ABSTRACT
A follow-up study over 12 years was conducted among 556 men aged 30 to 54 in 1960 and working at that time in factories around Paris (France). Various occupational exposures were recorded at the time of the 1960 survey after a technical study of each workplace. The annual rate of decline of FEV1 during 12 years was estimated for each subject from the measurements in 1960 and 1972. This rate (the FEV1 slope) was related independently of FEV1 level (which reflects the loss since the beginning of adult life) and of smoking habits to occupational exposure to dust, gases, and heat. FEV1 slope was significantly related to inhalation of mineral dust (even in the absence of silica) as well as to grain dust, and the slope was steeper with increased intensity of exposure to dust. Analysis of job changes showed that among heavily exposed subjects, those who changed jobs had a less steep slope than those who did not. Our results support the hypothesis of a causal role of exposure to dust in the development of chronic airflow obstruction and of a benefit when exposure to dust ceases. Exposure to dust, gas, and heat usually occurred together so data on gas and heat were analysed after taking account of exposure to dust. The influence of heat on FEV1 decline showed a clear trend. Results suggest that exposure to gases associated with exposure to dust or heat or both had a deleterious effect. After adjusting for age, smoking, and FEV1 level (ASLA) the following average slopes were obtained: 44 ml/a (for exposure to none or to only a slight amount of dust, or to gases alone), 51 ml/a (heat), 53 ml/a (noticeable dust), 55 ml/a (noticeable dust and heat), 60 ml/a (noticeable dust, heat, and high concentration of gases). Independently of the occupational exposures, ASLA FEV1 slopes among manual workers were related to skill, being 44 ml/a for skilled and 51 ml/a for unskilled men. Independently of social class and occupational exposures recorded, there were differences in FEV1 slopes by factory, suggesting that one should not rely on using one factory as the control of studies of occupational exposure to another.
Subject(s)
Lung/physiopathology , Occupational Diseases/etiology , Chemical Industry , Follow-Up Studies , Food-Processing Industry , Forced Expiratory Volume , Humans , Male , Metallurgy , Paris , Respiration , SmokingABSTRACT
Men with and men without a history of peptic ulcers were compared using respiratory symptoms and spirographic measurements taken from data recorded in an epidemiologic study. Among the 1,049 men examined, 7% reported a history of peptic ulcer. A clear relationship appeared between bronchial hypersecretion and peptic ulcers. It persisted after adjustment for age, smoking habits, social class, and country of origin. Men with ulcers inhaled tobacco smoke more often. Ulcers, smoking, and chronic phlegm were independently related to a lower body build index. It seems that the relationship between smoking and ulcers was greater among men with chronic phlegm, and it is postulated that peptic ulcers and "chronic bronchitis" might be related to a "common secretory disorder." After adjustment for age, men with a history of peptic ulcers had, not a lower FEV1, but a higher vital capacity. A slightly lower FEV1/VC ratio cannot in such cases be considered as an index of chronic airflow limitation.
Subject(s)
Bronchi/metabolism , Mucus/metabolism , Peptic Ulcer/complications , Respiratory Tract Diseases/etiology , Adult , Aged , Chronic Disease , Cross-Sectional Studies , Forced Expiratory Volume , France , Humans , Male , Middle Aged , Respiratory Tract Diseases/physiopathology , Vital CapacityABSTRACT
Various models predicting VC and FEV1 from age and height have been compared by both theoretical and practical approaches on several subgroups of a working population examined in 1960 and 1972. The models in which spirographic values are proportional to the cube of the height give a significantly worse fit of the data. All the other models give similar predicted values in practical terms, but cutoff points depend on the distributions of VC and FEV1 given age and height. Results show that these distributions are closer to a normal than to a lognormal distribution. The use of reference values and classical cutoffs is then discussed. Rather than using a single cutoff point, a more quantitative way is proposed to describe the subjects' functional status, for example by situating him in the percentile of the reference population. In screening, cutoff points cannot be choosen without specifying first the decision considered and the population concerned.
Subject(s)
Spirometry , Adult , Age Factors , Body Height , Forced Expiratory Volume , Humans , Male , Mass Screening , Middle Aged , Models, Biological , Reference Values , Vital CapacityABSTRACT
The aim of the study was to analyse the effects of smoking, in particular to show its causal role in the development of airflow obstruction, and to look at changes in smoking habits. The study was conducted among 556 men, aged 30 to 54 in 1960, surveyed twice, in 1960 and 1972. The hypothesis of tobacco as a causal factor of airflow obstruction is strengthened, following this study, by three results: 1) FEV1 slope was related to tobacco consumption, even after adjustement for FEV1 level (42 ml/yrs for non-smokers, 51 ml/yrs for heavy smokers); 2) FEV1 loss with age increased with the amount of tobacco consumption: one pack a day smoked for 25 years was equivalent to an aging of 5 years; 3) FEV1 loss decelerated if the subject gave up smoking, thus preventing any further risk. What appeared to be a spontaneous regulation in smoking habits was observed. The men who stopped smoking were those with low respiratory status. In this population, men who were ex-smokers in 1960 and maintained this status until 1972 had a FEV1 slope similar to that of the non-smokers.
Subject(s)
Forced Expiratory Volume , Smoking/epidemiology , Adult , Aging , Airway Obstruction/etiology , Humans , Male , Middle Aged , Paris , Smoking/complications , Smoking/physiopathology , Time FactorsABSTRACT
The effects of smoking habits, socio-occupational factors and respiratory symptoms in the development of airflow obstruction have been studied in a working population of 575 men aged 30-54 in 1960 and surveyed in 1960 and 1972. On average, FEV1 decreased by 47 ml/annum. Apart from FEV1 level, which reflects loss since the beginning of adult life, three factors were independently related to FEV1 slope: tobacco consumption, occupational exposure and social class. The decrease of FEV1 with smoking was dose related and decelerated among those who stopped smoking. This follow-up study ruled against phlegm as a causal factor of early stage airflow obstruction, although its role is not excluded at later stages.
Subject(s)
Airway Obstruction/epidemiology , Spirometry , Adult , Age Factors , Airway Obstruction/physiopathology , Environmental Exposure , Follow-Up Studies , Health Surveys , Humans , Male , Middle Aged , Occupations , Paris , Pulmonary Ventilation , Regression Analysis , Respiration Disorders/physiopathology , Smoking/complications , Social Class , Time FactorsABSTRACT
Because a previous retrospective study did not allow any conclusion as to the efficacy of home IPPB therapy in patients with chronic airflow obstruction, a control trial has been started. The protocol includes definition of patients, modalities of treatment, criteria for evaluation. Among criteria for a patient to enter the trial is a chronic hypercapnia (with PaCO2 greater than or equal to 48 mmHg) observed over a preliminary period of 4 months. At the end of this period patients are allocated at random into two groups with and without IPPB at home (at least 1 to 2 hours daily through a mouthpiece); medical prescriptions are same in the 2 groups so as surveillance which is planned for 2 years. Evaluation should be based upon 5 predetermined criteria. This trial is in progress.
Subject(s)
Clinical Trials as Topic/methods , Intermittent Positive-Pressure Breathing/standards , Positive-Pressure Respiration/standards , Respiratory Insufficiency/therapy , Activities of Daily Living , Carbon Dioxide/blood , Home Nursing , Humans , Hypercapnia/therapy , Oxygen/blood , PrognosisABSTRACT
In order to assess the usage of IPPB therapy at home in chronic respiratory insufficiency in France, a mail survey has been conducted among 2,062 chest physicians and physicians involved in intensive care. The response rate was 57%. Among those caring for chronic respiratory insufficient patients, 296, i.e. 38%, have prescribed IPPB to 3,778 patients from 1960 till 1977. A study among a sample of the non-spontaneous-responders allows the estimation of about 400 physicians who prescribed IPPB on the whole for France at this time. Those who prescribed, worked more often in hospital though 4% had only a private practice. Those involved in intensive care prescribed more often than the chest physicians (47% versus 37%). The development of this therapy was different according to the different regions in France. But, in a general way, the prescription of IPPB at home particularly spread out since 1975, 65% of all the prescriptions have been done in 1975, 76, 77.
Subject(s)
Intermittent Positive-Pressure Breathing/methods , Positive-Pressure Respiration/methods , Respiratory Insufficiency/therapy , France , Humans , Prescriptions , Surveys and QuestionnairesABSTRACT
A survey has been conducted among French chest physicians and physicians involved in intensive care. 296 physicians have prescribed IPPB at home to 3 778 patients with chronic respiratory insufficiency between 1960 and 1977. Acute respiratory failure was the first criteria considered in the indications (57% of the patients); hypercapnia, hypoxemia and right heart failure episode frequency were the other criteria of severity the most often taken into account. Since 1960, the indications among those with airflow obstruction have decreased, whereas they have increased for those with restrictive insufficiencies, expressing the questions raised about the efficacy of IPPB in these two types. 18% of the patients have had IPPB through tracheostomy canula. 70% of the patients have used a pressure cycling respirator and 30% a volume or flow cycling respiratory. This second type was quite always used in the case of IPPB through canula. Oxygen was added for half of the patients. The physicians have regularly followed the patients. Great importance was accorded to home care surveillance.
Subject(s)
Intermittent Positive-Pressure Breathing/methods , Positive-Pressure Respiration/methods , Respiratory Insufficiency/therapy , France , Home Nursing , Humans , Hypercapnia/diagnosis , Hypoxia/diagnosis , TracheotomyABSTRACT
A method is presented to study, in an epidemiological research, the social security records. This study is based upon records of workers affiliated to the french social security general system. To obtain data which may be compared, it was necessary to take the legislation as a basis; this legislation gives the data which must be in the records. A study of laws and rules has been done to find out these data in the medical record and in the administrative one. A questionnaire is presented. This basic questionnaire should be modified according to the precise objectives of each study and to the characteristics of the population sample. To illustrate this method, some results of a study of chronic bronchitis risk factors are presented in the second part. These results concern 950 men, born in France, aged 30 to 59 in 1960 an still alive in 1972. The study of the long reductions of the ability to work, happened from 1960 to 1971, confirm the disabling character of the group "chronic bronchitis, asthma, emphysema, respiratory insufficiency" which follows immediately cardiovascular and rheumatic diseases. The total number of beneficiaries of the social security is already very important and the whole population will be soon concerned. The use of the social security records as data source could give very interesting informations about morbidity. So, it is possible to study representative samples of the general population or of some particular groups, which has up to now, been done only in a slight extent.
Subject(s)
Bronchitis/diagnosis , Epidemiologic Methods , Records , Social Security , Adult , Chronic Disease , France , Humans , Male , Medical Records , Middle Aged , Prognosis , Surveys and QuestionnairesABSTRACT
Chronic obstructive bronchitis is defined as persistent diffuse airways obstruction frequently associated with chronic expectoration. This disease is particularly disabling and its medico-social burden implies that measures be taken. Risk factors of chronic obstructive bronchitis can be classified according to their presently known importance: tobacco, professional exposure, air pollution, viral and bacterial respiratory infections, poor socio-economic and cultural conditions, upper and lower airways infections during childhood, other environmental factors, genetic factors. Prevention needs that research be developed, in particular for factors, as hereditary ones, relations between childhood and adult respiratory diseases and characteristics of the "susceptible smokers". Knowledge of risk factors previously quoted allows to propose public-health actions. Firstly, true preventive action of general nature: fight against tobacco consumption, reduce atmospheric pollution, improve work and life conditions. Secondly, in order to prevent the disabling state of chronic bronchitis, it would be necessary to take care of patients at the initial state. A control trial is proposed to determine the level of symptoms and of reduction of ventilatory values at which an action is needed and the best "preventive therapeutical" protocol to be applied to these patients.
Subject(s)
Bronchitis/epidemiology , Air Pollution , Airway Obstruction/etiology , Airway Obstruction/prevention & control , Bronchitis/etiology , Bronchitis/prevention & control , Chronic Disease , Humans , Risk , Smoking/complicationsABSTRACT
The aim of the present study is to find out whether or not the diagnosis of chronic bronchitis at an early stage of the disease makes it possible to forecast an excess of mortality within 10 years, among 1487 men examined in 1960/61 while they were at work and aged at the time between 30 and 59 years. After having shown the prognostic value of chronic phlegm and spirographic measurements (VC, FEV1.0, FEV1.0/VC), we tried to state precisely their prognostic value by controlling the tobacco consumption and the socio-occupational class, which are bound to them and are themselves prognostic. FEV 1.0 is the most discriminant variable; its reduction is prognostic as young as 35. Survival-rates decrease regularly with the reduction of FEV1.0; this prognostic role seems to remain in all sociooccupational classes and for smokers as well as for non-smokers; it is more evident for the men who had chronic phlegm than in those who did not have such a symptom. It has been impossible to draw clear conclusions about the prognostic value of phlegm on these points because of interaction existing between phlegm and age.
