Lower diffusing capacity with chronic bronchitis predicts higher risk of acute exacerbation in chronic obstructive lung disease.
BACKGROUND
This study was designed to evaluate the effect of chronic bronchitis (CB) symptoms and degree of emphysema in a multicenter Korean cohort.


METHODS
From April 2012 to May 2015, patients diagnosed with chronic obstructive lung disease (COPD) who were aged above 40 years at 46 hospitals throughout Korea were enrolled. All of the patients were classified according to CB symptoms and the diffusing capacity of the lung for carbon monoxide (DLCO); demographic data, symptom scores, and the result of lung function tests and exacerbations were then analyzed.


RESULTS
A total of 812 patients were enrolled. Among these patients, 285 (35.1%) had CB symptoms. A total of 51% of patients had high DLCO without CB symptoms [CB (-) high DLCO], 24.9% had CB symptoms only [CB (+) high DLCO], 14.2% had low DLCO only [CB (-) low DLCO], and 10.2% had both low DLCO and CB [CB (+) low DLCO]. Patients with CB (+) low DLCO showed a significantly lower post-bronchodilator (BD) forced expiratory volume for 1 second (FEV1) and more severe dyspnea than patients with CB (-) high DLCO. On multivariate analysis, the risk of acute exacerbation was two times higher [odds ratio (OR) 2.06; 95% confidence interval (CI): 1.18-3.62; P=0.01] in the CB (+) low DLCO group than in the CB (-) high DLCO group.


CONCLUSIONS
In this COPD cohort, patients showed distinct clinical characteristics and outcomes according to the presence of CB and degree of DLCO. CB and low DLCO were associated with the risk of acute exacerbation.
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Hwa Young
HY
Lee
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Jin Woo
JW
Kim
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Sang Haak
SH
Lee
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Hyoung Kyu
HK
Yoon
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Jae Jeong
JJ
Shim
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Jeong-Woong
JW
Park
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Jae-Hyung
JH
Lee
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Kwang Ha
KH
Yoo
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Ki-Suck
KS
Jung
1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea ; 3 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 4 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea ; 5 Department of Pulmonary, Allergy and Critical Care Medicine, Korea University Guro Hospital, Seoul, Republic of Korea ; 6 Department of Pulmonary and Critical Care Medicine, Gachon University, Gil Medical Center, Incheon, Korea ; 7 Department of Internal Medicine, Eulji University College of Medicine, Seoul, Republic of Korea ; 8 Division of Pulmonary, Allergy and Critical Care Medicine Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea ; 9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Hallym University College of Medicine, Anyang, Republic of Korea.
Chin Kook
CK
Rhee
Chronic bronchitis (CB); acute exacerbation; chronic obstructive lung disease (COPD); diffusing capacity