Ortqvist Anne Kristina, Lundholm Cecilia, Carlström Eva, Lichtenstein Paul, Cnattingius Sven, Almqvist Catarina
Department of Medical Epidemiology and Biostatistics, Astrid Lindgren Children's Hospital, Karolinska Institute, Stockholm, Sweden.
Pediatrics. 2009 Oct;124(4):e737-43. doi: 10.1542/peds.2009-0305. Epub 2009 Sep 28.
Studies have found associations between low birth weight and asthma. However, this association could be due to familial confounding. Our objective was to investigate whether fetal growth and birth weight affect the risk of asthma in childhood, controlling for gestational age (GA), and shared (familial) environment and genetic factors.
Information on asthma, zygosity, birth characteristics, and potential confounders was collected for all 9- and 12-year-old twins through the Swedish Twin Register and Medical Birth Register. To obtain an overall effect of birth weight on risk of asthma, we performed cohort analyses on all twins (N = 10918). To address genetic and shared environmental confounding, we performed a co-twin control analysis by using the 157 monozygotic and 289 dizygotic same-sex twin pairs who were discordant for asthma.
The overall rate of asthma ever was 13.7%. In the cohort analysis, the adjusted odds ratio (OR) for asthma in relation to a 1000-g decrease in birth weight was 1.57 (95% confidence interval [CI]: 1.38-1.79), and for each reduced gestational week the OR was 1.10 (95% CI: 1.07-1.13). In the co-twin control analyses, a 1000-g decrease in birth weight corresponded to an OR of 1.25 (95% CI: 0.74-2.10) for dizygotic same-sex twins and 2.42 (95% CI: 1.00-5.88) for monozygotic twins.
There is an association between fetal growth and childhood asthma that is independent of GA and shared (familial) environment and genetic factors, which indicates that fetal growth restriction affects lung development, supporting additional studies on the early metabolic and physiologic mechanisms of childhood asthma.
研究发现低出生体重与哮喘之间存在关联。然而，这种关联可能是由于家族性混杂因素所致。我们的目的是在控制胎龄（GA）、共享（家族）环境和遗传因素的情况下，调查胎儿生长和出生体重是否会影响儿童患哮喘的风险。
通过瑞典双胞胎登记册和医疗出生登记册，收集了所有9岁和12岁双胞胎的哮喘、合子性、出生特征及潜在混杂因素的信息。为了获得出生体重对哮喘风险的总体影响，我们对所有双胞胎（N = 10918）进行了队列分析。为了解决遗传和共享环境混杂问题，我们对157对单卵双胞胎和289对双卵同性双胞胎中哮喘情况不一致的双胞胎进行了共双胞胎对照分析。
哮喘总发病率为13.7%。在队列分析中，出生体重每降低1000克，哮喘的校正比值比（OR）为1.57（95%置信区间[CI]：1.38 - 1.79），胎龄每减少1周，OR为1.10（95% CI：1.07 - 1.13）。在共双胞胎对照分析中，出生体重降低1000克，双卵同性双胞胎的OR为1.25（95% CI：0.74 - 2.10），单卵双胞胎的OR为2.42（95% CI：1.00 - 5.88）。
胎儿生长与儿童哮喘之间存在关联，且独立于胎龄、共享（家族）环境和遗传因素，这表明胎儿生长受限会影响肺部发育，支持对儿童哮喘早期代谢和生理机制进行更多研究。
