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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.

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.

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.

BackgroundOccupational asthma is a common type of asthma caused by a specific agent in the workplace. The basic alteration of occupational asthma is airways inflammation. Although most patients with occupational asthma are mature adults, there is evidence that airways inflammation starts soon after inception of exposure, including during apprenticeship. Airways hyper responsiveness to methacholine is a valid surrogate marker of airways inflammation, which has proved useful in occupational epidemiology. But it is time-consuming, requires active subject's cooperation and is not readily feasible. Other non-invasive and potentially more useful tests include the forced oscillation technique, measurement of fraction exhaled nitric oxide, and eosinophils count in nasal lavage fluid.Methods and designThis study aims to investigate early development of airways inflammation and asthma-like symptoms in apprentice bakers, pastry-makers and hairdressers, three populations at risk of occupational asthma whose work-related exposures involve agents of different nature. The objectives are to (i) examine the performance of the non-invasive tests cited above in detecting early airways inflammation that might eventually develop into occupational asthma; and (ii) evaluate whether, and how, constitutional (e.g. atopy) and behavioural (e.g. smoking) risk factors for occupational asthma modulate the effects of allergenic and/or irritative substances involved in these occupations. This paper presents the study rationale and detailed protocol.DiscussionAmong 441 volunteers included at the first visit, 354 attended the fourth one. Drop outs were investigated and showed unrelated to the study outcome. Sample size and follow-up participation rates suggest that the data collected in this study will allow it to meet its objectives.

Two sets of seven pulse oximeters (Criticare CSI-502; Nellcor-N200; Datex-Satlite; Physio-Control-Lifestat 1600; Critikon-Oxyshuttle; Ohmeda-Biox 3700; Ohmeda-Biox 3740; Radiometer-Oxi; Spectramed-Pulsat; Kontron-7840; Biochem-Ox2000; Invivo-4500; Engstrom-EOS; Novametrix-505) were studied in two groups of eight healthy subjects, aged 26-50 yrs. The transcutaneous oxygen saturation (SpO2) was compared with arterial oxygen saturation (SaO2) measured in simultaneously with drawn blood samples (OSM2 Radiometer) at four 20 min steady-state levels of inspired oxygen fraction (FIO2) (0.21, 0.10, 0.08 and 0.07; SaO2 99-55%) in a conditioned chamber. Both the error in accuracy (mean SpO2-SaO2 difference), and the error in precision (SD of the differences) remained less than 3% for the two highest FIO2 levels (SaO2 greater than 83%) but, during deeper hypoxia, they were increased to 8% and 5%, respectively. An instrumental systematic bias affected accuracy in particular. We concluded that a good agreement between SpO2 and SaO2, as reflected by the Bartko's intraclass coefficient, was observed in nine instruments.

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.

The accuracy and precision of transcutaneous pressure measurements of oxygen (Ptc,O2) and carbon dioxide (Ptc,CO2) in the monitoring of nocturnal assisted ventilation in adult patients were evaluated. Transcutaneous measurements obtained with two analysers, Radiometer TINATCM3 (R) and Kontron MicroGas-7650 (K), were compared with arterial blood gases analysed in blood samples withdrawn simultaneously in 10 patients. Sensors were heated to 43 degrees C. Measurements of transcutaneous blood gases and arterial blood gases were collected six times at 1-h intervals. The data obtained with both instruments were similar and did not significantly change over the 5 h test period. Measurement of Ptc,O2 underestimated arterial oxygen tension (Pa,O2) and this underestimation increased with the level of Pa,O2 (p

L'insuffisance respiratoire aigue (IRA) hypercapnique survient essentiellement enpresence de lesions pleuro-parenchymateuses pulmonaires ou d'atteinte fonctionnelle de la mecanique ventilatoire. Cependant, l'IRA peut survenir en l'absence de telles anomalies. Le but de cette etude, est de verifier l'hypothese selon laquelle une decompensation respiratoire aigue non accompagnee de trouble mecanique ventilatoire est favorisee par un deficit des systemes de regulation de la ventilation. Nous avons etudie 31 patients au decours d'une IRA hypercapnique. Nous avons analyse chez eux la fonction mecanique pulmonaire et lachemosensibilite des centres respiratoi res mesuree par la methode de re-inspirationhypercapnique et hypoxique ainsi que la reponse a l'imposition d'une charge resistiveinspiratoire. Des troubles de la mecanique ventilatoire de type obstructif sont presents dans 55% des cas. Treize patients restants, sans syndrome obstructif ni restrictif, presentent tous une reponse au CO2 inferieures aux limites normales obtenues chez 20 sujets temoins. Cette defaillance se retrouve aussi chez 16 des 18 autres patients. Ces resultats confirment l'hypothese formulee : la deficience de la regulation respiratoire constituerait un facteur essentiel a la survenue d'une IRA grave non expliquee par des troubles de la mecanique ventilatoire. Dans tous les cas, un deficit du control e respir atoire resterait un facteur favorisant la decompensation respiratoire.