title: A single bout of walking exercise enhances endogenous fibrinolysis in stroke patients.
abstract: OBJECTIVE
  Impaired endogenous fibrinolysis is an important predictor for increased risk of stroke and myocardial infarction. Acute exercise can enhance fibrinolysis, primarily by stimulating short-term increases in plasma tissue plasminogen activator (tPA), which is postulated to protect against atherothrombotic events. No prior studies have examined the fibrinolytic response to exercise in stroke survivors despite their high risk for recurrent stroke and myocardial infarction. The purpose of this study was to assess the fibrinolytic response to acute submaximal exercise in chronic hemiparetic stroke patients.
  
  
  METHODS
  Eighteen (16 men, 2 women) untrained stroke patients with chronic hemiparetic gait deficits volunteered for participation in this single session exercise study. Fasting blood samples for determination of tPA and plasminogen activator inhibitor (PAI-1) enzyme activities were obtained before, immediately after, and 60 min after submaximal treadmill walking. Patients walked at 60% maximal heart rate reserve (low-moderate intensity) for a cumulative total of 20 min.
  
  
  RESULTS
  The exercise bout increased tPA activity by 79% (P < 0.01) and decreased PAI-1 activity by 18% (P < 0.01). At 1 h after completing the walking exercise, plasma tPA activity levels were still significantly elevated (43%,P < 0.01), and PAI-1 activity levels were 25% lower (P < 0.01) than baseline.
  
  
  CONCLUSIONS
  These findings demonstrate that a single bout of aerobic walking exercise can improve fibrinolysis profiles in chronic stroke patients. Significant increases in endogenous tPA and reductions in PAI-1 activity persist for at least 1 h after exercise cessation. The implications are that alterations in physical activity during the day may modify clot lysing potential, thereby affecting atherothrombotic risk.
authors.affiliation: University of Maryland School of Medicine, Department of Medicine, division of Gerontology, Baltimore VA Medical Center/GRECC, Baltimore, MD 21201-1524, USA. fivey@grecc.umaryland.edu
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Ivey
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Womack
authors.forename: Onanong
authors.initials: O
authors.lastname: Kulaputana
authors.forename: C Lynne
authors.initials: CL
authors.lastname: Dobrovolny
authors.forename: Lara A
authors.initials: LA
authors.lastname: Wiley
authors.forename: Richard F
authors.initials: RF
authors.lastname: Macko
mesh_terms: D000368:Aged; D002908:Chronic Disease; D005081:Exercise Therapy; D005260:Female; D005342:Fibrinolysis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors; D020521:Stroke / Q000517:prevention & control; D000071939:Stroke Rehabilitation; D016138:Walking / Q000502:physiology*