Release of ANP and fat oxidation in overweight persons during aerobic exercise in water.

Exercise in water compared to land-based exercise (LE) results in a higher release of natriuretic peptides, which are involved in the regulation of exercise-induced adipose tissue lipolysis. The present study was performed to compare the release of atrial natriuretic peptide (ANP) and free fatty acids (FFA) during prolonged aerobic water-based exercise (WE) with the release after an identical LE. 14 untrained overweight subjects performed 2 steady state workload tests on the same ergometer in water and on land. Before and after exercise, venous blood samples were collected for measuring ANP, FFA, epinephrine, norepinephrine, insulin and glucose. The respiratory exchange ratio (RER) was determined for fat oxidation.The exercises resulted in a significant increase in ANP in LE (61%) and in WE (177%), and FFA increased about 3-fold in LE and WE with no significant difference between the groups. Epinephrine increased, while insulin decreased similarly in both groups. The RER values decreased during the exercises, but there was no significant difference between LE and WE. In conclusion, the higher ANP concentrations in WE had no additional effect on lipid mobilization, FFA release and fat oxidation. Moderate-intensity exercises in water offer no benefit regarding adipose tissue lipolysis in comparison to LE.

Asthma tests in the assessment of military conscripts.

BACKGROUND: Respiratory diseases such as asthma may affect individuals' fitness for military service. In order to assess fitness for military service in subjects with asthma symptoms at conscription, objective and reliable tests are needed. OBJECTIVE: To prospectively determine the diagnostic value of the mannitol and methacholine bronchial provocation test (BPT) as well as exhaled nitric oxide in assessing physician-diagnosed asthma in a group of Swiss Armed Forces conscripts. METHODS: Questionnaire, spirometry, BPT with methacholine and mannitol, exhaled nitric oxide (FeNO) and skin prick testing were conducted in 18-20-year-old male conscripts. Asthma was diagnosed by a military physician not involved in this study according to the medical record, results of BPT, current respiratory symptoms and use of asthma medication. RESULTS: Two hundred and eighty four subjects participated in the study. Complete data for the BPT with methacholine, mannitol and measurement of FeNO were available on 235 subjects. Forty-two conscripts (17.9%) had physician-diagnosed asthma. The sensitivity/specificity of mannitol to identify physician-diagnosed asthma was 41%/93% and for methacholine it was 43%/92%. Using a cut-off point of 36.5 p.p.b., FeNO had a similar negative predictive value to rule out physician-diagnosed asthma as BPT with mannitol or methacholine. CONCLUSION: BPT with mannitol has a sensitivity and specificity similar to methacholine for the diagnosis of physician-diagnosed asthma in military conscripts but is less costly to perform without the need to use and maintain a nebulizer.

Off seasonal and pre-seasonal assessment of circulating energy sources during prolonged running at the anaerobic threshold in competitive triathletes.

OBJECTIVES: To compare changes in circulating energy sources during prolonged exercise in off season (OS) and pre-season (PS) training of triathletes. METHODS: Nine athletes of the Swiss national triathlon team (three female, mean (SD) age 28.7 (4.9) years, height 169.8 (6.0) cm, weight 57.0 (6.2) kg, VO(2)max 66.5 (5.3) ml/min/kg; six male, mean (SD) age 24.0 (4.1) years, height 181.4 (6.9) cm, weight 73.5 (6.0) kg, VO(2)max 75.9 (4.9) ml/min/kg) were tested twice (2.5 months apart) during a 25 km aerobic capacity test run at the end of the OS and just before the season. The average training load during the OS was 9.9 h/week, and this increased to 14.4 h/week in the PS. With heart rates as reference, exercise intensity during the aerobic capacity test was 97.0 (4.9)% of the anaerobic threshold and 91.2 (4.5)% of VO(2)max. Blood samples were collected before, during, and after the aerobic capacity test. Samples were collected every 5 km during three minute rest intervals. RESULTS: Blood was analysed for triglyceride (TG), free fatty acids, cholesterol, high density lipoprotein cholesterol, glucose, insulin, lactate, and changes in plasma volume. A two factor (season by distance) repeated measures analysis of variance revealed an increase in capacity for prolonged exercise in the PS by a decrease in running intensity during the aerobic capacity test (% of speed at 2.0 mmol/l lactate threshold, p = 0.008), an increase in running speed at the anaerobic threshold (p = 0.003) and at 4.0 and 2.0 mmol/l (p<0.001) of the lactate threshold. A significant season by distance interaction was found for TG (p<0.001). TG concentrations peaked at 5 km and decreased logarithmically throughout the OS (1.48 (0.34) to 0.86 (0.20) mmol/l) and PS (1.90 (0.31) to 0.73 (0.18) mmol/l) tests. From the OS to the PS, there was an increase in the difference in TG at 5-15 km with a concomitant increase at 2.0 mmol/l of the lactate threshold. The peak TG concentrations at 5 km followed by a logarithmic decrease suggest that TG may also provide circulating energy. A greater logarithmic decrease in TG occurred in the PS than in the OS, indicating a higher rate of use. There was an increase in the difference in TG at 5-15 km similar to the increase in the speed at 2.0 mmol/l of the lactate threshold between the two seasons. Glucose, insulin, lactate, and free fatty acids were similar in the two seasons. CONCLUSION: Free fatty acid and TG concentrations were much higher than expected, and the two training seasons showed significantly different patterns of TG concentration during prolonged running. These responses may be related to aerobic capacity of prolonged exercise.

Competition performance and basal nocturnal catecholamine excretion in cross-country skiers.

UNLABELLED: Objective techniques to determine whether an athlete is optimally prepared for a competition are virtually nonexistent. Preparedness for sports competition is commonly judged through the experience of the athletes and their coaches. Evidence from overtraining studies suggests that catecholamine (Cat) excretion rates may correlate with performance in athletes. PURPOSE: We therefore attempted to determine whether a relationship existed between performances of world-class cross-country skiers and basal nocturnal Cat excretion (BNCE). METHOD: During the Cross-Country Skiing World Championships, we determined BNCE in nine cross-country skiers of the Swiss national team by measuring free Cat concentration (dopamine = D, norepinephrine = NE, epinephrine = E) in morning urine samples, using high performance liquid chromatography. Expert judgments of competition performance (ECP) were assessed by two experienced professional coaches of the national team by using an 11-step scale. RESULTS: The BNCE correlated significantly with ECP in cross-country skiers (r2 = 0.84 and P < for NE; r2 = 0.86 and P < 0.001 for D). Athletes who had their best absolute competition results (ACR) showed the highest NE and D concentrations. CONCLUSION: These data suggest that competitive cross-country skiers with higher D and NE excretion may reach better competition levels compared with those with lower levels. Measures of BNCE provide objective information about competition performance, which may benefit athletes in their precompetition preparation.

[Doping-related problems in clinical practice]. / Dopingprobleme in der ärztlichen Praxis.

The complexity of the new antidoping regulations of the International Olympic Committee (IOC), the International Federations (IF) and the National Olympic Committees (NOC) rises a lot of problems in handling the prescriptions of medication in athletes in the daily practice. In addition, several countries have passed antidoping laws which makes the prescription and the delivery of doping agens illegal. This may have severe consequences for the prescribing doctors. It is therefore the goal of the article to inform the practitioning doctors about the new antidoping regulations and their impact on prescribing or delivering potential doping agens to athletes. It will focus on the new dopinglists, the different doping control systems, the problems with the pharmacological treatment of certain diseases as asthma and the necessary reports which have to be sent to the NOC's or the IF's after prescribing certain medications or methods.

Immunological effects of competitive versus recreational sports in cross-country skiing.

For a period of two months during the competitive season the effects of endurance training in cross-country skiers were evaluated in order to compare the adaptive and innate immune systems between 10 competitive athletes, 10 moderately trained athletes and 10 untrained healthy controls. The main results were as follows: the peripheral T-lymphocyte count of the competitive athletes was decreased. In contrast the number of peripheral blood NK cells was increased in this group. These data imply a diminution of the adaptive immune system due to repeated bouts of intense exercise and contemporaneous reinforcement of the innate immune response. Moreover the inducible IL-12-expression following monocyte stimulation was significantly decreased in competitive athletes. Compared with the other two groups, the moderately trained athletes showed a significantly increased production of IFN-gamma upon T-cell stimulation. These data suggest that the immune system may profit from moderate endurance training by an increased capacity to generate IFN-gamma while the immune situation following repeated exhausting exercise of competitive athletes tends to deteriorate through downregulation of IFN-gamma and IL-12.

Increase in immune activation, vascular endothelial growth factor and erythropoietin after an ultramarathon run at moderate altitude.

The present study was performed to investigate the effects of exhaustive long lasting exercise at moderate altitude on the time course of serum immunomodulatory peptides, vascular endothelial growth factor (VEGF) and serum erythropoietin (EPO). Thirteen well trained runners participated at the Swiss Alpine Marathon of Davos (distance 67 km, altitude difference 2300 m). Interleukin-6 was significantly elevated in the first 2h after the run. In contrast, tumor necrosis factor-alpha and both soluble tumor necrosis factor-a receptors I and II were increased after exercise termination and showed sustained serum concentrations the following days. Neopterin, a serum marker for the activation of the cellular immune system, was increased until day two after the run. Immediately after the run VEGF was significantly elevated and further increased 2.4-fold until day five post exercise (p = 0.005). EPO was also increased after exercise but reached its maximum 2 h after the run (2-fold increase; p = 0.004) and decreased thereafter. The main findings of our study are that prolonged strenuous exercise at moderate altitude induced a significant long lasting increase in serum VEGF and EPO which was accompanied by an activation of the immune system.

Occupational exposure to inhalative irritants and methacholine responsiveness.

OBJECTIVES: Occupational exposures to inhalative irritants have been associated with an increased reporting of respiratory symptoms in previous studies. Methacholine responsiveness represents a continuous measure of airway responsiveness. As such, it may be less subject to recall bias and more sensitive to detecting effects of occupational exposure on airways. Such effects may be stronger among atopic persons. The objective of the study was to examine the relationship between self-reports of occupational exposure to dusts, gases, vapors, aerosols, and fumes and methacholine responsiveness. METHODS: A sample was studied of never smokers (N=3044) chosen randomly from 8 areas in Switzerland. Atopy was defined as any positive skin test to 8 inhalative allergens. Nonspecific bronchial reactivity was tested using methacholine chloride and quantified by calculating the slope of the dose-response. RESULTS: The methacholine slopes were 19% [95% confidence interval (95% CI) 6-32] higher for never smokers with exposure to dusts, fumes, vapors, gases, or aerosols than for the unexposed group. When only atopic never smokers were examined. the increase was larger (37%, 95% CI 7-75), and for persons with >2 positive skin prick tests the effect was still higher (42%, 95% CI -1.5-104). Exposure to vapors and aerosols was strongly associated with increased methacholine slopes among the atopic subjects. CONCLUSIONS: Occupational exposure, particularly to dusts and fumes, was associated with increased bronchial reactivity in never smokers in this study. The magnitude of the effect was larger among atopic subjects.

Long-term ambient air pollution and respiratory symptoms in adults (SAPALDIA study). The SAPALDIA Team.

The association between long-term exposure to ambient air pollution and respiratory symptoms was investigated in a cross-sectional study in random population samples of adults (aged 18 to 60 yr, n = 9,651) at eight study sites in Switzerland. Information on respiratory symptoms was obtained with an extended version of the European Community Respiratory Health Survey questionnaire. The impact of annual mean concentrations of air pollutants was analyzed separately for never-, former, and current smokers. After controlling for age, body mass index, gender, parental asthma, parental atopy, low education, and foreign citizenship, we found positive associations between annual mean concentrations of NO2, total suspended particulates, and particulates of less than 10 micrometers in aerodynamic diameter (PM10) and reported prevalences of chronic phlegm production, chronic cough or phlegm production, breathlessness at rest during the day, breathlessness during the day or at night, and dyspnea on exertion. We found no associations with wheezing without cold, current asthma, chest tightness, or chronic cough. Among never-smokers, the odds ratio (95% confidence interval) for a 10 micrograms/ m3 increase in the annual mean concentration of PM10 was 1. 35 (1.11 to 1.65) for chronic phlegm production, 1.27 (1.08 to 1.50) for chronic cough or phlegm production, 1.48 (1.23 to 1.78) for breathlessness during the day, 1.33 (1.14 to 1.55) for breathlessness during the day or at night, and 1.32 (1.18 to 1.46) for dyspnea on exertion. No associations were found with annual mean concentrations of O3. Similar associations were also found for former and current smokers, except for chronic phlegm production. The observed associations remained stable when further control was applied for environmental tobacco smoke exposure, past and current occupational exposures, atopy, and early childhood respiratory infections when restricting the analysis to long-term residents and to non- alpine areas, and when excluding subjects with physician-diagnosed asthma. The high correlation between the pollutants makes it difficult to sort out the effect of one single pollutant. This study provides further evidence that long-term exposure to air pollution of rather low levels is associated with higher prevalences of respiratory symptoms in adults.

[Rehabilitation in COPD]. / Rehabilitation bei COPD.

Pulmonary rehabilitation (PR) is an important tool in the treatment of COPD patients. It is now clearly established that PR improves exercise capacity, reduces symptoms and improves quality of life in COPD patients. There is further evidence that the programmes also improve survival and reduce medical consumption. Pulmonary rehabilitation programmes are multidisziplinary and consist of exercise training (endurance, power), chest physiotherapie, education, psychosocial and nutritional support. Patients with poor exercise capacity, peripheral muscle weakness, severe complaints and poor quality of life seem to profit most from in- and outpatients rehab programmes. The type of rehabilitation depends on the severity of symptoms, the competence of the rehab-team and the local possibilities.

[Changes in specific airway resistance after powder inhalation of formoterol or salmeterol in moderate bronchial asthma]. / Anderung des spezifischen Atemwegswiderstandes (sRaw) nach Pulverinhalation von Formoterol oder Salmeterol bei mittelschwerem Asthma bronchiale.

Formoterol and salmeterol are two long acting beta 2 agonists available for the treatment of asthma which show differences in onset of action. In a multicentre parallel group study, patients with moderate asthma were investigated by measuring the specific airway resistance (sRaw), a more sensitive parameter than FEV1. A total of 99 patients were randomised for open treatment with either 12 micrograms formoterol delivered via Turbohaler or 50 micrograms salmeterol via Diskus. The patients were between 18 and 66 years of age, had a medium FEV1 of 68.8% (+/- 17.8%) predicted and showed a medium reversibility of 28.8% (+/- 16.5%). The patients response to one inhalation of the study drug was investigated by sRaw measurements 2, 5, 10, 20 and 60 minutes after inhalation of the formulation. Additionally, FEV1 was measured. The results show a significant decrease in specific airway resistance of 29% within the first two minutes in patients who had received 12 micrograms formoterol via Turbohaler. However, patients on salmeterol showed no change (sRaw +/- 1%). This difference is statistically highly significant (p < 0.0001). Furthermore, in 49% of the patients treated with salmeterol an increase in sRaw was seen immediately after inhalation of the drug. This increase was +16.4% in an average of 2 minutes after inhalation. One hour after inhalation the differences between the groups were small and not significant neither between formoterol and salmeterol-treated patients nor within the salmeterol group. In the following week patients were treated with 12 micrograms formoterol Turbohaler b.i.d. or 50 micrograms salmeterol Diskus b.i.d., respectively. A further sRaw measurement was performed 11 +/- 1 hours after the last inhalation of the drug. The results for sRaw and FEV1 show no differences between both study drugs indicating a similar duration of action for both formoterol Turbohaler and Salmeterol Diskus in moderate asthma. No serious adverse events were reported. The adverse event profile observed in both study groups was comparable. Thus, this study shows once again that formoterol delivered via Turbohaler has a more rapid onset of bronchodilating action compared with salmeterol Diskus. Furthermore the inhalation of salmeterol via Diskus in one-half of the patients led to an increase in specific airway resistance within the first minutes after inhalation. It is worth discussing whether an unspecific reaction to the relatively large lactose particles which are components of the salmeterol Diskus formulation are responsible for this observation.

Associations between lung function and estimated average exposure to NO2 in eight areas of Switzerland. The SAPALDIA Team. Swiss Study of Air Pollution and Lung Diseases in Adults.

In this paper, we present results from the SAPALDIA study (Swiss Study on Air Pollution and Lung Diseases in Adults) regarding associations between lung function [forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1)], as assessed during the cross-sectional study in 1991, and average levels of NO2 exposure within the eight study communities. We distinguished average home outdoor exposure and average personal exposure to NO2 and obtained exposure estimates by computing regional averages of passive sampler measurements performed by a random subsample of SAPALDIA participants in 1993. Previous analyses had revealed associations between average lung function and average air pollution levels between communities. The present results show that such associations may also be seen within communities: a 10-micrograms per m3 increase in average home outdoor and personal exposure to NO2 between zones of residence of the same community was associated with a change in average FVC by -0.59% [95% confidence limits (CL) = 0.01, -1.19] and -0.74% (95% CL = -0.07, -1.41), respectively. These values, however, are smaller than the ones found for the corresponding associations between study communities: -1.67% (95% CL = -1.01, -2.33) and -2.93% (95% CL = -2.11, -3.75), respectively. The different magnitudes of these two types of associations might be explained by differences in spatial variation between various components of air pollution.

Effects of prolonged strenuous endurance exercise on plasma myosin heavy chain fragments and other muscular proteins. Cycling vs running.

BACKGROUND: This study evaluates creatine kinase, myosin heavy chain, and cardiac troponin blood levels following three types of exercise: 1) short-distance uphill or downhill running; 2) alpine ultramarathon; and 3) alpine long-distance cycling. EXPERIMENTAL DESIGN: Comparative field study; follow-up up to 10 days. SETTING: Department of Sports Medicine. All biochemical markers were analysed at the Department of Medical Chemistry and Biochemistry. PATIENTS OR PARTICIPANTS: Subjects included healthy, trained males (N = 53). All subjects were nonsmokers and free from medication prior to and during the study. Each volunteer was an experienced runner or cyclist, who had at least once successfully finished the Swiss Alpine Marathon of Davos or the Otztal-Radmarathon before. INTERVENTIONS: Running or cycling. MEASURES: Plasma concentrations of creatine kinase, myosin heavy chain fragments and cardiac troponins were measured to diagnose skeletal and cardiac muscle damage, respectively. RESULTS: Skeletal muscle protein release is markedly different between uphill and downhill running, with very little evidence for muscle damage in the uphill runners. There is considerable muscle protein leakage in the ultramarathoners (67 km distance; 30 km downhill running). In contrast, only modest amounts of skeletal muscle damage are found after alpine long-distance cycling (230 km distance). CONCLUSIONS: This study proves that there is slow-twitch skeletal muscle fiber damage after prolonged strenuous endurance exercise and short-distance downhill running. Exhaustive endurance exercise involving downhill running and short-distance downhill running lead to more pronounced injury than strenuous endurance exercise involving concentric actions. From our results there is no reason for suggesting that prolonged intense exercise may induce myocardial injury in symptom-less athletes without cardiac deseases.

[Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA)]. / Etude suisse sur la pollution de l'air et les maladies respiratoires chez l'adulte (SAPALDIA). Swiss Study on Air Pollution and Lung Diseases in Adults.

Long-term health effects of moderate ambient air pollution are rarely investigated. In Switzerland, no large-scale study has addressed this issue so far. Important results of the Swiss Study on Air Pollution and Lung Disease in Adults (SAPALDIA) are presented. During the period 1991-1993, SAPALDIA investigated a random population sample (18-60 years) in eight Swiss areas with different environmental characteristics (Aarau, Basel, Davos, Geneva, Lugano, Montana, Payerne, Wald). In total, 9651 adults (60%) participated in the cross-sectional investigation (part 1, 1991), consisting of the following standardized procedures: questionnaire (interview), forced expiratory lung function test, bronchial challenge with methacholine, atopy assessment (Phadiatop, unspecific total IgE), allergy skin tests, and endexpiratory CO-measurements. Subjects with a history of respiratory symptoms, increased bronchial reactivity, reduced lung function (FEV1/FVC < 80% predicted) and 150 healthy never-smokers were included in the subsequent diary study (part 2; n = 3281, 1992/93). Peak flow (morning and evening), symptoms, medication, personal activity and visits to the doctor were monitored. Across regions, annual mean values ranged from 9 to 52 mg/m3 (NO2) and 10 to 33 mg/m3 (PM10) respectively. Air pollution had effects on prevalence of dyspnea (+41% per 10 mg/m3 increment of the annual mean PM10, 95% CI 20-65%), on symptoms of chronic bronchitis (+31%, 10-55%), on FVC (-3.1%; -3.7 to -2.6%), and FEV1 (-1.1%; -1.7% to -0.5%), on the incidence of respiratory symptoms and the length of symptomfree intervals (11% change per 10 mg/m3 PM10), but not on the prevalence of asthma. Environmental tobacco smoke (ETS) showed impact on wheezing (OR 1.94; 1.39-2.70), asthma (1.39; 1.04-1.86), bronchitis (1.60; 1.24-2.08) and chronic bronchitis (1.50; 1.11-2.02). Health effects of moderate air pollution were confirmed in Switzerland. Although for the individual the relative risks are small, the public health impact may be considerable. An ongoing follow-up will investigate the mortality profile of the SAPALDIA cohort.

[The importance of training intensity for improving endurance capacity of patients with chronic obstructive pulmonary disease]. / Bedeutung der Trainingsintensität für die Verbesserung der Ausdauerleistungsfähigkeit bei Patienten mit chronischen obstruktiven Lungenerkrankungen.

BACKGROUND AND OBJECTIVE: Patients with COPD often have exertional dyspnoea. They are incapacitated less by impairment of pulmonary function than by deconditioning of the cardiovascular and muscular systems. Pulmonary rehabilitation through the currently customary "low intensity" training programme can at best achieve limited improvement of aerobic capacity. The aim of this study was to clarify whether in the course of in-patient rehabilitation with a medical "high intensity" training regimen patients with COPD can better their endurance capacity (e.c.). PATIENTS AND METHODS: Eleven patients with mild to moderate COPD (ten men, one woman; average age 59 [54-76] years) participated. In addition to optimal drug treatment they undertook "high intensity" training (to 85-95% of maximally achievable heart rate). RESULTS: The patients achieved significant (P < 0.05) improvement in maximal oxygen uptake, maximal performance and walking distance in the 6-minute walking test. CONCLUSION: Medically supervised "high intensity" training can produce a significant rise in endurance capacity even in patients with COPD.

Psychosocial predictors of long-term success of in-patient pulmonary rehabilitation of patients with COPD.

Studies of the long-term outcome of pulmonary rehabilitation have measured quality of life (QOL) mainly as disease-specific functional impairment, but long-term effects on overall satisfaction with health or life have not yet been adequately evaluated. Furthermore, the influence of personality traits on the long-term outcome of pulmonary rehabilitation have not so far been examined. The following questions were studied: 1) What are the short- and long-term effects of a rehabilitation programme on lung function (forced expiratory volume in one second as percentage of predicted (FEV1 % pred)), on satisfaction with life (defined as quality of life), and on health satisfaction (HS)? 2) Are there physical or psychosocial predictors for the success of pulmonary therapy? In this prospective clinical study, baseline data (FEV1 % pred, arterial oxygen tension (Pa,O2), QOL, HS, dyspnoea, coping scales) were studied at entry (t1); follow-up on discharge (t2); and 1 yr after hospitalization (t3) in 54 consecutive patients (mean age 64 yrs) with chronic obstructive pulmonary disease (COPD). Complete data were obtained at follow-up on 32 subjects. FEV1 % pred improved from 42% (t1) to 52% (t2) (p<0.001) but dropped to 46% at t3 (t1-t3: p<0.05). QOL improved significantly during hospitalization but dropped to initial levels 1 yr after discharge. A significant increase in health satisfaction during hospitalization was maintained at follow-up. Improvements in lung function were greater in patients with higher QOL scores on entry; subjects with the greatest tendency to use wishful thinking as a coping strategy had less improvement. In conclusion, the effects of pulmonary rehabilitation on lung function and health satisfaction are positive and enduring. Quality of life and coping have an effect on the long-term outcome of pulmonary rehabilitation, probably as expressions of patients' personality traits.

Management 1997 of chronic obstructive pulmonary disease. Working Group of the Swiss Society of Pneumology.

COPD is a disorder characterized by expiratory flow limitation that does not change markedly over periods of several months' observation. When the diagnosis is suspected, COPD patients should be submitted to full assessment and initiation of therapy. Initial assessment includes a complete history, a detailed physical examination, pulmonary function tests, a chest X-ray, and blood tests. Therapy of COPD aims at reducing symptoms, preventing exacerbations and preserving optimal lung function. Many COPD patients have a bronchospastic component and usually show some response to bronchodilator therapy. Anticholinergics, beta 2-agonists or theophylline are used as monotherapy or in combination. A subgroup of patients with COPD may benefit from oral long-term corticosteroid therapy. At prime diagnosis of COPD, a trial of oral steroid under optimal bronchodilator therapy is warranted in order to identify steroid responders early in the course of the disease. Stopping smoking is the most effective preventive measure and should be combined with complementary approaches such as eviction of environmental irritants, vaccines and prescription of antioxidants. Long-term oxygen therapy is beneficial in chronically hypoxemic patients. Respiratory rehabilitation uses a multidisciplinary approach aiming at decreasing dyspnea, increasing exercise tolerance and improving quality of life. Nocturnal home noninvasive mechanical ventilatory assistance can improve arterial blood gas tensions in patients with respiratory failure, but the long-term effect on survival is still under investigation. In selected patients, surgery (bullectomy, lung volume reduction, lung transplantation) may greatly improve pulmonary function.

SAPALDIA: methods and participation in the cross-sectional part of the Swiss Study on Air Pollution and Lung Diseases in Adults.

SAPALDIA--the Swiss Study on Air Pollution and Lung Diseases in Adults--focuses on the long term health effects of low to moderate levels of air pollutants as typically seen in different parts of Switzerland. The aim of the SAPALDIA cross-sectional study carried out in 1991 was to determine the prevalence of bronchial asthma, chronic bronchitis and allergic conditions in the adult population of Switzerland and to identify and to determine the respective importance of potentially influencing factors. These could be both personal (smoking habits, allergy status, family history, occupation) and environmental (outdoor and indoor pollution, aeroallergens, climate). A further aim of the cross-sectional study consisted in the identification of individuals susceptible to present symptoms during a two year observation period and to be included in the SAPALDIA follow-up study. This technical report represents the methodological documentation for the cross-sectional study of SAPALDIA. The instruments and the methods of standardisation are presented and discussed. The medical examination consisted of a computerised interview using a standardised questionnaire, the taking of a blood sample for serological tests, allergy skin testing, the measurement of end expiratory CO and body height, and pulmonary function testing followed by methacholine challenge testing or bronchodilatation testing. The pattern of participation and the 9651 participants of the study, representing 59.3% of the sample, are described. Based on information on non-participants gained by telephone interviews and mailed short questionnaires, possible selection biases are quantified and discussed.