Concentração de iodo urinário em urina de 24 horas de gestantes e sua associação com bócio tireoidiano materno, aborto e peso neonatal: estudo piloto / Urinary iodine concentration in 24-hour urine of pregnant women and its association with goiter in the mother, abortion and neonatal weight: pilot study

Introdução: A comida tem um papel proeminente na obtenção do iodo e uma das melhores estratégias é a iodização do sal. No Brasil, a Anvisa reduziu as doses de iodo no sal de cozinha desde 2014. Portanto, é importante avaliar a concentração urinária de iodo (CIU) em nossa população. Com base no exposto, propõe-se avaliar a CIU das gestantes, associando-a à frequência de bócio materno, aborto e peso neonatal. Métodos: Trata-se de um estudo observacional com um corte transversal composto por 37 pacientes atendidos no Serviço de Obstetrícia da Faculdade de Medicina de Barbacena e uma clínica particular em Juiz de Fora. A CIU foi verificada em 24 horas de urina. Resultados: A média de CIU foi de 213,6 µg/l de urina, com dose mínima de 29 µg/l e máxima de 437 µg/l. A glândula tireoide foi avaliada durante o exame clínico prénatal (palpação da glândula) e em 24 pacientes (38,1%) foi considerada normal. A palpação da glândula tireoide foi associada à CIU. Houve maior iodúria em gestantes com glândula não palpável (p = 0,004; T = 14,13). Não houve associação entre a CIU e história de aborto ou peso fetal ao nascimento (p > 0,05). Conclusões: Apesar de ser uma amostra pequena da população, identificamos pacientes expostas ao déficit. No entanto, a CIU não parece estar associada ao peso do recém-nascido ou a abortos, mas à dosagem de TSH e ao tamanho da glândula tireoide. Assim, a palpação da glândula tireoide poderia ser usada como uma medida indireta do CIU. (AU)

Introduction: Food has a prominent role in providing iodine and one of the best strategies is salt iodization. The Brazilian Health Regulatory Agency has reduced iodine content in table salt since 2014. Therefore, there is a need for evaluating urinary iodine concentration in our population, especially after the modified recommendations. Based on the above, we sought to assess urinary iodine concentration in pregnant women, associating it with frequency of maternal goiter, abortion and neonatal weight. Methods: This observational, cross-sectional study included 37 patients seen at the Obstetrics Service of Barbacena Medical School and a private clinic in Juiz de Fora, both in the state of Minas Gerais, Brazil. Iodine concentration was determined in 24- hour urine through chromatography. Results: The mean 24-hour urine iodine was 213.6 µg/l, with minimum and maximum measures of 29 µg/l and 437 µg/l, respectively. The thyroid gland was assessed by prenatal clinical examination (palpation of the gland). In 24 patients (38.1%) it was considered normal. Palpation of the thyroid gland was associated with 24-hour urine iodine concentration, although a higher iodine concentration was identified in pregnant women with non-palpable gland (p = 0.004; T = 14.13). There was no association between 24-hour urine iodine concentration and history of abortion or birth weight (p > 0.05). Conclusions: This study, although based on a small sample of the population, was important to identify that even in areas where iodine is considered sufficient there may be patients exposed to iodine deficit. However, urinary iodine concentration does not appear to be associated with birth weight or abortion frequency but is associated with thyroid-stimulating hormone (TSH) level and thyroid gland size, suggesting that clinical evaluation of the thyroid gland is an important element for predicting urinary iodine concentration. Thus, palpation of the thyroid gland could be used as an indirect measure of urinary iodine concentration. (AU)

Impacto del empleo de umbrales específicos de referencia en el diagnóstico de las alteraciones funcionales tiroideas en la mujer gestante / Impact of using specific reference intervals on the diagnosis of thyroid dysfunction during pregnancy

Objetivo: Establecer los umbrales específicos de referencia de cada uno de los parámetros de función tiroidea en cada trimestre de la gestación y determinar el impacto del uso de umbrales no específicos en el diagnóstico de las alteraciones funcionales en el primer trimestre. Métodos: Entre enero y septiembre de 2014 se contactaron 759 mujeres embarazadas con edad mayor de 18 años y sin alteraciones funcionales tiroideas conocidas. Tras excluir a todas las pacientes que no completaron el seguimiento durante toda la gestación y las que presentaron inmunidad tiroidea positiva, 411 gestantes configuraron nuestra población de referencia. Se determinaron los niveles de TSH, T4L y T3L en cada trimestre, los anticuerpos antiperoxidasa tiroidea y antitiroglobulina en el primero y se recogió una muestra de orina en los trimestres primero y tercero para la determinación del yodo urinario. Resultados: Un total de 411 gestantes completaron el seguimiento en los 3 trimestres. Un 38,69% consumían sal yodada y un 72,20% suplementos yodados. Los valores de referencia de TSH expresados como mediana y percentiles 2,5 y 97,5 fueron: 1,53 μUI/ml (0,26-3,95), 1,90 μUI/ml (0,78-3,85) y 1,89 μUI/ml (0,71-3,61) en el primer, segundo y tercer trimestre, respectivamente. El nivel de yoduria fue de 171,31 μg/l (90,7-274,9) en el primer trimestre y de 190,37 μg/l (96,44-360,38) en el tercero. La aplicación en el primer trimestre de los umbrales propuestos por las sociedades internacionales ocasionaría una clasificación errónea del 19,8% de las gestantes en relación con su función tiroidea, mientras que los umbrales no específicos de nuestro laboratorio lo harían en el 8,52%. Conclusiones: La utilización de umbrales no específicos para el diagnóstico de las alteraciones funcionales tiroideas durante la gestación ocasiona un importante porcentaje de errores de clasificación, contribuyendo a una atención inadecuada.

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Low iodine diet does not improve the efficacy of radioiodine for the treatment of Graves’ disease

Objective Consuming a low-iodine diet (LID) is a widely accepted practice before administering radioiodine (131I) to evaluate and to treat thyroid disease. Although this procedure is well established for the management of patients with differentiated thyroid cancer, its use in patients with benign disease is unclear. So, we aimed to evaluate the influence of a LID on the outcome in patients with Graves’ disease (GD) treated with131I. Subjects and methods We evaluated 67 patients with GD who were divided into 2 groups: one group (n = 31) consumed a LID for 1-2 weeks, and the second group (n = 36) was instructed to maintain a regular diet (RD). Results The LID group experienced a 23% decrease in urinary iodine after 1 week on the diet and a significant 42% decrease after 2 weeks on the diet. The majority (53%) of the patients in the LID group had urinary iodine levels that were consistent with deficient iodine intake. However, there was no difference in the rate of hyperthyroidism’s cure between the LID and the RD groups 6 months after 131I therapy. Furthermore, the therapeutic efficacy did not differ in patients with varying degrees of sufficient iodine intake (corresponding urinary iodine levels: < 10 μg/dL is deficient; 10-29.9 μg/dL is sufficient; and > 30 μg/dL is excessive). Conclusion In the present study, we demonstrated that although a LID decreased urinary iodine levels, those levels corresponding with sufficient or a mild excess in iodine intake did not compromise the therapeutic efficacy of131I for the treatment of GD.

Systematic review of studies evaluating urinary iodine concentration as a predictor of 24-hour urinary iodine excretion for estimating population iodine intake / Revisión sistemática de estudios que evalúan la concentración urinaria de yodo como factor predictivo de la excreción urinaria de yodo de 24 horas para calcular la ingesta de yodo en la población

OBJECTIVE: To examine the usefulness of "spot" urine iodine concentrations (UICs) in predicting 24-hour urine iodine excretion (UIE) for estimating average population iodine intake. METHODS: An electronic literature search was conducted for articles published through 19 May 2013 in MEDLINE (from 1950), EMBASE (from 1980), and the Cochrane Library (from 1993) using the terms "urinary excretion (timed or spot or random) and (24 h or 24 hour), iodine (iodine deficiency), iodine (intake)," and "urine (timed, spot, random, 24-hour)." Full-text articles about studies that examined > 40 healthy human subjects and measured UIE using the 24-hour urine collection method and UIC and/or UIE using one alternative method (spot (random), timed, and "overnight" (first morning urine), fasting or not fasting) were selected and reviewed. RESULTS: The review included data from 1 434 participants across the six studies that met the inclusion criteria. The main statistical methods for comparing data from the 24-hour urine collections with the values obtained from the alternative method(s) were either regression (β) or correlation (r) coefficients and concordance analysis through Bland-Altman plots. The urine samples collected using the alternative methods were subject to greater intra-individual and inter-individual variability than the 24-hour urine collections. There was a wide range in coefficient values for the comparisons between 24-hour URE measured in 24-hour urine collection and 24-hour UIE estimated using the alternative sampling methods. No alternative sampling method (spot, timed, or "overnight") was appropriate for estimating 24-hour UIE. CONCLUSIONS: The results of this systematic review suggest current data on UICs as a means of predicting 24-hour UIE for estimating population sodium intake are inadequate and highlight the need for further methodological investigations.

OBJETIVO: Analizar la utilidad de la concentraciones urinarias de yodo en una muestra puntual de orina como predicción de la excreción urinaria de yodo de 24 horas para calcular la ingesta promedio de yodo en la población. MÉTODOS: Se realizó una búsqueda de bibliografía electrónica de artículos publicados hasta el 19 de mayo del 2013 en MEDLINE (desde 1950), EMBASE (desde 1980) y la Biblioteca Cochrane (desde 1993) que utilizaran los términos "urinary excretion (timed or spot or random) y (24 h or 24 hour)", "iodine (iodine deficiency)", "iodine (intake)", y "urine (timed, spot, random, 24-hour)" ("excreción urinaria [programada o puntual o aleatoria] y [24 h o 24 horas]", "yodo [carencia de yodo]", "yodo [ingesta]", y "orina [programada, puntual, aleatoria, 24 horas]"). Se seleccionaron y analizaron artículos de texto completo acerca de estudios que hubieran examinado como mínimo a 40 personas sanas y medido la excreción urinaria de yodo mediante la recolección de orina de 24 horas, y la concentración urinaria de yodo o la excreción urinaria de yodo mediante un método alternativo (recolección puntual [aleatoria], programada y "de toda la noche" [primera orina de la mañana], en ayunas o no). RESULTADOS: La revisión incluyó datos de 1 434 participantes de los seis estudios que reunieron los criterios de inclusión. Los principales métodos estadísticos utilizados para comparar los datos de las recolecciones de orina de 24 horas con los valores obtenidos a partir de los métodos alternativos fueron los coeficientes de regresión (β) o correlación (r) y los análisis de concordancia mediante el gráfico de Bland-Altman. Las muestras de orina recolectadas mediante métodos alternativos presentaron una mayor variabilidad interpersonal y para una misma persona que las recolecciones de orina de 24 horas. Se observó una amplia gama de valores de los coeficientes en las comparaciones entre la excreción urinaria de yodo de 24 horas medida mediante la recolección de orina de 24 horas y la excreción urinaria de yodo de 24 horas calculada mediante métodos de muestreo alternativos. Ningún método de muestreo alternativo (puntual, programado o "de toda la noche") resultó apropiado para calcular la excreción urinaria de yodo de 24 horas. CONCLUSIONES: Los resultados de esta revisión sistemática indican que los datos actuales en cuanto a la concentración urinaria de yodo como factor predictivo de la excreción urinaria de yodo de 24 horas para calcular la ingesta de yodo en la población son inadecuados y subrayan la necesidad de nuevas investigaciones metodológicas.

Synergic actions of polyphenols and cyanogens of peanut seed coat (Arachis hypogaea) on cytological, biochemical and functional changes in thyroid.

In animals, long-term feeding with peanut (Arachis hypogaea) seed coats causes hypertrophy and hyperplasia of the thyroid gland. However, to date there have been no detailed studies. Here, we explored the thyroidal effects of dietary peanut seed coats (PSC) in rats. The PSC has high levels of pro-goitrogenic substances including phenolic and other cyanogenic constituents. The PSC was mixed with a standard diet and fed to rats for 30 and 60 days, respectively. Animals fed with the PSC-supplemented diet showed a significant increase in urinary excretion of thiocyanate and iodine, thyroid enlargement, and hypertrophy and/or hyperplasia of thyroid follicles. In addition, there was inhibition of thyroid peroxidase (TPO) activity, 5’-deiodinase-I (DIO1) activity, and (Na+-K+)-ATPase activity in the experimental groups of rats as compared to controls. Furthermore, the PSC fed animals exhibited decreased serum circulating total T4 and T3 levels, severe in the group treated for longer duration. These data indicate that PSC could be a novel disruptor of thyroid function, due to synergistic actions of phenolic as well as cyanogenic constituents.

Iodine nutritional status in Brazil: a meta-analysis of all studies performed in the country pinpoints to an insufficient evaluation and heterogeneity

Objectives Iodine deficiency disorder (IDD) is the result of an inadequate dietary intake of iodine, which physiological consequences are endemic goiter and thyroid dysfunction. The objective of this study was to a analyze studies that assessed the status of Brazil’s population iodine nutrition and IDD prevalence. Materials and methods Systematic review using PRISMA statement. Electronic database: PubMed, Medline, SciELO and Lilacs. Quality of studies: Newcastle-Ottawa Scale. Meta-analysis was carried out with R Core Team Statistical Software, version 3.1.0 (2014). The summary measure (WMD) and its confidence interval (CI) of 95% were calculated. The “Funnel plot” graph assessed publication bias and heterogeneity. Results Seventeen papers were eligible: pregnant women (2), school children (9), adults/elderly (4) and preschool children/infants (2). Geographic distribution: North (1), Northeast (1), Midwest (2), Southeast (13), South (3). Twenty-three thousand two hundred seventy-two subjects were evaluated between 1997 and 2013 and all have use urinary iodine (UI) measurement. However, only 7 studies could be included in meta-analysis, all from Southeast region. The overall prevalence of IDD in school children in southeast region was 15.3% (95% CI, 13-35%), however this data had an important heterogeneity, expressed by the I2 Statistic of 99.5%. Conclusion Only few studies have been performed and enrolled populations from south/southeast region of Brazil. The actual IDD prevalence analysis is complex because it was detected bias due influence of individual studies and very high heterogeneity. IDD might still be high in some areas but this remained unknown even after this meta-analysis evaluation. The generation of a national program for analysis of iodine status in all regions is urgently required. Arch Endocrinol Metab. 2015;59(1):13-22 .

Environmental, urinary iodine status and prevalence of goitre among schoolchildren in a high altitude area of Saudi Arabia

This study aimed to assess the iodine deficiency, prevalence of goitre among schoolchildren and measuring environmental iodine in Taif city, Saudi Arabia. A cross-sectional multistage cluster-sampling methodology was done on 1887 schoolchildren. Their urinary iodine concentration [UIC] and goitre prevalence was assessed. Blood level of triiodothyronin, thyroxine and thyroid-stimulating-hormone was carried out for students with normal, mild; moderate and sever iodine deficiency. The iodine content of salt, water and soil was also assessed. Goitre prevalence was 7.4% and about 71% of the participants had UIC less than 100 microg/L. An inverse relationship between median UIC and the percent prevalence of goitre was found. The mean serum T3, T4 and TSH were 1.05 ng/dL, 6.81 microg/dL, and 5.69mIU/L, respectively. A significant positive correlation was found between the mean value of urinary iodine and the mean value of both T3 and T4. While a significant negative correlation between the mean value of urinary iodine and the mean value of TSH was also noted. The results revealed the presence of a potential public health problem of iodine deficiency among school going children in high altitude areas of Saudi Arabia. There is a need to monitor and evaluate the salt iodization process, and distribute adequately iodized salt in the affected areas

Urinary iodine excretion in healthy Mexican adults / Excreción urinaria de yodo en adultos sanos mexicanos

The iodine nutritional status of a population is mainly measured by urinary iodine excretion (UI) and thyroid volume determined by ultrasound (US). The surveillance of nutritional iodine levels in the Mexican population has been insufficient. Our aim was to determine the UI in random samples from adults living in an urban area. We selected a sample of healthy individuals over the age of 18 that were students, physicians or administrative personnel at our Institution and had no known thyroid disease. Thyroid volume was determined by ultrasound in all volunteers as well as thyroid hormones and antithyroid antibodies and a urine sample was obtained. One hundred and two volunteers with a median age of 29, participated in the study. The group’s median UI was 221 μg/L,interquartile range (IQR)(135.0 to 356.8) and no differences were observed between genders: women had a UI of 218.0 μg/L IQR (129.0 a 351.0) vs. 223.0 μg/L IQR (138.0 to 374.0) in males, p 0.941. Excessive dietary iodine intake was established in 31.4% of all volunteers according to their UI, placing them at risk of thyroid dysfunction. It is fundamental to evaluate the national iodine nutritional status in Mexico. We discuss the current status of the nutritional state in the Americas, emphasizing that in Latin America and the observed tendency in the region to ingest a diet high in iodine.

El estatus nutricional del yodo en una población, principalmente es medido por la excreción del yodo urinario (UI) y el cálculo del volumen tiroideo por ultrasonido (US). La vigilancia nutricional del yodo en la población en México ha sido escasa. El objetivo fue determinar la UI en una muestra casual en adultos sanos que habitan en un área urbana. Se seleccionó una muestra de individuos mayores de 18 años, entre estudiantes, médicos y trabajadores administrativos de nuestra institución, sanos, sin enfermedad tiroidea conocida. A todos los voluntarios se les determinó el volumen tiroideo por US, hormonas y anticuerpos antitiroideos y se les solicitó una muestra de orina. Participaron 102 voluntarios, mediana de 29 años. La mediana de la UI del grupo fue 221 μg/L, rango intercuartílico (RIQ) (135.0 a 356.8), no hubo diferencias entre géneros, las mujeres tuvieron una UI de, 218.0 μg/L RIQ (129.0 a 351.0) vs 223.0 μg/L RIQ (138.0 a 374.0) p 0.941. El 31.4% de los voluntarios mostraron una ingestión excesiva de yodo en la dieta de acuerdo a la UI, lo cual los coloca en riesgo de sufrir disfunción tiroidea. Es necesario considerar la evaluación Nacional del estatus nutricional del yodo, en México. En el artículo se discute la situación actual del estatus nutricional en las Américas, haciendo énfasis en Latinoamérica y a la tendencia de la región a la dieta excedida en yodo.

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.

Impacto de las acciones para la eliminación sostenible de la deficiencia de yodo en Cuba / Impact of the actions for the sustainable elimination of iodine deficiency in Cuba

Objetivos: Evaluar la efectividad del “Programa de Eliminación Sostenible de Deficiencia de Yodo” mediante determinación de yoduria y prevalencia de bocio. Materiales y métodos. Se realizó un estudio transversal en el cual se incluyó a la población escolar cubana de 6 a 11 años que cursaba estudios en el periodo 2011-2012. Se empleó un muestreo estratificado polietápico. En el cual se determinaron los niveles de excreción de yodo en la orina (yoduria) y la presencia de bocio. Resultados. La mediana de yoduria fue de 176,3 µg/L; el 7,6% de los escolares presentaron alguna deficiencia de yodo, solo el 2,2% estaba por debajo de 50 µg/L (deficiencia severa) y el 15,3% tenía yodurias por encima de 300 µg/L. El porcentaje de escolares con nutrición óptima de yodo fue de 43,5%, esta categoría presentó una frecuencia significativamente mayor ( p=0,03) en el estrato montaña (52,5%). La prevalencia de bocio encontrada fue de 17,6%, que corresponde a una endemia ligera. Sin embargo, en el estrato montaña se encontró una prevalencia de 32,6 % (endemia severa). Conclusiones. El análisis integral del impacto de las acciones de control de la deficiencia de yodo evaluado a través de la excreción urinaria de yodo y la prevalencia de bocio refleja que ha dejado de ser un problema de salud poblacional en los estratos urbano y rural de Cuba, atribuible a un adecuado proceso de yodación de la sal. Sin embargo, aún se observa una alta prevalencia de bocio en la zona de montaña de Cuba.

Objectives: To assess the effectiveness of the Sustainable Elimination of Iodine Deficiency Program through determination of urinary iodine and goiter prevalence. Materials and methods. A cross-sectional study was conducted in Cuban school children aged 6 to 11 years old in 2011-2012. A stratified multistage sample was used in which the levels of iodine excretion in urine (urinary iodine) and the presence of goiter were determined. Results. The median urinary iodine was 176.3 µg/L; 7.6% of the students showed some deficiency of iodine, only 2.2% were below 50 µg/L (severe deficiency), and 15.3% had urinary iodine above 300 µg/L. The percentage of school children with optimal iodine nutrition was 43.5%, this category showed a significantly higher frequency (p=0.03) in the mountain areas (52.5%). Goiter prevalence was 17.6% which corresponds to a mild endemic. However, in the mountain area the prevalence was 32.6% (severe endemic). Conclusions. The comprehensive analysis of the impact of iodine deficiency control measures assessed by urinary iodine excretion and goiter prevalence reflects that it is no longer a population health problem in urban and rural areas of Cuba, attributable to a proper process of salt iodization. Nevertheless, high goiter prevalence is still observed in the mountain area of Cuba.

Urinary and milk iodine status in neonates and their mothers during congenital hypothyroidism screening program in eastern Azerbaijan: a pilot study

Iodine is essential element in thyroid hormones synthesis and normal growth and development of the brain. Milk and iodine concentrations can be appropriate indicator of body iodine status; in this study, we evaluated the concentrations of urine and milk iodine in newborns and their mothers. In a cross-sectional study conducted in 2013, urine and milk iodine in 106 neonates and their mothers referred to healthcare center in Shabestar, Eastern Azerbaijan for congenital hypothyroidism screening program were determined. Median urinary iodine < 100 micro g/L and milk iodine < 50 micro g/L was considered as iodine deficiency. The median urine iodine concentrations [UIC] in mothers and infants were 142.31 micro g/L [.0 - 1260] and 306.76 micro g/L [23.56-1020] respectively. Urine iodine concentrations were < 100 micro g/L in 33.9% of mothers and 14.2% of neonates. The median milk iodine concentration [MIC] was 58.23 micro g/L [20.31- 425] and in 41.9% of mothers was <50 micro g/L. A positive significant correlation was found between milk iodine and maternal urinary iodine concentration [r=0.533, P= 0.000]. There was significant correlation between neonatal UIC and maternal UIC [r=0.462, P= 0.000], neonatal UIC and MIC [r=0.414, P= 0.000]. Urinary and milk iodine concentrations in mothers and infants were within acceptable range, which indicates adequate iodine intake. However, there were moderate and marginal iodine deficiencies in about half percentage of participants. Insufficient amount of milk iodine in about half of the mothers can result in iodine deficiency in breast-fed infants

Correlação entre níveis de iodo na urina e alterações anatomopatológicas em tireoide / Correlation between iodine urinary levels and pathological changes in thyroid glands

OBJETIVOS: Determinar o aporte nutricional de iodo na população estudada e correlacionar os níveis de iodo encontrados em amostras casuais de urina (iodúria) com alterações anatomopatológicas observadas nas tireoides dessa população. MATERIAIS E MÉTODOS: Determinou-se a iodúria em 30 amostras casuais de urina e realizou-se o estudo anatomopatológico de 55 tireoides colhidas de cadáveres que deram entrada no Departamento Médico Legal de Vitória, Espírito Santo, Brasil, no período de maio a agosto de 2011. RESULTADOS: Em 29 amostras de urina (96,7%) encontrou-se iodúria acima do limite máximo preconizado pela Organização Mundial da Saúde (OMS) de 300 µg/L. Em 14 tireoides (25,5%) foi identificada a presença de quadros histológicos compatíveis com tireoidite. Níveis mais elevados de iodo na urina foram observados no sexo feminino e nos casos de tireoides com presença de achados inflamatórios (tireoidites). CONCLUSÕES: Podemos concluir que na população estudada houve um excesso de iodo em seu aporte nutricional e uma maior incidência de quadros inflamatórios tireoidianos.

OBJECTIVES: To determine iodine nutrition in the population and to correlate levels of iodine found in random samples of urine with pathological changes observed in thyroids collected in this population. MATERIALS AND METHODS: Urinary iodine was determined in 30 random samples of urine and the pathological study was carried out in 55 thyroid glands from corpses received by the Department of Forensic Medicine of Vitória, Espírito Santo, Brazil from May to August 2011. RESULTS: In 29 urine samples (96.7%) urinary iodine was above the maximum limit recommended by the World Health Organization (WHO), of 300 mg/L. Fourteen thyroids (25.5%) showed the presence of histological changes compatible with thyroiditis. Higher levels of iodine in urine were observed in females and in of thyroid that showed inflammation (thyroiditis). CONCLUSIONS: We conclude that, in this population, there is excess iodine intake, and greater incidence of inflammatory thyroid disease.

Iodine nutrition in elementary state schools of Queretaro, Mexico: correlations between urinary iodine concentration with global nutrition status and social gap index / Consumo de iodo em escolas de ensino fundamental de Querétaro, México: correlação entre a concentração urinária de iodo, o estado nutricional geral e o índice de desigualdade social

OBJECTIVE AND METHODS: To estimate median urinary iodine concentration (UIC), and to correlate it with global nutrition indicators and social gap index (SGI) in 50 elementary state schools from 10 municipalities in the State of Queretaro, Mexico. RESULTS: 1,544 students were enrolled and an above of requirements of iodine intake was found (median UIC of 297 µg/L). Iodine status was found as deficient, adequate, more than adequate and excessive in 2, 4, 19 and 25 schools, respectively. Seventy seven percent of table salt samples showed adequate iodine content (20-40 ppm), while 9.6% of the samples had low iodine content (< 15 ppm). Medians of UIC per school were positively correlated with medians of body mass index (BMI) by using the standard deviation score (SDS) (r = 0.47; p < 0.005), height SDS (r = 0.41; p < 0.05), and overweight and obesity prevalence (r = 0.41; p < 0.05). Medians of UIC per school were negatively correlated with stunting prevalence (r = -0.39; p = 005) and social gap index (r = -0.36; p < 0.05). Best multiple regression models showed that BMI SDS and height were significantly related with UIC (p < 0.05). CONCLUSIONS: There is coexistence between the two extremes of iodine intake (insufficient and excessive). To our knowledge, the observed positive correlation between UIC and overweight and obesity has not been described before, and could be explained by the availability and consumption of snack food rich in energy and iodized salt.

OBJETIVO E MÉTODOS: Estimar a concentração de iodo urinário (CIU) mediana e correlacioná-la com os indicadores de nutrição geral e com o índice de desigualdade social (IDS) de 50 escolas estaduais de ensino fundamental de 10 municípios do estado de Querétaro, no México. RESULTADOS: Utilizou-se um total de 1.544 crianças e encontrou-se uma ingestão acima das necessidades de iodo (CIU mediana de 297 µg/L). O nível de iodo determinado foi deficiente, adequado, mais do que adequado e excessivo em 2, 4, 19 e 25 escolas, respectivamente. Setenta e sete por cento de amostras de sal de mesa mostraram uma quantidade de iodo adequada (20-40 ppm), enquanto 9,6% das amostras tinham um teor de iodo baixo (< 15 ppm). As medianas de CIU por escola foram correlacionadas positivamente com as medianas do índice de massa corporal (IMC) usando o desvio-padrão da contagem (DP) (r = 0,47; p < 0.005), o DP da altura (r = 0,41; p < 0.05) e a prevalência de sobrepeso e de obesidade (r = 0,41; p < 0,05). As medianas de CUI por escola foram correlacionadas negativamente com a prevalência de desnutrição (r = -0.39; p = 005) e com o índice de desigualdade social (r = -0.36; p < 0,05). Os melhores modelos de regressão múltipla mostraram que a DP do IMC e a altura foram relacionados significativamente com a CIU (p < 0,05). CONCLUSÃO: Existe uma convivência entre os dois extremos de ingestão de iodo (insuficiente e excessiva). Em nosso conhecimento, a correlação positiva entre a CIU, o excesso de peso e a obesidade não foi descrita anteriormente e poderia ser explicada pela disponibilidade e consumo de alimentos ou refeições ricos(as) em energia e sal iodado.

Evaluation of the Performance of a Micromethod for Measuring Urinary Iodine by Using Six Sigma Quality Metrics

BACKGROUND: The urinary iodine micromethod (UIMM) is a modification of the conventional method and its performance needs evaluation. METHODS: UIMM performance was evaluated using the method validation and 2008 Iodine Deficiency Disorders survey data obtained from four urinary iodine (UI) laboratories. Method acceptability tests and Sigma quality metrics were determined using total allowable errors (TEas) set by two external quality assurance (EQA) providers. RESULTS: UIMM obeyed various method acceptability test criteria with some discrepancies at low concentrations. Method validation data calculated against the UI Quality Program (TUIQP) TEas showed that the Sigma metrics were at 2.75, 1.80, and 3.80 for 51+/-15.50 microg/L, 108+/-32.40 microg/L, and 149+/-38.60 microg/L UI, respectively. External quality control (EQC) data showed that the performance of the laboratories was within Sigma metrics of 0.85-1.12, 1.57-4.36, and 1.46-4.98 at 46.91+/-7.05 microg/L, 135.14+/-13.53 microg/L, and 238.58+/-17.90 microg/L, respectively. No laboratory showed a calculated total error (TEcalc)

Avaliação do efeito do uso de conservante e dos diferentes momentos de coleta para a determinação de iodo na urina / The effect of the use of preservative and of the different samples collection times on the iodine determination in urine

A determinação do iodo urinário é o marcador bioquímico mais utilizado para avaliação de suas concentrações, auxiliando em estudos epidemiológicos e na clínica médica. Neste trabalho, foi avaliado o efeito do uso de conservante na coleta de urina em frasco coletor, nos períodos antes (A) e após (B) o almoço, e nas amostras distribuídas em tubos com (C) e sem (S) conservante para determinar as concentrações de iodo e creatinina. A dosagem de creatinina foi utilizada para aferir a função renal. Foram analisadas amostras de 20 indivíduos entre 18 a 40 anos de ambos os sexos. Houve concordância nas concentrações de iodo no (A), sendo o coeficiente de correlação intraclasse (CCI) = 0,769 nos tubos (C) e CCI = 0,724 nos tubos (S), assim como entre (A) CCI = 0,941 e (B) CCI = 0,983. Não houve concordância nas concentrações de creatinina nos tubos (C) CCI = 0,369 e (S) CCI = 0,264 nos dois períodos e, também, entre (A) (CCI =0,916) e (B) (CCI = 0,998). Por não terem sido detectadas variações nas concentrações de iodo nas amostras de urina, ambos os tubos, (C) ou (S), podem ser utilizados com igual confiabilidade. Não foi detecta da variabilidade na determinação de iodo na amostras de urina coletadas nos períodos (A) e (B).

Deficiência de iodo e fatores associados em lactentes e pré-escolares de um município do semiárido de Minas Gerais, Brasil, 2008 / Iodine deficiency and associated factors in infants and preschool children in an urban community in the semiarid region of Minas Gerais State, Brazil, 2008

O objetivo do estudo foi avaliar a prevalência de deficiência de iodo em crianças de 6 a 71 meses em Novo Cruzeiro, Minas Gerais, Brasil. Foram analisadas 475 crianças alocadas por amostragem probabilística estratificada em relação às concentrações de iodo no sal de consumo familiar e excreção urinária de iodo. Observou-se excreção deficiente de iodo em 34,4 por cento das crianças; entre as quais, 23,5 por cento apresentaram deficiência leve; 5,9 por cento, moderada; e 5 por cento, grave. Diferença na distribuição da deficiência de iodo urinário foi constatada entre o meio urbano e rural (p < 0,001), registrando concentrações medianas de iodúria de 150,8µg/L e 114,3µg/L, respectivamente. Observou-se alta proporção de deficiência entre crianças cujo teor de iodo no sal de consumo encontrava-se abaixo da recomendação. A deficiência de iodo em Novo Cruzeiro não constitui problema de saúde pública segundo a Organização Mundial da Saúde (OMS), embora apresente prevalência ainda expressiva. A distribuição limítrofe de iodúria associada a baixos níveis de iodo no sal sugere que as ações de controle dessa carência ainda não são completas no país.

The aim of this study was to evaluate the prevalence of iodine deficiency in children aged 6 to 71 months in Novo Cruzeiro, Minas Gerais State, Brazil. A total of 475 children, allocated by stratified probability sampling, were analyzed with respect to the iodine concentrations in the salt consumed by the family and urinary iodine. Iodine deficiency was verified in 34.4 percent of the children, of which 23.5 percent showed slight deficiency, 5.9 percent moderate and 5 percent serious deficiency. A difference in the distribution of iodine deficiency was observed between the urban and the rural environments (p < 0.001) where average urinary iodine concentrations of 150.8 and 114.3µg/L respectively were found. A greater proportion of iodine deficiency was observed among children where the proportion of iodine in the salt consumed was below the recommended level. Although expressive, iodine deficiency in Novo Cruzeiro is not a public health problem according to World Health Organization (WHO), The limitrophe distribution of the urinary iodine associated with low iodine levels in salt suggests that efforts to control this deficiency are not yet complete.

Prevalencia de hipotiroidismo y relación con niveles elevados de anticuerpos antiperoxidasa y yoduria en población de 35 y más años en Armenia. 2009-2010 / Hypothyroidism prevalence and its relationship to high levels of thyroid peroxidase antibodies and urinary iodine in a population aged 35 and over from Armenia, 2009-2010

Objetivos Determinar la frecuencia de hipotiroidismo y su relación con anticuerpos antiperoxidasa y yoduria elevada, con la finalidad de realizar recomendaciones a las autoridades sanitarias sobre el consumo de sal yodada y detección temprana de enfermedad tiroidea. Métodos Participaron 437 personas de la población general de Armenia (Quindío). Se realizaron pruebas ELISA para Tiroxina-L, hormona estimulante de la tiroides, anticuerpos antiperoxidasa y análisis fotocolorimétrico para yoduria. Resultados La prevalencia de hipotiroidismo fue de 18,5 %. Los anticuerpos antiperoxidasa fueron positivos en el 28,9 %, con prevalencia significativamente más alta entre aquellos con hormona estimulante de la tiroides mayor a 10 uUI/ml comparados con valores de 5,1 a 10 uUI/ml (O.R 3,2) y en fumadores (O.R 3,4). La Tiroxina-L fue normal en el 98,2 % de participantes con hormona estimulante de la tiroides mayor a 5 uUI/ml y en el 92 % de aquellos con valores mayores a 10 uUI/ml. El promedio de yoduria fue de 565,1; niveles por encima de 300 µg/l se obtuvieron en un 81,8 % de los participantes. Conclusiones El aumento en la prevalencia de anticuerpos antiperoxidasa positivo a medida que aumentan los valores de hormona estimulante de la tiroides podría evidenciar una elevado riesgo en Armenia de desarrollo de hipotiroidismo de origen autoinmune; a pesar de los elevados niveles de yoduria, no se logró establecer relación con los niveles de anticuerpos antiperoxidasa ni de hormona estimulante de la tiroides.

Objectives Determining the prevalence of hypothyroidism and its interrelationship with peroxidase antibodies and high urinary iodine levels as a means for devising a set of recommendations for health authorities regarding the consumption of iodised salt and the early detection of thyroid disease. Methods 437 people in the municipality of Armenia (Quindío) participated in the study. ELISA tests were performed for free thyroxine, thyroid-stimulating hormone and thyroid peroxidase antibodies; a photocolorimetric analysis was carried out to determine urinary iodine levels. Results Hypothyroidism prevalence was 18.5%. Thyroid peroxidase antibodies were positive in 28.9% of the study population, with significantly higher prevalence amongst those with levels > 10 mIU/mL thyroid-stimulating hormone compared to 5.1 to 10 mIU/mL in those without it (OR 3.2) and smokers (O.R 3,4). Free thyroxine was normal in 98.2% of participants (> 5 mIU/mL thyroid-stimulating hormone levels) and 92% in those in whom > 10 mIU/mL thyroid-stimulating hormone levels were found. The average iodine level was 565.1; levels above 300µg/L were obtained in 81.8% of the participants. Conclusions Increased positive thyroid peroxidase antibody prevalence with increasing thyroid-stimulating hormone values could demonstrate a high risk of developing autoimmune hypothyroidism in Armenia; despite high iodine levels, a relationship with thyroid peroxidase antibodies or thyroid-stimulating hormone levels could not be established.

Tendencia de la nutrición de yodo durante las últimas décadas en escolares chilenos y sus consecuencias / Trend of iodine nutrition in recent decades and its consequences in Chilean schoolchildren

The endemic goiter, nutritional collective problem due to iodine deficience, constitutes a chronic disease with easy prevention and control, nevertheless still it constitutes a serious problem of public world health, being thought that about 650 million persons have goiter, 43 millions suffer from endemic cretinism and 1570 millions are in risk of suffering this disease for living in areas that present a deficit of iodine. Both patterns, deficit and the excess of iodine can conducted to a thyroid disease. The relation between the ingestion of iodine and the risk of disease corresponds to a U curve, where both, the low one and high ingestion of iodine it is associate to high risk of thyroid disease. To have a program of iodine supplementation, it should imply a constant vigilance of iodine nutrition to see its effect on the goiter prevalence in the population, to control his degree of fulfillment, to avoid a possible excess of ingestion of iodine it might help to correct any precocious alteration. Endemic goiter is not longer a problem in Chile. Salt iodination is in agreement with present legislation, but it is very important to have a continuous surveillance of iodine nutrition in Chile to control if salt fortification is appropiate.

Urine iodine excretion in patients with euthyroid nodular disease

Different nutritional and environmental factors are responsible for the pathogenesis of goiter, but iodine deficiency is the most important factor. However, little is known about the natural course of benign thyroid nodules in euthyroid patients over time. Few studies have used ultrasonographic evaluation to address this issue, especially in iodine-deficient areas. In this study, we present the long-term follow-up of benign thyroid nodules in a iodine-deficient area. Cross-sectional study at a tertiary referral center. This study included 62 randomly selected patients with benign euthyroid nodule. Thyroid volume and nodules were measured with sonography. Iodine intake was estimated by patient diet history and by measuring iodine excretion in spot urine samples. Patients were followed one year. Patients were divided into three groups according to level of urine iodine excretion: Group 1: <50 micro g/L [severe iodine deficiency group], Group 2: 50-100 micro g/L [mild iodine deficiency group], Group 3: >100 micro g/L [iodine sufficient group]. The presence of additional disease [hypertension, diabetes mellitus, coronary heart disease, chronic renal failure and a history of any medication for chronic disorder] and smoking rates were significantly higher in first group compared to the second and third group. Among groups, no significant difference was observed in either right or left thyroid lobe volume after one year. A clinically significant increase in nodule volume was observed in the first group, while there was a significant decrease in the second and third group. In this study, iodine deficiency was associated with an increase in thyroid nodule volumes. Smoking rates were higher in iodine deficient groups. It is thought that smoking impairs iodine intake or absorption consistent with a previous report

[Comparison of the thyroid autoantibodies and urinary iodine concentration in hypothyroid and normal individuals in Rafsanjan city in 2006]

Thyroid disorders are among the most prevalent autocrine diseases. The aim of this study was to compare the prevalence of thyroid autoantibodies and iodine consumption in hypothyroid patients and healthy subjects. This cross-sectional study was performed through simple non-probability sampling on 75 hypothyroid subjects [TSH >5 mIU/ml, T4 <60 nmol/L and T3RUP=30 -40%] age 20-75 [M/F=28/47] as cases, and 75 normal individuals [TSH and T4 normal, sex and age matched with the case group] as control. Urinary iodine concentration, antithyroperoxidase [Anti-TPO] and antithyroglobulin [Anti-Tg] were measured in all individuals. Statistical analysis was done in SPSS, using t-test and Fisher's exact test. P-value of <0.05 was considered statistically significant. In hypothyroid individuals urinary iodine concentration was less than the control group [p<0.0001], whereas Anti-TPO and Anti-Tg were significantly higher [p<0.0001 and p<0.0001 respectively]. Fifty percent of the subjects, above 60 years old, had urinary iodine deficiency. Thyroid autoimmunity is one of the main causes of hypothyroidism in Rafsanjan city and it seems that autoimmunity is not due to the increase of iodine consumption. In addition, iodine deficiency is a health problem in elderly individuals in this study and considering the special conditions of these individuals it must be replaced with other manners