title: The Prognostic Value of Residual Volume/Total Lung Capacity in Patients with Chronic Obstructive Pulmonary Disease.
abstract: The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC ≥ 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD.
authors.affiliation: Division of Pulmonology, Allergy & Critical Care Medicine, Department of Internal Medicine, Hallym University Medical Center, Seoul, Korea.
authors.forename: Tae Rim
authors.initials: TR
authors.lastname: Shin
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yeon-Mok
authors.initials: YM
authors.lastname: Oh
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Joo Hun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Keu Sung
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Office of Biostatistics, Medical Humanities and Social Medicine, Ajou University School of Medicine, Seoul, Korea.
authors.forename: Sunghee
authors.initials: S
authors.lastname: Oh
authors.affiliation: Office of Biostatistics, Medical Humanities and Social Medicine, Ajou University School of Medicine, Seoul, Korea.
authors.forename: Dae Ryoung
authors.initials: DR
authors.lastname: Kang
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Seungsoo
authors.initials: S
authors.lastname: Sheen
authors.affiliation: Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Joon Beom
authors.initials: JB
authors.lastname: Seo
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Kwang Ha
authors.initials: KH
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
authors.forename: Tae-Hyung
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seong Yong
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Ho Il
authors.initials: HI
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea.
authors.forename: Chin Kook
authors.initials: CK
authors.lastname: Rhee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Chungbuk National University, Cheongju, Korea.
authors.forename: Kang-Hyeon
authors.initials: KH
authors.lastname: Choe
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sang-Do
authors.initials: SD
authors.lastname: Lee
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000175:diagnosis / Q000503:physiopathology; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D005540:Forced Expiratory Flow Rates / Q000502:physiology; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D056910:Republic of Korea; D012115:Residual Volume / Q000502:physiology*; D012129:Respiratory Function Tests; D011795:Surveys and Questionnaires; D014109:Total Lung Capacity / Q000502:physiology*; D014797:Vital Capacity; D016138:Walking / Q000502:physiology
keywords: COPD; Hyperinflation; Residual Volume; Survival; Total Lung Capacity