Recovery of parathyroid function in patients with thyroid cancer treated by total thyroidectomy: An analysis of 685 patients with hypoparathyroidism at discharge of surgery.

OBJECTIVE: We aimed to study the predictive factors for recovery of parathyroid function in hypoparathyroid patients after total thyroidectomy for thyroid cancer. METHODS: We designed a retrospective, multicentre and nation-wide analysis of patients with total thyroidectomy who were seen in twenty endocrinology departments from January to March 2018. We selected patients with histologically proven thyroid cancer and retrieved information related to surgical procedure and thyroid cancer features. Survival analysis and Cox regression analysis were used to study the relationship between these variables and the recovery of parathyroid function. RESULTS: From 685 patients with hypoparathyroidism at discharge of surgery, 495 (72.3%) recovered parathyroid function over time. Kaplan-Meier analysis showed that this recovery was significantly related to the presence of specialized surgical team (P<0.001), identification of parathyroid glands at surgery (P<0.001), papillary histopathology (P=0.040), and higher levels of postoperative calcium (Ca) (P<0.001) and parathyroid hormone (PTH) (P<0.001). Subjects with gross extrathyroidal extension (P=0.040), lymph node metastases (P=0.004), and surgical re-intervention after initial surgery (P=0.024) exhibited a significant risk of persistence of hypoparathyroidism. Multivariate Cox regression analysis showed that the significant and independent factors for recovery of parathyroid function were postoperative concentrations of Ca (P=0.038) and PTH (P=0.049). The presence of lymph node metastases was a negative predictor of recuperation of parathyroid function (P=0.042) in this analysis. CONCLUSION: In patients with thyroid cancer, recovery of parathyroid function after total thyroidectomy was directly related to postoperative Ca and PTH concentrations, and inversely related to lymph node metastases.

Permanent postoperative hypoparathyroidism: an analysis of prevalence and predictive factors for adequacy of control in a cohort of 260 patients.

BACKGROUND: Recent guidelines for the treatment of hypoparathyroidism emphasize the need for long-term disease control, avoiding symptoms and hypocalcaemia. Our aim has been to analyze the prevalence of poor disease control in a national cohort of patients with hypoparathyroidism, as well as to evaluate predictive variables of inadequate disease control. METHODS: From a nation-wide observational study including a cohort of 1792 patients undergoing total thyroidectomy, we selected 260 subjects [207 women and 53 men, aged (mean ± SD) 47.2±14.8 years] diagnosed with permanent hypoparathyroidism. In every patient demographic data and details on surgical procedure, histopathology, calcium (Ca) metabolism, and therapy with Ca and calcitriol were retrospectively collected. A patient was considered not adequately controlled (NAC) if presented symptoms of hypocalcemia or biochemical data showing low serum Ca levels or high urinary Ca excretion. RESULTS: Two hundred and twenty-one (85.0%) patients were adequately controlled (AC) and 39 (15.0%) were NAC. Comparison between AC and NAC patients did not show any significant difference in demographic, surgical, and pathological features. Rate of hospitalization during follow-up was significantly higher among NAC patients in comparison with AC patients (35.9% vs. 10.9%, P<0.001). Dose of oral Ca and calcitriol were also significantly higher in NAC subjects. In a subgroup of 129 patients with serum parathyroid hormone (PTH) levels available, we found that NAC patients exhibited significantly lower postoperative PTH concentrations than AC patients [median (interquartile range) 3 (1.9-7.8) vs. 6.9 (3.0-11) pg/mL; P=0.009]. CONCLUSIONS: In a nation-wide cohort of 260 subjects with definitive hypoparathyroidism, 15% of them had poor disease control. These patients required higher doses of oral Ca and calcitriol, had higher rate of hospitalization during follow-up and showed lower PTH concentrations in the postoperative period.

Correction to: Prevalence and risk factors for hypoparathyroidism following total thyroidectomy in Spain: a multicentric and nation-wide retrospective analysis.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Glucagon-like peptide 1 and Glucagon-like peptide 2 in relation to osteoporosis in non-diabetic postmenopausal women.

Osteoporosis results from an imbalance in bone remodeling, which is known to follow a circadian rhythm determined by a functional relationship between intestine and bone tissue. Specific intestinal peptides have been identified as mediators. Glucagon-like peptide 1 and glucagon-like peptide 2, have been associated with bone health. Our main objective was to determine whether postprandial plasma levels of glucagon-like peptide 1, glucagon-like peptide 2 and dipeptidyl-peptidase 4 activity, are associated with osteoporosis in non-diabetic postmenopausal women. We studied non-diabetic postmenopausal women with osteoporosis diagnosed by dual-energy X-ray absorptiometry (cases, n = 43) and age-matched (±1 yr) controls without osteoporosis or a history of osteoporotic fracture (n = 43). We measured postprandial plasma levels of glucagon-like peptide 1, glucagon-like peptide 2, and dipeptidyl-peptidase 4 activity, bone mineral density, and baseline levels of bone remodeling markers and analyzed the food intake using a food-frequency questionnaire. Postprandial glucagon-like peptide 1 values were lower (p < 0.001) in cases, µ (SEM) = 116.25 (2.68), than in controls, µ (SEM) = 126.79 (2.68). Glucagon-like peptide 1 was associated with reduced osteoporosis risk in the crude logistic regression analysis [OR (95% CI) = 0.724 (0.53-0.97), p = 0.031] and adjusted analysis [OR = 0.603 (0.38-0.94), p = 0.027]. We found no association of glucagon-like peptide 2, or dipeptidyl-peptidase 4 activity with osteoporosis. Postprandial glucagon-like peptide 1 levels are related to osteoporosis and osteoporosis risk in non-diabetic postmenopausal women. Further studies are required to verify these findings.

Prevalence and risk factors for hypoparathyroidism following total thyroidectomy in Spain: a multicentric and nation-wide retrospective analysis.

PURPOSE: The prevalence of postoperative hypoparathyroidism has been studied in registries and in surgical series with highly variable and imprecise results. However, the frequency of this hormonal deficiency in the clinical practice of endocrinologists is not known with accuracy. We aimed to assess the prevalence and risk factors of hypoparathyroidism in patients undergoing total thyroidectomy in Spain. METHODS: We designed a retrospective, multicentre and nation-wide protocol including all patients with total thyroidectomy who were seen in the endocrinology clinic of the participant centers from January to March 2018. Prevalence of hypoparathyroidism was evaluated at discharge of surgery, 3-6 months after surgery, 12 months after surgery and at last visit. Twenty hospitals participated in the study. RESULTS: Of 1792 patients undergoing total thyroidectomy, 866 (48.3%) developed postoperative hypoparathyroidism at discharge of surgery. Most of them recover parathyroid function over time. Prevalence of hypoparathyroidism at 3-6 months, 12 months and at last visit was 22.9%, 16.7% and 14.5%, respectively. The risk of developing definitive hypoparathyroidism was related to the presence of parathyroid tissue at histology, lymph node dissection, and two-stage thyroidectomy. Patients with thyroid cancer, with higher postoperative calcium levels and treated by expert surgical teams exhibited lower risk of developing permanent hypoparathyroidism. CONCLUSIONS: Although most patients with postsurgical hypoparathyroidism recover parathyroid function, the prevalence of permanent disease in clinical practice is non negligible (14.5%). Postoperative calcium, extent and timing of surgery, the presence of cancer, expert surgical team, and parathyroid tissue at histology are predictors of permanent hypoparathyroidism.

[Iodine prophylaxis, voices from the past after 65 years]. / Yodoprofilaxis, 65 años después suenan las voces del pasado.

In 1953, Dr. Felipe Rodríguez Moreno joined the Granada Research Group on Endemic Goiter, which was led by Dr. Ortiz de Landázuri. A high goiter prevalence (62% in women) was found out within the area, and that prevalence was observed to be related to the dietary habits of the time, being the most disadvantaged those who were showing a greater prevalence. A relationship between the high goiter prevalence and the family of the subjects with goiter was also found out, as they usually had a first-degree relative with affection. Iodine content of drinking water was poor throughout the area, so the prevalence was not significantly different between individuals who drank from different water sources. There were only two females with cretinism and two males affected by "idiocy", so the goiters were probably euthyroid. After introducing iodine prophylaxis with iodized salt in Güejar-Sierra, prevalence decreased from 53% to 13% between 1953 and 1958.

En el año 1953, el Dr. Felipe Rodríguez Moreno se incorpora para continuar el trabajo sobre endemia bociosa de la escuela de Granada, liderada por el Dr. Ortiz de Landázuri. En ese paisaje descubre una alta prevalencia de bocio (62% en mujeres), que se relacionaba con el tipo de dieta consumida, de tal forma que los más desfavorecidos tenían una prevalencia de bocio aún mayor. Así mismo, se encuentra una relación familiar en cuanto al bocio, de manera que los sujetos con bocio normalmente tienen un familiar en primer grado también afectado. El agua de bebida es pobre en yodo de forma generalizada, por lo que no hay diferencias significativas en la prevalencia de bocio según la fuente de la que se surtan los paisanos.  Solo se encontraron dos mujeres con cretinismo y dos varones afectados de "idiocia". Por ello, cabe pensar que se trata de bocios normofuncionantes.  Tras iniciar yodoprofilaxis con sal yodada en Güejar Sierra, se produce un descenso de la prevalencia de bocio de un 53% a un 13% entre los años 1953-1958.

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.

Yodoprofilaxis, 65 años después suenan las voces del pasado / Iodine prophylaxis, voices from the past after 65 years

En el año 1953, el Dr. Felipe Rodríguez Moreno se incorpora para continuar el trabajo sobre endemia bociosa de la escuela de Granada, liderada por el Dr. Ortiz de Landázuri. En ese paisaje descubre una alta prevalencia de bocio (62% en mujeres), que se relacionaba con el tipo de dieta consumida, de tal forma que los más desfavorecidos tenían una prevalencia de bocio aún mayor. Así mismo, se encuentra una relación familiar en cuanto al bocio, de manera que los sujetos con bocio normalmente tienen un familiar en primer grado también afectado. El agua de bebida es pobre en yodo de forma generalizada, por lo que no hay diferencias significativas en la prevalencia de bocio según la fuente de la que se surtan los paisanos. Solo se encontraron dos mujeres con cretinismo y dos varones afectados de «idiocia». Por ello, cabe pensar que se trata de bocios normofuncionantes. Tras iniciar yodoprofilaxis con sal yodada en Güejar Sierra, se produce un descenso de la prevalencia de bocio de un 53% a un 13% entre los años 1953-1958 (AU)

In 1953, Dr. Felipe Rodríguez Moreno joined the Granada Research Group on Endemic Goiter, which was led by Dr. Ortiz de Landázuri. A high goiter prevalence (62% in women) was found out within the area, and that prevalence was observed to be related to the dietary habits of the time, being the most disadvantaged those who were showing a greater prevalence. A relationship between the high goiter prevalence and the family of the subjects with goiter was also found out, as they usually had a first-degree relative with affection. Iodine content of drinking water was poor throughout the area, so the prevalence was not significantly different between individuals who drank from different water sources. There were only two females with cretinism and two males affected by «idiocy», so the goiters were probably euthyroid. After introducing iodine prophylaxis with iodized salt in Güejar-Sierra, prevalence decreased from 53% to 13% between 1953 and 1958 (AU)

Iodine is associated to semen quality in men who undergo consultations for infertility.

The role that adequate iodine intake could have on the male reproductive function is not entirely known. The aim of this study is to determine whether there is a relation between male infertility and urinary and semen iodine levels in 96 couples who underwent consultation for infertility. The median of semen iodine was higher in men who consumed iodized salt than in those who consumed non-iodized salt (p=0.019). Men with a higher semen iodine level had more morphological alterations in spermatozoa (p=0.032). Men with a higher urinary iodine level had a lower motile sperm count according to the "direct swim-up" technique (p=0.044). Men >3years without successfully achieving pregnancy had a higher urinary iodine level than those with ≤ 3years (p=0.035). In conclusion, iodine may play a role in the quality of semen: an increase in semen iodine levels is associated with different variables related to male infertility.

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.

Diabetes, tumor ovárico, hiperparatiroidismo y cáncer papilar: ¿una asociación casual? / Diabetes, ovarian tumor, hyperparathyroidism, and papillary cancer: association by chance?

No disponible

Genetic diagnosis of idiopathic hypogonadotrophic hypogonadism: a new point mutation in the KAL2 gene.

Kallmann Syndrome (KS) is a genetic disease of embryonic development which is characterized by the association of hypogonadotropic hypogonadism (HH) due to a deficit of the gonadotropin-releasing hormone (GnRH) and a hypo/anosmia (including a hypoplasia of the nasal sulcus and agenesis of the olfactory bulbs). Even though it is a genotypically and phenotypically heterogeneous clinical disease, there are some key genes related to KS (KAL1, FGFR1 (KAL2), GNRHR, KISSR1 (GPR54), GNRH1, NELF and PROK2). The aim of this study was to present a case report of a genetic diagnosis of KS linked to the presence of mutations in the FGFR1 (fibroblast growth factor receptor 1, also known as KAL2) gene. This diagnosis was made in a 44-year old female affected by a hypogonadism for which she had received intermittent treatment until she was 30 years old based on the patient's own decision. The molecular analysis of FGFR1 identified the mutation c. 246_247delAG (p.T82Xfs110) in heterozygosis on exon 3 of the KAL2 gene. This is the first report of this mutation related to idiopathic hypogonadotrophic hypogonadism (IHH).

Newborn TSH concentration and its association with cognitive development in healthy boys.

OBJECTIVE: An association between thyroid function during pregnancy or infancy and neurodevelopment in children has been demonstrated. We aimed to investigate whether newborn TSH concentrations are related to subsequent neurocognitive development. DESIGN: We conducted a longitudinal study on 178 children from a general population birth cohort in Granada (Spain) born in 2000-2002. METHODS: TSH concentrations were measured in umbilical cord blood, and cognitive functions were assessed at 4 years of age using the McCarthy's scales of children's abilities (MSCA). Organochlorine (OC) compound concentrations and the combined oestrogenicity (total effective xeno-oestrogenic burden (TEXB)) were also determined in the placentae. RESULTS: Mean newborn TSH was 3.55  mU/l (range=0.24-17 mU/l). In multivariate regression analyses, adjusting for maternal and child characteristics, higher newborn TSH concentrations showed a decrease of 3.51 and 3.15 points on the MSCA general cognitive and executive function scores respectively and were associated with a higher risk of scoring below the 20th percentile (P20) on the quantitative score (odds ratio (OR)=2.64). Children with TSH in the upper quartile (4.19-17.0 mU/l) were at higher risk of scoring

Efectos de la deficiencia de yodo sobre variables intelectuales en una población infantil / Effects of the iodine deficiency on intellectual variables among children

Existen numerosos estudios que relacionan la deficiencia grave de yodo con la disminución de diferentes capacidades mentales superiores. En este trabajo se pretende conocer qué ocurre cuando la deficiencia de yodo no es tan grave como en los citados trabajos, sino que se trata de una falta de yodo leve o incluso moderada, y si los problemas comunes con una deficiencia grave de yodo (incluyendo el retraso mental) siguen apareciendo de una manera más sutil. Además, también interesa conocer si la metodología clásica (comparar zona yododeficiente contra zona no yododeficiente) es la más adecuada, proponiendo combinar esa agrupación por zonas con la yoduria presentada por los individuos de cada zona. Se evalúa cociente intelectual, capacidad manipulativa y verbal, atención, habilidad visomotora y comportamiento disruptivo, estudiadas muy pocas veces o ninguna en este tipo de investigaciones. La muestra la componen 760 escolares de la provincia de Jaén. Los resultados muestran que se encuentra un cociente intelectual más bajo en la zona yododeficiente y en niños con baja yoduria, cosa que no sucede en la zona yodosuficiente. También se ha visto asociado al nivel de yoduria el comportamiento disruptivo. Las otras variables medidas no se han asociado con déficit de yodo

An association between severe iodine deficiency and poor mental development has been found in many studies. We examined the relationship between moderate or mild iodine deficiency and intellectual capacity in order to determine whether problems common to severe iodine deficiency (including mental retardation) also emerge in a more subtle form. We also wished to know whether the classic methodology (comparing iodine-deficient zones with nondeficient zones) is the most adequate, and propose to combine this grouping by zones with urinary iodine presented by individuals in each zone. We measured IQ, manipulative and verbal capacity, attention, visual motor ability and disruptive behaviour, variables that have barely been studied in this kind of investigations. The sample comprised 760 schoolchildren from the province of Jaén (southern Spain). Our results show that children with low levels of iodine intake and with urinary iodine concentration lower than 100 µg/litre had a lower IQ and displayed more disruptive behaviour than children with high levels of the criteria. The other variables were not associated with iodine deficiency

[Effects of the iodine deficiency on intellectual variables among children]. / Efectos de la deficiencia de yodo sobre variables intelectuales en una población infantil.

An association between severe iodine deficiency and poor mental development has been found in many studies. We examined the relationship between moderate or mild iodine deficiency and intellectual capacity in order to determine whether problems common to severe iodine deficiency (including mental retardation) also emerge in a more subtle form. We also wished to know whether the classic methodology (comparing iodine-deficient zones with nondeficient zones) is the most adequate, and propose to combine this grouping by zones with urinary iodine presented by individuals in each zone. We measured IQ, manipulative and verbal capacity, attention, visual motor ability and disruptive behaviour, variables that have barely been studied in this kind of investigations. The sample comprised 760 schoolchildren from the province of Jaén (southern Spain). Our results show that children with low levels of iodine intake and with urinary iodine concentration lower than 100 microg/litre had a lower IQ and displayed more disruptive behaviour than children with high levels of the criteria. The other variables were not associated with iodine deficiency.

Intelligence quotient and iodine intake: a cross-sectional study in children.

The association between iodine deficiency and poor mental and psychomotor development is known. However, most studies were undertaken in areas of very low iodine intake. We investigated whether a similar association is found in schoolchildren from southern Europe with a median urinary iodine output of 90 microg/liter. Urinary iodine levels were measured in 1221 children who also completed a questionnaire about their usual dietary habits. Intelligence quotient (IQ) was measured by Cattell's g factor test. IQ was significantly higher in children with urinary iodine levels above 100 microg/liter. The risk of having an IQ below the 25th percentile was significantly related to the intake of noniodized salt and drinking milk less than once a day. As expected, the risk of having an IQ below 70 was greater in children with urinary iodine levels less than 100 microg/liter. In conclusion, this study demonstrates that the IQ of schoolchildren in a developed country can be influenced by iodine intake. The results support the possibility of improving the IQ of many children from areas with mild iodine deficiency by ensuring an iodine intake sufficient to achieve a urinary iodine concentration greater than 100 microg/liter.