title: Daily physical activity in subjects with newly diagnosed COPD.
abstract: BACKGROUND
  Information about daily physical activity levels (PAL) in subjects with undiagnosed chronic obstructive pulmonary disease (COPD) is scarce. This study aims to assess PA and to investigate the associations between PA and clinical characteristics in subjects with newly diagnosed COPD.
  
  
  METHODS
  Fifty-nine subjects with a new spirometry-based diagnosis of mild (n=38) and moderate (n=21) COPD (63±6 years, 68% male) were matched with 65 smoking controls (62±7 years, 75% male). PA (daily steps, time spent in moderate-to-vigorous intense physical activities (MVPA) and PAL) was measured by accelerometry. Dyspnoea, complete pulmonary function tests, peripheral muscle strength and exercise capacity served as clinical characteristics.
  
  
  RESULTS
  PA was significantly lower in COPD versus smoking controls (7986±2648 vs 9765±3078 steps, 64 (27-120) vs 110 (55-164) min of MVPA, 1.49±0.21 vs 1.62±0.24 PAL respectively, all p<0.05). Subjects with COPD with either mild symptoms of dyspnoea (mMRC 1), those with lower diffusion capacity (T(L),co), low 6 min walking distance (6MWD) or low maximal oxygen uptake (VO(2) peak) had significantly lower PA. Multiple regression analysis identified 6 MWD and T(L),co as independent predictors of PA in COPD.
  
  
  CONCLUSIONS
  The reduction in PA starts early in the disease, even when subjects are not yet diagnosed with COPD. Inactivity is more pronounced in subjects with mild symptoms of dyspnoea, lower levels of diffusion capacity and exercise capacity.
authors.affiliation: Faculty of Kinesiology and Rehabilitation Sciences, Department of Rehabilitation Sciences, KU Leuven, , Leuven, Belgium.
authors.forename: Hans
authors.initials: H
authors.lastname: Van Remoortel
authors.forename: Miek
authors.initials: M
authors.lastname: Hornikx
authors.forename: Heleen
authors.initials: H
authors.lastname: Demeyer
authors.forename: Daniel
authors.initials: D
authors.lastname: Langer
authors.forename: Chris
authors.initials: C
authors.lastname: Burtin
authors.forename: Marc
authors.initials: M
authors.lastname: Decramer
authors.forename: Rik
authors.initials: R
authors.lastname: Gosselink
authors.forename: Wim
authors.initials: W
authors.lastname: Janssens
authors.forename: Thierry
authors.initials: T
authors.lastname: Troosters
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D004417:Dyspnea / Q000503:physiopathology*; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012907:Smoking / Q000503:physiopathology*; D013147:Spirometry