Extrapulmonary effects of chronic obstructive pulmonary disease on physical activity: a cross-sectional study.
BACKGROUND
Physical activity is reduced in patients with chronic obstructive pulmonary disease (COPD). COPD has a systemic component that includes significant extrapulmonary effects that may contribute to its severity in individual patients.


OBJECTIVE
To investigate the association of extrapulmonary effects of the disease and its comorbidities with reduced physical activity in patients with COPD.


METHODS
In a cross-sectional study, 170 outpatients with COPD (GOLD [Global Initiative for Chronic Obstructive Lung Disease] stages I-IV; BODE [body mass index, airway obstruction, dyspnea, and exercise capacity] score 0-10) underwent a series of tests. Physical activity was assessed over 5 to 6 consecutive days by using a multisensor accelerometer armband that records steps per day and the physical activity level (total daily energy expenditure divided by whole-night sleeping energy expenditure). Cardiovascular status was assessed by echocardiography, vascular Doppler sonography, and levels of N-terminal pro-B-type natriuretic peptide. Mental status, metabolic/muscular status, systemic inflammation, and anemia were assessed by Beck Depression Inventory, bioelectrical impedance analysis, handgrip strength, high-sensitivity C-reactive protein/fibrinogen, and hemoglobin, respectively.


RESULTS
In a multivariate linear regression analysis using either steps per day or physical activity level as a dependent variable, the extrapulmonary parameters that were associated with reduced physical activity in patients with COPD independently of GOLD stages or BODE score were N-terminal pro-B-type natriuretic peptide levels, echocardiographically measured left ventricular diastolic function, and systemic inflammation.


CONCLUSIONS
Higher values of systemic inflammation and left cardiac dysfunction are associated with reduced physical activity in patients with COPD.
Watz
Henrik
H
Pulmonary Research Institute at Hospital Grosshansdorf, Center for Pneumology and Thoracic Surgery, Woehrendamm 80, D-22927 Grosshansdorf, Germany. magnussen@pulmoresearch.de
Waschki
Benjamin
B
Boehme
Corinna
C
Claussen
Martin
M
Meyer
Thorsten
T
Magnussen
Helgo
H
D000203:Activities of Daily Living; D000210:Acute-Phase Reaction / Q000453:epidemiology / Q000503:physiopathology; D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000503:physiopathology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000503:physiopathology*; D012720:Severity of Illness Index; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology / Q000503:physiopathology