PT  - JOURNAL ARTICLE
AU  - Judith Garcia-Aymerich
AU  - Federico P Gómez
AU  - Marta Benet
AU  - Eva Farrero
AU  - Xavier Basagaña
AU  - Àngel Gayete
AU  - Carles Paré
AU  - Xavier Freixa
AU  - Jaume Ferrer
AU  - Antoni Ferrer
AU  - Josep Roca
AU  - Juan B Gáldiz
AU  - Jaume Sauleda
AU  - Eduard Monsó
AU  - Joaquim Gea
AU  - Joan A Barberà
AU  - Àlvar Agustí
AU  - Josep M Antó
TI  - Identification and prospective validation of clinically relevant chronic obstructive pulmonary disease (COPD) subtypes
AID  - 10.1136/thx.2010.154484
DP  - 2011 May 01
TA  - Thorax
PG  - 430--437
VI  - 66
IP  - 5
4099  - http://thorax.bmj.com/content/66/5/430.short
4100  - http://thorax.bmj.com/content/66/5/430.full
SO  - Thorax2011 May 01; 66
AB  - Background Chronic obstructive pulmonary disease (COPD) is increasingly considered a heterogeneous condition. It was hypothesised that COPD, as currently defined, includes different clinically relevant subtypes.Methods To identify and validate COPD subtypes, 342 subjects hospitalised for the first time because of a COPD exacerbation were recruited. Three months after discharge, when clinically stable, symptoms and quality of life, lung function, exercise capacity, nutritional status, biomarkers of systemic and bronchial inflammation, sputum microbiology, CT of the thorax and echocardiography were assessed. COPD groups were identified by partitioning cluster analysis and validated prospectively against cause-specific hospitalisations and all-cause mortality during a 4 year follow-up.Results Three COPD groups were identified: group 1 (n=126, 67 years) was characterised by severe airflow limitation (postbronchodilator forced expiratory volume in 1 s (FEV1) 38% predicted) and worse performance in most of the respiratory domains of the disease; group 2 (n=125, 69 years) showed milder airflow limitation (FEV1 63% predicted); and group 3 (n=91, 67 years) combined a similarly milder airflow limitation (FEV1 58% predicted) with a high proportion of obesity, cardiovascular disorders, diabetes and systemic inflammation. During follow-up, group 1 had more frequent hospitalisations due to COPD (HR 3.28, p<0.001) and higher all-cause mortality (HR 2.36, p=0.018) than the other two groups, whereas group 3 had more admissions due to cardiovascular disease (HR 2.87, p=0.014).Conclusions In patients with COPD recruited at their first hospitalisation, three different COPD subtypes were identified and prospectively validated: ‘severe respiratory COPD’, ‘moderate respiratory COPD’, and ‘systemic COPD’.