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Background A field survey used a “sleep-breathing” questionnaire to estimate the prevalence of the excessive daytime sleepiness in a sample of middle-aged males. Methods Eight hundred and fifty men aged 22 to 66 years agreed to answer a questionnaire and have anthropometric measurements. To the question on excessive daytime sleepiness, 90 subjects (10.8%) responded “often” or “almost always”; 740 gave a negative answer. Results The sleepy subjects were older and had a higher “central” weight. All the sleep-disturbed breathing symptoms and those suggesting sleep disturbances were more frequent in sleepy subjects. Sleepiness was significantly associated with sleep apnea and chronic bronchitis. Logistic regression identified six items independently associated with daytime sleepiness; there were three indirect indicators of sleepiness, age, a history of chronic bronchitis and disruptive movements during sleep. Conclusions This epidemiologic study in a sample of active middle-aged males confirms the association of daytime sleepiness with a series of respiratory and non-respiratory sleep disturbances. The original findings are the role of a “central” obesity, the association with nightmares, and the role of chronic bronchitis as a determinant of daytime sleepiness.

Resume Introduction Une etude epidemiologique basee sur un questionnaire « sommeil/respiration » a ete realisee dans un echantillon de sujets de sexe masculin, en activite. Methodes Les 850 hommes, âges de 22 a 66 ans, ont repondu a un questionnaire de sommeil complete avec des informations sur leur mode de vie et leurs antecedents medicaux. Deux groupes ont ete compares : les « sedentaires » (sans aucun exercice) et les sujets faisant au moins cinq heures d’exercice de loisirs par semaine. Resultats Parmi les troubles respiratoires pendant le sommeil, seule la reponse a la question trop peu specifique « Vous a-t-on dit que vous avez ronfle ? » etait significativement plus frequente parmi les sedentaires. Par ailleurs, ces sujets declaraient plus souvent une hypertension arterielle sous traitement. Conclusions Cette enquete sur une population active ne met pas en evidence une difference significative de prevalence des symptomes de troubles respiratoires pendant le sommeil entre sujets sedentaires et les sujets pratiquant un exercice modere de loisirs. Le groupe sedentaire declare plus souvent hypertension arterielle sous traitement. Ce resultat peut s’expliquer par les limites d’une enquete par questionnaire et par le relativement faible contraste du niveau d’exercice de loisirs entre les temoins et les sedentaires.

Obstructive sleep apnoeas affect a significant proportion of the middle-aged population. They are due to the closure of upper airways during sleep and cause fragmented sleep, which leads to excessive daily drowsiness. Sleepiness due to apnoea is acknowledged by 10 to 30% of subjects in epidemiological surveys. It impairs vigilance, and therefore represents a risk factor for traffic, domestic and work-related accidents. In the case of domestic accidents, a study shows an increased number of accidents have been reported by subjects with apnoeas; a second study reports the reduction in the frequency of such accidents after receiving appropriate treatment. Subjects suffering from sleep apnoeas also have a higher frequency of accidents at work. Workers with persistent daily drowsiness were also found to have a higher rate of absenteeism as well.

Resume Introduction Cette etude a evalue l’hypothese de la presence de troubles respiratoires du sommeil chez des sujets exposes a des faibles concentrations de CO sur leur lieu de travail. Methodes Deux cent trente sujets exposes a des concentrations moyennes de 1 a 5 ppm de CO a leur travail et 116 sujets temoins non exposes ont ete etudies avec un protocole comprenant un questionnaire de sommeil auto rempli et des mesures anthropometriques. Resultats Les deux groupes avaient des donnees anthropometriques et des habitudes de vie similaires, a l’exception d’un âge legerement plus bas pour les sujets exposes. Aucune difference n’a ete trouvee pour les antecedents medicaux, pour les troubles respiratoires pendant le sommeil ou les alterations du sommeil. Conclusions L’exposition professionnelle a des basses concentrations de CO ne semble pas affecter la motricite pharyngienne pendant le sommeil, Il faut souligner que ce resultat est obtenu avec une approche relativement peu sensible (questionnaire) ; un protocole comprenant des enregistrements polysomnographiques, applique a des sujets exposes a des concentrations CO plus elevees pourrait arriver a d’autres conclusions.

Resume Introduction Nous avons analyse la prevalence et les facteurs de risque du ronflement habituel dans un echantillon de sujets masculins de la population active de Lorraine. Methodes Les 850 sujets, âges de 22 et 66 ans, ont repondu a un questionnaire sur la frequence du ronflement, leur mode de vie, leurs antecedents personnels et familiaux. Des mesures anthropometriques ont ete completees par un examen non invasif de permeabilite de voies aeriennes superieures. Resultats La prevalence du ronflement habituel etait de 34,6 % ; augmentant avec l’âge, le poids et ses indices derives. Nous avons identifie (par regression logistique) les variables independamment associees au ronflement habituel : l’âge, le poids, l’obstruction nasale nocturne, le diagnostic d’apnees du sommeil par un medecin, et l’hypertrophie du voile du palais et de la luette. Le resultat original a ete la mise en evidence d’un effet « protecteur » d’une grande taille ; l’exercice de loisir n’apparait significatif qu’a l’analyse univariee. Conclusions Cette etude rapporte une prevalence du ronflement habituel similaire a d’autres etudes utilisant les memes methodes. Elle confirme le risque lie a l’âge, au poids, a l’obstruction nasale, et aux modifications nasopharyngees. Un effet protecteur d’une haute taille apparait comme element original, jamais signale par les enquetes precedentes.

SummaryThe aim of the study was to evaluate the prevalence, the covariates and determinants of respiratory pauses during sleep in a sample of French middle-aged males.Study subjects were 850 active males, aged 22–66 years; 88.4% of them answered the question on breathing pauses during sleep from a structured, validated sleep questionnaire.Forty-one (=5.4%) subjects reported breathing pauses at least once a week; these “positive responders” were older, heavier and had larger neck- and waist girths as compared to subjects with negative answers. Loud habitual snoring, various sleep disturbances, excessive daytime sleepiness, a doctor diagnosis of sleep apnoea, history of stroke and hypertension were significantly more frequent among subjects with breathing pauses during sleep.The prevalence found in this survey was close to that reported from the UK (5.2%). However, by logistic regression, we identified novel determinants of breathing pauses i.e. habitual snoring, loud snoring, and excessive sleepiness, factors well known in clinical setting, but never previously reported in epidemiologic studies.

Background There is no unanimous agreement on the use of a diluent step to preface methacholine challenge testing. The "pros" for this step are that it allows a better training of the patient; the "cons" are that it requires additional time and effort. Objective We examined if there were any systematic effects when either the baseline or postdiluent (saline) forced expiratory volume in 1 second (FEV 1 ) was used to define the reactivity status. Methods All methacholine challenge tests performed during a 1-year period by a group of occupationally exposed workers (n = 183) were examined. Results The mean percentage change in FEV 1 from baseline to postsaline was −1.44 (± 3.47)% and the mean absolute change was −0.043 (± 0.11) L ( P 1 from baseline were −12.7% and +10.9%, respectively. Three subjects had a fall in FEV 1 after saline of 10% or more and were not given methacholine. From the remaining 180 subjects, 172 were equally classified as reactors (n = 67) or nonreactors (n = 105), both by baseline FEV 1 and postsaline FEV 1 . Eight subjects were classified as reactors by baseline FEV 1 but as nonreactors by saline FEV 1 . In these subjects, the average FEV 1 dropped 4.9% from baseline to saline and 17.3% from saline to end-test; thus, the total FEV 1 drop (22.5%) exceeded the 20% required for the test to be positive. Among reactors, no relationship was found between the response to saline and the subsequent response to methacholine ( r = 0.13). Conclusions Our data did not provide evidence to support the compulsory use of a diluent step when measuring bronchial responsiveness in populations. In general, the diluent step added time and expense to the test and, on occasion, forced a greater absolute drop in FEV 1 than is needed to demonstrate bronchial hyperresponsiveness.

Background: No data on snoring prevalence obtained with a standard questionnaire exist for France. Major nose-throat abnormalities have been demonstrated in cases with obstructive sleep apnea; evidence of ‘minor’ abnormalities in community studies is scarce. Objectives: The fist objective of our study was to estimate the prevalence of habitual snoring in a sample of middle-aged active males in France. The second objective was to test the hypothesis that ‘minor’ nose-throat abnormalities could be associated with habitual snoring in a field survey. Methods: Three hundred thirty-four male employees of a local university volunteered for the study (93.6% of those contacted by mail); 300 returned a sleep questionnaire. The protocol also included anthropometry and a noninvasive nose-throat examination. Results: Complete data were obtained in 299 subjects aged 23–63 years. When ‘habitual snorers’ (= 32%) were compared with never-snorers, significant differences were found for all anthropometric variables, except height. In univariate analysis, habitual snoring was associated with a large number of variables, including a large soft palate, a large uvula, and altered nose patency. A logistic regression model retained 8 factors independently associated with snoring: age, neck circumference, tobacco consumption, breathing pauses during sleep, not feeling rested during the day, need for coffee to stay awake, blocked or running nose at night and a large soft palate. Conclusions: The prevalence of habitual snoring in this sample of middle-aged French males was 32%. We confirmed the significant association of habitual snoring with age, weight excess, and tobacco smoking, and identified two further factors: blocked nose at night and a large soft palate.

Sleep-disordered breathing (SDB) and lower socio-professional status have in common a series of risk factors for ill health such as sedentary lifestyle, weight excess, heavy alcohol and tobacco consumption. We hypothesised that SDB will be more prevalent in lower socio-professional groups. A total of 496 male middle aged subjects (23–66 years) were tested with a protocol including a self-completed structured sleep questionnaire (translation of the Madison sleep cohort study form), anthropometry (including neck, waist and hip girth) and a simple, non-invasive nose–throat examination by a specialist physician. The subjects were classified according to the 10 major groups of the ISCO-88 classification (International Labour Office). Our sampling base did not contain subjects in the major groups 1 (senior officials, legislators), 6 (fishery and agricultural workers), and zero (armed forces), thus these groups were not represented in the analysis. To improve the power of the statistical analysis, groups 3 and 4, 5 and 7, 8 and 9 were merged, the analysis thus including four categories. The differences in demographic data were negligible; as expected, smoking was more prevalent in low socio-occupational groups (difference non-significant). A history of chronic bronchitis was more frequent in low socio-occupational groups, while a low physical job labour was more frequent in higher occupational groups. We did not find any differences in the prevalence of sleep-related respiratory disturbances (snoring, sleep apnoeas). This first study of the possible association between socio-occupational factors and sleep disordered breathing was negative, but we believe further studies, on larger samples, with a more homogeneous distribution of social groups are warranted.

Because some authors have reported high rates of failure in performing the single breath N2 (SBN2) test in rural areas, the present study aimed at evaluating its acceptability in a female population, unfamiliar with lung function testing, in a rural area of northeastern France. Two hundred ninety-eight women from a rural area volunteered for a preventive medicine examination (91.6% of those invited); four of them were excluded for clinical reasons, and six (2%) were unable to perform spirometry. The protocol included completion of a questionnaire, spirometry with a bronchial reactivity test, skin prick test, and the SBN2 test utilizing a computerized assembly. Although failures caused by the apparatus were few (n = 7, 2.4%) 96 of 281 women (34.1%) were unable to produce two valid SBN2 tests in a series of six attempts. Compared with the group who succeeded in the test (n = 185), women who failed were older and had a higher prevalence of bronchial hyperresponsiveness. Logistic regression confirmed the independent association of these two variables with an inability to perform. We conclude that in a female population completely unfamiliar with lung function testing the SBN2 test has a high rate of failure associated with higher age and the presence of bronchial hyperresponsiveness.

In population studies, the provocative dose (PD) of bronchoconstrictor causing a significant decrement in lung function cannot be calculated for most subjects. Dose-response curves for carbachol were examined to determine whether this relationship can be summarized by means of a continuous index likely to be calculable for all subjects, namely the two-point dose response slope (DRS) of mean resistance (Rm) and resistance at 10 Hz (R10) measured by the forced oscillation technique (FOT). Five doses of carbachol (320 microg each) were inhaled by 71 patients referred for investigation of asthma (n=16), chronic cough (n=15), nasal polyposis (n=8), chronic rhinitis (n=8), dyspnoea (n=8), urticaria (n=5), post-anaphylactic shock (n=4) and miscellaneous conditions (n=7). FOT resistance and forced expiratory volume in one second (FEV1) were measured in close succession. The PD of carbachol leading to a fall in FEV1 > or = 20% (PD20) or a rise in Rm or R10 > or = 47% (PD47,Rm and PD47,R10) were calculated by interpolation. DRS for FEV1 (DRSFEV1), Rm (DRSRm) and R10 (DRSR10) were obtained as the percentage change at last dose divided by the total dose of carbachol. The sensitivity (Se) and specificity (Sp) of DRSRm, DRS10 delta%Rm and delta%R10 in detecting spirometric bronchial hyperresponsiveness (BHR, fall in FEV1 > or = 20%) were assessed by receiver operating characteristic (ROC) curves. There were 23 (32%) "spirometric" reactors. PD20 correlated strongly with DRSFEV1 (r=-0.962; p=0.0001); PD47,Rm correlated significantly with DRSRm (r=-0.648; p=0.0001) and PD47,R10 with DRSR10 (r=-0.552; p=0.0001). DRSFEV1 correlated significantly with both DRSRm (r=0.700; p=0.0001) and DRSR10 (r=0.784; p=0.0001). The Se and Sp of the various FOT indices to correctly detect spirometric BHR were as follows: DRSRm: Se=91.3%, Sp=81.2%; DRSR10: Se=91.3%, Sp=95.8%; delta%Rm: Se=86.9%, Sp=52.1%; and delta%R10: Se=91.3%, Sp=58.3%. Dose-response slopes of indices of forced oscillation technique resistance, especially the dose-response slope of resistance at 10Hz are proposed as simple quantitative indices of bronchial responsiveness which can be calculated for all subjects and that may be useful in occupational epidemiology.

To assess whether the evolution to pneumoconiosis may be suspected in coal miners, we conducted a 4-yr longitudinal study of 80 dust-exposed miners with chest X-ray findings classified 0/1 or 1/0 according to the International Labor Organization (ILO) classification (exposed to coal mine dust, suspected of pneumoconiosis [ES group]) and two control groups having normal X-rays. The first of these latter two groups included 80 miners with similar exposure to that of the first group (exposure with normal X-rays [EN]), whereas the second group consisted of markedly less exposed miners (no exposure with normal X-rays [NN]). The protocol comprised a questionnaire on respiratory symptoms and smoking, assessment of cumulative coal-mine-dust exposure, X-rays, computed tomographic (CT) scans, and lung-function tests. The study was conducted in 1990 and 1994 by the same medical team. At the end of the follow-up, 24 members of the ES group had worsened X-ray findings, and 10 of them had X-ray findings classified as 1/1 or greater. In the EN and NN groups, six and one subjects, respectively, had worsened X-ray findings. At the first examination, subjects who developed pneumoconiosis had significantly lower values for FEV1/FVC ratio, maximum midexpiratory flow (MMEF), and maximal forced expiratory flow at 25% of vital capacity (FEF25%), and higher CT-scan micronodule scores. This latter score and FEF25% were significantly associated with the evolution to pneumoconiosis in the ES group, and scanner micronodule score and MMEF were significantly associated with this in all three groups combined. Worsening findings on X-ray and change to pneumoconiosis must be controlled in coal miners. The findings in this study offer the possibility of identifying miners who especially need follow-up and monitoring.

Study objectives: To verify that sick building symptoms are present in north-eastern France office workers; to try to identify new confounding factors. Methods: The design was that of a cross-sectional study with control group.We studied with the same methods the personnel of an air-conditioned building (n = 425), and of a naturally ventilated building (n = 351). Air temperature and humidity, bacterial and fungal densities were measured by the same technical staff in the two buildings. A standard questionnaire on irritative and respiratory symptoms, personal and family history, and lifestyle was completed by the participants. Results: In univariate analysis, exposure to air-conditioning was associated with an increased prevalence of symptoms (odds ratios-OR-between 1.54 and 2.84). A significant increase in sickness absence was also found among subects working in air-conditioned offices. As a series of factors were suspected to interfere with these associations, logistic regression was applied. This method confirmed exposure to be an independent determinant of 7 symptoms, and also identified two determinants not previously described: a family history of respiratory diseases and “do-it-yourself” activities. In Conclusion: we found the sick building symptoms to be present in a group of French office workers exposed to air-conditioning. We confirmed the influence of a number of confounding factors and described two further confounders – do-it-yourself activities at home and a history of familial respiratory disease.

The single-breath nitrogen washout (SBN 2 ) test was used, along with spirometry, in the baseline examination of a longitudinal study in a cohort of active coal miners from North-eastern France. The procedure was computerized, allowing the technician to coach and encourage the subject, and excluding computation errors. While all miners performed satisfactory spirometry, a significant number were unable to meet the National Heart and Lung Institute recommendation concerning a 10% agreement of vital capacities. When the limits were set at ± 12%, 57 miners (24·2%) were still classified as failing to perform. When compared to those who succeeded, those failing proved to be significantly older, had more cumulated dust exposure, a higher prevalence of chronic cough and sputum, and a trend for more micronodulation on the chest radiographs. The ventilatory function did not differ between the two groups. These results confirm previous data on spirometric test failure concerning older age and respiratory symptoms, extending them to the SBN 2 test. The present study further indicates that dust exposure and roentgenologic pneumoconiosis nodulation are associated with failure to perform the SBN 2 test.

Methacholine airway challenge (MAC) is a simple and useful means to assess bronchial hyperreactivity in workers exposed to various occupational hazards. Recently, wheeze detection by tracheal auscultation has been proposed as an indicator of bronchial responsiveness during bronchial provocation test in children. Our aim was to examine the relationship between the appearance of wheezes and the concurrent changes in forced expiratory volume in one second (FEV1) observed during MAC test in adults. Three cumulative doses of a methacholine solution (100 micrograms, 500 micrograms and 1500 micrograms) were inhaled by 45 workers with occupational exposure to flour dust. Spirometry was done using an electronic spirometer. Tracheal sounds were recorded with an electronic stethoscope placed over the anterior cervical triangle, 2 cm above the sternal notch. The amplified sounds were stored on magnetic tape, band-pass filtered (50-2000 Hz), and digitized at a sampling rate of 4096 Hz into a GenRad Vibration Control System. Wheezes were detected by fast Fourier transform (FFT) analysis and their presence compared to a 20% fall in FEV1. A positive MAC test by spirometry was found in 12 subjects whereas wheezes were identified in 14 subjects. Among the wheezing subjects, nine had a positive MAC test (range of fall in FEV1 = 20.6 to 42.3%) and five had a negative one (range of fall in FEV1 = 3.6 to 16.9%). Moreover, no wheezes were found in the remaining three subjects with a positive MAC test (range of fall in FEV1 = 20.7 to 27.4%). Taking a 20% fall in FEV1 as reference, wheezes were 75% sensitive and 84.8% specific to detect airflow obstruction. In conclusion, since it carries a significant although small false-negative rate, the acoustic technique based upon wheeze detection cannot, at the present time, fully replace spirometry during airway challenge testing in subjects with suspected asthma.

International audience; BACKGROUND: Exposure to pollutants in bakeries and hairdressing salons can cause airway syndromes varying from bronchial irritation to asthma. Workplace respiratory health surveillance aims to identify possible cases requiring further investigation. AIMS: To compare the performance of fractional exhaled nitric oxide (FE(NO)) and spirometry for health surveillance of apprentice bakers (ABs) and apprentice hairdressers (AHDs). Determinants of FE(NO) were also identified. METHODS: Symptoms and physician-diagnosed asthma were evaluated by questionnaire. FE(NO) was measured and spirometry was carried out. Subjects with elevated FE(NO) (FE(NO) > upper limit normal), airway obstruction [forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) < 95th percentile] and atopy (history of allergies) were identified. RESULTS: A total of 126 apprentices (59 ABs and 67 AHDs) participated. Twenty-nine (23%) apprentices had abnormal tests: 4 had associated high FE(NO) and airway obstruction, while 25 had either high FE(NO) (n = 15) or airway obstruction (n = 10) alone. Compared with ABs (n = 16), AHDs (n = 13) had more asthma (38 versus 0%; P < 0.05) and atopy (62 versus 6%; P < 0.05). There was no difference in symptoms, smoking FE(NO) or airways obstruction. Among 97 subjects with normal tests, no differences existed between ABs (n = 53) and AHDs (n = 44). Average FE(NO) was increased in atopic non-smokers compared with atopic smokers and non-atopic subjects (P < 0.05). Smoking, a history of allergies, FEV(1)/FVC % observed and respiratory symptoms were the main determinants of FE(NO). CONCLUSIONS: FE(NO) and spirometry were not overlapping dimensions in ABs and hairdressers, each test contributing unique information on the physiological status of the respiratory system. FE(NO) may provide added information on airway inflammation not provided by spirometry.

Summary. Within-subject (difference between paired tests, or coefficient of variation [c. var.] of three consecutive measurements) and between-subjects (standard deviation of the mean group) variability were assessed for the variables derived from the single-breath nitrogen (SBN2) test in a group of healthy, asymptomatic subjects (n= 289) aged 20–64 years, from a rural area in North-East France. Duplicate measurements in 99 subjects showed excellent agreement between the two attempts (correlation coefficients between 0.94 and 0.98) for static lung volumes and the alveolar N2 slope (PIII); closing volumes (CV) were more variable (r= 0.77 for absolute value, 0.79 for % VC) while closing capacities (CC) were in intermediate position (r= 0.86 for absolute value, and 0.88 for % TLC). The variability of three consecutive measures in 190 subjects showed the coefficients of variation to be low for static volumes and closing capacity (2.4–7.4%) and higher for PIII (15.1%) and CV or CV7VC (18.2 and 17.8%). The analysis of variance did not detect significant differences between the three sets of measurements, with the exception of a progressive increase of vital capacity (VC), and decrease in residual volume (RV) from test 1 to test 3, the total lung capacity being the same. Variability was uninfluenced by age or sex, except a higher c. var. for female VC as compared to males (2.8 vs. 2.2%, P= 0.02) and a higher variability of TLC (2.9 vs. 2.3%, P= 0.03) and VC (2.8 vs. 1.9%, P= 0.003) in people older than 40 years as opposed to those younger than 40 years.

The prevalence of habitual snoring and its associations with respiratory symptoms, personal and familial risk factors, ear, nose, and throat (ENT) abnormalities, and its influence on ventilatory function were studied in a sample of 190 children aged 5 to 6 years from nine kindergartens in Nancy (northeastern France). Nineteen (10%; 95% CI 5.7-14.3%) of the children were habitual snorers; the prevalence was the same in boys and girls. In univariate analysis habitual snoring was significantly associated with a personal history of exercise-induced bronchospasm [relative risk (RR) 4.50]; a history of adenotonsillectomy (RR, 2.56); a personal history of allergy (RR, 2.83); a sibling history of atopy (RR, 2.39); and doctor-assessed tonsillar hypertrophy (RR, 2.51). These factors were entered into a logistic regression model that retained as independent determinants exercise-induced asthma, personal history of allergy, sibling history of allergy, and tonsillar hypertrophy. The height-adjusted peak expiratory flow rate was slightly, non-significantly lower in habitual snorers as compared to non-snorers (2.01 +/- 0.32 vs 2.10 +/- 0.38 L/s/m2). Due to the limited numbers in the sample, the increased risk for paternal (RR, 1.8) and maternal (RR, 1.6) smoking at home remained nonsignificant.

An analysis of the risk factors for pertussis and the possible respiratory sequels was carried out in a sample of 499 children and adolescents aged 10-16 years from the general population in north-eastern France. 44 subjects (8.8%) had pertussis during childhood; and the sex ratio was 1 in these cases. Pertussis was significantly associated with a maternal history of respiratory disease, residence in a rural area and coal heating. In a multiple logistic regression model, a maternal history of respiratory disease was the only significant factor (p = 0.01), the number of siblings being of borderline significance (p = 0.06). No increase in respiratory symptoms or asthma prevalence was found in our subjects who had pertussis during childhood.

The aim of the present study was to test the hypothesis that unmarried (single) men have more sleep-disordered breathing symptoms due to a higher prevalence of obesity and a less healthy lifestyle than men living with a partner. Men (499) aged 23–66 years completed a structured questionnaire, had standard anthropometric measurements and a simple, noninvasive nose-throat examination. Of the 499, 496 subjects answered the question concerning their marital status; 86% of them were married or lived with a partner (reference group) and the other 14% had never been married, divorced, or widowed (“single” group, considered at risk). Single subjects were younger, included slightly more smokers (30 vs. 23%) and more subjects with a history of chronic bronchitis, and less frequently had a large soft palate. The prevalence of sleep-disordered symptoms was not significantly different between the two groups. However, a study involving a larger number of subjects with information regarding alcoholic consumption may be needed to further evaluate this question.

Background: Most studies on habitual snoring have focused on its prevalence. However, from the clinical point of view, the intensity of snoring is of upmost importance, as it suggests the existence of sleep apnoeas. Objectives: The aim of the study was to assess the prevalence of loud snoring using a standard questionnaire and to evaluate the anthropometric and sleep characteristic differences between loud and light snorers in a sample of middle-aged males. Methods: The subjects were middle-aged active male employees. They completed a structured sleep questionnaire and had standard anthropometric measurements. Subjects reporting habitual snoring (≧3 nights/week) were further classified as loud or light snorers. Results: Of the 850 male subjects volunteering, 149 (17.5%) were habitual loud snorers. Loud snorers were older and had a greater waist-to-hip ratio as compared with light snorers. In univariate analysis, loud snoring was associated with gasping/snorting during sleep, breathing stops during sleep, waking up too early, excessive daytime sleepiness and falling asleep while watching TV. Logistic regression identified four independent associates of loud snoring: gasping during sleep, excessive daytime sleepiness, falling asleep watching TV and age. Conclusions: Loud snoring is present in a significant proportion of middle-aged men and is associated with central obesity and age. It disturbs sleep and elicits significant daytime sleepiness. Its association with breathing pauses (univariate) and its independent association with gasping during sleep suggests that loud snoring could be considered a clinical correlate of obstructive sleep apnoeas.

Studies over the past few decades have showed a clear association between cigarette smoking and the development of chronic airway obstruction. Yet, only a minority of smokers is affected so that in many, even heavy, smokers, pulmonary function remains within normal limits. While carcinogens have been well characterized, there is only limited information about the constituents of cigarette smoke responsible for inducing chronic airway obstruction. In addition, the associated risks factors for airway obstruction in smokers have not been totally identified. The present paper is a review of the recently accumulated facts concerning the intimate action of cigarette smoke at the level of large and small airways and lung parenchyma. The role of classical inflammatory cells such as neutrophils and alveolar macrophages is reviewed, but emphasis is put on recent evidence indicating the involvement of CD8+ T-lymphocytes and possibly eosinophils in the genesis of the structural changes leading to airways obstruction. The mechanisms by which airway inflammation and remodelling cause airway narrowing and airflow limitation are discussed, along with the associated loss of lung elasticity secondary to destructive emphysema. Other biological, epidemiological, physiopathological, and clinical aspects are analyzed, stressing such fundamental aspects as the defence mechanisms, the morpho-functional correlations, the identification of susceptible smokers, and the early detection of airway obstruction, both in specialized laboratories and in primary care.

Study objectives: To assess the prevalence of occasional snoring in a group of middle-aged men, and to compare anthropometric variables and prevalence of sleep-related symptoms of subjects who occasionally snore with those of other snoring categories. Design: A field survey of a sample of middle-aged men in France. Participants: Male employees of a local university and subjects from the community attending a preventive medicine center. Participation rate was 93.5%. Measurements: Anthropometric variables were recorded in 499 subjects aged 23 to 66 years (mean, 44.3 years). The subjects completed a standard sleep questionnaire and were classified according to the snoring frequency as never, rarely, sometimes, occasional, several nights per week, and every night. The subjects who snore occasionally represented 8.6% of the total. Results: The anthropometric data of subjects who snore occasionally were similar to those of subjects who habitually snore. When compared with subjects who do not snore, older age and a larger neck girth were significant. Subjects who snore occasionally were also significantly more often subjects who snore loudly, and tended more frequently to have breathing stops during sleep. Conclusions: Our epidemiologic study shows that approximately 9% of a sample of middle-aged men snore occasionally. Subjects who snore occasionally have anthropometric characteristics close to those of subjects who snore habitually. The prevalence of the main sleep-related symptoms is between that of subjects who do not snore and of subjects who snore habitually. In an epidemiologic setting, inclusion of subjects who snore occasionally as subjects who do not snore or subjects who snore habitually will lead to bias. The present results suggest they should be identified and considered as a separate category. (CHEST 2002; 122:562–568)

Asthma has a tendency, to destabilize and get worse at night, probably due to a nocturnal increase in airiway inflammation and bronchial responsiveness. Nocturnal airway narrowing in asthma is often associated with sleep disorders, such as episodes of nocturnal and early morning awakening, difficulty in maintaining sleep, and day time sleepiness. On the other hand, an association has been documented between nocturnal sleep-disordered breathing and asthma. This review highlights the causes of nocturnal worsening of asthma and examines the evidence pointing toward a causal relationship between nocturnal asthma and sleep-disordered breathing.

In patients with obstructive sleep apnoea (OSA) anatomic and functional upper airway abnormalities are frequent and severe. Invasive methods are used to identify and quantitate the obstruction, to precisely locate its site, etc. as part of pre-treatment or of preoperative evaluations. These methods (lateral skull radiographs, computerized tomography, MRI, fibroscopies, etc) are too expensive and too invasive to be utilized in field surveys. To the classical sleep questionnaires and anthropometric measurements, some simple nose-throat examinations, easily accepted by the volunteers in a population study, could add useful information for the identification of the subjects at risk for sleep-disordered breathing. The present paper is a review of these examinations and of their utility.

There is only limited information on the factors associated with nonspecific bronchial hyperresponsiveness (BHR) in farmers. Our purpose was to examine the relationship between BHR and respiratory symptoms, atopy, and abnormalities of lung function in a sample of French farmers. Farmers scheduled for a preventive medicine check-up in northeastern France were examined. Occupational exposure, respiratory symptoms, and work-related symptoms were assessed by questionnaire, sensitization to 34 common and agricultural allergens by skin prick tests, and BHR by the single-dose (1,200 microg) acetylcholine (ACh) challenge test. Data were obtained from 741 farmers (95% of those invited). Seventy-seven subjects (10.3%) had BHR defined as a fall in forced expiratory volume in 1 s (FEV1)/= 10% after the inhalation of ACh or, for those with a poor lung function, an increase in FEV110% and200 ml after the inhalation of 200 microg of salbutamol. The proportion of asthmalike symptoms, especially wheeze during work, positive skin tests to acarian (storage mites) and cereal dust allergens, and low levels of lung function was significantly greater among reactors than among nonreactors. Stepwise logistic regression analysis showed a significant and independent association between BHR and wheezing during work (OR = 4.99; 95% CI = 2.29-10.89; p = 0.0001) and baseline FEV1 (OR = 1.49; 95% CI = 1.05-2.20; p = 0.026). In conclusion, hyperreactive farmers had significantly more asthmalike symptoms, positive skin tests, and abnormal lung function than normoreactive farmers. Work-related wheeze and low baseline FEV1 were significantly and independently associated with BHR.

Comparative manual and computer measurements of the alveolar N2 slope and closing volumes have indicated systematic differences. When a computerized system is used in field surveys, predicted values are to be obtained under the same conditions. Therefore, we measured the alveolar nitrogen slope (phase ITI, PIII), closing volume (CV), and closing capacity (CC) from single-breath N2 washout maneuvers in 158 healthy subjects (68 females), ages 21 to 64 years, from a rural community living in a nonpolluted area of northeast France. PIII, the CV to vital capacity ratio (CV:VC, %), and the CC to the total lung capacity ratio (CC:TLC, %) were regressed against age, height, weight, and the body mass index (BMI, kg/m2) and prediction equations with 95% confidence intervals were computed. PIII increased with age in both sexes and tended to decrease with height in males (r = −0.19, p = .08). The CV:VC and CC: TLC ratios depended on age and, in males, increased with the BMI. Despite accepting a 15% difference between the test VC and the spirometric VC, only 46.3% of asymptomatic nonsmokers produced a valid single-breath nitrogen washout (SBN2) test. This high failure rate limits the usefulness of the test for epidemiologic purposes when older populations “naive” to pulmonary function testing are studied under field-survey conditions.

The aim of this study was to evaluate the usefulness of the forced oscillation technique (FOT) in the assessment of occupation-related airway changes. The forced oscillation technique and conventional lung function tests were applied in 80 underground coalface workers, aged 35-48 yrs, with chest roentgenogram films classified 0/1 or 1/0 according to the International Labour Office (ILO) classification (G group), and two control groups matched for age and smoking habits. The first control group, was made up of face-workers having normal chest radiographs, whilst the second comprised underground non-face-workers with normal chest radiographs. Spirometric, plethysmographic and transfer factor of the lungs for carbon monoxide single-breath (TL,CO,sb) indices revealed no significant differences between the three groups. As regards the forced oscillation technique, a higher value of resistance/frequency slope (Pa.L-1.s2) was found in the G group compared with the control groups; 2.11 vs 1.06 in the face-workers, and 1.58 in the underground workers. In all three groups, the forced oscillation technique indices (mean resistance (R), resistance at zero frequency (RO), resistance/frequency slope (S), and resonant frequency (fo)) were found to be higher in subjects having a decreased forced expiratory volume in one second (FEV1) (< or = 90% predicted) or a mildly obstructive pattern of ventilatory function, even though this did not reach statistical significance in each of the groups. These findings together with the feasibility and acceptability of the forced oscillation technique would suggest that it may be a suitable tool for epidemiological studies of occupational respiratory diseases.

1167 workers of Lorraine (France) iron mines, a random sample of 5600 workers aged 35 to 55 years, at work in 1975 constituted the initial cohort that was examined twice at 5-year intervals after the first examination. A questionnaire on respiratory symptoms and smoking habits (MRC questionnaire) plus questions on the work history of each participant was completed, vital capacity (VC), forced expiratory volume in one second (FEV1.0), residual volume (RV) and fractional uptake of CO (FuCO) were measured at the first examination and repeated five and ten years later. At the end of the ten year follow-up, 522 subjects were re-examined, 186 were lost to follow-up, 328 answered a mail questionnaire, and 111 had died. The total number of deaths was not different from that of the general population, but for lung cancer the standardized mortality ratio (SMR) was significantly increased (SMR = 3.7). For the miners re-examined, frequency of bronchitis and decrease of functional tests were more related to age and smoking habits than to occupation.

The alveolar nitrogen slope (PIII), closing volume (CV), and closing capacity (CC) were measured by the single-breath nitrogen washout method (SBN2) in a group of 187 healthy children and adolescents (92 boys, 95 girls), 10 to 16 yr old, from the general population of Lorraine, France. The test was performed using a computerized system, which also made the calculations. About one out of five healthy subjects in this population were unable to satisfactorily perform the test; the failure rate was the same for the two sexes (20% in boys, 21.5% in girls) and significantly higher in younger children (26.6 and 14.5% for children under and over the age of 13, respectively; p = 0.03). The distribution of results was skewed for PIII and practically normal for log PIII, CV, VC, and CV/VC or CC/TLC ratios. PIII was highly significantly, inversely related to anthropometric variables; the highest coefficient was that for the age-weight interaction term in boys (= r -0.57 for PIII, -0.62 for log PIII) and for weight in girls (r = -0.57 for both PIII and log PIII). Because the anthropometric variables were strongly interrelated (r between 0.45 and 0.79), multiple regressions did not materially improve the prediction of PIII. In simple regression, weight alone explained 36% of the variability of log PIII in boys and 32% in girls. The mean PIII was significantly higher in girls as compared to boys (1.14 +/- 0.38 versus 0.98 +/- 0.17% N2/L, p = 0.02); CV and CC in milliliters were related to body build as other lung volumes; the CV/VC in girls and CC/TLC ratio in both sexes were not related to anthropometric variables. In boys, CV/VC decreased significantly with height (p = 0.035 for CV/VC versus height3).

Pulmonary function variables (forced expiratory flows and vital capacity, static lung volume, alveolar N2 slopes closing volume and closing capacity) were compared in a group of 10–16 year old children with (n=65) and without (n=440) symptoms or signs of mild acute respiratory infection (‘common cold’). Symptomatic children had a significant impairment of forced expiratory vital capacity and flows, with no change In static volumes, alveolar N2 slopes and closing volumes. The effect was present only In boys (in whom RV/TLC and phase III slope were borderline abnormal), was more evident in older children (13 to 16 years) and was independent of the smoking habits or the presence of chronic respiratory symptoms. The results are in favour of a predominant involvement of upper airways, but signs of lower airways dysfunction are present in boys and in children 13 to 16 years old.

An epidemiological, cross-sectional study was conducted in order to assess non-neoplasic effects on the lung due to chronic exposure to arc welding fumes and gases. The study involved 346 arc welders and 214 control workers from a factory producing industrial vehicles. These workers (welders and controls) had never been exposed to asbestos. Respiratory impairments were evaluated by using a standardized questionnaire, a clinical examination, chest radiophotography and several lung function tests (spirometry, bronchial challenge test to acetylcholine, CO transfer tests according to the breath-holding and the steady-state methods, N2 washout test). The only significant differences between the welders overall compared to the controls were a slightly higher bronchial hyper-reactivity to acetylcholine and a lower lung diffusing capacity for CO in the welders. However, non-specific, radiologic abnormalities (reticulation, micronodulation) and obstructive signs were more frequent in the most exposed welders (welding inside tanks) than in welders working in well ventilated workplaces. The nature of the metal welded (mild-steel, stainless steel, aluminium) did not seem to have an influence on respiratory impairments. In the mild-steel welders, respiratory symptoms (dyspnoea, recurrent bronchitis) and obstructive signs were more frequent in the welders using a manual process than in the welders involved with the semi-automatic process (MIG). For all the workers (welders and controls), smoking had a markedly adverse effect on respiratory symptoms and lung function. Moreover, smoking seemed to interact with welding since CO lung transfer was more impaired in smoking welders than in smoking controls.

We studied the correlation between density-dependence parameters (delta He, volume of isoflow) and age, body build, spirography and forced expiratory fows in 69 healthy non-smokers (16 females) aged 18 to 51 years. Density dependence variables showed no significant differences between young (less than 35 years) males and females. Volume of isoflow per cent of forced vital capacity (Viso V % FVC) was poorly significantly related to age (r = +0.25 P less than 0.05) and weight (r = +0.27 P less than 0.05). Significant correlations were found between density dependence at low lung volume and the FEV1/VC ratio (r = 0.31, P = 0.01 for delta He 25%; r = -0.40, P less than 0.001 for Viso V% FVC) or the forced expiratory flows with air (Viso V% FVC vs. FEF 25% r = -0.42, P less than 0.001). These correlations were closer in females as compared to males. Volume of isoflow was well related to delta He 25% (r = -0.64, P less than 0.001), but the relationship with delta He 50% was weaker (r = -0.38; P less than 0.01).

The main aspects and consequences of tobacco use resulting from a series of field surveys in Romania are reviewed. The proportion of smokers in middle-aged adults is about 10 per cent for women and 40 to 50 per cent for men. Cigarettes are practically the only form of tobacco consumed--cigars are very rarely smoked and pipe-smoking accounts for less than 1 per cent of tobacco use. Less than 10 per cent of smokers use more than 25 cigarettes a day. Age at starting to smoke is low, with a quarter of smokers taking up the habit by the age of 15. Ninety per cent of the smokers admit to inhaling, and about half the men and nearly all the women smoke filter cigarettes.

Ageing of the lung function in 5 years was studied in a group of 140 iron-ore miners, aged initially from 36 to 55 years. These men had no respiratory symptom and no pulmonary radiological abnormality. The sample was stratified on age and smoking. These factors were studied by a two-way analysis of variance. Lung function testing was performed twice, at 5 years of interval, in the same conditions. It consisted in: spirometry (for measuring FVC, FEV1, FEV1/FVC); a bronchial challenge test with acetylcholine (measurement of the fall of FEV1 after the test); measurement of total lung capacity (TLC) and residual volume (RV) by the open-circuit helium dilution method, and measurement of the transfer factor of the lung for CO, by the steady-state method (TCO/V). The only indices, whose values significantly changed in 5 years were: FVC, FEV1 and TCO/V. Their decrease rate did not appear to be significantly linked to age nor to smoking. According to these results, it seems that the decline of the pulmonary function is relatively constant during the middle period of life and that it is not strongly influenced by smoking, but only among subjects who remain without any respiratory symptom.

The helium to air difference in maximal expiratory flow at mid-vital capacity (ΔHe 50%) and the volume at which air and helium expired flow rates become identical (Viso\(\mathop V\limits^ \bullet \)) are currently measured from maximal expiratory flow-volume (MEFV) curves with the largest forced vital capacities (FVC) superimposed at residual volume (RV). True FVC and maximal flows may be obtained by superimposing several MEFV tracings to construct a “composite” (envelope) curve. From both theoretical and practical points of view, total lung capacity (TLC) is a more logical and more reproducible reference for matching air and helium-oxygen MEFV curves. The use of composite MEFV matched at TLC was compared to the conventional procedure in 41 healthy subjects aged 18 to 54 years. No significant difference for δHe 50% and Viso\(\mathop V\limits^ \bullet \) resulted from the application of the modifications proposed but the number of subjects with absent Viso\(\mathop V\limits^ \bullet \) increased with superimposition at TLC. The intersubject variability of the ΔHe 50% was decreased and that of Viso\(\mathop V\limits^ \bullet \) was increased. The sensitivity of both variables to the relationship between air and He + O2 FVC is stressed.

1. In 96 miners in various stages of silicosis, smokers and non-smokers, without clinical signs of chronic bronchitis or obstructive ventilatory impairment, the distribution of ventilation was assesse

The CO transfer factor for the lung was measured, Key Words using the breath-holding technique, in 37 patients with moderate or severe chronic obstructive lung disease, classified as ‘bronchitis Chron

Thirty-three subjects with bronchial asthma and 15 subjects with asthmatic bronchitis caused by occupational exposure to simple chemicals were submitted to an allergologic investigation. Essentially this consisted of skin tests, inhalation tests, determination of some types of circulating antibodies, carried out with nonirritant concentrations of simple chemicals and with usual allergens. Results indicated that bronchial asthma and asthmatic bronchitis, due to micromolecular substances, may be either irritative (28 cases) or allergic (15 cases). In five subjects the mechanism could not be established. A certain substance may give rise, in different subjects, to both types of bronchial asthma and asthmatic bronchitis mentioned above. Besides the well-known picture of bronchial asthma with reagins, the authors describe another pattern of skin and bronchial response; this pattern has many features in common with the delayed hypersensitivity.

'Conventional' (lung volumes, airway conductance, CO transfer factor) and 'small-airway dysfunction' (single-breath N2 washout, maximal expiratory flows with air and a helium-oxygen mixture) tests were performed in a group of asymptomatic male ex-smokers (n = 20) with normal spirometry and compared to those of a similar group of middle-aged nonsmokers (n = 41). The study group had a mean life-long consumption of 13.2 +/- (SD) 8.8 pack-years and had stopped smoking 1-21 years ago, mean 7.3 +/- (SD) 5.8 years. Among the conventional tests, a minimal increase in residual volume and residual volume/total lung capacity ratio was found. Ex-smokers had a steeper phase III slope, a higher closing volume/vital capacity ratio, lower forced flows with air and a higher volume of isoflow, but neither difference between the group means was significant. There was a trend to more abnormal small-airway tests as a function of increased smoking, but only the correlation between percent of predicted closing volume and pack-years reached significance (r = +0.51, p less than 0.05). We conclude that small-airway function normalizes in the long term in most ex-smokers if they become asymptomatic, with less than 10% still having abnormal results years after they stopped smoking.