title: Influence of regular physical activity on warfarin dose and risk of hemorrhagic complications.
abstract: OBJECTIVE
  To determine the influence of regular physical activity on stable warfarin dose and risk of major hemorrhage in patients on chronic anticoagulation therapy.
  
  
  METHODS
  Regular physical activity (maintained over > 80% of visits) was ascertained by self-report at initiation of warfarin therapy (target international normalized ratio [INR] = 2-3) in 1272 patients, with changes documented at monthly anticoagulation clinic visits in a population-based prospective cohort. Multi-variable linear regression and survival analysis, respectively, were used to assess influence on warfarin and risk of hemorrhage.
  
  
  METHODS
  Outpatient anticoagulation clinic
  
  
  METHODS
  1272 anticoagulated patients
  
  
  RESULTS
  There were 683 (53.7%) patients who were regularly physically active (≥ 30 min ≥ 3 times/week). Physically active patients required warfarin doses that were 6.9% higher (p=0.006) than in physically inactive patients after controlling for sociodemographic factors, vitamin K intake, clinical factors, and genetic variations.The overall incidence of major hemorrhagic events was 7.6/100 person-years (p-yrs, 95% confidence interval [CI] 6.4-8.9) in our population. The incidence was lower for physically active patients (5.6/100 p-yrs, 95% CI 4.2-7.2) than in inactive patients (10.3/100 p-yrs, 95% CI 8.2-12.9, p=0.0004). Active patients had a 38% lower risk of hemorrhage (hazard ratio 0.62, 95% CI 0.42-0.98, p=0.03) compared with inactive patients.
  
  
  CONCLUSIONS
  Regular physical activity is associated with higher warfarin dose requirements and lower risk of hemorrhage. The influence of physical activity on drug response needs to be further explored, and the mechanisms through which it exerts these effects need to be elucidated
authors.forename: Aditi
authors.initials: A
authors.lastname: Shendre
authors.forename: Timothy Mark
authors.initials: TM
authors.lastname: Beasley
authors.forename: Todd M
authors.initials: TM
authors.lastname: Brown
authors.forename: Charles E
authors.initials: CE
authors.lastname: Hill
authors.forename: Donna K
authors.initials: DK
authors.lastname: Arnett
authors.forename: Nita A
authors.initials: NA
authors.lastname: Limdi
mesh_terms: D000328:Adult; D000368:Aged; D000553:Ambulatory Care; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D019934:International Normalized Ratio; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D015999:Multivariate Analysis; D011446:Prospective Studies; D016019:Survival Analysis; D013997:Time Factors; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin