Ijzerman R G, Stehouwer C D, van Weissenbruch M M, de Geus E J, Boomsma D I
Department of Internal Medicine, Institute for Cardiovascular Research-Vrije Universiteit, Academic Hospital Vrije Universiteit, Amsterdam, The Netherlands.
Twin Res. 2001 Oct;4(5):337-43. doi: 10.1375/1369052012687.
Epidemiological studies have consistently shown a positive association between size at birth (i.e. birth weight or birth length) and height in children, adolescents and adults. To examine whether this association is explained by genetic or nongenetic (intra-uterine) factors, we investigated birth weight, birth length and height in 60 dizygotic and 68 monozygotic adolescent twin pairs still living with their parents. Birth weight of the twins was obtained from their mothers. Height was measured in a standardised way. The mean age was 17+/-1.7 years for the dizygotic twins and 16+/-1.8 years for the monozygotic twins. Both dizygotic and monozygotic twins with the lowest birth weight from each pair had a height that was lower compared to their co-twins with the highest birth weight (dizygotic twins: 172.2+/-7.9 vs. 173.8+/-9.4 cm [p = 0.05]; monozygotic twins: 171.1+/-9.4 vs. 171.8+/-9.5 cm [p = 0.01]). Similarly, both dizygotic and monozygotic twins with the shortest birth length from each pair had a height that was lower compared to their co-twins with the longest birth length (dizygotic twins: 172.3+/-7.9 vs. 174.9plus minus9.7 cm [p < 0.05]; monozygotic twins: 168.9+/-10.6 vs. 169.9+/-10.2 cm [p < 0.01]). In addition, intra-pair differences in birth weight and birth length were significantly associated with differences in height in both dizygotic twins (regression coefficient: 4.3 cm/kg [95% confidence interval: 1.0 to 7.5] and 0.96 cm/cm [0.17 to 1.74], respectively) and monozygotic twins (2.8 cm/kg [1.4 to 4.1] and 0.73 cm/cm [0.40 to 1.06], respectively). These associations were stronger in dizygotic than in monozygotic twins, but this difference was not statistically significant (for birth weight p = 0.4; and for birth length p = 0.6). However, genetic model fitting indicated that models incorporating a genetic source of the covariance gave a better description of the observed association of birth weight and length with height in later life than models not incorporating this genetic source. The results were similar for data on adult height after 12 years of follow-up in a subgroup of these twin pairs. These data suggest that the association between size at birth and height in later life is influenced by non-genetic intra-uterine and by genetic factors.
流行病学研究一直表明，出生时的体型（即出生体重或出生身长）与儿童、青少年及成年人的身高之间存在正相关。为了探究这种关联是由遗传因素还是非遗传（子宫内）因素所致，我们调查了仍与父母同住的60对异卵和68对同卵青少年双胞胎的出生体重、出生身长和身高。双胞胎的出生体重由其母亲提供。身高以标准化方式测量。异卵双胞胎的平均年龄为17±1.7岁，同卵双胞胎的平均年龄为16±1.8岁。每对中出生体重最低的异卵双胞胎和同卵双胞胎，其身高均低于出生体重最高的同胞双胞胎（异卵双胞胎：172.2±7.9厘米 vs. 173.8±9.4厘米 [p = 0.05]；同卵双胞胎：171.1±9.4厘米 vs. 171.8±9.5厘米 [p = 0.01]）。同样，每对中出生身长最短的异卵双胞胎和同卵双胞胎，其身高均低于出生身长最长的同胞双胞胎（异卵双胞胎：172.3±7.9厘米 vs. 174.9±9.7厘米 [p < 0.05]；同卵双胞胎：168.9±10.6厘米 vs. 169.9±10.2厘米 [p < 0.01]）。此外，异卵双胞胎和同卵双胞胎中，出生体重和出生身长的双胞胎内差异均与身高差异显著相关（回归系数分别为：4.3厘米/千克 [95%置信区间：1.0至7.5] 和0.96厘米/厘米 [0.17至1.74]，异卵双胞胎；2.8厘米/千克 [1.4至4.1] 和0.73厘米/厘米 [0.40至1.06]，同卵双胞胎）。这些关联在异卵双胞胎中比在同卵双胞胎中更强，但这种差异无统计学意义（出生体重p = 0.4；出生身长p = 0.6）。然而，遗传模型拟合表明，纳入协方差遗传来源的模型比未纳入该遗传来源的模型能更好地描述观察到的出生体重和身长与晚年身高之间的关联。对这些双胞胎亚组进行12年随访后的成人身高数据结果相似。这些数据表明，出生时的体型与晚年身高之间的关联受非遗传子宫内因素和遗传因素的影响。
