Researchers from the University of Colorado (UC) tested the relative effects of low- and high-impact athletic activity on the joints of school-aged children with severe hemophilia A or B on a prophylaxis (preventive) treatment regimen. The lead author of the study was Marilyn J. Manco-Johnson, MD, director of the Mountain States Regional Hemophilia and Thrombosis Center, UC in Denver.

In all, 37 children ages 6 to 21 years old participated in the study, with 73% engaging in high-impact activities and 27% in low-impact activities. Investigators retrospectively reviewed clinical data on joint status, body mass index (BMI), treatment, joint assessments, bleeding episodes, athletic participation and injuries. "Structured" phone interviews were also conducted in some instances to fill in gaps in a patient's medical records. 

Some of the high-impact activities included tennis, basketball, skiing, running/jogging, soccer, karate and rollerblading. The low-impact activities included walking, cycling, swimming, hiking, circuit weight training and frisbee golf.     

Manco-Johnson and her colleagues found that there was no significant difference in the frequency of joint bleeds and new injuries between high- and low-impact athletic activities. In most cases, the children experienced less than one bleed or injury per season. In addition, a new target joint emerged in only one child. Based on BMI measurements, 16% of the children were identified as overweight, while 3% were obese.

"Regular participation in high-impact athletic activity, supported by adult coaching and supervision, did not seem to increase the risk for development of joint hemorrhages or new target joints in this population of school-aged children who had severe hemophilia and received routine prophylactic factor replacement," concluded the authors. "These findings have important implications in the context of recommendations for appropriate physical activities for children who have hemophilia and receive prophylaxis."

The study was funded by an unrestricted grant from the CSL Behring Foundation.

Source: Ross C, Goldenberg N, Hund D, Manco-Johnson M. Athletic Participation in Severe Hemophilia: Bleeding and Joint Outcomes in Children on Prophylaxis. Pediatrics. Published online October 12, 2009.