Available online 23 January 2013
Publication year: 2013
Source:Revue de Pneumologie Clinique



La fibrose pulmonaire idiopathique (FPI) est la plus commune des pneumopathies interstitielles. En dépit des progrès apportés dans la compréhension des mécanismes physiopathologiques à l’origine du développement de la maladie, son pronostic reste sombre. Pour cette raison, toute mesure visant à améliorer la qualité de vie de ces patients doit être privilégiée. Certains auteurs se sont donc intéressés aux troubles du sommeil, ainsi qu’à leurs éventuelles répercussions sur la qualité de vie. Les patients atteints de FPI ont des scores de qualité de vie abaissés par rapport à ceux retrouvés dans la population générale, une corrélation existant avec les scores de qualité de sommeil. Le sommeil des patients atteints de FPI est caractérisé par une hyperfragmentation avec de nombreux micro-éveils et des phénomènes de désaturation. Certains auteurs rapportent également un index apnée-hypopnée plus élevé chez ces patients, mais ces données ne sont pas retrouvées dans tous les travaux. La correction de ces phénomènes obstructifs pourrait avoir un effet bénéfique sur la survie, ce qui rendrait le dépistage des troubles du sommeil indispensable chez ces patients. Enfin, les relations entre FPI, reflux gastro-œsophagien et syndrome d’apnée du sommeil restent à préciser. Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease. Despite progress made in understanding the pathophysiological mechanisms behind the development of the disease, its prognosis is poor. For this reason, any measure to improve the quality of life for these patients should be preferred. Some authors are interested in sleep disorders, and possible impact on quality of life. Patients with IPF have lowered scores of quality of life compared to those found in general population, with some correlation with the scores of sleep quality. There is a hyperfragmentation with many arousals and desaturation events. Some authors also report an apnea-hypopnea index higher in these patients, but these data are not found in all the studies. Correcting these obstructive phenomena may have a beneficial effect on survival, which would make systematic the sleep assessment in these patients. Finally, the relationship between IPF, gastroesophageal reflux and sleep apnea syndrome remains unclear.

Background: Reduced gas transfer in patients with pulmonary arterial hypertension (PAH) is traditionally attributed to remodeling and progressive loss of pulmonary arterial vasculature that results in decreased capillary blood volume available for gas exchange. Methods: We tested this hypothesis by determination of lung diffusing capacity (DL) and its components, the alveolar capillary membrane diffusing capacity (Dm) and lung capillary blood volume (Vc) in 28 individuals with PAH in comparison to 41 healthy individuals, and in 19 PAH patients over time. Using single breath simultaneous measure of diffusion of carbon monoxide (DLCO) and nitric oxide (DLNO), DL and Dm were respectively determined, and Vc calculated. Dm and Vc were evaluated over time in relation to standard clinical indicators of disease severity, including brain natriuretic peptide (BNP), 6-minute walk distance (6MWD) and right ventricular systolic pressure (RVSP) by echocardiography. Results: Both DLCO and DLNO were reduced in PAH as compared to controls and the lower DL in PAH was due to loss of both Dm and Vc (all p < 0.01). While DLCO of PAH patients did not change over time, DLNO decreased by 24 ml/min/mmHg/year (p = 0.01). Consequently, Dm decreased and Vc tended to increase over time, which led to deterioration of the Dm/Vc ratio, a measure of alveolar-capillary membrane functional efficiency without changes in clinical markers. Conclusions: The findings indicate that lower than normal gas transfer in PAH is due to loss of both Dm and Vc, but that deterioration of Dm/Vc over time is related to worsening membrane diffusion.

Background: Increased airway wall thickness (AWT) and parenchymal lung destruction both contribute to airflow limitation. Advances in computed tomography (CT) post-processing imaging allow to quantify these features. The aim of this Dutch population study is to assess the relationships between AWT, lung function, emphysema and respiratory symptoms. Methods: AWT and emphysema were assessed by low-dose CT in 500 male heavy smokers, randomly selected from a lung cancer screening population. AWT was measured in each lung lobe in cross-sectionally reformatted images with an automated imaging program at locations with an internal diameter of 3.5 mm, and validated in smaller cohorts of patients. The 15th percentile method (Perc15) was used to assess the severity of emphysema. Information about respiratory symptoms and smoking behavior was collected by questionnaires and lung function by spirometry. Results: Median AWT in airways with an internal diameter of 3.5 mm (AWT3.5) was 0.57 (0.44 - 0.74) mm. Median AWT in subjects without symptoms was 0.52 (0.41-0.66) and in those with dyspnea and/or wheezing 0.65 (0.52-0.81) mm (p<0.001). In the multivariate analysis only AWT3.5 and emphysema independently explained 31.1%and 9.5%of the variance in FEV1%predicted, respectively, after adjustment for smoking behavior. Conclusions: Post processing standardization of airway wall measurements provides a reliable and useful method to assess airway wall thickness. Increased airway wall thickness contributes more to airflow limitation than emphysema in a smoking male population even after adjustment for smoking behavior.

Background: The pathogenesis of COPD is complex and remains poorly understood. The European Respiratory Society Study on Chronic Obstructive Pulmonary Disease (EUROSCOP) investigated long-term effects of budesonide; 18% of the COPD participants were atopic. So far effects of atopy on the long-term course of COPD have not been elucidated. Methods: Factors related to the presence of atopy (positive phadiatop) in 1277 mild-to-moderate COPD patients participating in EUROSCOP were analysed using regression analysis. Incidence and remission of respiratory symptoms during 3-year follow-up were analysed using generalised estimating equations models, and association of atopy with lung function decline using linear mixed effects models. Results: Independent predisposing factors associated with the presence of atopy were: male gender (OR: 2.21; 95% CI: 1.47--3.34), overweight/obese (OR: 1.41; 95% CI: 1.04--1.92) and lower age (OR: 0.98; 95% CI: 0.96--0.99). Atopy was associated with a higher prevalence of cough (OR: 1.71; 95% CI: 1.26--2.34) and phlegm (OR: 1.50; 95% CI: 1.10--2.03), but not with lung function levels or FEV1 decline. Atopic COPD patients not treated with budesonide had an increased incidence of cough over time (OR: 1.79, 95% CI: 1.03--3.08, p = 0.038), while those treated with budesonide had increased remission of cough (OR: 1.93, 95% CI: 1.11--3.37, p = 0.02) compared to non-atopic COPD patients. Conclusions: Atopic COPD patients are more likely male, have overweight/obesity and are younger as compared with non-atopic COPD patients. Atopy in COPD is associated with an increased incidence and prevalence of respiratory symptoms. If atopic COPD patients are treated with budesonide, they more often show remission of symptoms compared to non-atopic COPD patients who are treated with budesonide. We recommend including atopy in the diagnostic work-up and management of COPD.