Christensen K, Støvring H, McGue M
Institute of Public Health, Epidemiology, and Institute for Demography and Statistics, University of Southern Denmark, Odense, Denmark.
J Epidemiol Community Health. 2001 Aug;55(8):583-7. doi: 10.1136/jech.55.8.583.
To evaluate whether genetic factors contribute to the association between low birth weight and increased blood pressure among adolescents.
Historical cohort study of twin pairs. It was evaluated whether (1) a negative association between birth weight and systolic blood pressure was found in the overall twin sample and (2) whether the intrapair difference in birth weight correlated with the intrapair difference in systolic blood pressure-thereby controlling for the effect of genetic factors (all in monozygotic and on average half in dizygotic pairs).
The Minnesota Twin Family Study.
1311 pairs of adolescent twins.
A negative association between birth weight and systolic blood pressure was retrieved in the overall sample. The regression coefficient after controlling for current weight was -1.88 mm Hg/kg (SE 0.61), which corresponds to results from previous studies of singleton adolescents. The regression coefficient fell to -0.64 mm Hg/kg (SE 0.86) when the intrapair analyses were used. The largest reduction was observed among monozygotic twins: from -2.44 mm Hg/kg (SE 0.75) in the overall monozygotic twin sample to -1.06 mm Hg/kg (SE 1.14) in the analyses of the within monozygotic pair differences.
The association between low birth weight and increased blood pressure later in life is well established. "The fetal programming hypothesis" suggests that the association is caused by intrauterine malnutrition while a new hypothesis "the fetal insulin hypothesis" proposes that genetically determined insulin resistance also contributes significantly to the association. A recent twin study of middle aged twins showed no evidence for an influence of genetic factors while this larger study provides support for the fetal insulin hypothesis: the association between birth weight and blood pressure attenuated among adolescents when genetic factors were controlled. Together this suggests an important contribution of genetic factors to the association between fetal growth and systolic blood pressure in adolescence.
评估遗传因素是否促成青少年低出生体重与血压升高之间的关联。
对双胞胎进行历史性队列研究。评估了：（1）在整个双胞胎样本中是否发现出生体重与收缩压之间存在负相关；（2）出生体重的双胞胎内差异是否与收缩压的双胞胎内差异相关，从而控制遗传因素的影响（单卵双胞胎中全部，异卵双胞胎中平均一半）。
明尼苏达双胞胎家庭研究。
1311对青少年双胞胎。
在整个样本中发现出生体重与收缩压之间存在负相关。控制当前体重后的回归系数为-1.88 mmHg/kg（标准误0.61），这与之前对单胎青少年的研究结果一致。当采用双胞胎内分析时，回归系数降至-0.64 mmHg/kg（标准误0.86）。在单卵双胞胎中观察到最大幅度的下降：从整个单卵双胞胎样本中的-2.44 mmHg/kg（标准误0.75）降至单卵双胞胎内差异分析中的-1.06 mmHg/kg（标准误1.14）。
低出生体重与日后血压升高之间的关联已得到充分证实。“胎儿编程假说”认为这种关联是由宫内营养不良引起的，而新的“胎儿胰岛素假说”提出，基因决定的胰岛素抵抗也对这种关联有显著影响。最近一项对中年双胞胎的研究没有发现遗传因素影响的证据，而这项规模更大的研究为胎儿胰岛素假说提供了支持：在控制遗传因素后，青少年中出生体重与血压之间的关联减弱。总体而言，这表明遗传因素对青少年期胎儿生长与收缩压之间的关联有重要影响。
