Patients with chronic obstructive pulmonary disease (COPD) frequently suffer from comorbidities. COPD severity may be evaluated by the Global initiative for chronic Obstructive Lung Disease (GOLD) combined risk assessment score (GOLD score). Spirometry, body plethysmography, diffusing capacity of the lung for carbon monoxide (DLCO), and high-resolution computed tomography (HR-CT) measure lung function and elucidate pulmonary pathology. This study assesses associations between GOLD score and measurements of lung function in COPD patients with and without (=1) comorbidities. It evaluates whether the presence of comorbidities influences evaluation by GOLD score of COPD severity, and questions whether GOLD score describes morbidity rather than COPD severity.
In this prospective study, 106 patients with stable COPD were included. Patients treated for lung cancer were excluded. Demographics, oxygen saturation (SpO2), modified Medical Research Council Dyspnea Scale, COPD exacerbations, and comorbidities were recorded. Body plethysmography and DLCO were measured, and HR-CT performed and evaluated for emphysema and airways disease. COPD severity was stratified by the GOLD score. Correlation analyses: 1) GOLD score, 2) emphysema grade, and 3) airways disease and lung function parameters, described by: forced expiratory volume in the first second in percent of expected value (FEV1%), inspiratory capacity (IC%), total lung volume (TLC%), IC/TLC, and SpO2. Correlation analyses between subgroups and hierarchical cluster analysis were performed.
Significant associations were found between GOLD score and both emphysema grade (correlation coefficients [cc]: -0.2, P=0.03) and lung function parameters (cc: -0.5 to -0.7, P-values all 1 comorbidity (cc: -0.4 to -0.5, P-values all 0.001). Significant differences between subgroups were found in GOLD score and both FEV1% (cc: -0.2, P=0.02) and IC/TLC (cc: -0.2, P=0.02). Comorbidities were associated with GOLD score and composite measures in hierarchical cluster analysis.
The presence of comorbidities influences the relationship between GOLD score and lung function measurements. GOLD score may be more representative of morbidity than of COPD severity.
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Cites: Am J Respir Crit Care Med. 2012 Nov 15;186(10):975-8122997207
Cites: Eur Respir J. 2003 Mar;21(3):450-412662000
Cites: Chest. 1988 Mar;93(3):580-63342669
Cites: Eur Respir J. 1995 Mar;8(3):492-5067789503
Cites: Can Respir J. 1998 Jul-Aug;5(4):270-79753528
Cites: Thorax. 1999 Jul;54(7):581-610377201
Cites: Eur Respir J. 2005 Sep;26(3):511-2216135736
Cites: Eur Respir J. 2005 Oct;26(4):720-3516204605
Cites: AJR Am J Roentgenol. 2005 Dec;185(6):1509-1516304005
Cites: AJR Am J Roentgenol. 2008 Oct;191(4):1032-918806139
Cites: Am J Med. 2009 Apr;122(4):348-5519332230
Cites: Am J Respir Crit Care Med. 2010 Feb 15;181(4):353-919926869
Cites: Respir Res. 2011;12:13521988843
Cites: COPD. 2012 Feb;9(1):16-2122292594
Cites: Int J Chron Obstruct Pulmon Dis. 2012;7:119-2622399851
Cites: Respir Res. 2012;13(1):1322309369
Cites: COPD. 2012 Apr;9(2):151-922429093
Cites: Respiration. 2012;83(5):383-9021832824
Cites: Am J Respir Crit Care Med. 2012 Jul 15;186(2):155-6122561964
Cites: Respir Res. 2012;13:6622866681
Cites: Int J Chron Obstruct Pulmon Dis. 2012;7:697-70923093901
Cites: BMC Fam Pract. 2013;14:1123324308
Cites: Chest. 2013 Mar;143(3):694-70223187891
Cites: Eur Respir J. 2013 Sep;42(3):647-5423258783
Cites: Eur Respir J. 2013 Sep;42(3):636-4623766334