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P Leuenberger

Publications and source records attributed to P Leuenberger.

At least 19 recordsLinked to original sources
PubMed2006

Bronchial hyperresponsiveness and the development of asthma and COPD in asymptomatic individuals: SAPALDIA cohort study.

BACKGROUND: Bronchial hyperresponsiveness (BHR) is a common feature of asthma. However, BHR is also present in asymptomatic individuals and its clinical and prognostic significance is unclear. We hypothesised that BHR might play a role in the development of chronic obstructive pulmonary disease (COPD) as well as asthma. METHODS: In 1991 respiratory symptoms and BHR to methacholine were evaluated in 7126 of the 9651 participants in the SAPALDIA cohort study. Eleven years later 5825 of these participants were re-evaluated, of whom 4852 performed spirometric tests. COPD was defined as an FEV1/FVC ratio of <0.70. RESULTS: In 1991 17% of participants had BHR, of whom 51% were asymptomatic. Eleven years later the prevalence of asthma, wheeze, and shortness of breath in formerly asymptomatic subjects with or without BHR was, respectively, 5.7% v 2.0%, 8.3% v 3.4%, and 19.1% v 11.9% (all p<0.001). Similar differences were observed for chronic cough (5.9% v 2.3%; p = 0.002) and COPD (37.9% v 14.3%; p<0.001). BHR conferred an adjusted odds ratio (OR) of 2.9 (95% CI 1.8 to 4.5) for wheezing at follow up among asymptomatic participants. The adjusted OR for COPD was 4.5 (95% CI 3.3 to 6.0). Silent BHR was associated with a significantly accelerated decline in FEV1 by 12 (5-18), 11 (5-16), and 4 (2-8) ml/year in current smokers, former smokers and never smokers, respectively, at SAPALDIA 2. CONCLUSIONS: BHR is a risk factor for an accelerated decline in FEV1 and the development of asthma and COPD, irrespective of atopic status. Current smokers with BHR have a particularly high loss of FEV1.

Adult↗
PubMed2006

[Pneumonology. Ultrasound-guided transbronchial needle aspiration].

After discovering a lung cancer without extrathoracic metastases, the preoperative mediastinal check-up is of great importance to determine the patients operability. The 78% specificity of activity measuring FDG in a PET examination is clearly insufficient to avoid a biopsy of the incriminated lymph nodes. The investigation of a suspected malignant adenopathy justifies a complete examination by mediastinoscopy or-tomy, which are considered gold standards. The transbronchial fine needle aspiration guided by ultrasound (EBUS-TBNA) constitutes the recent evolution of TBNA, method known for 20 years now but underused. Depending on the operators skill, this new procedure needs a learning curve before being able to replace mediastinoscopy.

Biopsy, Needle↗
PubMed2005

[Pneumology. Treatment of idiopathic pulmonary fibrosis: hopes and disappointment].

Idiopathic pulmonary fibrosis (IPF) is now recognized as a separate nosological entity. Despite the progresses in understanding the basic mechanisms of the disease, its prognosis remains poor. The classical treatment combines prednisone with a cytotoxic agent. Interferon gamma has the in vitro capacity of inhibiting fibroblasts proliferation. A pilot study showed positive results, but a more recent randomized double blind trial was unable to demonstrate a clear benefit to the patients. On the other hand there are many evidences for an oxydant-antioxydant imbalance in the pathogenesis of IPF. In a human controlled study N-acetylcysteine (NAC) at high doses (1800 mg per day orally) improved the pulmonary function tests when given on top of a combined therapy with prednisone and azathioprine.

Humans↗
PubMed2001

[Endogenous fungal endophthalmitis: results of antifungal treatment with and without vitrectomy].

BACKGROUND: Fungal endophthalmitis represents a significant cause of ocular morbidity, affecting in the majority of cases patients in poor general conditions. The eye is typically involved by hematogen dissemination, and the germ induces a chorioretinitis associated with an important panuveitis. PATIENTS AND METHODS: Four patients were examined. They complained of a progressive reduction of vision, associated with photophobia. Ophthalmologic examination disclosed an important panuveitis. Investigations showed a fungal chorio-retinitis in all cases. Risk factors were intra-venous toxicomania, longterm parenteral nutrition and traumatism of the sinuses. RESULTS: Vitreous cultures were positive for Candida albicans (3 patients) and for Aspergillus fumigatus (1 patient). Blood cultures were negative in the four cases. Three patients were treated with anti-fungal medication (fluconazole, itraconazole) associated with a vitrectomy by pars plana. One patient was treated by anti-fungal therapy only. Clinical evolution was satisfactory in all cases. Final vision was 10/10 in three cases and 5/10 in one. One patient developed a retinal detachment and an epiretinal membrane. Follow-up was 7 months (2-16 months). CONCLUSION: The evolution of these four cases suggests that a rapid anti-fungal therapy associated with or without a vitrectomy represent a favourable therapeutic option when a fungal infection is suspected.

Adult↗
PubMed2001

Short-term variation in air pollution and in average lung function among never-smokers. The Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA).

The present analysis was directed at investigating associations between short-term variations in air pollutant levels (NO2, total suspended particulates [TSP], O3) and cross-sectional lung function (FVC, FEV1, and forced expiratory flow at 25% to 75% of FVC [FEF25-75]) within a random sample of 3,912 adult never-smokers from eight areas of Switzerland (i.e., participants in the Swiss Study on Air Pollution and Lung Diseases in Adults [SAPALDIA] cross-sectional study, 1991). Within each local data set, the logarithms of FVC, FEV1, and FEF25-75 were regressed against the 24-h-means of NO2 and TSP and the 8-h mean of O3 (10:00 A.M. to 6:00 P.M.) on the examination day, with control for subjects' sex, age, height and weight, seasonal fluctuations and weekly cycles and meteorologic factors. On average, a 10-microg/m3 increment in the daily level of NO2, TSP, and O3 was associated with decrements in FEV1 of 0.67% (95% confidence interval [CI]: 0.13% to 1.21%), 0.46% (95% CI: 0.14% to 0.78%), and 0.51% (95% CI: 0.13% to 0.88%), respectively. Moreover, 10-microg/m3 increments in NO2 and TSP were associated with decrements in FVC of 0.73% (95% CI: 0.22% to 1.23%) and 0.36% (95% CI: 0.06% to 0.66%), respectively, and a 10-microg/m3 increment in O(3) was associated with a decrement in FEF25-75 of 1.04% (95% CI: 0.22% to 1.85%). Our results suggest that FVC, FEV1, and FEF25-75 vary with the daily level of NO2, TSP, and O3, but that these measures of lung function do not allow separation of the effects of particulates from those of NO2.

Adolescent↗
PubMed2001

Clinical diagnosis of current asthma: predictive value of respiratory symptoms in the SAPALDIA study. Swiss Study on Air Pollution and Lung Diseases in Adults.

Bronchial asthma is a very common disease which often remains underdiagnosed. The aim of this study was to determine the predictive value of the most common respiratory symptoms and to explore the best symptom combinations to predict diagnosis of asthma. A questionnaire comprising common respiratory symptoms was submitted to 9,651 subjects aged 18-60 yrs, randomly selected from the Swiss population, of whom 225 subjects (2.3%) had current asthma as confirmed by their general practitioner. Based on these data the authors calculated the predictive values of single symptoms and symptom combinations to diagnose asthma. Wheezing was the most sensitive single symptom (sensitivity 75%). Simple symptoms such as wheezing with dyspnoea, chronic phlegm or chronic cough had specificity greater than 95%. Wheezing with dyspnoea (WD) or nocturnal dyspnoea (ND) had the best positive predictive value (PPV) as isolated symptoms (24% and 21%, respectively). When combining symptoms, wheezing associated with daily dyspnoea at rest or nocturnal dyspnoea showed the best PPV (42% and 39%, respectively), almost double single symptoms such as WD or ND. Wheezing associated with at least two of the three nocturnal symptoms (nocturnal dyspnoea, nocturnal cough or nocturnal chest tightness) had a sensitivity of 80% to diagnose asthma. In conclusion, respiratory symptoms obtained by medical history are reliable predictors of asthma. The findings suggest that particular combinations of symptoms are clinically useful in the differential diagnosis of asthma.

Adolescent↗
PubMed2000

Validity of annoyance scores for estimation of long term air pollution exposure in epidemiologic studies: the Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA).

In air pollution epidemiology, estimates of long term exposure are often based on measurements made at one fixed site monitor per area. This may lead to exposure misclassification. The present paper validates a questionnaire-based indicator of ambient air pollution levels and its applicability to assess their within-area variability. Within the framework of the SAPALDIA (Swiss Study on Air Pollution and Lung Diseases in Adults) cross-sectional study (1991), 9,651 participants reported their level of annoyance caused by air pollution on an 11-point scale. This subjective measure was compared with annual mean concentrations of particulate matter less than 10 microm in diameter (PM10) and nitrogen dioxide. The impact of individual factors on reported scores was evaluated. Nitrogen dioxide concentrations at home outdoors (measured in 1993), smoking, workplace dust exposure, and respiratory symptoms were found to be predictors of individual annoyance scores. Regression of population mean annoyance scores against annual mean PM10 and nitrogen dioxide concentrations (measured in 1993 and 1991, respectively) across areas showed a linear relation and strong correlations (r>0.85). Analysis within areas yielded consistent results. The observed associations between subjective and objective air pollution exposure estimates suggest that population mean scores, but not individual scores, may serve as a simple tool for grading air quality within areas. Reported annoyance due to air pollution should be considered an indicator for a complex environmental condition and thus might be used for evaluating the implementation of environmental policies.

Adolescent↗
PubMed2000

[SAPALDIA: past, present and future].

The cross-sectional part of SAPALDIA studied the associations between respiratory symptoms or functional abnormalities and chronic exposure to a polluted environment. The results showed an elevated risk of developing respiratory symptoms in regions with higher levels of particulate matters (PM10). The same was observed with passive smoking exposure. Decreased spirometric parameters (especially FVC) were measured in areas with the highest levels of PM10. While the functional alteration is clinically minimal in the individual, the effect is significant when one considers the prevalence of an abnormal functional parameter in a general population. Exposure to pollutants at the workplace increases bronchial reactivity to non-specific stimuli, with atopy acting as amplifier of this effect. The longitudinal part of SAPALDIA examined the associations between the dynamics of respiratory symptoms or functional abnormalities and average levels, as well as short-term fluctuations, of atmospheric pollutants. It was observed that symptomatic episodes tend to last longer in more polluted regions, whichever marker of pollution is used (PM10 or NO2). Passive smoking tends to prolong respiratory symptoms and shorten asymptomatic intervals. Short-term increases in outdoor pollutants are associated with an increase in incidence of peak flows below individual baseline values. Numerous questions remain regarding the relationship between respiratory health and environment. A SAPALDIA II study is under preparation which will follow the evolution of SAPALDIA I participants with regard to respiratory symptoms, pulmonary function, bronchial reactivity and markers of atopy.

Air Pollution↗
PubMed2000

Cost-effectiveness analysis of oral N-acetylcysteine as a preventive treatment in chronic bronchitis.

UNLABELLED: Chronic bronchitis has a prevalence of approximately 11% in the population aged over 35 years and its frequent acute exacerbations (AECBs) are an important cause of morbidity and costs in health-care resources. Oral N -acetylcysteine (NAC) is administered during the winter months as a way of reducing AECBs. This cost-effectiveness analysis was done from the payers' point of view in the Swiss health-care system, based on a retrospective analysis of published placebo-controlled studies. The pooled data show that continuous administration of 400 mg day(-1)per os of NAC leads to a significant reduction in the number of AECBs (NAC: 16.2 vs 25.2% AECBs per month); a significantly smaller percentage of days of sick leave (NAC: 3.6 vs 5.3%) and a lower rate of hospitalizations (NAC: 1.5 vs 3.5% over a period of 6 months). Taking into account the poor compliance of these patients, calculations assumed a compliance of 80%. Direct costs were those of an NAC treatment, the management of an AECB (biological tests in 59%, X-rays in 65% and pulmonary function tests in 45%; antibiotics 70%, bronchodilators in 89%, corticosteroids in 24% and 'others' in 25% of the patients), and of hospitalizations (estimated at 10 days per case). Based on these figures, the mean direct costs of an untreated patient were CHF 869 vs CHF 700 in the NAC-treated patient. Univariate sensitivity analysis indicated that cost neutrality is reached with 0.6 (<0.25-1. 94, 95% CI) AECBs per 6 months. Indirect costs (based on sick leave) were also significantly different; the mean in untreated patients was CHF 1324 vs CHF 779 in the NAC-treated patients. CONCLUSION: Treating chronic bronchitis patients with NAC during the winter months is cost-effective both from the payer's and a social point of view.

Acetylcysteine↗
PubMed2000

Association of environmental tobacco smoke at work and forced expiratory lung function among never smoking asthmatics and non-asthmatics. The SAPALDIA-Team. Swiss Study on Air Pollution and Lung Disease in Adults.

Inconsistencies across studies on the association of environmental tobacco smoke (ETS) and pulmonary function may be clarified addressing potentially susceptible subgroups. We determined the association of ETS exposure at work with FVC, FEV1, and FEF25-75% in life-time never smokers (N = 3534) of the SAPALDIA random population sample (age 18-60). We considered sex, bronchial reactivity, and asthma status as a priori indicators to identify susceptible riskgroups. The multivariate regression models adjusted for height, age, education, dust/aerosol exposure, region, and ETS at home. Overall, ETS was not significantly associated with FVC (0.7%; -0.4 to +1.8), FEV1 (-0.1%; 95% CI: -1.3 to +1.1) or FEF25-75% (-1.9%; -4.2 to +0.5). Effects were observed among asthmatics (n = 325), FEV1 (-4.8%; 0 to -9.2); FEF25-75% (-12.4%; -3.7 to -20.4); FVC: (-1.7%; +2.1 to -5.5), particularly in asthmatic women (n = 183): FVC -4.4% (-9.6 to +1.1); FEV1: -8.7% (-14.5 to -2.5); FEF25-75%: -20.8% (-32 to -7.6), where duration of ETS exposure at work was associated with lung function (FEV1 -6% per hour of ETS exposure at work (p = 0.01); FEF25-75%: -3.4%/h (p < 0.05). In non-asthmatic women (n = 1963) and in men no significant effect was observed. The size of the observed effect among susceptible subgroups has to be considered clinically relevant. However, due to inherent limitations of this cross-sectional analysis, selection or information biases may not be fully controlled. For example, asthmatic women reported higher ETS exposure at work than asthmatic men. Given the public health importance to identify susceptible subgroups, these results ought to be replicated.

Adolescent↗
PubMed2000

Efficacy of oral long-term N-acetylcysteine in chronic bronchopulmonary disease: a meta-analysis of published double-blind, placebo-controlled clinical trials.

OBJECTIVE: This meta-analysis was performed to assess the possible prophylactic benefit of prolonged treatment with oral N-acetylcysteine (NAC) in chronic bronchitis (CB) based on qualifying clinical trials. Treatment of acute exacerbations with NAC was not investigated. BACKGROUND: Prolonged treatment with oral NAC has been investigated in a number of studies of patients with CB. NAC prevented acute exacerbations and symptoms of CB in some but not all trials. METHODS: The trials included in this analysis were selected from a MEDLINE search of the period from January 1, 1980, through June 30, 1995; references in the articles retrieved in the initial search; and consultation with 2 experts. Selection was based on the following criteria: published, double-blind, placebo-controlled, chronic bronchopulmonary disease, duration of therapy > or =2 months, and data sufficient to calculate an outcome variable permitting direct comparison of studies (effect size) for both NAC and placebo groups. The primary end point was the incidence of acute exacerbations in 7 of 8 trials and clinical assessment in the other. In 7 studies, inclusion criteria were based on Medical Research Council criteria for CB, with an additional criterion in some trials. For the meta-analysis, the end points of individual trials were transformed into an effect size as a common outcome. RESULTS: Of 21 trials initially identified, 8 qualified for inclusion. References from the 8 papers and consultation with the experts produced 8 additional publications, 1 of which qualified for inclusion. NAC was administered orally at a daily dose of 400 mg (1 study), 600 mg (5 studies), or 1200 mg (1 study). One other trial used a dose of 600 mg 3 times per week. The duration of treatment was 3 months (1 study), > or =5 months (2 studies), or 6 months (7 studies). The results of this meta-analysis showed a statistically significant effect size for NAC compared with placebo. The overall value of effect size was -1.37 (95% CI, -1.5 to -1.25). Sensitivity analyses did not significantly alter these results. In a subset analysis of trials with the number of acute exacerbations as a clinical end point, a mean difference of -0.32 clinical event (95% CI, -0.50 to -0.18) was found (ie, a 23% decrease in the number of acute exacerbations compared with placebo). CONCLUSION: These findings suggest that a prolonged course of oral NAC prevents acute exacerbations of CB, thus possibly decreasing morbidity and health care costs.

Acetylcysteine↗
PubMed2000

Exposure to motor vehicle traffic and allergic sensitization. The Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) Team.

We examined the association between the presence of an allergic sensitization and seasonal allergic diseases or symptoms and the exposure to road traffic in Basel, Switzerland. Traffic counts at the domiciles of subjects ranged from 24 to 32,504 cars per 24 hours, with a median of 1,624. To investigate the relation of road traffic and allergies, we matched the data of the traffic inventory of Basel with those of the 820 participants of the SAPALDIA study (Swiss Study on Air Pollution and Lung Diseases in Adults), ages 18-60 years, who had completed a detailed respiratory health questionnaire and had undergone allergy testing (skin prick tests and serologic examinations). We observed a positive association with a sensitization to pollen that was most pronounced among persons with a duration of residence of at least 10 years. The odds ratios (adjusted for educational level, smoking behavior, number of siblings, age, sex, and family history of atopy) for cars, contrasting four exposure categories with the lowest quartile as referent category, were 1.99 [95% confidence interval (CI) = 0.91-4.38], 2.47 (95% CI = 1.06-5.73), and 2.83 (95% CI = 1.26-6.31). These results suggest that living on busy roads is associated with a higher risk for a sensitization to pollen and could possibly be interpreted as an indication for interactions between pollen and air pollutants. We did not, however, find a similar relation between motor vehicle traffic and hay fever or seasonal allergic symptoms, and we saw no trend that increasing traffic exposure was associated with a rise in sensitization rates to indoor allergens.

Adult↗
PubMed2000

Clinically "small" effects of air pollution on FVC have a large public health impact. Swiss Study on Air Pollution and Lung Disease in Adults (SAPALDIA) - team.

Epidemiological studies have repeatedly established adverse health effects due to long-term exposure to ambient air pollution. The Swiss Study on Air Pollution and Lung Disease in Adults (SAPALDIA) published a -3.14% decrease in forced vital capacity (FVC) per 10 microg x m(-3) increment in particulate matter (particles with a 50% cut-off aerodynamic diameter of 10 microm (PM(10)). Compared to the within-subject variability of FVC, the effect may be considered small. This individual (or clinical) perspective is, however, misleading. The purpose of this study was to demonstrate the public health relevance of apparently "small" effects, using the impact of PM10 on FVC as an example. The scenario compares a population A, exposed to an annual mean PM10 of 20 microg x m(-3), with a population B exposed to 30 microg x m(-3) mean PM10. A shift of -3.14% in the population distribution of FVC increases the number of subjects in the lower tail of the distribution. In population B a relative increase was expected of 47% (16-91%) in the prevalence of "FVC <80% predicted", (i.e., from 5.17 to 7.59% and 5.88 to 8.65% among males and females, respectively). The relative increase in the prevalence of "FVC <70% predicted" (approximately 1% of population) was 63% (30-98%, males) and 57% (21-86%, females). An epidemiological estimate of a change in the mean value of the population distribution should not be misinterpreted as an effect on the individual level. However, the impact of a 10 microg x m(-3) increase in particles with a 50% cut-off aerodynamic diameter of 10 microm (PM10) on the number of subjects with a clinically relevant reduction in lung function is quantitatively important.

Adult↗
PubMed2000

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.

Adolescent↗
PubMed1999

Linear opacities on HRCT in bronchiolitis obliterans organising pneumonia.

The aim of this study was to report the high-resolution computed tomography (HRCT) appearances of linear opacities that may occur in isolation or in combination with other changes in bronchiolitis obliterans organising pneumonia (BOOP). Eleven patients with BOOP and linear opacities on HRCT were identified at three independent teaching hospitals. The HRCT images and clinical course of each patient were reviewed. Two distinct types of linear opacity were identified. The type-1 opacity extended in a radial manner along the line of the bronchi towards the pleura and was usually intimately related to bronchi. The type-2 opacity occurred in a sub-pleural location and bore no relationship to the bronchi. Both types occurred most commonly in the lower lobes, frequently were associated with multi-focal areas of consolidation and usually completely resolved with treatment. There was no associated bronchiectasis, irreversible volume loss or a reticular or honeycomb pattern. In 2 patients linear opacities were the sole abnormality on HRCT. Bronchiolitis obliterans organising pneumonia may occur in a pure "linear form" or HRCT may demonstrate linear opacities in addition to multi-focal consolidation.

Adult↗