Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, NY, USA.
Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
Environ Res. 2019 Mar;170:65-72. doi: 10.1016/j.envres.2018.12.003. Epub 2018 Dec 5.
Lead exposure is associated with children's growth, but this relationship may depend on the presence of susceptibility factors, including genetic variation. Blood lead levels (BLL) differ by ALAD (aminolevulinic acid dehydratase) genotype. We investigated the association between BLL and growth in Mexican first-graders with different ALAD genotypes.
Children between the ages of 6-8 years (n = 602) attending first grade in schools within the vicinity of a metal foundry in Torreón, Mexico were enrolled into a randomized controlled trial (RCT) testing the efficacy of iron and/or zinc supplementation on blood lead levels (BLL) and cognition. BLL and anthropometry were assessed at baseline (height, height-for-age z-score (HAZ), knee height, head circumference), after 6 (head circumference) and 12 months (height, HAZ, knee height). Children with ALAD and ALAD were compared. The study sample included 538 and 470 participants who had complete data at baseline and follow-up, respectively. Separate multivariable linear regression models adjusted for covariates were used to test the association between BLL at baseline and each anthropometric measure. Covariates included age, sex, hemoglobin, crowding, and maternal education. BLL x ALAD genotype interaction term was tested.
Median BLL (10.1 μg/dL) did not differ by ALAD genotype. After covariate adjustment, baseline BLL was inversely associated with baseline height, HAZ, and knee height. The association (β [95% CI]) between BLL and baseline height (-0.38[-0.68, -0.09]), HAZ (-0.07[-0.12, -0.02]) and knee height (-0.14[-0.25, -0.02]), was somewhat stronger in children with ALAD than ALAD (-0.09[-0.16, -0.02], -0.02[-0.03, -0.004] and -0.04[-0.06, -0.01], respectively). No associations between BLL and growth at 6 or 12 months were detected irrespective of ALAD genotype.
BLL was adversely associated with anthropometric measures among Mexican children. ALAD genotype may be a susceptibility factor for the effects of lead on child growth.
铅暴露与儿童的生长有关，但这种关系可能取决于易感因素的存在，包括遗传变异。血铅水平（BLL）因 ALAD（氨基酮戊酸脱水酶）基因型而异。我们研究了不同 ALAD 基因型的墨西哥一年级儿童中 BLL 与生长之间的关系。
在墨西哥托雷翁的一家金属铸造厂附近的学校就读 6-8 岁的儿童（n=602）参加了一项随机对照试验（RCT），该试验测试了铁和/或锌补充剂对血铅水平（BLL）和认知的疗效。在基线时（身高、身高年龄 z 评分（HAZ）、膝高、头围）、6 个月后（头围）和 12 个月后（身高、HAZ、膝高）评估 BLL 和人体测量值。比较了具有 ALAD 和 ALAD 的儿童。研究样本包括分别在基线和随访时具有完整数据的 538 名和 470 名参与者。使用调整了协变量的单独多变量线性回归模型来测试基线 BLL 与每个人体测量指标之间的关联。协变量包括年龄、性别、血红蛋白、拥挤和母亲教育。测试了 BLL x ALAD 基因型交互项。
中位 BLL（10.1μg/dL）不因 ALAD 基因型而异。在调整协变量后，基线 BLL 与基线身高、HAZ 和膝高呈负相关。BLL 与基线身高（-0.38[-0.68，-0.09]）、HAZ（-0.07[-0.12，-0.02]）和膝高（-0.14[-0.25，-0.02]）之间的关联（β[95%CI]）在具有 ALAD 的儿童中比具有 ALAD 的儿童更强（-0.09[-0.16，-0.02]、-0.02[-0.03，-0.004]和-0.04[-0.06，-0.01]）。无论 ALAD 基因型如何，均未检测到 BLL 与 6 或 12 个月时生长之间的关联。
BLL 与墨西哥儿童的人体测量指标呈负相关。ALAD 基因型可能是铅对儿童生长影响的易感因素。
