Recent Research Activities from the EOM Working Groups

Reduced lung function due to biomass smoke exposure in young adults in rural Nepal

Om P. Kurmi, Graham S. Devereux,W. Cairns S. Smith, Sean Semple, Markus F.C. Steiner, Padam Simkhada, Kin-Bong Hubert Lam and Jon G. Ayres

Eur Respir J 2013 41:25-30

This study aimed to assess the effects of biomass smoke exposure on lung function in a Nepalese population, addressing some of the methodological issues seen in previous studies.

We carried out a cross-sectional study of adults in a population exposed to biomass smoke and a non-exposed population in Nepal. Questionnaire and lung function data were acquired along with direct measures of indoor and outdoor air quality.

Ventilatory function (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and forced expiratory flow at 25–75% of FVC) was significantly reduced in the population using biomass across all age groups compared to the non-biomass-using population, even in the youngest (16–25 yrs) age group (mean FEV1 (95% CI) 2.65 (2.57–2.73) versus 2.83 (2.74–2.91) L; p=0.004). Airflow obstruction was twice as common among biomass users compared with liquefied petroleum gas users (8.1% versus 3.6%; p<0.001), with similar patterns for males (7.4% versus 3.3%; p=0.022) and females (10.8% versus 3.8%; p<0.001), based on the lower limit of normal. Smoking was a major risk factor for airflow obstruction, but biomass exposure added to the risk

Exposure to biomass smoke is associated with deficits in lung function, an effect that can be detected as early as the late teenage years. Biomass smoke and cigarette smoke have additive adverse effects on airflow obstruction in this setting.

Ceramide Expression and Cell Homeostasis in Chronic Obstructive Pulmonary Disease

Scarpa M.C., Baraldo S., Marian E., Turato G., Calabrese F., Saetta M., Maestrelli P.

Respiration, Vol. 85, No. 4, 2013

Background: Increased expression of ceramide has been detected in emphysema. Ceramide promotes autophagy and apoptosis, which concur with cellular homeostasis. Objectives: To determine whether ceramide expression is associated with the development of chronic obstructive pulmonary disease (COPD) and with altered cellular homeostasis in lung parenchyma. Methods: We studied 10 subjects with severe COPD, 13 with mild/moderate COPD, 11 with idiopathic pulmonary fibrosis (IPF), 12 non-COPD smokers, and 11 nonsmoking controls. The immunoreactivity for ceramide along with markers of autophagy (LC3B), apoptosis (cleaved caspase-3), and cell proliferation (MIB1) was quantified in alveolar walls. Results: Ceramide expression was increased in COPD patients compared with control smokers and was related to the impairment of gas exchange but not to the degree of airflow limitation. In COPD, an important activation of apoptosis and autophagy pathways was observed, particularly in patients with severe disease, that was not counterbalanced by cell proliferation. Upregulation of ceramide was observed even in subjects with IPF in whom activation of apoptosis and autophagy was negligible and cell proliferation was instead the most prominent feature. Conclusions: Ceramide expression, which is increased in COPD and even more so in IPF, appears to be neither specific nor related to COPD severity, probably representing a broader marker of lung damage. In contrast, apoptosis and autophagy are characteristics of the COPD pathology, particularly in its most severe stage.

Mechanisms of decrease in fractional exhaled nitric oxide during acute bronchoconstriction

Ilaria Cattoni; Gabriella Guarnieri; Alessandro Tosetto; Paola Mason; Maria C. Scarpa; Marina Saetta; Piero Maestrelli

Chest. 2013. doi:10.1378/chest.12-1374

Abstract Exhaled nitric oxide (FeNO50), a biomarker of airway inflammation, is affected by changes in airway calibre. Whether lower FeNO50 levels during bronchoconstriction is only an artifact due to the strong flow-dependence of this parameter is controversial.We aimed to evaluate the dynamics of airway and alveolar NO during acute bronchoconstriction induced by methacholine.Exhaled NO was measured at expiratory flows of 10, 50, 100, 150 and 250 ml/s before and after metacholine in 26 responders to methacholine and 37 non-responders. Flow-independent parameters (airway wall NO flux, airway NO diffusing capacity, airway wall NO concentration, alveolar NO concentration) were calculated using two-compartment model and correction for NO axial back-diffusion was applied.Bronchoconstriction in responders was associated with a decrease in FeNO50 (-28%, p<0.0001), in airway wall NO flux (-34%, p<0.0001) and in airway NO diffusing capacity (-15%, p<0.05). In contrast, alveolar NO concentration was not affected by bronchoconstriction. Post-methacholine changes in FeNO50 were more strictly related to the ventilation distribution, assessed by single breath carbon monoxide uptake, than to larger airways caliber, assessed by FEV1. When bronchoconstriction was reversed by salbutamol, airway wall NO flux and airway NO diffusing capacity returned to values comparable to those measured pre-methacholine.In conclusion, the changes in airway caliber induced by non-inflammatory stimuli alters NO transport in the lung. The changes in NO dynamics are limited to conductive airways and are characterized by a reduction of NO flow to luminal space.

Traffic Density in Area of Residence is Associated With Health-Related Quality of Life in Women, The Community-Based Hordaland Health Study

Hilde Gundersen MSc, PhDa, Nils Magerøy MD, PhDb, Bente E. Moen MD, PhDa & Magne Bråtveit MSc, PhDa

Archives of Environmental & Occupational Health, Volume 68, Issue 3, 2013

Vehicle traffic is increasing worldwide, and this is a major concern because traffic-related air pollution and noise may influence health. The aim of this study was to evaluate whether health-related quality of life (HRQoL) is associated with vehicle traffic density in area of residence. A total of 16,410 individuals, 40 to 45 years old, were asked to participate in this study (response rate: 55% for men, 66% for women). Using the 12-Item Short Form Health Survey (SF-12) questionnaire, both physical and mental HRQoL were investigated. Multiple linear regression analyses showed that women living in areas with high traffic density had significantly poorer physical HRQoL than women living in areas with moderate or low vehicle traffic density. There were no similar findings among men. Mental HRQoL was not associated with vehicle traffic density in the area of residence, neither for women nor for men. There is an association between high vehicle traffic density in residential area and reduced HRQoL in women.