The effect of steady-state bicycle exercise on the activity level of F -VIII in patients with mild and moderate haemophilia A

Hemophilia is an X chromosome-linked inherited bleeding disorder. Frequent intra- articular and intra-muscular haemorrhage in severe haemophiliacs can cause significant disability. In order to resolve a simple bleeding in a 20-kilogram child, some 500 IV of factor VIII is usually required. The cost of this replacement therapy is enormous, especially for less wealthy countries. Vigorous exercise in normal individuals has been known to increase levels of F. VIII:C and vWF:Ag transiently through β-adrenergic stimulation. The goal of this research study was to investigate the effect of ergometric exercise on F. VIII activity in patients with mild and moderate hemophilia-A. Research studies on this phenomenon have not been reported since 1984. Since the previous studies have mainly been carried out on either healthy individuals or patients with cardiac functional abnormalities, it appears appropriate to further characterize the effect of exercise on the coagulation parameters in patients suffering from bleeding disorders. For this purpose, 10 hemophiliacs (a mean age of 24 years) were exercised on a bicycle ergometer in accordance with accepted protocols for a period of 23 to 46 minutes. We deliberately limited the periods of activity because of the low exercise tolerance of these patients. Venous blood samples were drawn before and at 8 and 45 minutes after the exercise. The results showed that the increase in the activity of F .V VIII:C following exercise was very significant among mildly-affected patients, and the reduction in a PTT at 45 minutes after the exercise, the increase in vWF activity 8 minutes after the exercise, and the rise in vWF:Ag in both stages were all significant. It is concluded that ergometric exercise induces a significant increase in F-V VIII activity in both mild and moderate hemophiliacs. Establishing a suitable exercise program in patients with hemophilia A not only improves the status of their musculo-skeletal system, but also transiently increases the activity of F-V VIII activity. Prophylaxis in severe hemophiliacs could be achieved by means of replacement therapy. Among mildly- or moderately-affected patients, exercise may serve the same purpose and effectively reduce the need for replacement therapy.