Phenotyping of difficult asthma using longitudinal physiological and biomarker measurements reveals significant differences in stability between clusters
| Autor: | Sara Ahmed, Christopher J. Walsh, Andrea Benedetti, Ronald Olivenstein, Qutayba Hamid, Tasneem Zaihra, James G. Martin, C. Fugère |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Pulmonary and Respiratory Medicine
Adult Male medicine.medical_specialty Cross-sectional study Stability (probability) Severity of Illness Index 03 medical and health sciences 0302 clinical medicine Adrenal Cortex Hormones Internal medicine Severity of illness Medicine Cluster Analysis Humans 030212 general & internal medicine Longitudinal Studies Asthma business.industry Predictors Quebec Sputum Repeated measures design Eosinophil Middle Aged medicine.disease respiratory tract diseases Respiratory Function Tests Eosinophils medicine.anatomical_structure Phenotype Cross-Sectional Studies 030228 respiratory system Immunology Longitudinal Disease Progression Biomarker (medicine) Female medicine.symptom Exacerbation and Clusters business Biomarkers Research Article |
| Zdroj: | BMC Pulmonary Medicine |
| ISSN: | 1471-2466 |
| Popis: | Background Although the heterogeneous nature of asthma has prompted asthma phenotyping with physiological or biomarker data, these studies have been mostly cross-sectional. Longitudinal studies that assess the stability of phenotypes based on a combination of physiological, clinical and biomarker data are currently lacking. Our objective was to assess the longitudinal stability of clusters derived from repeated measures of airway and physiological data over a 1-year period in moderate and severe asthmatics. Methods A total of 125 subjects, 48 with moderate asthma (MA) and 77 with severe asthma (SA) were evaluated every 3 months and monthly, respectively, over a 1-year period. At each 3-month time point, subjects were grouped into 4 asthma clusters (A, B, C, D) based on a combination of clinical (duration of asthma), physiological (FEV1 and BMI) and biomarker (sputum eosinophil count) variables, using k-means clustering. Results Majority of subjects in clusters A and C had severe asthma (93 % of subjects in cluster A and 79.5 % of subjects in cluster C at baseline). Overall, a total of 59 subjects (47 %) had stable cluster membership, remaining in clusters with the same subjects at each evaluation time. Cluster A was the least stable (21 % stability) and cluster B was the most stable cluster (71 % stability). Cluster stability was not influenced by changes in the dosage of inhaled corticosteroids. Conclusion Asthma phenotyping based on clinical, physiologic and biomarker data identified clusters with significant differences in longitudinal stability over a 1-year period. This finding indicates that the majority of patients within stable clusters can be phenotyped with reasonable accuracy after a single measurement of lung function and sputum eosinophilia, while patients in unstable clusters will require more frequent evaluation of these variables to be properly characterized. |
| Databáze: | OpenAIRE |
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