Poster Topical Area: Global Nutrition
Location: Hall D
Poster Board Number: 551
Objectives: Exposure to heavy metals is high among children in low-income countries, and many metals have neurotoxic effects. Iron deficiency (ID) is prevalent in these regions and also has neurobehavioral consequences. The dual burden of metal exposure and ID is not well described. Divalent metal transporter-1 (DMT1) is the intestinal transporter for ferrous (Fe2+) iron, but also transports other divalent (2+) metals. Absorption of these metals may be upregulated if dietary iron is insufficient. We recently found that blood levels of 5 2+ metals [copper, cadmium, cobalt (Co), lead (Pb), and manganese (Mn)] were high in Ugandan children. Assessment of the relationship between these metals and iron status may highlight intervention points to improve both ID and metal toxicity. 1) Determine the prevalence of ID in Ugandan children; and 2) Establish the association between metals and iron status makers [ferritin, soluble transferrin receptor (sTFR), hepcidin].
Methods: We conducted a cross-sectional survey of 100 children 6-59 mos from the Katanga area of Kampala, Uganda. We measured blood metals by LC/MS/MS and plasma ferritin, sTfR, hepcidin, and C-reactive protein (CRP) by ELISA. We examined 2 ID definitions: 1) ferritin 10 mg/L; and 2) sTfR>= 8.3 mg/L. We compared metals by ID category with Wilcoxon rank-sum test and constructed multiple regression models with each iron marker as the outcome variable and each metal as the predictor.
Results: 25.5% and 23.5% of children were ID based on ferritin and sTfR, respectively. Greater blood Mn and Co were significantly associated with lower ferritin, greater sTfR, and lower hepcidin, collectively reflecting poorer iron stores, diminished iron delivery to bone marrow, and increased ability to absorb iron and other 2+metals. Greater blood Pb was associated with lower sTfR and greater hepcidin, reflecting better iron status, but blood Mn modified this relationship. Among children with Mn50thp, higher sTfR was associated with lower blood Pb.
Conclusion(s): Children with poorer iron status have significantly higher blood Mn and Co, suggesting absorption of these metals may be upregulated in ID children. The finding of lower blood Pb in children with better iron status was unexpected, but its modification by Mn may reflect the preferential absorption of Mn over Pb by DMT1.
University of Minnesota