Anthropometric Predictors of the Female Athlete Triad among Adolescent Athletes

Abstract

Early detection of the Female Athlete Triad is essential for the long-term health of many adolescent female athletes. Recent studies suggest that anthropmetric factors such as low body mass or percent body fat increase the risk for the Triad components. PURPOSE: The purpose of this study was to assess relationships of common anthropometric markers [Ideal Body Weight (IBW) via the Hamwi formula, youth-percentile Body Mass Index (BMI), adult BMI categories, and body fat percentage (BF%)] and the increased likelihood of the three Triad components [1.)low energy availability (LEA), as measured by dietary restraint (DR), 2.) menstrual dysfunction (MD), and 3.) low bone mineral density (BMD)] in female adolescent athletes. METHODS: A total of 320 high school female athletes (age 16.1.7 ± 0.2y) completed the Eating Disorder Examiniation-Questionnaire (EDE-Q), a menstrual history questionnaire, and a dual-energy x-ray absorptiometry (DXA) assessment to measure DR, MD, and BMD, respectively. IBW and BMI were calculated using height and weight, and BF% was determined by DXA. Clinically recognized cut-off points were used for each anthropometric marker. Logistic regression analyses indicated the likelihood [odds ratios (OR) and 95% Confidence Intervals (CI)] of the anthropometric factors predicting Triad components. RESULTS: Underweight categories for the anthropometric measures predicted greater likelihood of MD and low BMD. Athletes with an IBW <85% were nearly four times more likely to report MD (OR= 3.7, 95% CI=1.8-7.9) and have low BMD (OR=3.5, 95% CI=1.7-7.5) than those in their respective reference groups. Those in <5th percentile for their age appropriate BMI were nine times more likely to report MD (OR 9.1, 95% CI=1.8-46.9) and and have low BMD compared with those in the 50-85th percentile. Athletes with a high BF% were almost three times more likely to report DR (OR= 2.6, 95% CI=1.4-4.8). CONCLUSIONS: Our study indicates that low age-adjusted BMI and low IBW (Hamwi formula), may be practical, inexpensive tools to identify MD and low BMD in adolescent athletes. These measures should be tested for their ability to serve as a tool to minimize the risk for the Female Athlete Triad.