Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou, China.
Ministry of Education Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Research Sciences, Zhejiang University, Hangzhou, China.
Environ Pollut. 2018 Jun;237:581-591. doi: 10.1016/j.envpol.2018.02.044. Epub 2018 Mar 15.
Prenatal exposure to polychlorinated biphenyl (PCB) is suspected to interfere with fetal development including reproductive and thyroid function and birth outcomes, but published evidence are still sparse. We designed a cross-sectional study to analyze the associations between PCB levels in umbilical cord sera and hormones and birth outcomes of mothers and newborns who are residents from an island. Seven indicator-PCB (PCB-28, 52, 101, 118, 138, 153, 180), and five reproductive hormones including luteotropic hormones (LH), estradiol (E2), testosterone (T), follicle-stimulating hormones (FSH) and anti-Mullerian hormones (AMH), and three thyroid hormones including tri-iodothyronine (T3), tetra-iodothyronine (T4) and thyroid stimulating hormones (TSH) were measured in 106 cord sera specimens. Birth outcomes include birth weight, length, head circumference, and gestational age. Multiple linear regression and quartile regression were used to analyze the associations between PCB and each of the hormones and birth outcomes, adjusting for selected potential confounders. The median value of total PCB in umbilical cord sera was 2.02 μg L (IQR, 1.13-4.64). Several negative associations between PCB exposure and reproductive hormones were found. Among them, the β value of PCB-101 for FSH reached -0.38 (95%CI, -0.69, -0.07; p = 0.02). Moreover, we also found some sex-specific associations i.e. PCB-28 was negatively correlated with LH and T and PCB-118 was negatively correlated with T in male newborns but not in female newborns. The associations between PCB and birth outcomes seem to differ by molecular weight of the PCB congeners i.e. the low-chlorinated PCB congeners were negatively associated with gestational age and head circumference while high-chlorinated PCB congeners were positively associated birth weight and gestational age. In this study, we found that PCB congeners with different molecular weight has different associations with hormones and birth outcomes, and future studies are recommended to investigate underlying mechanisms of these associations.
产前多氯联苯（PCB）暴露被怀疑会干扰胎儿发育，包括生殖和甲状腺功能以及出生结局，但已发表的证据仍然很少。我们设计了一项横断面研究，以分析脐带血清中 PCB 水平与来自一个岛屿的母亲和新生儿的激素及出生结局之间的关系。我们测量了 106 份脐带血清标本中的 7 种指示性 PCB（PCB-28、52、101、118、138、153、180）和 5 种生殖激素（促黄体激素（LH）、雌二醇（E2）、睾酮（T）、卵泡刺激素（FSH）和抗苗勒氏管激素（AMH））以及 3 种甲状腺激素（三碘甲状腺原氨酸（T3）、四碘甲状腺原氨酸（T4）和促甲状腺激素（TSH）。出生结局包括出生体重、身长、头围和胎龄。我们采用多元线性回归和四分位回归分析了 PCB 与每种激素和出生结局之间的关系，并对选定的潜在混杂因素进行了调整。脐带血清中总 PCB 的中位数为 2.02μg/L（IQR，1.13-4.64）。研究发现，PCB 暴露与生殖激素之间存在一些负相关关系。其中，PCB-101 与 FSH 的β值达到-0.38（95%CI，-0.69，-0.07；p=0.02）。此外，我们还发现了一些性别特异性关联，即 PCB-28 与 LH 和 T 呈负相关，PCB-118 与男婴 T 呈负相关，但与女婴 T 不相关。PCB 与出生结局之间的关系似乎因 PCB 同系物的分子量而异，即低氯化 PCB 同系物与胎龄和头围呈负相关，而高氯化 PCB 同系物与出生体重和胎龄呈正相关。在这项研究中，我们发现不同分子量的 PCB 同系物与激素和出生结局的关联不同，建议未来的研究调查这些关联的潜在机制。
