Airway wall thickening and emphysema show independent familial aggregation in chronic obstructive pulmonary disease.

RATIONALE: It is unclear whether airway wall thickening and emphysema make independent contributions to airflow limitation in chronic obstructive pulmonary disease (COPD) and whether these phenotypes cluster within families. OBJECTIVES: To determine whether airway wall thickening and emphysema (1) make independent contributions to the severity of COPD and (2) show independent aggregation in families of individuals with COPD. METHODS: Index cases with COPD and their smoking siblings underwent spirometry and were offered high-resolution computed tomography scans of the thorax to assess the severity of airway wall thickening and emphysema. MEASUREMENTS AND MAIN RESULTS: A total of 3,096 individuals were recruited to the study, of whom 1,159 (519 probands and 640 siblings) had technically adequate high-resolution computed tomography scans without significant non-COPD-related thoracic disease. Airway wall thickness correlated with pack-years smoked (P < or = 0.001) and symptoms of chronic bronchitis (P < 0.001). FEV(1) (expressed as % predicted) was independently associated with airway wall thickness at a lumen perimeter of 10 mm (P = 0.0001) and 20 mm (P = 0.0013) and emphysema at -950 Hounsfield units (P < 0.0001). There was independent familial aggregation of both the emphysema (adjusted odds ratio, 2.1; 95% confidence interval, 1.1-4.0; P < or = 0.02) and airway disease phenotypes (P < 0.0001) of COPD. CONCLUSIONS: Airway wall thickening and emphysema make independent contributions to airflow obstruction in COPD. These phenotypes show independent aggregation within families of individuals with COPD, suggesting that different genetic factors influence these disease processes.

Gender differences in respiratory symptoms-does occupation matter?

Little attention has been given to gender differences in respiratory health, particularly in occupational settings. The purpose of this paper was to evaluate gender differences in respiratory morbidity based on surveys of hospitality workers, radiographers, and respiratory therapists. Data were available from mail surveys of 850 hospitality industry workers (participation rate 73.9%; 52.6% female), 586 radiographers (participation rate 63.6%; 85% female), and 275 respiratory therapists (participation rate 64.1%; 58.6% female). Cross-tabulations by gender were evaluated by chi(2) analysis and logistic regression with adjustment for personal and work characteristics. Women consistently had greater respiratory morbidity for symptoms associated with shortness of breath, whereas men usually had a higher prevalence of phlegm. There were few differences in work exposures apart from perception of exposure to ETS among hospitality workers. Gender differences in symptoms were often reduced after adjustment for personal and work characteristics but for respiratory therapists there were even greater gender disparities for asthma attack and breathing trouble. Population health findings of elevated symptoms among women were only partially supported by these occupational respiratory health surveys. The influence of differential exposures and personal factors should be considered when interpreting gender differences in health outcomes.

Women and occupational lung disease: sex differences and gender influences on research and disease outcomes.

We have attempted to describe the current state of knowledge regarding occupational lung disease in women. A large section of this article was devoted to describing the methodologic challenges that face researchers when evaluating gender differences in occupational lung disease. The findings of the presented studies are likely limited by many of the methodologic problems that were identified earlier. To accurately identify the true risk of occupational lung disease in women workers, these findings must be replicated in future studies with special attention paid to the various aspects of occupational lung disease research that are susceptible to gender-related bias.