A. Guillien

Asymptomatic subjects with airway obstruction have significant impairment at exercise

Background The relevance of screening for airway obstruction in subjects not complaining of COPD symptoms may depend on the definition of airway obstruction. Response to exercise in asymptomatic subjects with persistent airway obstruction as defined by a postbronchodilator FEV1/FVC <5th centile lower limit of normal (LLN) remains unknown. Methods Dyspnoea (Borg scale), exercise tolerance and ventilatory constraints on tidal volume expansion were assessed in 20 consecutive asymptomatic subjects with persistent mild airway obstruction detected by screening (postbronchodilator FEV1/FVC z-score: −2.14±0.29; FEV1 z-score: −1.02±0.64) undergoing incremental cycle cardiopulmonary exercise testing, compared with 20 healthy controls with normal spirometry matched for age, sex, body mass index and smoking history (FEV1/FVC z-score: −0.13±0.57; FEV1 z-score: 0.32±0.67) and with 20 symptomatic patients with COPD matched for the same characteristics (FEV1/FVC z-score: −2.36±0.51; FEV1 z-score: −1.02±0.48). Results Asymptomatic subjects with airway obstruction had higher dyspnoea ratings than controls during incremental exercise. Asymptomatic subjects with airway obstruction had also peak oxygen consumption and peak power output that were lower than controls, and similar to those observed in patients with COPD. Although less frequent than in COPD, dynamic hyperinflation was more frequent in asymptomatic subjects with airway obstruction than in controls (85%, 50% and 10%, respectively; p=0.01 in asymptomatic subjects vs controls and p=0.04 vs COPD). Conclusions Although they did not present with chronic activity-related dyspnoea, subjects with a postbronchodilator FEV1/FVC<LLN as detected by screening had poorer exercise tolerance than healthy controls on exertion, and a significant proportion of them had dynamic hyperinflation. These subjects may, therefore, deserve further attention and may warrant regular follow-up.

Prevalence and risk factors for COPD in farmers: a cross-sectional controlled study

There are conflicting data regarding the magnitude and determinants of chronic obstructive pulmonary disease (COPD) risk in farmers. In a cross-sectional study of 917 nonfarming working controls and 3787 farmers aged 40–75 years, we assessed respiratory symptoms, tobacco exposure, job history (without direct exposure measurement) and lung function. COPD was defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criterion (post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.70) and by the Quanjer reference equation (post-bronchodilator FEV1/FVC <lower limit of normal (LLN)). The prevalence (95% CI) of COPD according to the GOLD criterion was 5.1% (4.4–5.8%) and 2.9% (1.8–4.0%) in farmers and controls, respectively (p=0.005), and 3.1% (2.5–3.6%) and 1.5% (0.7–2.3%), respectively, for the LLN criterion (p<0.01). For both COPD criteria after adjustment for age, sex and smoking status, COPD prevalence was similar in controls and crop farmers. Compared to controls, four job categories had a higher prevalence of COPD according to the GOLD criterion, namely, cattle breeders, swine breeders, poultry breeders and breeders of two or more livestock types. Among cattle breeders, only those from Franche-Comté had higher prevalence of COPD according to both GOLD and LLN criteria. The prevalence of COPD in farmers is higher than in nonfarming working controls, and depends on the farming activity, the region and the criterion used to define COPD. Prevalence of COPD is higher in agricultural workers than in nonfarming working control subjects http://ow.ly/RUYe8

Smoking habits in French farmers: a cross-sectional study

BackgroundFarmers are exposed to multiple air contaminants that may interact with tobacco smoking in the development of respiratory diseases. Farmers are currently considered to smoke less than non-farmers, but precise data in different categories of age and farming activities are lacking.MethodsSmoking habits were studied in a cross-sectional study involving 4105 farmers and 996 non-farming controls aged 40–74 years in 9 French departments between October 2012 and May 2013. Three age groups were defined (40–54, 55–64 and 65-74years). Farmers were divided into four activity groups, namely cattle breeders, livestock farmers working in confined spaces, crop farmers and others. Smoking prevalence was compared between farmers and controls, and odds ratios (ORs) for smoking adjusted for age were calculated.ResultsThe adjusted OR for ever-smoking was lower among farmers than among non-farmers in all age categories, but the ORs for current smoking were similar in farmers and controls. Smoking prevalence varied according to the type of farming activity, and was lower than in non-farming controls only among cattle breeders and confined livestock farmers. In farmers, the proportion of smokers was higher in the youngest age categories compared with the older age classes.ConclusionsOur results confirm that the prevalence of ever-smokers is lower in farmers than in non-farmers. Nevertheless, our data show that active smoking prevalence is similar in farmers and in non-farmers. This suggests that farmers, just like non-farmers, should be targeted by primary prevention campaigns against smoking.

In cystic fibrosis, lung clearance index is sensitive to detecting abnormalities appearing at exercise in children with normal spirometry

Symptom-limited incremental cardiopulmonary exercise test was performed in school-age children with clinically stable cystic fibrosis (CF), all with normal spirometry. Physiological parameters were compared between patients with normal lung clearance index (LCI; n=6) and patients with elevated LCI (n=6). Dyspnoea ratings during exercise were similar in both groups. Although no patient had significant dynamic hyperinflation, end-expiratory lung volumes were higher throughout exercise in patients with elevated LCI. In addition, alveolar-arterial oxygen gradient at peak exercise was higher, and SpO2 was lower in patients with elevated LCI. LCI can thus be regarded as a test performed at rest that predicts some abnormalities appearing at exercise in CF children with normal spirometry.

Global Lung Initiative equations for pulmonary hypertension screening in systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disease characterised by widespread vasculopathy and excessive fibrosis in multiple organs, including the lungs [1]. The most frequent pulmonary involvement in SSc is interstitial lung disease (ILD), but the most harmful is pulmonary hypertension (PH), a complication found in about 10% of SSc patients [2]. In patients with SSc, early diagnosis of and prompt therapy for PH (either isolated or associated with ILD) are beneficial from a prognostic standpoint and recommendations for active screening of PH in SSc have therefore been established [3]. GLI equations provide new cut-offs for TLCO for detection of PH in patients with SSc, either with or without ILD http://ow.ly/aCpD30l2zch

Anxiety and depression among dairy farmers: the impact of COPD

Background Chronic obstructive pulmonary disease (COPD) and farming are two conditions that have been associated with an increased risk of anxiety and depression. Dairy farming is an independent risk factor for COPD. Objective To test the hypotheses that the prevalence of anxiety and/or depression is higher in dairy farmers with COPD than in farmers without COPD, and higher in dairy farmers with COPD than in non-farmers with COPD. Methods Anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale in 100 dairy farmers with COPD (DF-COPD), 98 dairy farmers without COPD (DF-controls), 85 non-farming patients with COPD (NF-COPD) and 89 non-farming subjects without COPD (NF-controls), all identified by screening in the Franche-Comté region of France. Anxiety and depression were considered present when the Hospital Anxiety and Depression Scale score was ≥8. COPD was defined by a post-bronchodilator forced expiratory volume in 1 second/forced vital capacity ratio <0.7. Results The crude prevalence of anxiety did not differ between the four groups, ranging from 36% in NF-controls to 47% in NF-COPD (p=0.15 between groups). Similarly, the prevalence of depression did not differ significantly between the four groups (p=0.16 between groups). In dairy farmers (n=198), the only factors associated with anxiety were quality of life and current smoking. Depression in dairy farmers was associated with airflow limitation (lower forced expiratory volume in 1 second and COPD grade 2 or more) as well as with some COPD-related features (dyspnea severity, current smoking, and poorer quality of life). In non-farmers, both anxiety and depression were associated with airflow limitation and COPD-related features. Conclusion In our population, the prevalence of anxiety and/or depression was similar in dairy farmers with and without COPD and in non-farmers with COPD. Nevertheless, the degree of airway obstruction and some COPD-related features were associated with depression among dairy farmers, whereas these factors were not associated with anxiety.

Combined measurement of carbon monoxide and nitric oxide lung transfer does not improve the identification of pulmonary hypertension in systemic sclerosis

Screening is important to determine whether patients with systemic sclerosis (SSc) have pulmonary hypertension because earlier pulmonary hypertension treatment can improve survival in these patients. Although decreased transfer factor of the lung for carbon monoxide (TLCO) is currently considered the best pulmonary function test for screening for pulmonary hypertension in SSc, small series have suggested that partitioning TLCO into membrane conductance (diffusing capacity) for carbon monoxide (DMCO) and alveolar capillary blood volume (VC) through combined measurement of TLCO and transfer factor of the lung for nitric oxide (TLNO) is more effective to identify pulmonary hypertension in SSc patients compared with TLCO alone. Here, the objective was to determine whether combined TLCO–TLNO partitioned with recently refined equations could more accurately detect pulmonary hypertension than TLCO alone in SSc. For that purpose, 572 unselected consecutive SSc patients were retrospectively recruited in seven French centres. Pulmonary hypertension was diagnosed with right heart catheterisation in 58 patients. TLCO, TLNO and VC were all lower in SSc patients with pulmonary hypertension than in SSc patients without pulmonary hypertension. The area under the receiver operating characteristic curve for the presence of pulmonary hypertension was equivalent for TLCO (0.82, 95% CI 0.79–0.85) and TLNO (0.80, 95% CI 0.76–0.83), but lower for VC (0.75, 95% CI 0.71–0.78) and DMCO (0.66, 95% CI 0.62–0.70). Compared with TLCO alone, combined TLCO–TLNO does not add capability to detect pulmonary hypertension in unselected SSc patients. Compared with T LCO alone, combined T LCO–T LNO measurement does not improve detection of PH in unselected SSc patients http://ow.ly/ITHO30eldMk

Case-Finding for Persistent Airway Obstruction in Farmers: A Questionnaire With Optimal Diagnosis Criteria

INTRODUCTION Appropriate identification of subjects who are candidates for spirometry through case-finding questionnaires may help solve the problem of chronic obstructive pulmonary disease misdiagnosis. The performance of case-finding questionnaires depends at least partially on the characteristics of the population used for their development. The use of an accurate threshold for the forced expiratory volume in 1 second / forced vital capacity ratio to define persistent airway obstruction is also vital in ascertaining chronic obstructive pulmonary disease. METHODS Using a population examined between October 2012 and May 2013 that included a large subset of agricultural workers both exposed and unexposed to tobacco smoking, the authors aimed to select a combination of items that would identify persons most likely to have persistent airway obstruction defined as forced expiratory volume in 1 second / forced vital capacity less than the lower limit of normal according to the Global Lung Initiative-2012 equations. Two thirds of the population (n=3,397) were randomly selected to develop a questionnaire, and one third (n=1,698) was reserved for questionnaire validation. Statistical analysis was performed in 2016. RESULTS The selected items were sex, dyspnea, BMI, tobacco smoking habits, age, history of respiratory diseases, and history of occupation at risk. The C-index of the model was 0.84 (95% CI=0.80, 0.88) for the development population and 0.76 (95% CI=0.66, 0.86) for the validation population. Using the selected items in combination, the sensitivity and specificity in identifying persistent airway obstruction were 76% and 77%, respectively, in the development population (and 68% and 73%, respectively, in the validation population) for a threshold value of 2.50%. CONCLUSIONS This seven-item questionnaire is the first developed from a population comprising a large subset of agricultural workers and using the Global Lung Initiative-2012 equations.

COPD or not COPD: Answer in FEV1

Systematic screening of COPD allows identification of subjects with persistent airway obstruction who do not complain of any symptom. Little is known about subjects with undiagnosed persistent airway obstruction. We aimed to compare some clinical and spirometric data between subjects with spirometrically-defined COPD (i.e., persistent airway obstruction without any COPD symptom [OBS group]) and clinically-defined COPD (i.e., persistent airway obstruction with at least one COPD symptom [COPD group]), all detected by screening. A spirometry was performed in 5095 subjects aged 40-75 years. Persistent airway obstruction was defined as a post-bronchodilator FEV1FVC In total, 138/5095 subjects (2.70%) had persistent airway obstruction. Among them, 78 had at least one COPD-related symptom (COPD group), 52 have none of the COPD-related symptoms (OBS group) and 8 had missing data and were not analyzed. The main characteristics are in Table 1. Mean FVC was normal (z-score>-1.64) in both groups. By contrast, mean FEV1 was abnormal only in the COPD group (mean z-score A significant subset of subjects detected by screening with persistent airway obstruction are asymptomatic; a majority of these asymptomatic subjects have normal FEV1.