Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
Environ Int. 2018 Dec;121(Pt 1):658-666. doi: 10.1016/j.envint.2018.09.017. Epub 2018 Oct 10.
Epidemiologic and animal-based studies have raised concern over the potential impact of fluoride exposure on neurobehavioral development as manifested by lower IQ and deficits in attention. To date, no prospective epidemiologic studies have examined the effects of prenatal fluoride exposure on behavioral outcomes using fluoride biomarkers and sensitive measures of attention.
We aimed to examine the association between prenatal fluoride exposure and symptoms associated with attention-deficit/hyperactivity disorder (ADHD).
213 Mexican mother-children pairs of the Early Life Exposures to Environmental Toxicants (ELEMENT) birth cohort study had available maternal urinary samples during pregnancy and child assessments of ADHD-like behaviors at age 6-12. We measured urinary fluoride levels adjusted for creatinine (MUF) in spot urine samples collected during pregnancy. The Conners' Rating Scales-Revised (CRS-R) was completed by mothers, and the Conners' Continuous Performance Test (CPT-II) was administered to the children.
Mean MUF was 0.85 mg/L (SD = 0.33) and the Interquartile Range (IQR) was 0.46 mg/L. In multivariable adjusted models using gamma regression, a 0.5 mg/L higher MUF (approximately one IQR higher) corresponded with significantly higher scores on the CRS-R for DSM-IV Inattention (2.84 points, 95% CI: 0.84, 4.84) and DSM-IV ADHD Total Index (2.38 points, 95% CI: 0.42, 4.34), as well as the following symptom scales: Cognitive Problems and Inattention (2.54 points, 95% CI: 0.44, 4.63) and ADHD Index (2.47 points; 95% CI: 0.43, 4.50). The shape of the associations suggested a possible celling effect of the exposure. No significant associations were found with outcomes on the CPT-II or on symptom scales assessing hyperactivity.
Higher levels of fluoride exposure during pregnancy were associated with global measures of ADHD and more symptoms of inattention as measured by the CRS-R in the offspring.
流行病学和基于动物的研究引起了人们对氟暴露对神经行为发育潜在影响的关注，表现为智商降低和注意力缺陷。迄今为止，尚无前瞻性流行病学研究使用氟化物生物标志物和敏感的注意力测量方法来检查产前氟暴露对行为结果的影响。
我们旨在研究产前氟暴露与注意力缺陷多动障碍（ADHD）相关症状之间的关系。
ELement 出生队列研究共纳入 213 对墨西哥母婴，这些母婴在怀孕期间有可用的尿液样本，在 6-12 岁时有儿童 ADHD 样行为评估。我们测量了怀孕期间收集的尿液样本中肌酐调整后的尿液氟化物水平（MUF）。母亲完成了 Conners' 修订评级量表（CRS-R），儿童完成了 Conners 连续绩效测试（CPT-II）。
MUF 的平均值为 0.85mg/L（标准差=0.33），四分位距（IQR）为 0.46mg/L。在使用伽马回归的多变量调整模型中，MUF 每增加 0.5mg/L（大约增加一个 IQR），DSM-IV 注意力不集中的 CRS-R 评分显著升高（2.84 分，95%CI：0.84，4.84）和 DSM-IV ADHD 总分指数（2.38 分，95%CI：0.42，4.34），以及以下症状量表：认知问题和注意力不集中（2.54 分，95%CI：0.44，4.63）和 ADHD 指数（2.47 分；95%CI：0.43，4.50）。关联的形状表明暴露可能存在上限效应。在 CPT-II 或评估多动的症状量表上的结果没有发现显著的关联。
怀孕期间氟暴露水平较高与子女的 CRS-R 测定的 ADHD 整体指标和更多的注意力不集中症状有关。
