Vigorous physical activity may increase risk of bleeds in children with hemophilia, but the magnitude of the risk is unknown, reveals background information in an article.

There were 436 bleeds, of which 336 were study bleeds (i.e., bleeding episodes without another bleeding episode in the preceding 2 weeks). Eighty-eight participants (84 percent) reported at least 1 bleed. The most frequent sites of bleeding were the knee (15 percent), ankle (14 percent), and elbow (10 percent). Compared with inactivity and category 1 activities (e.g., swimming), category 2 activities (e.g., basketball) were associated with a transient increase in the risk of bleeding (30.6 percent of bleed windows vs. 24.8 percent of first control windows; odds ratio, 2.7). Category 3 activities (e.g., wrestling) were associated with a greater transient increase in risk (7.0 percent of bleed windows vs. 3.4 percent of first control windows; odds ratio, 3.7). These odds of bleeding suggest that for most children, the absolute increase in risk associated with physical activity is low. "To illustrate absolute risk increase, for a child who bleeds 5 times annually and is exposed on average to category 2 activities twice weekly and to category 3 activities once weekly, exposure to these activities was associated with only 1 of the 5 annual bleeds," the authors write. Most bleeds associated with physical activity were present within an hour of activity.
"This study confirms that physical activity is associated with an increased risk of bleeds in children and adolescents with moderate or severe hemophilia A or B. It demonstrates that the relative increase in risk is moderate. However, for most children, the absolute increase in risk is likely to be low," the researchers conclude.
Source-Newswise