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Table 3 Relationships between bone mineral parameters and quartile groups of IGF-I levels

From: Associations between serum levels of insulin-like growth factor-I and bone mineral acquisition in pubertal children: a 3-year follow-up study in Hamamatsu, Japan

 BaselineFollow-upBaseline and follow-up
MeanSDP for ANOVAP for ANCOVAP for TrendMeanSDP for ANOVAP for ANCOVAP for TrendP for repeated measures ANOVAP for repeated measures ANCOVA
Boys, N = 121TBLH BMC (g)
 IGF-I Q156797< 0.001nsansa963179< 0.0010.013ansa< 0.001a0.044a
 IGF-I Q2607881110195
 IGF-I Q36541391167259
 IGF-I Q47461591333222
TBLH aBMD (g/cm2)
 IGF-I Q10.5940.0380.003nsbnsb0.6920.059< 0.0010.011b0.007b< 0.001b0.004b
 IGF-I Q20.6030.0300.7400.072
 IGF-I Q30.6070.0380.7390.072
 IGF-I Q40.6300.0460.7860.066
TB BMAD (g/cm3)
 IGF-I Q10.0850.006< 0.001nsbnsb0.0760.0050.039nsbnsb< 0.001bnsb
 IGF-I Q20.0830.0060.0770.004
 IGF-I Q30.0800.0080.0740.004
 IGF-I Q40.0770.0080.0750.004
Girls, N = 133TBLH BMC (g)
 IGF-I Q1562113< 0.001nsansa918156< 0.001nsansa< 0.001ansa
 IGF-I Q26921241042159
 IGF-I Q37381441090165
 IGF-I Q48081581125176
TBLH aBMD (g/cm2)
 IGF-I Q10.5860.039< 0.001nsbnsb0.6790.053< 0.001nsbnsb<0.001bnsb
 IGF-I Q20.6250.0410.7180.063
 IGF-I Q30.6340.0430.7340.056
 IGF-I Q40.6530.0500.7490.057
TB BMAD (g/cm3)
 IGF-I Q10.0830.006< 0.001nsbnsb0.0770.005nsb0.036b0.006bnsbnsb
 IGF-I Q20.0800.0050.0780.004
 IGF-I Q30.0780.0060.0780.006
 IGF-I Q40.0770.0050.0790.004
  1. IGF-I insulin-like growth factor-I; TBLH total body less head, BMC bone mineral content, N number, Q quartile, ns not significant, aBMD areal bone mineral density, TB total body, BMAD bone mineral apparent density as an estimate of volumetric bone mineral density, IGF-I Q1 the lowest quartile group of IGF-I levels, IGF-I Q4 the highest quartile group of IGF-I levels
  2. ANOVA and ANCOVA were performed to explore differences among quartiles
  3. Multiple linear regression analysis was performed for trend tests from lowest to highest quartiles of IGF-I levels
  4. Repeated measures ANOVA and ANCOVA were performed to explore differences among quartiles. P < 0.05 was considered statistically significant
  5. aAdjusted for 25-hydroxyvitamin D, sedentary behavior, pubic hair appearance, weight, and height at baseline
  6. bAdjusted for 25-hydroxyvitamin D, sedentary behavior, pubic hair appearance, and weight at baseline