PT  - JOURNAL ARTICLE
AU  - A.W. Musk
AU  - M. Knuiman
AU  - M. Hunter
AU  - J. Hui
AU  - L. Palmer
AU  - J. Beilby
AU  - M. Divitini
AU  - S. Mulrennan
AU  - A. James
TI  - Patterns of airway disease and the clinical diagnosis of asthma in the busselton population
AID  - 10.1183/09031936.00102110
DP  - 2011 May 12
TA  - European Respiratory Journal
PG  - erj01021-2010
4099  - http://erj.ersjournals.com/content/early/2011/05/26/09031936.00102110.short
4100  - http://erj.ersjournals.com/content/early/2011/05/26/09031936.00102110.full
AB  - Common airway diseases are phenotypically heterogeneous syndromes which do not fit closely into the conventional diagnostic categories of asthma and COPD. Identification of more homogeneous phenotypes of airflow limitation may lead to more appropriate treatments and better understanding of their pathophysiology and genetic basis.To examine how objective measures related to lung function cluster in the general population and how the resulting patterns relate to “asthma” and “bronchitis” as diagnosed by a doctor, recent wheezing, cough and sputum production and tobacco smoking.Age-stratified random general population sample of 1,969 adults identified from the electoral register of Busselton, Western Australia.Cross-sectional survey 2005-7 comprising questionnaire on respiratory symptoms, doctor-diagnosed asthma (DDA)-ever, doctor-diagnosed bronchitis (DDB)-ever, recent wheezing and smoking history together with anthropometric measurements, spirometry (FEV1, FVC), methacholine challenge or bronchodilator response to diagnose airway hyper-responsiveness (AHR), exhaled nitric oxide (eNO), prick skin tests to common allergens, and peripheral blood eosinophil and neutrophil counts. Cluster analysis (SAS version 9.2) with variables sex, age, atopy, FEV1 %predicted, FEV1/FVC, AHR, eNO, log eosinphil count, log neutrophil count and body mass index (BMI) was used to identify phenotypic patterns.Seven clusters (number of subjects, % with DDA, % with recent wheeze, % with DDB) were identified: “normal males” (467, 7%, 15%, 13%), “normal females” (477, 12%, 13%, 18%), “obese females” (250, 16%, 26%, 28%), “atopic younger adults” (330, 21%, 27%, 17%), “atopic adults with high eNO” (130, 30%, 34%, 25%), “atopic males with reduced FEV1” (103, 33%, 54%, 32%), and “atopic adults with BHR” (212, 40%, 38%, 26%). Overall 51% of subjects had never smoked but this varied from 20% to 67% across clusters.The clinical diagnosis of asthma (ever) (and also recent wheeze and bronchitis-ever) is not specific for any of the clustering patterns of airway abnormality in the general population underlining the heterogeneity of the entity of “asthma” clinically and for understanding the genetic basis of the asthma syndromes.