Assessment of thyroid function, ioduria and oxidative stress in women in the first trimester of pregnancy.

INTRODUCTION: adequate iodine intake during pregnancy is essential for the synthesis of thyroid hormones, which are important for the physiological functions of the mother and appropriate maturation of the central nervous system of the fetus. OBJECTIVE: the objective of the present study was to determine the levels of urinary iodine excretion and thyroid function, antioxidants and oxidative stress markers in pregnant women. METHODS: the study was conducted on 191 pregnant women and 62 non-pregnant women who were evaluated regarding nutritional status. Analyses of urinary iodine, of oxidative stress markers and thyroid function were performed, revealing iodine insufficiency in 81 pregnant women. RESULTS: there was no change in the thyroid stimulating hormone concentration in 89% of the pregnant women. Antithyroperoxidase antibody values were higher in the control group compared to the pregnant women's group (64.5% and 12.6%, respectively) and antithyroglobulin antibody values were also higher in the control group (11.6%). Assessment of oxidative stress revealed higher levels of advanced oxidation protein products, of total antioxidant capacity and of superoxide dismutase antioxidants in pregnant women. Classification of ioduria with respect to oxidative stress markers revealed lower α-tocopherol levels for the pregnant women with iodine insufficiency. CONCLUSION: on this basis, the results suggest that iodine insufficiency did not induce changes in thyroid stimulating hormone levels or antibodies and those pregnant women with adequate urinary iodine excretion had a better profile of the α-tocopherol antioxidant, indicating that iodine may play a significant role in antioxidant capacity during gestation.

Assessment of thyroid function, ioduria and oxidative stress in women in the first trimester of pregnancy / Evaluación de la función tiroidea, yoduria y estrés oxidativo en mujeres en el primer trimestre de embarazo

Introduction: adequate iodine intake during pregnancy is essential for the synthesis of thyroid hormones, which are important for the physiological functions of the mother and appropriate maturation of the central nervous system of the fetus. Objective: the objective of the present study was to determine the levels of urinary iodine excretion and thyroid function, antioxidants and oxidative stress markers in pregnant women. Methods: the study was conducted on 191 pregnant women and 62 non-pregnant women who were evaluated regarding nutritional status. Analyses of urinary iodine, of oxidative stress markers and thyroid function were performed, revealing iodine insufficiency in 81 pregnant women. Results: there was no change in the thyroid stimulating hormone concentration in 89% of the pregnant women. Antithyroperoxidase antibody values were higher in the control group compared to the pregnant women's group (64.5% and 12.6%, respectively) and antithyroglobulin antibody values were also higher in the control group (11.6%). Assessment of oxidative stress revealed higher levels of advanced oxidation protein products, of total antioxidant capacity and of superoxide dismutase antioxidants in pregnant women. Classification of ioduria with respect to oxidative stress markers revealed lower α-tocopherol levels for the pregnant women with iodine insufficiency. Conclusion: on this basis, the results suggest that iodine insufficiency did not induce changes in thyroid stimulating hormone levels or antibodies and those pregnant women with adequate urinary iodine excretion had a better profile of the α-tocopherol antioxidant, indicating that iodine may play a significant role in antioxidant capacity during gestation

Introducción: la ingesta adecuada de yodo durante el embarazo es esencial para la síntesis de las hormonas tiroideas, que son importantes para las funciones fisiológicas de la madre y la maduración apropiada del sistema nervioso central del feto. Objetivo: el objetivo del presente estudio fue determinar los niveles de excreción de yodo urinario y función tiroidea, antioxidantes y marcadores de estrés oxidativo en mujeres embarazadas. Métodos: el estudio se realizó en 191 mujeres embarazadas y 62 mujeres no embarazadas que fueron evaluadas con respecto al estado nutricional. Se realizaron análisis de yodo urinario, marcadores de estrés oxidativo y función tiroidea, que revelaron insuficiencia de yodo en 81 embarazadas. Resultados: no hubo cambios en la concentración de hormona estimulante tiroidea en el 89% de las mujeres embarazadas. Los valores de anticuerpos antitiroperoxidasa fueron mayores en el grupo control en comparación con el grupo de mujeres embarazadas (64,5% y 12,6%, respectivamente) y los de anticuerpos antitiroglobulina fueron también mayores en el grupo control (11,6%). La evaluación del estrés oxidativo reveló niveles más altos de productos avanzados de proteína de oxidación, de capacidad antioxidante total y de antioxidantes de superóxido dismutasa en mujeres embarazadas. La clasificación de la yoduria con respecto a marcadores de estrés oxidativo reveló menores niveles de α-tocoferol para las mujeres embarazadas con insuficiencia de yodo. Conclusión: sobre esta base, los resultados sugieren que la insuficiencia de yodo no indujo cambios en los niveles de hormona estimulante de la tiroides o anticuerpos y las mujeres embarazadas con excreción urinaria adecuada de yodo tuvieron un mejor perfil del antioxidante α-tocoferol, lo que indica que el yodo puede desempeñar un papel significativo en la capacidad antioxidante durante la gestación

Iodine insufficiency in pregnant women from the State of São Paulo.

OBJECTIVE: The intake of adequate amounts of iodine during pregnancy is essential for the neurological development of the fetus. The aim of this study was to assess iodine nutrition status in pregnant women from the state of São Paulo, Brazil. MATERIAL AND METHODS: We analyzed urinary iodine concentration (UIC) in 191 pregnant and 58 non-pregnant women matched by age. We used the World Health Organization criteria to define sufficient iodine supply (median UIC: 150-249 µg/L among pregnant women, and 100-199 µg/L for non-pregnant women). RESULTS: Median UIC of the pregnant women studied was lower than the recommended value (median = 137.7 µg/L, 95% CI = 132.9 - 155.9), while non-pregnant women had UIC levels within the appropriate range (median = 190 µg/L; 95% IC = 159.3-200.1). UIC was below 150 µg/L in 57% of the pregnant women. CONCLUSIONS: Although a larger sample is needed to consolidate these findings, these results raise concerns about the adequacy of the iodine supply of pregnant women in Brazil, especially considering the new determinations of the Brazilian government, which have recently reduced the concentrations of iodine in table salt to 15-45 mg/kg of salt.

Iodine insufficiency in pregnant women from the State of São Paulo / Insuficiência iódica em gestantes paulistas

Objective : The intake of adequate amounts of iodine during pregnancy is essential for the neurological development of the fetus. The aim of this study was to assess iodine nutrition status in pregnant women from the state of São Paulo, Brazil.Material and methods : We analyzed urinary iodine concentration (UIC) in 191 pregnant and 58 non-pregnant women matched by age. We used the World Health Organization criteria to define sufficient iodine supply (median UIC: 150-249 µg/L among pregnant women, and 100-199 µg/L for non-pregnant women).Results : Median UIC of the pregnant women studied was lower than the recommended value (median = 137.7 µg/L, 95% CI = 132.9 – 155.9), while non-pregnant women had UIC levels within the appropriate range (median = 190 μg/L; 95% IC = 159.3-200.1). UIC was below 150 µg/L in 57% of the pregnant women.Conclusions : Although a larger sample is needed to consolidate these findings, these results raise concerns about the adequacy of the iodine supply of pregnant women in Brazil, especially considering the new determinations of the Brazilian government, which have recently reduced the concentrations of iodine in table salt to 15-45 mg/kg of salt. Arq Bras Endocrinol Metab. 2014;58(3):282-7.

Objetivo : O consumo de quantidade adequada de iodo durante a gestação é de fundamental importância para o desenvolvimento neurológico do feto. O objetivo deste estudo foi avaliar o estado nutricional iódico em gestantes do estado de São Paulo, Brasil.Material e métodos : Analisamos a concentração urinária de iodo (UIC) em 191 gestantes e em 58 mulheres não gestantes de mesma faixa etária. Foram utilizados os critérios da OMS para definir suficiência iódica (mediana de UIC: 150-249 µg/L entre as gestantes e 100-199 µg/L para as não gestantes).Resultados : A mediana de UIC das gestantes estudadas esteve abaixo da recomendada (mediana = 137,7 μg/L; 95% IC = 132,9 – 155,9) enquanto a das mulheres não grávidas se mostrou na faixa adequada (mediana = 190 μg/L; 95% IC = 159,3 – 200,1). Entre as gestantes, 57% apresentaram UIC < 150 μg/L.Conclusões : Apesar de uma maior amostragem ser necessária para a confirmação desses achados, os resultados levantam preocupação quanto à suficiência iódica nas mulheres grávidas no Brasil, principalmente diante das novas determinações governamentais brasileiras quanto à redução das concentrações de iodo no sal de cozinha para 15-45 mg/kg. Arq Bras Endocrinol Metab. 2014;58(3):282-7.