Abstract
Background:
The female athlete triad (Triad) has been associated with increased risk of bone stress injury (BSI) in certain populations.
Methods:
Thirty-nine female HS distance runners completed a questionnaire, which included disordered eating (DE)/eating disorder (ED), menstrual irregularities, BSI history, and height/weight. Serum labs were obtained, including ferritin, 25-hydroxyvitamin D, estradiol, insulin-like growth factor, and free T3. Runners completed dual-energy x-ray absorptiometry to measure bone mineral density (BMD) using Z-scores that are age, sex and ethnicity-matched. Body fat percentage was also obtained. A risk score was then calculated using energy availability (EA), body mass index (BMI), age of menarche, oligomenorrhea, BMD, and history of BSI. The statistical model used was Spearman correlation coefficient. P-values<0.05 were considered statistically significant.
Results:
The average age was 16.9 years. 76.3% of runners reported history of DE/ED, 23.7% delayed menarche, 45.0% amenorrhea or oligomenorrhea. 35.9% had low BMD (Z-score<-1.0) and 15.8% reported prior BSI. Average BMI was 19.8 kg/m2 and average BMI percentile was 36.2. Low free T3 was significantly associated with higher Triad risk scores (Spearman=-0.36, p=0.028). The association of low BMD with low 25-hydroxyvitamin D neared statistical significance (Spearman=0.28, p=0.086). BMD was significantly correlated with body fat percentage and BMI percentile (body fat percentage rs=0.36, p=0.028; BMI percentile rs=0.48, p=0.002).
Conclusions:
The prevalence of individual Triad risk factors in HS distance runners was high, with an alarmingly increased number of athletes with history of DE/ED and over 1/3 of runners with low BMD. Free T3 was inversely associated with Triad risk scores, which may be an indicator of low EA. Proper screening for the Triad in HS runners is imperative to help identify risk factors which may lead to future BSI. Further research is needed on the role of lab assessments in risk stratification.
Demographics
| Mean | SD | Lower 95% CI | Upper 95% CI | |
|---|---|---|---|---|
| Age (yr) | 16.9 | 1.0 | 16.6 | 17.2 |
| Current Mileage (miles) | 29.1 | 15.3 | 24.2 | 34 |
| BMI kg/m2 | 19.8 | 1.9 | 19.2 | 20.4 |
| BMI Percentile | 36.2 | 20.8 | 29.6 | 42.8 |
| Body Fat % | 27.1 | 3.4 | 26.0 | 28.2 |
| Spine Z-Score | -0.6 | 1.0 | -0.9 | -0.3 |
Correlation of Hormonal Factors with Female Athlete Triad Risk Score
|
|
|
|
|---|---|---|
| Free T3 | -0.36 | 0.028 |
| 25-Hydroxy Vitamin D | -0.16 | 0.325 |
| Estradiol | -0.30 | 0.075 |
| ILGF | -0.14 | 0.416 |