Bone mineral density in collegiate female athletes: comparisons among sports

Context: Some female athletes may have decreased bone mineral density (BMD), which puts them at higher risk for stress fractures and future osteoporosis.

Objective: To compare site-specific BMD among National Collegiate Athletic Association Division I varsity female athletes and to determine predictor variables of BMD measurements.

Design: Between-groups design.

Setting: University health care system.

Patients or other participants: All women varsity athletes were invited to participate in a cross-sectional study. Of 12 sports, we obtained complete data from 99 women (mean age = 20.2 +/- 1.3 years) representing gymnastics, softball, cross-country, track, field hockey, soccer, crew, and swimming/diving.

Main outcome measure(s): Each participant was weighed, measured, and questioned about her menstrual status. Using dual-energy x-ray absorptiometry, we measured total-body BMD and region-of-interest scores for lumbar spine, pelvis, and average leg (average from right and left leg measurements) BMD. Using analyses of covariance, we compared BMD measurements among sports at each site while controlling for menstrual status and mass, and we performed a stepwise regression analysis to determine significant predictors of BMD at each site.

Results: Twenty-three athletes were oligomenorrheic or amenorrheic. Runners had the lowest total-body (1.079 +/- 0.055 g.cm (-2)) and site-specific ( P < .01) BMD values for every site except average leg score when compared with gymnasts and softball players. Swimmers and divers had significantly lower average leg BMD (1.117 +/- 0.086 g.cm (-2)) than athletes in every other sport except runners and rowers ( P < .01). Regression analysis revealed only mass and sport as significant predictors of total-body BMD.

Conclusions: Runners and swimmers and divers demonstrated some deficits in site-specific BMD values when compared with athletes in other sports. When treating a female varsity athlete, athletic trainers should consider her mass and sport type with regard to her bone health.