Prospective Evaluation of Stress Fractures/Overuse Injuries in a Population ofWest Point Cadets

摘要

The objective of this study was to examine the effect of physical training inadolescent males and females on the interrelationship of the hypothaliunic-pituitary-gonadal axis, bone mineral density, and incidence of stress fractures. Participants consisted of male and female Cadets enrolled at the U.S. Military Academy, West Point, NY. Both male and female Cadets had reduced plasma gonadal steroid levels during an intense period of physical training over the first six months of enrollment at the Academy. Female Cadets had a reduction in BMD with six months. Gains in bone mineral density were not noted until the second year in both males and females. In female Cadets who had persistently low estradiol levels, BMD did not increase over the study. In males with persistently low testosterone concentrations, BMD did not increase and was decreased compared to other subjects. The incidence of stress fractures was 6 percent and did not appear related to hypogonadism or low BMD. Initiation of rigorous physical training results in a period of hypogonadism and absence of BMD gain in both male and female adolescents. Persistence of hypogonadism is associated with attenuated BMD gain in both females and males. The initial incidence of stress fractures is similar in males and females and does not appear related to gonadal hormone levels or BMD. The undertajing by adolescents of rigorous physical training, which reduces gonadal steroid levels and BMD gain, does not appear to result in a significant incidence of stress fractures irrespective of gender.