Environment & Health Research Unit, Medical Research Council, South Africa; MRC/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
MRC/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; DST-NRF Centre of Excellence in Human Development, University of the Witwatersrand, Johannesburg, South Africa.
Sci Total Environ. 2018 Jul 1;628-629:1437-1445. doi: 10.1016/j.scitotenv.2018.02.150. Epub 2018 Feb 20.
The effects of environmental lead exposure in the neuro-endocrine system have been shown to impact the maturation and tempo of puberty development in adolescents. In low and middle income countries very little is known regarding the detrimental health effects of childhood lead exposure with regard to the tempo of puberty development. To help address this gap in data, we examined the association between lead exposure and puberty progression in males and females. Study participants from the urban Birth to Twenty Plus (BT20+) birth cohort in Soweto-Johannesburg, South Africa with data for blood lead levels at age 13years, cord blood lead levels, pubic hair development and breast development in females, and pubic hair development and genital development in males, were included in this study. The sample comprised 1416 study participants (n=684 females). Pubertal development trajectory classes were defined using Latent Class Growth Analysis. Data were examined for (i) an association between cord blood lead levels and pubertal trajectory classes; and (ii) an association between blood lead levels at age 13years and pubertal trajectory classes. In females, there was an association between adolescent elevated blood lead levels (≥5μg/dL) and lower level of maturation at age 9years and slower progression of pubic hair and breast development (relative risk ratio (RRR)=0.45, p<0.0001; 95% CI (0.29-0.68)) and (RRR=0.46, p<0.01; 95% CI (0.27-0.77)), respectively. In males, elevated blood lead levels at birth were associated with slower tempo of pubic hair development (RRR=0.20, p<0.05). Findings from this study suggest a possible role for environmental lead in altering pubertal development in South African adolescents as shown by slower tempo of progression through the Tanner stages pubertal development in females and males. There were also gender-differences between the effects of prenatal and postnatal lead exposure during pubertal development.
环境铅暴露对神经内分泌系统的影响已被证明会影响青少年青春期的成熟和进程。在中低收入国家，对于儿童铅暴露对青春期进程的有害健康影响，人们知之甚少。为了填补这一数据空白，我们研究了铅暴露与男性和女性青春期进展之间的关系。本研究纳入了南非约翰内斯堡索韦托市城市出生至二十岁以上（BT20+）出生队列的研究参与者，这些参与者在 13 岁时具有血液铅水平、脐带血铅水平、女性阴毛和乳房发育以及男性阴毛和生殖器发育的数据。该样本包括 1416 名研究参与者（n=684 名女性）。使用潜在类别增长分析定义青春期发育轨迹类别。检查了（i）脐带血铅水平与青春期轨迹类别的关系；和（ii）13 岁时的血液铅水平与青春期轨迹类别的关系。在女性中，青少年血液铅水平升高（≥5μg/dL）与 9 岁时成熟度较低以及阴毛和乳房发育进展较慢有关（相对风险比（RRR）=0.45，p<0.0001；95%置信区间（0.29-0.68））和（RRR=0.46，p<0.01；95%置信区间（0.27-0.77））。在男性中，出生时血液铅水平升高与阴毛发育速度较慢有关（RRR=0.20，p<0.05）。这项研究的结果表明，环境铅可能在改变南非青少年的青春期发育方面发挥作用，表现为女性和男性的青春期发育中通过 Tanner 阶段的进展速度较慢。在青春期发育过程中，产前和产后铅暴露的影响也存在性别差异。
