title: Association of objectively measured physical activity with established and novel cardiovascular biomarkers in elderly subjects: every step counts.
abstract: OBJECTIVE
  To analyse the relationship between objectively measured daily walking duration and cardiovascular biomarkers of inflammation, cardiac dysfunction and renal impairment.
  
  
  METHODS
  Between March 2009 and April 2010, physical activity was assessed in 1253 community-dwelling individuals living in Germany aged ≥65 years (57% men) over 1 week using a thigh-worn accelerometer. C reactive protein (CRP), white blood cells (WBC), N-terminal pro-brain natriuretic peptide, high-sensitive troponin T (hsTnT), creatinine (Cr) and cystatin C (CysC) were also measured. Least-square means of daily walking duration were calculated for quartiles of each biomarker adjusted for sex, age, pre-existing cardiovascular disease and smoking status.
  
  
  RESULTS
  After adjustment for covariates, statistically significant linear associations with walking duration were observed for WBC, hsTnT, Cr and CysC. CRP quartiles 1 and 2 showed no significant difference followed by a significant inverse dose-response relationship. A similar pattern, but less pronounced, was seen for N-terminal pro-brain natriuretic peptide. Mean differences between the first two quartiles of CRP and its fourth quartile were 17 min. Between categories 1 (more beneficial) and 4 of WBC, hsTnT, Cr and CysC the differences were 15, 12, 23 and 20 min, respectively.
  
  
  CONCLUSIONS
  Increased walking duration is associated with a more favourable profile of cardiovascular biomarkers in elderly subjects.
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany. jochen.klenk@uni-ulm.de
authors.forename: Jochen
authors.initials: J
authors.lastname: Klenk
authors.forename: Michael
authors.initials: M
authors.lastname: Denkinger
authors.forename: Thorsten
authors.initials: T
authors.lastname: Nikolaus
authors.forename: Richard
authors.initials: R
authors.lastname: Peter
authors.forename: Dietrich
authors.initials: D
authors.lastname: Rothenbacher
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Koenig
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D005858:Germany; D006801:Humans; D007249:Inflammation / Q000097:blood; D008297:Male; D009043:Motor Activity; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011159:Population Surveillance; D051437:Renal Insufficiency / Q000097:blood; D012307:Risk Factors; D013997:Time Factors; D019210:Troponin I / Q000097:blood*; D016138:Walking / Q000502:physiology*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D019210:Troponin I; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein