title: Physical inactivity and arterial stiffness in COPD.
abstract: BACKGROUND
  Arterial stiffness is an important predictor of cardiovascular risk besides classic cardiovascular risk factors. Previous studies showed that arterial stiffness is increased in patients with COPD compared to healthy controls and exercise training may reduce arterial stiffness. Since physical inactivity is frequently observed in patients with COPD and exercise training may improve arterial stiffness, we hypothesized that low daily physical activity may be associated with increased arterial stiffness.
  
  
  METHODS
  In 123 patients with COPD (72% men; mean [standard deviation] age: 62 [7.5] years; median [quartile] forced expiratory volume in 1 second 35 [27/65] %predicted), arterial stiffness was assessed by augmentation index (AI). Daily physical activity level (PAL) was measured by an activity monitor (SenseWear Pro™) >1 week. The association between AI and PAL was investigated by univariate and multivariate regression analysis, taking into account disease-specific characteristics and comorbidities.
  
  
  RESULTS
  Patients suffered from moderate (35%), severe (32%), and very severe (33%) COPD, and 22% were active smokers. Median (quartile) PAL was 1.4 (1.3/1.5) and mean (standard deviation) AI 26% (9.2%). PAL showed a negative association with AI (B=-9.32, P=0.017) independent of age, sex, blood pressure, and airflow limitation.
  
  
  CONCLUSIONS
  In COPD patients, a higher PAL seems to favorably influence arterial stiffness and therefore may reduce cardiovascular risk.
  
  
  BACKGROUND
  http://www.ClinicalTrials.gov, NCT01527773.
authors.affiliation: Division of Pulmonology, University Hospital of Zurich, Zurich, Switzerland.
authors.forename: Noriane A
authors.initials: NA
authors.lastname: Sievi
authors.affiliation: Division of Pulmonology, University Hospital of Zurich, Zurich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Franzen
authors.affiliation: Division of Pulmonology, University Hospital of Zurich, Zurich, Switzerland ; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Kohler
authors.affiliation: Division of Pulmonology, University Hospital of Zurich, Zurich, Switzerland.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Clarenbach
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D015897:Comorbidity; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D015999:Multivariate Analysis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012044:Regression Analysis; D012307:Risk Factors; D012720:Severity of Illness Index; D059289:Vascular Stiffness / Q000502:physiology*
keywords: COPD; activity monitor; airflow limitation; physical activity level