目前有关儿童青少年坐高、下肢长及其比值的报道多为非双生子人群的研究。为了解遗传和环境因素对儿童青少年坐高、下肢长及坐高与下肢长比值影响的相对大小,我们对796对6~18岁双生子的身高和坐高进行了测量,计算下肢长及坐高与下肢长比值,采用结构方程模型分析其遗传和环境相对效应。结果发现,校正年龄后,男女15~18岁年龄组坐高和下肢长的遗传度（0.63~0.78）均分别高于同性别低年龄段儿童青少年（0.31~0.68）;坐高与下肢长比值的遗传度除9~11岁女生（0.84）外,其他年龄组均较低（男0.16~0.46,女0.21~0.57）;共同环境因素和特殊环境因素对6~14岁儿童青少年各指标的作用较大。本研究提示,在快速发育时期,坐高、下肢长和坐高与下肢长比值对环境因素更为敏感,遗传度较低;机体越成熟,其遗传效应更强。

Most of the studies on sitting height(h), lower limb length(L), and their ratio(h/L) were based on non-twin populations. To understand the relative influence of genetic and environmental factors on the sitting height, lower limb length and the ratio of sitting height to lower limb length of children and adolescents, we measured their standing height(H) and sitting height of 796 pairs of twins aged 6-18 years old, and computed their lower limb length and the ratio of h and L. Genetic analyses was done using structural equation models. After adjusting the age, the degree of heritability(d) of h and L in the 15-18 years old group(0.63≤d<0.78) was higher than that for h and L in other younger age groups(0.31≤d<0.68) in both sexes; the heritability of h/L in boys(0.16≤d<0.46) and girls (0.21≤d<0.57) was low except for that of h/L in girls (d=0.84) aged 9-11 years. Our study findings show that common and unique environmental factors exerted a stronger influence on these anthropometric measurements in children and adolescents aged 6-14 years, suggesting during the period of rapid growth, their h, L and h/L are more sensitive to environmental effects. When individuals approached maturity, the genetic effects became stronger.