Effects of warm-up on exercise capacity, platelet activation and platelet–leucocyte aggregation in patients with claudication †

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 µmol/l adenosine 5′-diphosphate at all time points. Conclusion: 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. Copyright © 2004 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.