MIAMI — Weight and type of sport played by Division I varsity female athletes were significant predictors of bone mineral density measurements, according to a study presented at the annual meeting of the American Medical Society for Sports Medicine.
Dr. Willa Fornetti performed a cross-sectional analysis of 103 female athletes in gymnastics, softball, running, track, field hockey, rowing, swimming/diving, and volleyball at Michigan State University.
“BMI was markedly similar among groups—not what we anticipated. The runners were slightly lower than others, though,” said Dr. Fornetti, of Michigan State University, East Lansing.
As might be expected, gymnasts had the lowest mean height, and volleyball players had the highest. Runners and gymnasts had the lowest weights and fat-free mass, as well as the highest percentage of menstrual dysfunction.
Dr. Fornetti used dual-energy x-ray absorptiometry to measure total body, lumbar spine, pelvic, and average right/left leg BMD. She compared BMD measurements between athletes involved in sports by using analyses of covariance. She also determined significant predictors of BMD for each site through a stepwise regression analysis.
The 6 athletes with amenorrhea and 18 with oligomenorrhea had statistically significant lower bone mineral density than did other participants, Dr. Fornetti said.
The World Health Organization defines osteopenia as a bone density between 1 and 2.5 standard deviations below the bone density of a normal young adult.
“The good news is that none of our athletes met WHO criteria for osteopenia, regardless of menstrual function,” Dr. Fornetti said.
Runners, swimmers, and divers had significantly lower BMD than the other athletes. Runners also had the lowest mean lumbar spine BMD. Pelvic BMD was lower for runners, swimmers, and divers, Dr. Fornetti said. “Runners had significantly lower BMD at every site, except average leg score, versus athletes in field hockey, softball, and volleyball.”
Limitations of the study include its lack of data on nutrition and eating disorders, and history of training or injury. A large number of participants, multiple-site BMD measurements, and an ability to compare different types of sports are among its strengths, Dr. Fornetti said.
Because lower body weight was associated with lower BMD, “it can be used to screen runners, swimmers and divers,” Dr. Fornetti said. She added that clinicians should consider weight and type of sport played by a female varsity athlete when evaluating bone health.