Journal of Osteoporosis

Research Article

The Relationship between Physical Activity and Bone during Adolescence Differs according to Sex and Biological Maturity

Table 2

Bone parameters for adolescent boys and girls (

n = 99

). Mean (SD).


Variables	Boys	Girls	P value
Variables	$n = 46$	$n = 53$	P value

BUA (dB $\cdot$ MHz⁻¹)	75.9 (1.9)	81.7 (1.9)	.03
FN area (cm²)	4.81 (0.36)	4.46 (0.46)	.001
FN BMC (g)	4.34 (0.14)	3.86 (0.09)	.005
FN BMD (g $\cdot$ cm⁻²)	0.903 (0.025)	0.867 (0.018)	.19
FN BMAD (g $\cdot$ cm⁻³)	0.361 (0.062)	0.364 (0.055)	.80
FN CSMI (cm⁴)	2.98 (0.33)	2.49 (0.70)	.01
TR BMC (g)	9.39 (0.56)	7.17 (0.33)	.001
TR BMD (g $\cdot$ cm⁻²)	0.748 (0.023)	0.674 (0.018)	.01
LS area (cm²)	41.1 (5.5)	40.3 (3.8)	.46
LS BMC (g)	32.9 (1.5)	35.4 (1.2)	.15
LS BMD (g $\cdot$ cm⁻²)	0.791 (0.021)	0.875 (0.020)	.006
LS BMAD (g $\cdot$ cm⁻³)	0.116 (0.015)	0.134 (0.019)	.001
LS IBS (g² $\cdot$ cm⁻⁴)	0.813 (0.229)	0.997 (0.280)	.005
WB BMC (g)	2194 (78)	2147 (53)	.66
WB BMD (g $\cdot$ cm⁻²)	0.854 (0.017)	0.849 (0.014)	.88

Variable definitions: BMAD, bone mineral apparent density, BMC, bone mineral content; BMD, bone mineral density; BUA, broadband ultrasound attenuationl; CSMI, cross-sectional moment of inertia; FN, femoral neck; IBS, index of bone structural strength; LS, lumbar spine; WB, whole body.