title: Percent Emphysema and Daily Motor Activity Levels in the General Population: Multi-Ethnic Study of Atherosclerosis.
abstract: COPD is associated with reduced physical capacity. However, it is unclear whether pulmonary emphysema, which can occur without COPD, is associated with reduced physical activity in daily life, particularly among people without COPD and never smokers. We hypothesized that greater percentage of emphysema-like lung on CT scan is associated with reduced physical activity assessed by actigraphy and self-report.
  
  
  
  The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants free of clinical cardiovascular disease from the general population. Percent emphysema was defined as percentage of voxels < -950 Hounsfield units on full-lung CT scans. Physical activity was measured by wrist actigraphy over 7 days and a questionnaire. Multivariable linear regression was used to adjust for age, sex, race/ethnicity, height, weight, education, smoking, pack-years, and lung function.
  
  
  
  Among 1,435 participants with actigraphy and lung measures, 47% had never smoked, and 8% had COPD. Percent emphysema was associated with lower activity levels on actigraphy (P = .001), corresponding to 1.5 hour less per week of moderately paced walking for the average participant in quintile 2 vs 4 of percent emphysema. This association was significant among participants without COPD (P = .004) and among ever (P = .01) and never smokers (P = .03). It was also independent of coronary artery calcium and left ventricular ejection fraction. There was no evidence that percent emphysema was associated with self-reported activity levels.
  
  
  
  Percent emphysema was associated with decreased physical activity in daily life objectively assessed by actigraphy in the general population, among participants without COPD, and nonsmokers.
authors.affiliation: Department of Medicine, Columbia University, New York, NY.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Lo Cascio
authors.affiliation: Department of Medicine, Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
authors.forename: Mirja
authors.initials: M
authors.lastname: Quante
authors.affiliation: Department of Internal Medicine, University of Iowa, Iowa City, IA.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Hoffman
authors.affiliation: Department of Epidemiology and Prevention, Wake Forest University, Winston-Salem, NC.
authors.forename: Alain G
authors.initials: AG
authors.lastname: Bertoni
authors.affiliation: Department of Medicine, Columbia University, New York, NY.
authors.forename: Carrie P
authors.initials: CP
authors.lastname: Aaron
authors.affiliation: Department of Medicine, Columbia University, New York, NY; Department of Psychiatry and Behavioral Science, Stony Brook University, Stony Brook, NY.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Schwartz
authors.affiliation: Department of Internal Medicine, UC Davis School of Medicine, Sacramento, CA.
authors.forename: Mark V
authors.initials: MV
authors.lastname: Avdalovic
authors.affiliation: VA Puget Sound Health Care System, Seattle, WA; Department of Medicine, University of Washington, Seattle, WA.
authors.forename: Vincent S
authors.initials: VS
authors.lastname: Fan
authors.affiliation: Department of Medicine, Columbia University, New York, NY.
authors.forename: Gina S
authors.initials: GS
authors.lastname: Lovasi
authors.affiliation: Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kawut
authors.affiliation: Department of Radiology, Columbia University, New York, NY.
authors.forename: John H M
authors.initials: JHM
authors.lastname: Austin
authors.affiliation: Department of Medicine, Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
authors.affiliation: Department of Medicine, Columbia University, New York, NY. Electronic address: rgb9@columbia.edu.
authors.forename: R Graham
authors.initials: RG
authors.lastname: Barr
mesh_terms: D056044:Actigraphy; D000368:Aged; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000453:epidemiology; D005006:Ethnicity; D015444:Exercise; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D016014:Linear Models; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D012720:Severity of Illness Index; D012907:Smoking / Q000453:epidemiology; D013318:Stroke Volume; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000453:epidemiology; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology; D014797:Vital Capacity; D000070857:Walk Test
keywords: actigraphy; computed tomography; emphysema; multicenter prospective cohort study; physical activity