Table 1. Clinical characteristics of amenorrheic athletes (AA), eumenorrheic athletes (EA) and non-athletes (NA).
AA N = 38 | EA N = 24 | NA N = 23 | ANOVA P-value | AA vs. EA P-value | AA vs. NA P-value | EA vs. NA P-value | |
Age (years) | 19.3±2.0 | 18.0±2.0 | 19.1±1.7 | 0.04 | 0.03 | 0.86 | 0.16 |
Bone age (years) | 17.4±1.0 | 17.2±1.2 | 17.5±1.1 | 0.49 | 0.60 | 0.91 | 0.50 |
Tanner stage distribution (T2, 3, 4, 5) | 2.6%, 10.5%, 15.8%, 71.1% | 0%, 4.2%, 20.8%, 75.0% | 0%, 8.7%, 0%, 91.3% | 0.31 | 0.66 | 0.17 | 0.06 |
Age at menarche (y) | 14.0±1.8 | 12.8±1.4 | 12.2±1.5 | 0.0004 | 0.02 | 0.0004 | 0.45 |
Days since last menses | 165 (24–360) | - | - | - | |||
BMI (kg/m2) | 20.3±2.2 | 22.4±2.3 | 21.5±2.5 | 0.005 | 0.004 | 0.15 | 0.43 |
Height (cm) | 165.7±6.7 | 165.7±8.2 | 162.6±7.2 | 0.23 | 0.98 | 0.37 | 0.35 |
Fat mass (kg) | 11.7±3.7 | 15.1±4.4 | 16.0±4.9 | 0.0004 | 0.009 | 0.001 | 0.79 |
Lean mass (kg) | 43.5±5.7 | 46.3±7.7 | 40.5±4.4 | 0.006 | 0.18 | 0.15 | 0.004 |
Percent body fat | 20.3±5.1 | 23.5±3.8 | 27.0±5.2 | <0.0001 | 0.03 | <0.0001 | 0.04 |
Hours/week of exercise | 10.4±5.6 | 11.0±4.9 | 0.8±0.7 | <0.0001 | 0.87 | <0.0001 | <0.0001 |
Resting energy expenditure (calories) | 1247±183 | 1444±218 | 1255±193 | 0.0005 | 0.0007 | 0.99 | 0.004 |
REE/lean mass (cal/kg) | 28.9±3.8 | 31.6±5.3 | 31.2±4.9 | 0.04 | 0.06 | 0.13 | 0.95 |
History of fractures | 50% | 16.7% | 8.7% | 0.0007 | 0.01 | 0.0009 | 0.67 |
25(OH) vit D (ng/ml) | 38.3±12.5 | 30.5±13.8 | 21.1±7.8 | <0.0001 | 0.04 | <0.0001 | 0.03 |
Irisin (mcg/ml) § | 3.20 (2.58–3.53) | 3.85 (3.50–4.80) | 3.60 (3.30–4.20) | 0.0004 | 0.001 | 0.009 | 0.83 |
FGF21 (pg/ml) § | 54.5 (32.3–102.3) | 94.5 (60.3–189.8) | 132.0 (109.0–230.0) | 0.0001 | 0.02 | <0.0001 | 0.26 |
Mean ± SD or Median (Interquartile Range); FGF21: fibroblast growth factor 21; AA: amenorrheic athletes; EA: eumenorrheic athletes; NA: non-athletes.
P values reported for log converted data.