Braun Joseph M, Wright Rosalind J, Just Allan C, Power Melinda C, Tamayo Y Ortiz Marcela, Schnaas Lourdes, Hu Howard, Wright Robert O, Tellez-Rojo Martha Maria
Department of Epidemiology, Brown University, 121 S, Main St, Providence, RI 02912, USA.
Environ Health. 2014 Jun 10;13(1):50. doi: 10.1186/1476-069X-13-50.
Lead (Pb) exposure during pregnancy may increase the risk of adverse maternal, infant, or childhood health outcomes by interfering with hypothalamic-pituitary-adrenal-axis function. We examined relationships between maternal blood or bone Pb concentrations and features of diurnal cortisol profiles in 936 pregnant women from Mexico City.
From 2007-11 we recruited women from hospitals/clinics affiliated with the Mexican Social Security System. Pb was measured in blood (BPb) during the second trimester and in mothers' tibia and patella 1-month postpartum. We characterized maternal HPA-axis function using 10 timed salivary cortisol measurements collected over 2-days (mean: 19.7, range: 14-35 weeks gestation). We used linear mixed models to examine the relationship between Pb biomarkers and cortisol area under the curve (AUC), awakening response (CAR), and diurnal slope.
After adjustment for confounders, women in the highest quintile of BPb concentrations had a reduced CAR (Ratio: -13%; Confidence Interval [CI]: -24, 1, p-value for trend < 0.05) compared to women in the lowest quintile. Tibia/patella Pb concentrations were not associated with CAR, but diurnal cortisol slopes were suggestively flatter among women in the highest patella Pb quantile compared to women in the lowest quantile (Ratio: 14%; CI: -2, 33). BPb and bone Pb concentrations were not associated with cortisol AUC.
Concurrent blood Pb levels were associated with cortisol awakening response in these pregnant women and this might explain adverse health outcomes associated with Pb. Further research is needed to confirm these results and determine if other environmental chemicals disrupt hypothalamic-pituitary-adrenal-axis function during pregnancy.
孕期铅（Pb）暴露可能通过干扰下丘脑 - 垂体 - 肾上腺轴功能，增加孕产妇、婴儿或儿童出现不良健康结局的风险。我们研究了墨西哥城936名孕妇的母血或骨铅浓度与昼夜皮质醇谱特征之间的关系。
2007年至2011年，我们从墨西哥社会保障系统下属的医院/诊所招募了女性。在孕中期测量血铅（BPb），产后1个月测量母亲胫骨和髌骨中的铅含量。我们通过在2天内收集10次定时唾液皮质醇测量值（平均孕周：19.7周，范围：14 - 35周）来表征孕产妇下丘脑 - 垂体 - 肾上腺轴功能。我们使用线性混合模型来研究铅生物标志物与皮质醇曲线下面积（AUC）、觉醒反应（CAR）和昼夜斜率之间的关系。
在调整混杂因素后，与血铅浓度最低五分位数的女性相比，血铅浓度最高五分位数的女性的CAR降低（比值：-13%；置信区间[CI]：-24，1，趋势p值<0.05）。胫骨/髌骨铅浓度与CAR无关，但与最低髌骨铅五分位数的女性相比，最高髌骨铅五分位数的女性的昼夜皮质醇斜率明显更平缓（比值：14%；CI：-2，33）。血铅和骨铅浓度与皮质醇AUC无关。
这些孕妇的血铅水平与皮质醇觉醒反应相关，这可能解释了与铅相关的不良健康结局。需要进一步研究来证实这些结果，并确定其他环境化学物质是否会在孕期干扰下丘脑 - 垂体 - 肾上腺轴功能。
