Moderate-to-Severe Iodine Deficiency in the "First 1000 Days" Causes More Thyroid Hypofunction in Infants Than in Pregnant or Lactating Women.
J Nutr
; 147(4): 589-595, 2017 04.
Article
em En
| MEDLINE
| ID: mdl-28202636
ABSTRACT
Background:
Iodine deficiency early in the life cycle-the "first 1000 days"-can cause hypothyroidism and irreversibly impair neuromotor development. However, the relative vulnerability among women and infants during this critical period is unclear, making it difficult for country-based programs with limited resources to prioritize their iodine interventions.Objective:
Our aim was to determine the prevalence of thyroid hypofunction in women and infants living in an area of moderate-to-severe iodine deficiency.Methods:
In a cross-sectional survey in Morocco, we measured urinary iodine concentrations (UICs) and concentrations of thyroid-stimulating hormone (TSH) and total or free thyroxine (TT4 or fT4, respectively) in women of reproductive age (n = 156), pregnant women (n = 245), and lactating women (n = 239) and their young infants (n = 239). We calculated daily iodine intakes and measured iodine concentrations in breast milk and household salt. We compared the incidence of hypothyroidism between the 3 groups of women and with the infants.Results:
Women of reproductive age, pregnant women, and lactating women had median (IQR) UICs of 41 (29-63), 32 (17-58), and 35 (19-62) µg/L; and estimated iodine intakes were â¼60%, 22%, and 26% of Recommended Nutrient Intakes (RNIs). The infants' median UIC was 73 (28-157) µg/L, which was greater than for all 3 groups of women (P < 0.001), and their dietary intakes were 27% of the RNI. The prevalence of hypothyroidism was not significantly different between the 4 groups, whereas the prevalence of hypothyroxinemia was higher in infants (40%) than in the 3 groups of women (11-14%) (P < 0.001). The median breast-milk iodine concentration was 42 (26-81) µg/L. Only 6% of salt samples were adequately iodized to a concentration of ≥15 ppm; 54% were inadequately iodized and 40% contained no measurable iodine.Conclusions:
In an area of moderate-to-severe iodine deficiency, the prevalence of thyroid hypofunction is â¼4-fold higher in young infants compared with the 3 groups of women, suggesting that, in the "first 1000 days," infants are more vulnerable than their mothers and that programs should prioritize iodine prophylaxis for this group.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças da Glândula Tireoide
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Tiroxina
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Lactação
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Tireotropina
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Iodo
Tipo de estudo:
Etiology_studies
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Observational_studies
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Prevalence_studies
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Risk_factors_studies
Limite:
Female
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Humans
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Infant
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Male
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Newborn
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Pregnancy
Idioma:
En
Revista:
J Nutr
Ano de publicação:
2017
Tipo de documento:
Article
País de publicação:
EEUU
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ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA