Wheezing, a significant clinical phenotype of COPD: experience from the Taiwan Obstructive Lung Disease Study.
BACKGROUND
COPD is an important public health challenge with significant heterogeneity of clinical presentation and disease progression. Clinicians have been trying to find phenotypes that may be linked to distinct prognoses and different therapeutic choices. Not all patients with COPD present with wheezing, a possible clinical phenotype that can help differentiate patient subgroups.


METHODS
The Taiwan Obstructive Lung Disease study was a retrospective, multicenter research study to investigate the treatment patterns of COPD after the implementation of the Global Initiative for Chronic Obstructive Lung Disease 2011 guidelines. Between November 2012 and August 2013, medical records were retrieved from patients with COPD aged ≥40 years; patients diagnosed with asthma were excluded. Demographic data, lung function, symptom scores, and acute exacerbation were recorded and analyzed, and the differences between patients with and without wheezing were evaluated.


RESULTS
Of the 1,096 patients with COPD, 424 (38.7%) had the wheezing phenotype. The wheezing group had significantly higher COPD Assessment Test scores (12.4±7.8 versus 10.5±6.7, P<0.001), higher modified Medical Research Council grade (2.0±1.0 versus 1.7±0.9, P<0.001), and more acute exacerbations within the past year (0.9±1.3 versus 0.4±0.9, P<0.001) than the nonwheezing group. The postbronchodilator forced expiratory volume in 1 second was lower in wheezing patients (1.2±0.5 L versus 1.5±0.6 L, P<0.001). Even in patients with maintenance treatment fitting the Global Initiative for Chronic Obstructive Lung Disease 2011 guidelines, the wheezing group still had worse symptom scores and more exacerbations.


CONCLUSIONS
Wheezing is an important phenotype in patients with COPD. Patients with COPD having the wheezing phenotype are associated with worse symptoms, more exacerbations, and worse lung function.
Division of Pulmonary Medicine, Department of Internal Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan, Republic of China.
Wan-Chun
WC
Huang
Department of Internal Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan, Republic of China.
Ying-Huang
YH
Tsai
Department of Internal Medicine, E-Da Hospital/I-Shou University, Kaohsiung, Taiwan, Republic of China.
Yu-Feng
YF
Wei
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan, Republic of China.
Ping-Hung
PH
Kuo
Department of Internal Medicine, Cheng-Hsin General Hospital, Taipei, Taiwan, Republic of China.
Chi-Wei
CW
Tao
Division of Thoracic Medicine, Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan, Republic of China.
Shih-Lung
SL
Cheng
Division of Pulmonary and Critical Care Medicine, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China.
Chao-Hsien
CH
Lee
Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Tzu Chi Hospital, Taipei, Taiwan, Republic of China.
Yao-Kuang
YK
Wu
Department of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan, Republic of China.
Ning-Hung
NH
Chen
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan, Republic of China.
Wu-Huei
WH
Hsu
Division of Chest Medicine, Taichung Veterans Genera Hospital, Taichung, Taiwan, Republic of China.
Jeng-Yuan
JY
Hsu
Division of Pulmonary and Critical Care Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan, Republic of China.
Chin-Chou
CC
Wang
Division of Pulmonary Medicine, Department of Internal Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan, Republic of China ; Department of Respiratory Care, Chang Gung University of Science and Technology, Chiayi, Taiwan, Republic of China.
Ming-Shian
MS
Lin
D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D010808:Physical Examination / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D012129:Respiratory Function Tests / Q000379:methods; D012135:Respiratory Sounds / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D000067251:Symptom Flare Up; D013624:Taiwan / Q000453:epidemiology
acute exacerbation; chronic obstructive pulmonary disease; wheezing phenotype