VU University, Department of Biological Psychology, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands.
J Am Acad Child Adolesc Psychiatry. 2011 Dec;50(12):1247-54.e2. doi: 10.1016/j.jaac.2011.09.007. Epub 2011 Oct 22.
Low birth weight (LBW) is associated with attention problems (AP) and attention-deficit/hyperactivity disorder (ADHD). The etiology of this association is unclear. We investigate whether there is a causal influence of birth weight (BW) on AP and whether the BW effect is mediated by catch-up growth (CUG) in low-BW children.
Longitudinal data from >29,000 twins registered with the Netherlands Twin Register with BW ≥1,500 g and gestational age (GA) ≥32 weeks were analyzed with the cotwin control method. Hyperactivity and AP were assessed at ages 3, 7, 10, and 12 years; weight was assessed at birth and age 2 years.
Children in the lowest BW category of 1,500 to 2,000 g scored 0.18 to 0.37 standard deviations (SD) higher on AP than children in the reference category of 3,000 to 3,500 g. This effect was present in term-born and preterm-born children. Importantly, in BW discordant monozygotic (MZ), dizygotic (DZ), and unrelated (UR) pairs, the child with the lower BW scored higher on hyperactivity and AP than the child with the higher BW and within-pair differences were similar for MZ, DZ, and UR pairs. This pattern is consistent with a causal effect of BW on AP. MZ and DZ twin pairs concordant for LBW but discordant for CUG showed similar AP scores, thus ruling out any effect of CUG on AP.
These results strongly indicate that the association of birth weight and AP represents a causal relationship. The effects of BW are not explained by CUG in LBW children.
低出生体重（LBW）与注意力问题（AP）和注意缺陷多动障碍（ADHD）有关。这种关联的病因尚不清楚。我们研究出生体重（BW）对 AP 是否存在因果影响，以及低 BW 儿童的追赶生长（CUG）是否介导了 BW 效应。
使用荷兰双胞胎登记处≥29,000 对双胞胎的纵向数据进行分析，这些双胞胎的 BW≥1,500g，GA≥32 周。采用同卵双胞胎对照法评估 3、7、10 和 12 岁时的多动和 AP；在出生时和 2 岁时评估体重。
BW 处于 1,500 至 2,000g 最低类别中的儿童比 BW 处于 3,000 至 3,500g 参考类别的儿童在 AP 上的得分高出 0.18 至 0.37 个标准差（SD）。这种影响在足月出生和早产出生的儿童中均存在。重要的是，在 BW 不一致的同卵（MZ）、异卵（DZ）和无关（UR）双胞胎中，BW 较低的儿童在多动和 AP 方面的得分高于 BW 较高的儿童，并且 MZ、DZ 和 UR 双胞胎之间的个体内差异相似。这种模式与 BW 对 AP 的因果影响一致。LBW 但 CUG 不一致的 MZ 和 DZ 双胞胎具有相似的 AP 评分，因此排除了 CUG 对 AP 的任何影响。
这些结果强烈表明，出生体重与 AP 的关联代表了一种因果关系。LBW 儿童的 CUG 不能解释 BW 对 AP 的影响。
