TY - JOUR
T1 - Adequacy of Iodine Status and Associations with Gut Health
T2 - A Prospective Cohort Study among Infants in 8 Low- and Middle-Income Countries
AU - MAL-ED Network Investigators
AU - Doggui, Radhouene
AU - McCormick, Benjamin JJ
AU - Caulfield, Laura E.
AU - Schulze, Kerry J.
AU - Murray-Kolb, Laura E.
N1 - Funding Information:
This work was supported, in whole, by the Bill & Melinda Gates Foundation [grant ID OPP47075]. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 Generic License has already been assigned to the Author Accepted Manuscript version that might arise from this submission. The supporting source had no such involvement or restrictions regarding publication.
Publisher Copyright:
© 2023
PY - 2023/3
Y1 - 2023/3
N2 - Background: Environmental enteric dysfunction increases the likelihood of micronutrient deficiencies among infants, but few studies have assessed the potential impact of gut health on urinary iodine concentration (UIC) among this vulnerable group. Objectives: We describe the trends of iodine status among infants from 6 to 24 mo old and examine the associations between intestinal permeability, inflammation, and UIC from 6 to 15 mo of age. Methods: Data from 1557 children enrolled in this birth cohort study conducted in 8 sites were included in these analyses. UIC was measured at 6, 15, and 24 mo of age by using the Sandell-Kolthoff technique. Gut inflammation and permeability were assessed using the concentrations of fecal neopterin (NEO), myeloperoxidase (MPO) and alpha-1–antitrypsin (AAT), and lactulose–mannitol ratio (LM). A multinomial regression analysis was used to assess the classified UIC (deficiency or excess). Linear mixed regression was used to test the effect of interactions among biomarkers on logUIC. Results: All studied populations had adequate (≥100 μg/L) to excess (≥371 μg/L) median UIC at 6 mo. Between 6 and 24 mo, 5 sites displayed a significant decline in the infant's median UIC. However, median UIC remained within the optimal range. An increase of NEO and MPO concentrations by +1 unit in ln scale reduced the risk of low UIC by 0.87 (95% CI: 0.78–0.97) and 0.86 (95% CI: 0.77–0.95), respectively. AAT moderated the association between NEO and UIC (P < 0.0001). The shape of this association appears to be asymmetric and in a reverse J-shape, with a higher UIC observed at both lower NEO and AAT concentrations. Conclusions: Excess UIC was frequent at 6 mo and tended to normalize at 24 mo. Aspects of gut inflammation and increased permeability appear to reduce the prevalence of low UIC in children aged 6 to 15 mo. Programs addressing iodine-related health should consider the role of gut permeability in vulnerable individuals.
AB - Background: Environmental enteric dysfunction increases the likelihood of micronutrient deficiencies among infants, but few studies have assessed the potential impact of gut health on urinary iodine concentration (UIC) among this vulnerable group. Objectives: We describe the trends of iodine status among infants from 6 to 24 mo old and examine the associations between intestinal permeability, inflammation, and UIC from 6 to 15 mo of age. Methods: Data from 1557 children enrolled in this birth cohort study conducted in 8 sites were included in these analyses. UIC was measured at 6, 15, and 24 mo of age by using the Sandell-Kolthoff technique. Gut inflammation and permeability were assessed using the concentrations of fecal neopterin (NEO), myeloperoxidase (MPO) and alpha-1–antitrypsin (AAT), and lactulose–mannitol ratio (LM). A multinomial regression analysis was used to assess the classified UIC (deficiency or excess). Linear mixed regression was used to test the effect of interactions among biomarkers on logUIC. Results: All studied populations had adequate (≥100 μg/L) to excess (≥371 μg/L) median UIC at 6 mo. Between 6 and 24 mo, 5 sites displayed a significant decline in the infant's median UIC. However, median UIC remained within the optimal range. An increase of NEO and MPO concentrations by +1 unit in ln scale reduced the risk of low UIC by 0.87 (95% CI: 0.78–0.97) and 0.86 (95% CI: 0.77–0.95), respectively. AAT moderated the association between NEO and UIC (P < 0.0001). The shape of this association appears to be asymmetric and in a reverse J-shape, with a higher UIC observed at both lower NEO and AAT concentrations. Conclusions: Excess UIC was frequent at 6 mo and tended to normalize at 24 mo. Aspects of gut inflammation and increased permeability appear to reduce the prevalence of low UIC in children aged 6 to 15 mo. Programs addressing iodine-related health should consider the role of gut permeability in vulnerable individuals.
KW - gut inflammation
KW - gut permeability
KW - infant
KW - iodine excess
KW - urinary iodine
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U2 - 10.1016/j.tjnut.2022.11.027
DO - 10.1016/j.tjnut.2022.11.027
M3 - Article
C2 - 36797135
AN - SCOPUS:85150073149
SN - 0022-3166
VL - 153
SP - 828
EP - 838
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 3
ER -