Beardsall Kathryn, Ong Ken K, Murphy Nuala, Ahmed M Lynn, Zhao Jing Hua, Peeters Maarten W, Dunger David B
Department of Paediatrics, University of Cambridge, Addenbrooke's Hospital, Box 116, Cambridge CB2 0QQ, United Kingdom.
J Clin Endocrinol Metab. 2009 Oct;94(10):3708-13. doi: 10.1210/jc.2009-0757. Epub 2009 Sep 1.
Associations between size at birth, postnatal weight gain, and potential risk for adult disease have been variably explained by in utero exposures or genetic risk that could affect both outcomes. We utilized a twin model to explore these hypotheses.
One hundred pairs of healthy twins aged 8.9 yr (range, 7.2-10.9 yr) had fasting blood samples collected, blood pressure (BP) measured, and anthropometry assessed. All measurements were converted to sd scores (SDS) to adjust for age and sex.
Mean birth weights in both monozygotic and dizygotic twins were -0.90 SDS lower than the UK reference. In postnatal life, 58% of monozygotic twins and 59% of dizygotic twins showed rapid weight gain (a change of more than +0.67 in weight SDS) from birth. Postnatal weight gain was positively associated with sum of skinfolds (r = 0.51; P < 0.0005), fasting insulin levels (r = 0.35; P < 0.0005), systolic BP (r = 0.30; P < 0.0005), and diastolic BP (r = 0.15; P < 0.05) at follow-up. Heritability estimates (additive genetic components) were calculated using variance components models for: birth weight, 44%; postnatal weight gain, 80%; childhood height, 89%; body mass index, 72%; sum of skinfolds, 89%; waist circumference, 74%; fasting insulin, 65%; systolic BP, 33%; and diastolic BP, 29%.
Postnatal weight gain from birth, rather than birth weight, was associated with childhood risk markers for adult metabolic disease. Childhood weight gain was highly heritable, and genetic factors associated with postnatal weight gain are likely to also contribute to risks for adult disease.
出生时的大小、出生后体重增加与成人疾病潜在风险之间的关联，已通过可能影响这两种结果的子宫内暴露或遗传风险得到了不同程度的解释。我们采用双胞胎模型来探究这些假设。
收集了100对年龄为8.9岁（范围7.2 - 10.9岁）的健康双胞胎的空腹血样，测量了血压（BP），并评估了人体测量学指标。所有测量值均转换为标准差分数（SDS）以调整年龄和性别。
同卵双胞胎和异卵双胞胎的平均出生体重均比英国参考值低0.90 SDS。在出生后的生活中，58%的同卵双胞胎和59%的异卵双胞胎出生后体重快速增加（体重SDS变化超过 +0.67）。随访时，出生后体重增加与皮褶厚度总和（r = 0.51；P < 0.0005）、空腹胰岛素水平（r = 0.35；P < 0.0005）、收缩压（r = 0.30；P < 0.0005）和舒张压（r = 0.15；P < 0.05）呈正相关。使用方差成分模型计算遗传力估计值（加性遗传成分），结果如下：出生体重，44%；出生后体重增加，80%；儿童身高，89%；体重指数，72%；皮褶厚度总和，89%；腰围，74%；空腹胰岛素，65%；收缩压，33%；舒张压，29%。
出生后的体重增加，而非出生体重，与儿童期成人代谢疾病风险标志物相关。儿童期体重增加具有高度遗传性，与出生后体重增加相关的遗传因素可能也会导致成人疾病风险。
