TABLE 4

Regression Modeling With Covariates Including Diagnostic Category, Bone Age, BMI z Score, Lean Mass, Activity Score, and IGF-I Levels

Parameter EstimatePVariability Explained, %
Lumbar BMD
    Lean body mass8.33 × 10−3.00242.2
    Bone age0.024.004
    Diagnostic category (athletes with amenorrhea vs athletes with eumenorrhea and control subjects)−0.037.004
Lumbar BMD z score
    Lean body mass6.84 × 10−2.00426.2
    Diagnostic category (athletes with amenorrhea vs athletes with eumenorrhea and control subjects)−0.245.02
Lumbar BMAD
    BMI z score0.008.0127.5
    Bone age0.003.03
    IGF-I level2.00 × 10−5.04
Lumbar BMAD z score
    BMI z score0.595.00224.4
    IGF-I level9.26 × 10−4.09
Hip BMD
    Lean body mass9.57 × 10−3.00132.5
    Diagnostic category (athletes with amenorrhea and control subjects vs athletes with eumenorrhea)−0.034.01
Hip BMD z score
    Lean body mass7.67 × 10−2.00130.0
    Diagnostic category (athletes with amenorrhea and control subjects vs athletes with eumenorrhea)−0.237.03
WB BMD
    Lean body mass6.72 × 10−3.00142.8
    Diagnostic category (athletes with amenorrhea vs athletes with eumenorrhea and control subjects)−0.027.005
    Bone age0.165.007
WB BMD z score
    Lean body mass8.12 × 10−2.000729.7
    Diagnostic category (athletes with amenorrhea vs athletes with eumenorrhea and control subjects)−0.227.04
WB BMC/height
    Lean body mass0.149.000154.5
    Diagnostic category (athletes with amenorrhea vs athletes with eumenorrhea and control subjects)−0.503.0007
    Bone age0.250.009
WB BMC/height z score
    Lean body mass5.95 × 10−2.000135.7
    Diagnostic category (athletes with amenorrhea vs athletes with eumenorrhea and control subjects)−0.153.03