(HealthDay News) – There is a moderate but significant transient increased risk in bleeding following vigorous physical activity in children and adolescent boys with hemophilia, according to a study published in the Oct 10 issue of the Journal of the American Medical Association.

Carolyn R Broderick, MBBS, from the University of Sydney in Australia, and colleagues conducted a case-crossover study involving 104 children and adolescent boys aged 4–18 years with moderate or severe hemophilia A or B participating in a multicenter prospective cohort. Patients were monitored for one year and, following each bleed, the child or parent was interviewed to ascertain physical activity exposure.

The researchers found that, over the follow-up period, 436 bleeds occurred. The bleeds used in the primary risk analysis were 336 bleeds that occurred more than two weeks after the preceding bleed. Category 2 activities (eg, basketball) were associated with a significant transient increase in the risk of bleeding (odds ratio, 2.7) compared to inactivity or Category 1 activities (eg, swimming). There was a greater significant transient increase in risk (odds ratio, 3.7) associated with Category 3 activities (eg, wresting). For a child who participates in an average of Category 2 activities twice weekly and Category 3 activities once weekly and who bleeds five times per year, these activities were associated with only one of the annual bleeds. Bleeding incidence was significantly lower (2%; P=0.004) for every 1% increase in clotting factor level.

“In children and adolescents with hemophilia, vigorous physical activity was transiently associated with a moderate relative increase in risk of bleeding,” the authors write.

Several authors disclosed financial ties to the pharmaceutical and health care industries.

Full Text (subscription or payment may be required)
Editorial (subscription or payment may be required)