Quantitative ultrasound of the tibia and radius in prepubertal and early-pubertal female athletes.

BACKGROUND

Physical exercise during childhood has been shown to enhance bone mineral density, thus reducing the risk of osteoporosis.

OBJECTIVE

To examine bone properties, as measured by quantitative ultrasound, in prepubertal and early-pubertal female athletes engaged in impact and nonimpact sports.

DESIGN

Survey.

SETTING

General community.

PARTICIPANTS

Twenty-five acrobatic gymnasts, 21 swimmers, and 21 control subjects. Athletes had been training for at least 1(1/2) years.

MAIN OUTCOME MEASURE: Bone speed of sound (bilateral) at the distal radius and the midtibia.

RESULTS

Gymnasts were significantly shorter and lighter than swimmers and control girls (P<.001) but had a body mass index similar to that of swimmers. Adiposity was lower in athletes than in controls. Speed of sound did not correlate with measures of body size. Higher mean +/- SD radial speed of sound values (nondominant side) were observed in gymnasts (3764 +/- 104 m/s; P =.045) than in swimmers and control girls (3732 +/- 99 and 3721 +/- 83 m/s, respectively). Mean +/- SD tibial speed of sound values (nondominant side) were similar in gymnasts and swimmers (3629 +/- 87 and 3619 +/- 78 m/s, respectively) and higher in the athletic groups than in the control group (3516 +/- 127 m/s; P<.001). In all 3 groups, no differences were observed between dominant and nondominant sides in the radii or tibias.

CONCLUSIONS

Physical exercise, impact and nonimpact, is related to enhanced bone properties, as measured by quantitative ultrasound. Longitudinal studies using various modes of bone evaluation are necessary to determine the long-term effect of various types of exercise on bone properties.