Jackowski Stefan A, Faulkner Robert A, Farthing Jonathan P, Kontulainen Saija A, Beck Thomas J, Baxter-Jones Adam D G
University of Saskatchewan, Saskatoon, SK, Canada.
Bone. 2009 Jun;44(6):1186-90. doi: 10.1016/j.bone.2009.02.008. Epub 2009 Feb 21.
We examined the timing of the age and the magnitude of peak lean tissue mass accrual (PLTV) relative to the age and magnitude of two variables of bone strength [peak cross sectional area velocity (PCSAV), and peak section modulus velocity, (PZV)] at the proximal femur in males and females during the adolescent growth spurt. We hypothesized that the age of PLTV would precede the ages of PCSAV and PZV and that there is a positive relationship between the magnitude of PLTV and both PCSAV and PZV in both genders.
41 males and 42 females aged 8-18 years were selected from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2005). Participants' total body lean tissue mass was assessed annually for 6 consecutive years using DXA. Narrow neck and femoral shaft cross sectional areas (CSA) and section modulus (Z) were determined using the hip structural analysis (HSA) program. Participants were aligned by maturational age (years from peak height velocity). Lean tissue mass, CSA, and Z were converted into whole year velocities and the maturational age of peak tissue velocities was determined using a cubic spline curve fitting procedure. A 2 x 3 (gender x tissue) factorial MANOVA with repeated measures was used to test for differences between age of PLTV and the ages of PCSAV and PZV between genders. Multiple regression analyses were used to examine the relationship between PLTV and both PCSAV and PZV.
There were no sex differences in the ages at which tissue peaks occurred when aligned by maturational age. There were significant differences between the age of PLTV and both PCSAV and PZV at the narrow neck (p=0.001) and femoral shaft (p=0.03), where the age of PLTV preceded both PCSAV and PZV when pooled by gender. PLTV was a significant predictor of the magnitude of both PCSAV and PZV at all sites (p<0.05).
These findings support the hypothesis that the age of PLTV precedes the age of PCSA and PZV at the proximal femur. Results support the theory that muscle development is an important factor in affecting bone strength.
我们研究了青春期生长突增期间，男性和女性股骨近端瘦组织质量峰值累积（PLTV）的年龄及峰值大小相对于骨强度两个变量[峰值横截面积速度（PCSAV）和峰值截面模量速度（PZV）]的年龄及大小的时间关系。我们假设PLTV的年龄会先于PCSAV和PZV的年龄，且在两性中PLTV的大小与PCSAV和PZV均呈正相关。
从萨斯喀彻温省儿童骨矿物质累积研究（1991 - 2005年）中选取了41名男性和42名年龄在8 - 18岁的女性。连续6年每年使用双能X线吸收法（DXA）评估参与者的全身瘦组织质量。使用髋部结构分析（HSA）程序确定窄颈和股骨干的横截面积（CSA）以及截面模量（Z）。根据成熟年龄（距身高速度峰值的年数）对参与者进行分组。将瘦组织质量、CSA和Z转换为全年速度，并使用三次样条曲线拟合程序确定峰值组织速度的成熟年龄。采用重复测量的2×3（性别×组织）析因多变量方差分析（MANOVA）来检验两性之间PLTV的年龄与PCSAV和PZV的年龄差异。使用多元回归分析来研究PLTV与PCSAV和PZV之间的关系。
按成熟年龄分组时，各组织峰值出现的年龄不存在性别差异。在窄颈（p = 0.001）和股骨干（p = 0.03）处，PLTV的年龄与PCSAV和PZV的年龄之间存在显著差异，按性别合并后，PLTV的年龄先于PCSAV和PZV。在所有部位，PLTV都是PCSAV和PZV大小的显著预测因子（p < 0.05）。
这些发现支持了以下假设，即股骨近端PLTV的年龄先于PCSA和PZV的年龄。结果支持了肌肉发育是影响骨强度的重要因素这一理论。
