Definición de los rangos de referencia de T4 libre, TSH y tiroglobulina en sujetos sanos del Distrito Sanitario de Jaén / Definition of reference ranges for free T4, TSH, and thyroglobulin levels in healthy subjects of the Jaén Health District

Antecedentes y objetivos: Las guías de tratamiento de disfunción tiroidea recomiendan definir los intervalos de referencia de las hormonas tiroideas de cada área mediante la evaluación de datos de población local considerando el grado de nutrición yódica de la misma. El objetivo de este estudio fue definir los rangos de referencia de la tiroxina libre (T4L), TSH y tiroglobulina en población general de Jaén, área con un nivel de nutrición yódica adecuado, y si estos estaban afectados por la yoduria. Material y métodos: Estudio descriptivo transversal realizado en 1.003 sujetos de población general en el Distrito Sanitario de Jaén. El yodo urinario, T4L, TSH, tiroglobulina y los anticuerpos antitiroperoxidasa (anti-TPO) fueron analizados en función de la edad y el sexo. Resultados: La mediana de yoduria fue 110,59μg/l y la media 130,11μg/l. La mediana de TSH fue 1,83μUI/ml (p2,5=0,56μUI/ml, p97,5=4,66μUI/ml). La mediana de T4L fue 0,84ng/dl (p2,5=0,62ng/dl, p97,5=1,18ng/dl). El 5,7% de los sujetos tenían anticuerpos anti-TPO positivos. No existía correlación entre los valores de T4L, TSH ni los anticuerpos anti-TPO con los niveles de yoduria. Los sujetos con anticuerpos anti-TPO positivos tenían una TSH más elevada (3,34μUI/ml frente 2,14μUI/ml; p=0,001; odds ratio=2,42). Conclusiones: El yodo urinario en Jaén está dentro de los valores recomendados por la Organización Mundial de la Salud. Los rangos de referencia de T4L, TSH y tiroglobulina no son diferentes a lo descrito en la literatura y no difieren según la yoduria. La prevalencia de anticuerpos anti-TPO positivos es semejante a la descrita en otras poblaciones de España (AU)

Background and objectives: The treatment guidelines for thyroid dysfunction recommend defining reference ranges for thyroid hormones in each area through assessment of local population data considering the iodine nutritional status. The aim of this study was to define the reference ranges of free thyroxine (FT4), TSH, and thyroglobulin levels in a general population from Jaen, an area of southern Spain with an adequate iodine nutritional status, and whether they were associated with urinary iodine levels. Patients and methods: A cross-sectional study was conducted in 1,003 subjects of the general population of the Jaen Health District. Levels of urinary iodine, FT4, TSH, thyroglobulin, and thyroid peroxidase (TPO) antibodies were measured according to age and sex. Results: Median and mean urinary iodine levels were 110.59μg/L and 130.11μg/L respectively. Median TSH level was 1.83μIU/mL (p2.5=0.56μIU/mL, p97.5=4.66μIU/mL). Median FT4 level was 0.84ng/dL (p2.5=0.62ng/dL, p97.5=1.18ng/dL). TPO antibodies were detected in 5.7% of subjects. There was no correlation between urinary iodine levels and FT4, TSH or TPO antibodies. Subjects with positive TPO antibodies had higher TSH levels (3.34μIU/L versus 2.14μIU/mL, P=.001; odds ratio=2.42). Conclusions: Urinary iodine levels in Jaen are optimal according to World Health Organization standards. Reference ranges of FT4, TSH, and thyroglobulin do not differ from those reported in the literature and are no associated to urinary iodine levels. The prevalence of positive TPO antibodies was similar to that reported in other Spanish areas (AU)

Definition of reference ranges for free T4, TSH, and thyroglobulin levels in healthy subjects of the Jaén Health District. / Definición de los rangos de referencia de T4 libre, TSH y tiroglobulina en sujetos sanos del Distrito Sanitario de Jaén.

BACKGROUND AND OBJECTIVES: The treatment guidelines for thyroid dysfunction recommend defining reference ranges for thyroid hormones in each area through assessment of local population data considering the iodine nutritional status. The aim of this study was to define the reference ranges of free thyroxine (FT4), TSH, and thyroglobulin levels in a general population from Jaen, an area of southern Spain with an adequate iodine nutritional status, and whether they were associated with urinary iodine levels. PATIENTS AND METHODS: A cross-sectional study was conducted in 1,003 subjects of the general population of the Jaen Health District. Levels of urinary iodine, FT4, TSH, thyroglobulin, and thyroid peroxidase (TPO) antibodies were measured according to age and sex. RESULTS: Median and mean urinary iodine levels were 110.59µg/L and 130.11µg/L respectively. Median TSH level was 1.83µIU/mL (p2.5=0.56µIU/mL, p97.5=4.66µIU/mL). Median FT4 level was 0.84ng/dL (p2.5=0.62ng/dL, p97.5=1.18ng/dL). TPO antibodies were detected in 5.7% of subjects. There was no correlation between urinary iodine levels and FT4, TSH or TPO antibodies. Subjects with positive TPO antibodies had higher TSH levels (3.34µIU/L versus 2.14µIU/mL, P=.001; odds ratio=2.42). CONCLUSIONS: Urinary iodine levels in Jaen are optimal according to World Health Organization standards. Reference ranges of FT4, TSH, and thyroglobulin do not differ from those reported in the literature and are no associated to urinary iodine levels. The prevalence of positive TPO antibodies was similar to that reported in other Spanish areas.

Evaluación del estado de nutrición yódica en población general en la provincia de Jaén / Assessment of iodine nutritional status in the general population in the province of Jaén

ANTECEDENTES Y OBJETIVO: En Jaén se conoce que existe una deficiencia de yodo (DY) de leve a moderada, y que afecta tanto a escolares como a mujeres embarazadas. Se sabe que la DY es una de las causas principales de disfunción tiroidea y bocio, habiéndose establecido que una yodoprofilaxis adecuada en zonas yododeficientes, tanto en forma de sal yodada, leche y sus derivados, o la toma de suplementos yodados, en caso de gestación, conlleva una mejoría significativa de estos problemas. El objetivo de este estudio es evaluar el grado de nutrición yódica en población general en una zona catalogada como yododeficiente y sin que se hayan llevado a cabo, por el momento, campañas institucionales de yodoprofilaxis. MATERIAL Y MÉTODOS: Estudio descriptivo de corte transversal. Se ha realizado determinación de la yoduria en población general en el distrito sanitario de Jaén, separando en grupos según la edad y el género, y se ha encuestado sobre del consumo de sal yodada. RESULTADOS: La mediana de yoduria fue de 110,59 μg/l y la media de 130,11 μg/l. Se encuentran diferencias estadísticamente significativas en los niveles de yoduria en los escolares con respecto al resto de grupos de edad, siendo la media de yoduria en este grupo de 161,52 μg/l vs 109,33 μg/l en los mayores de 65 años. Encontramos que el 43% de la población tiene una yoduria menor de 100 μg/l y que en las mujeres, en el grupo de edad fértil, hay un 66,8% con niveles de yoduria inferior a 150 μg/l. CONCLUSIONES: la situación nutricional de yodo indicaría que se encuentra dentro de lo que se considera una nutrición adecuada, si bien encontramos que el porcentaje de población que presenta yodurias por debajo de 100 μg/l es aún muy elevado, y que la prevalencia del consumo de sal yodada en hogares es del 30,9%, muy por debajo de las recomendaciones de la OMS

BACKGROUND AND OBJECTIVE: Iodine deficiency affecting both pregnant women and schoolchildren has been reported in Jaén. Iodine deficiency is one of the leading causes of thyroid dysfunction and goiter, and adequate iodine prophylaxis with iodized salt, milk, and dairy products, or iodine supplementation have been shown to significantly improve iodine status in pregnancy. The purpose of this study was to assess iodine nutritional status in the general population of a iodine-deficient area with no previous institutional campaigns of iodine prophylaxis. MATERIAL AND METHODS: A descriptive, cross-sectional study. Urinary iodine levels were measured in subjects from the Jaén healthcare district. The data were stratified by sex and age groups, and a survey was conducted on iodized salt consumption. RESULTS: Median and mean urinary iodine levels were 110.59 mcg/L and 130.11 mcg/L respectively. Urinary iodine levels were significantly higher in schoolchildren as compared to other age groups (161.52 μg/L vs 109.33 μg/L in subjects older than 65 years). Forty-three percent of the population had urinary iodine levels less than 100 μg/L, and 68% of women of childbearing age had levels less than 150 μg/L. CONCLUSIONS: Iodine nutritional status appears to be adequate, but the proportion of the population with urinary iodine levels less than 100 μg/L is still very high, and iodized salt consumption is much less common than recommended by the WHO

Assessment of iodine nutritional status in the general population in the province of Jaén.

BACKGROUND AND OBJECTIVE: Iodine deficiency affecting both pregnant women and schoolchildren has been reported in Jaén. Iodine deficiency is one of the leading causes of thyroid dysfunction and goiter, and adequate iodine prophylaxis with iodized salt, milk, and dairy products, or iodine supplementation have been shown to significantly improve iodine status in pregnancy. The purpose of this study was to assess iodine nutritional status in the general population of a iodine-deficient area with no previous institutional campaigns of iodine prophylaxis. MATERIAL AND METHODS: A descriptive, cross-sectional study. Urinary iodine levels were measured in subjects from the Jaén healthcare district. The data were stratified by sex and age groups, and a survey was conducted on iodized salt consumption. RESULTS: Median and mean urinary iodine levels were 110.59 mcg/L and 130.11 mcg/L respectively. Urinary iodine levels were significantly higher in schoolchildren as compared to other age groups (161.52µg/L vs 109.33µg/L in subjects older than 65 years). Forty-three percent of the population had urinary iodine levels less than 100µg/L, and 68% of women of childbearing age had levels less than 150µg/L. CONCLUSIONS: Iodine nutritional status appears to be adequate, but the proportion of the population with urinary iodine levels less than 100µg/L is still very high, and iodized salt consumption is much less common than recommended by the WHO.