title: Effects of warm-up on exercise capacity, platelet activation and platelet-leucocyte aggregation in patients with claudication.
abstract: BACKGROUND
  The effects of exercise and warm-up were investigated in patients with claudication.
  
  
  METHODS
  This case-control crossover study involved two treadmill exercise tests, one preceded by a warm-up. Exercise continued until maximal leg pain (patients with claudication) or exhaustion (controls). Blood was taken before, and 5 and 60 min after exercise for flow cytometric analysis of platelet activation and platelet-leucocyte aggregation.
  
  
  RESULTS
  Both cohorts (eight patients with claudication of median age 63 years and eight healthy controls of median age 63.5 years) demonstrated improvement in exercise capacity after warm-up (13.1 per cent, P = 0.012 and 15.6 per cent, P = 0.008 respectively). Platelet activation increased after exercise in patients with claudication (fibrinogen binding: 1.11 per cent before exercise versus 2.63 per cent after exercise, P = 0.008; P-selectin: 0.68 versus 1.11 per cent, P = 0.028). Neither agonist stimulation nor warm-up altered this trend. Platelet-leucocyte (PLA) and platelet-neutrophil (PNA) aggregation were similarly increased immediately after exercise in patients with claudication (PLA: 7.6 versus 13.0 per cent, P = 0.004; PNA: 6.8 versus 10.2 per cent, P = 0.012). These remained high 60 min after exercise only in patients with claudication, but recovered to baseline levels when preceded by warm-up. Warm-up significantly desensitized PNA after stimulation with 10 micromol/l adenosine 5'-diphosphate at all time points.
  
  
  CONCLUSIONS
  Warm-up increased the exercise capacity of patients with claudication. Exercise induced a thromboinflammatory response, with PLA and PNA persistently increased after 60 min in patients with claudication, an effect diminished after warm-up.
authors.affiliation: Vascular Surgical Unit, Leeds General Infirmary, Leeds, Bradford, UK.
authors.forename: S
authors.initials: S
authors.lastname: Pasupathy
authors.forename: K M
authors.initials: KM
authors.lastname: Naseem
authors.forename: S
authors.initials: S
authors.lastname: Homer-Vanniasinkam
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007383:Intermittent Claudication / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018375:Neutrophil Activation / Q000502:physiology; D009504:Neutrophils / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism; D015539:Platelet Activation / Q000502:physiology*; D010974:Platelet Aggregation / Q000502:physiology
chemical_list: D019007:P-Selectin; D000244:Adenosine Diphosphate; D005340:Fibrinogen