Division of Epidemiology and Community Health, University of Minnesota School of Public Health, Minneapolis, Minnesota, United States of America.
Department of Pediatrics and Child Health, Makerere University, Kampala, Uganda.
J Nutr. 2023 Oct;153(10):3023-3031. doi: 10.1016/j.tjnut.2023.08.014. Epub 2023 Aug 19.
Iron deficiency (ID) and environmental exposure to metals frequently co-occur among Ugandan children, but little is known about their associations, although iron and other divalent metals share the same intestinal absorption transporter, divalent metal transporter 1 (DMT1).
We examined associations between iron status and blood concentrations of lead, manganese (Mn), cobalt (Co), and cadmium, both singly and as a mixture.
We used data on sociodemographic status, iron biomarkers, and blood concentrations of heavy metals collected from a cross-sectional survey of 100 children aged 6-59 mo in Kampala, Uganda. We compared blood concentrations of metals in ID with iron-sufficient children. We examined associations between a metal mixture and iron biomarkers using multiple linear regression and weighted quintile sum regression.
The median (interquartile range) blood Mn (μg/L) was higher in ID children defined by soluble transferrin receptor (sTfR) and ferritin (ID compared with iron-sufficient children): (sTfR [21.3 {15.1, 28.8}, 11.2 {8.6, 18.5}], ferritin [19.5 {15.0, 27.2}, 11.2 {8.8, 19.6}]; P < 0.001 for both). Similarly, the median (interquartile range) blood Co (μg/L) was higher in ID children by ferritin ([0.5 {0.4, 0.9}, 0.4 {0.3, 0.5}], P = 0.05). Based on the multiple linear regression results, higher blood Co and Mn were associated with poorer iron status (defined by all 4 iron indicators for Co and by sTfR for Mn). The weighted quintile sum regression result showed that higher blood concentrations of a metal mixture were associated with poorer iron status represented by sTfR, ferritin, and hepcidin, mainly driven by Co and Mn.
Our study findings suggest that poorer iron status is associated with overall heavy metal burden, predominantly Co and Mn, among Ugandan children. Further prospective studies should confirm our primary findings and investigate the combined effects of coexposures to neurotoxicants on the neurodevelopment of young children.
在乌干达儿童中，缺铁（ID）和环境暴露于金属经常同时发生，但它们之间的关联知之甚少，尽管铁和其他二价金属共享相同的肠道吸收转运蛋白，二价金属转运蛋白 1（DMT1）。
我们研究了铁状态与血铅、锰（Mn）、钴（Co）和镉浓度之间的关联，包括单独和混合存在的情况。
我们使用了来自乌干达坎帕拉一项横断面调查的数据，该调查涉及 100 名 6-59 月龄儿童的社会人口统计学状况、铁生物标志物和重金属血浓度。我们比较了 ID 儿童和铁充足儿童的金属血浓度。我们使用多元线性回归和加权五分位数总和回归来研究金属混合物与铁生物标志物之间的关联。
根据可溶性转铁蛋白受体（sTfR）和铁蛋白定义的 ID 儿童的中位（四分位距）血 Mn（μg/L）较高（sTfR [21.3{15.1, 28.8}，11.2{8.6, 18.5}]，铁蛋白[sTfR [19.5{15.0, 27.2}，11.2{8.8, 19.6}]；均<0.001）。同样，根据铁蛋白定义的 ID 儿童的中位（四分位距）血 Co（μg/L）较高（[0.5{0.4, 0.9}，0.4{0.3, 0.5}]，P=0.05）。根据多元线性回归结果，较高的血 Co 和 Mn 与较差的铁状态相关（Co 用所有 4 种铁指标，Mn 用 sTfR 定义）。加权五分位数总和回归结果表明，金属混合物的血浓度较高与 sTfR、铁蛋白和 hepcidin 表示的较差铁状态相关，主要由 Co 和 Mn 驱动。
我们的研究结果表明，乌干达儿童的整体重金属负担（主要是 Co 和 Mn）与较差的铁状态相关。进一步的前瞻性研究应确认我们的主要发现，并研究神经毒物共同暴露对幼儿神经发育的联合影响。
