Adane A A, Tooth L R, Mishra G D
The University of Queensland, School of Public Health, Centre for Longitudinal and Life Course Research, Herston QLD, Australia.
J Dev Orig Health Dis. 2019 Oct;10(5):570-577. doi: 10.1017/S2040174418001137. Epub 2019 Jan 10.
While birthweight of offspring is associated with pre-pregnancy body mass index (BMI) and later risk of obesity, its mediating effect between the association of maternal pre-pregnancy BMI and offspring's childhood anthropometrics has rarely been investigated. This study aimed to examine whether offspring birthweight is a mediator in the association between pre-pregnancy BMI and offspring's childhood anthropometrics. The study included 1,618 mother-child pairs from the Australian Longitudinal Study on Women's Health and Mothers and their Children's Health Study. Children's anthropometrics [mean age 8.6 (s.d. =3.0) years] were calculated from the mothers' self-reported child weight and height measures. G-computation was used to estimate the natural direct and indirect (via birthweight) effects of pre-pregnancy BMI. In the fully adjusted model for maternal sociodemographic and lifestyle factors, the natural direct effects of pre-pregnancy obesity on child BMI-for-age, height-for-age, weight-for-age and weight-for-height outcomes were, β (95% confidence interval, CI), 0.75 (0.55, 0.95), 0.13 (-0.07, 0.32), 0.62 (0.44, 0.80) and 0.57 (0.24, 0.90), respectively. The corresponding natural indirect effects were 0.04 (-0.04, 0.12), -0.01 (-0.09, 0.07), -0.01 (-0.08, 0.07) and 0.09 (-0.05, 0.23). Similar results were observed for pre-pregnancy overweight and pre-pregnancy BMI as a continuous scale. Most of the effect of pre-pregnancy obesity on childhood weight-related anthropometric outcomes appears to be via a direct effect, not mediated through offspring's birthweight.
虽然子代出生体重与孕前体重指数（BMI）以及后期肥胖风险相关，但其在母亲孕前BMI与子代儿童期人体测量指标之间关联中的中介作用鲜有研究。本研究旨在探讨子代出生体重是否为孕前BMI与子代儿童期人体测量指标之间关联的中介因素。该研究纳入了来自澳大利亚妇女健康纵向研究以及母亲与子女健康研究的1618对母婴。儿童的人体测量指标[平均年龄8.6（标准差=3.0）岁]根据母亲自我报告的孩子体重和身高测量值计算得出。采用G计算法估计孕前BMI的自然直接效应和间接效应（通过出生体重）。在对母亲社会人口学和生活方式因素进行完全调整的模型中，孕前肥胖对子代年龄别BMI、年龄别身高、年龄别体重和身高别体重结果的自然直接效应分别为β（95%置信区间，CI）：0.75（0.55，0.95）、0.13（-0.07，0.32）、0.62（0.44，0.80）和0.57（0.24，0.90）。相应的自然间接效应分别为0.04（-0.04，0.12）、-0.01（-0.09，0.07）、-0.01（-0.08，0.07）和0.09（-0.05，0.23）。对于孕前超重以及作为连续变量的孕前BMI，也观察到了类似结果。孕前肥胖对儿童期体重相关人体测量指标结果的影响大多似乎是通过直接效应，而非通过子代出生体重介导。
