Low Bone Density Risk Is Higher in Exercising Women with Multiple Triad Risk Factors

The cumulative effect of the female athlete triad (Triad) risk factors on the likelihood of low bone mineral density (BMD) in exercising women is unclear. Purpose This study aimed to determine the risk of low BMD in exercising women with multiple Triad risk factors. Methods We retrospectively examined cross-sectional data from 437 exercising women (mean +/- SD age of 18.0 +/- 3.5 yr, weighed 57.5 +/- 7.1 kg with 24.5% +/- 6.1% body fat) obtained at baseline from 4 prospective cohort studies examining Triad risk factors. Questionnaires were completed to obtain information on demographic characteristics, self-reported eating attitudes/behaviors, menstrual function, sport/activity participation, and medication use. Height and body weight were measured. BMD was measured using dual energy x-ray absorptiometry. Low BMD was defined as z-scores of <-1 and <=-2. Chi-square tests were performed to determine the percentage of women with low BMD who met the criteria for individual (current oligo/amenorrhea, late menarche, low body mass index (BMI), elevated dietary restraint, lean sport/activity participation) or multiple (2, 3, 4, or 5) Triad risk factors. Results Late menarche and low BMI were associated with the highest percentage of low BMD (z-score < -1), 55% and 54%, respectively, and low BMD (z-score <=-2), 14% and 16%, respectively. The percentage of participants with low BMD (z-score < -1 and <=-2) increased from 10% to 62% and from 2% to 18%, respectively, as women met the criteria for an increasing number of Triad risk factors. Conclusions A cumulative number of Triad risk factors were associated with an increased risk of low BMD, suggesting a dose-response association between the number of Triad risk factors and BMD in exercising women. Further research should be conducted to develop a user-friendly algorithm integrating these indicators of risk for low BMD in exercising women (particularly factors associated with low BMI/body weight, menstrual dysfunction, lean sport/activity participation, and elevated dietary restraint).