Table 3

Least squares means for peak height velocity and age 17 bone outcomes (adjusted for height and weight) by MVPA trajectory group membership*

 Girls (N=189)Pairwise comparisons (p Values)
Group 1
N=92
Group 2
N=86
Group 3
N=11
Group 1
v 2
Group 1
v 3
Group 2
v 3
Age at PHV, years11.811.812.0
DXA and hip structural analysis
 Whole body BMC, g1756.81812.41956.90.04020.00040.0111
 Hip BMC, g32.0733.4437.030.03470.00030.0084
 Hip BMD, g/cm20.9941.0361.0820.01460.01560.2133
 Femoral Neck CSA, cm23.133.293.500.01170.00410.0962
 Femoral Neck Section Modulus, cm31.401.521.700.0009<0.00010.0159
Bone strength (pQCT)
 Bone Stress Index (tibia 4% site), mg2/mm493.84101.30112.080.01100.00290.0782
 Polar moment of inertia (tibia 38% site), mm41445.81521.51714.90.0089<.00010.0015
 Polar moment of inertia (tibia 66% site), mm42158.92251.02431.30.02600.00160.0364
 Boys (N=160)Pairwise comparisons (p Values)
Group 1
N=68
Group 2
N=60
Group 3
N=32
Group 1
v 2
Group 1
v 3
Group 2
v 3
Age at PHV, years13.613.513.8
DXA and hip structural analysis
 Whole Body BMC, g2310.12393.32485.50.10180.00480.1352
 Hip BMC, g45.6747.0250.260.30630.00460.0448
 Hip BMD, g/cm21.1051.1301.1980.31120.00150.0185
 Femoral Neck CSA, cm24.054.154.430.35880.00570.0433
 Femoral Neck Section Modulus, cm32.122.142.320.74510.01590.0319
Bone strength (pQCT)
 Bone Stress Index (tibia 4% site), mg2/mm4126.44136.31142.580.04150.00610.2798
 Polar moment of inertia (tibia 38% site), mm41940.42088.12102.90.00460.00990.8132
 Polar moment of inertia (tibia 66% site), mm42940.93102.23078.70.04830.16010.8104
  • SAS GLM procedure was used for comparison: group 3—most active over time, group —consistently low activity.

  • p Values from pairwise comparisons not adjusted for multiple comparisons (p Value<=0.05/3 corresponds to Bonferroni adjustment for multiple comparisons).

  • BMC, bone mineral content; BMD, bone mineral density; CSA, cross-sectional area; MVPA, moderate-and-vigorous intensity physical activity; PHV, peak height velocity; pQCT, peripheral quantitative CT.