following exposure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cross-sectional and longitudinal studies of ageing Ageing in bone as a model

Whereas cross-sectional studies, in which a comparison is made between measurements made on groups of individual of various ages, will disclose age differences, true age changes can only be discerned by carrying out longitudinal studies. Certain physiological parameters change little with age but others change markedly and it is important to define the limits of normality. Loss of bone with age is universal; the construction of percentile ranking curves showing the amount of bone in the second metacarpal in different age groups makes it possible to compare the skeletal status of one individual with others of the same age and sex. There is evidence that the amount of bone in the skeleton in old age is determined by the degree of skeletal development at maturity, but longitudinal studies are required to assess the part played by such factors as disease, physical activity, nutrition and therapeutic agents. Old people in their eighties are not just the random survivors of a population of 70 year olds, they are individuals with special characteristics. In men particularly, this biological éliteness is shown not only by their better developed bones but also by their sustained health and vigour which enable them to survive to extreme old age.     

Analysis of pulmonary function test results in a health check-up population

Background

To explore the incidences of chronic obstructive pulmonary disease (COPD), obstructive ventilatory dysfunction, and obstructive small airway disease and their risk factors in a health check-up population, with an attempt to inform the early diagnosis and treatment of COPD.

Methods

Subjects who aged 20 years and older and received health check-up in the Health Management Center, Third Xiangya Hospital, Central South University from June 2013 to June 2015 were enrolled in this study. The results of detection and survey for COPD, obstructive ventilatory dysfunction, and obstructive small airway disease were analyzed.

Results

Among 6,811 subjects enrolled in this study, the detection rate of COPD, obstructive ventilator dysfunction, and obstructive small airway disease was 0.8%, 2.6%, and 4.0%, respectively, which showed a positive correlation with male gender, age, and smoking index.

Conclusions

Health check-up is an important approach for screening COPD, obstructive ventilator dysfunction, and obstructive small airway disease. Smoking cessation and controlling of relevant risk factors are helpful to lower the incidences of these conditions.     

Validation of the smoking habits of a sample of the patient population seen in a pulmonary function laboratory

From a structured history of 32 current smokers seen in the pulmonary function laboratory of a community hospital, we determined the number of cigarettes they smoked in 24 h. We also asked them to estimate their cigarette butt lengths from a visual model and to collect all cigarette butts over the next 24 h and mail them to us. We counted the butts, individually measured their lengths, and compared these with their previous estimates in order to validate their claims. While in the laboratory, we determined the level of carboxyhemoglobin in the peripheral blood of each patient. Patients tended to estimate the numbers of cigarettes that they smoked in units of five. Light smokers returned more butts and heavy smokers returned fewer butts than the numbers they reported as usually smoking. All patients were able to precisely estimate the average length of their cigarette butts, and they left butts of consistent lengths. There was no association between the numbers of cigarettes smoked and the butt lengths. Carboxyhemoglobin levels were positively associated with the numbers of cigarettes smoked in 24 h and negatively associated with the butt length and the time elapsed since the last cigarette was smoked, but these were not associated with the amount of tar in the cigarettes or with the number of years the person had smoked.     

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.     

Effects of marijuana smoking on pulmonary function and respiratory complications: a systematic review

BACKGROUND: The relationship between marijuana smoking and pulmonary function or respiratory complications is poorly understood; therefore, we conducted a systematic review of the impact of marijuana smoking on pulmonary function and respiratory complications. METHODS: Studies that evaluated the effect of marijuana smoking on pulmonary function and respiratory complications were selected from the MEDLINE, PsychINFO, and EMBASE databases according to predefined criteria from January 1, 1966, to October 28, 2005. Two independent reviewers extracted data and evaluated study quality based on established criteria. Study results were critically appraised for clinical applicability and research methods. RESULTS: Thirty-four publications met selection criteria. Reports were classified as challenge studies if they examined the association between short-term marijuana use and airway response; other reports were classified as studies of long-term marijuana smoking and pulmonary function or respiratory complications. Eleven of 12 challenge studies found an association between short-term marijuana administration and bronchodilation (eg, increases of 0.15-0.25 L in forced expiratory volume in 1 second). No consistent association was found between long-term marijuana smoking and airflow obstruction measures. All 14 studies that assessed long-term marijuana smoking and respiratory complications noted an association with increased respiratory symptoms, including cough, phlegm, and wheeze (eg, odds ratio, 2.00; 95% confidence interval, 1.32-3.01, for the association between marijuana smoking and cough). Studies were variable in their overall quality (eg, controlling for confounders, including tobacco smoking). CONCLUSIONS: Short-term exposure to marijuana is associated with bronchodilation. Physiologic data were inconclusive regarding an association between long-term marijuana smoking and airflow obstruction measures. Long-term marijuana smoking is associated with increased respiratory symptoms suggestive of obstructive lung disease.     

Clinical, epidemiologic, and pulmonary function studies in alpha,-antitrypsin-deficient subjects of Pi Z type.

The results of pulmonary function testing and systematic medical history and epidemiologic data collection are reported for 20 persons with alpha 1-antitrypsin deficiency of Pi Z phenotype. The most common symptom, reported in 19 subjects (95 per cent), was dyspnea on exertion; 16 subjects (80 per cent) gave a history of wheezing, and 8 (40 percent) reported chronic cough and sputum production. The 8 women who had been pregnant reported a miscarriage rate of 29 per cent for all pregnancies. Respiratory symptoms and disease were commonly reported in the children of study subjects. Pulmonary function testing revealed abnormalities for 18 of 20 subjects, all of those 26 or more years of age. The test that was most frequently abnormal was the 1-sec forced expiratory volume expressed as a per cent of the forced vital capacity. All pulmonary function studies demonstrated a trend toward increased impairment with increased age, which was evident by the fourth decade. Within this group of persons having severe alpha1-antitrypsin deficiency, there was no correlation between serum concentrations of antitrypsin and subjective or objective indices of pulmonary disease. A group of 7 subjects who were incidentally found to have Pi Z alpha1-antitrypsin deficiency exhibited symptoms and pulmonary function abnormalities comparable to those of 13 subjects who were originally referred for known or suspected pulmonary disease. These data suggest that if interventions such as smoking cessation and occupational counseling are to be effective, they should be initiated before the fourth decade of life.