Erradicación de los trastornos por deficiencia de yodo en Asturias (España): 18 años de yodoprofilaxis con sal

Nutritional Iodine Status in Pregnant Women from Health Area IV in Asturias (Spain): Iodised Salt Is Enough

Background: Iodine deficiency during pregnancy may have adverse effects on the neurodevelopment of the foetus. Recent studies of pregnant women in Asturias (Spain) indicate that nutritional iodine levels are sufficient. The objective of this study was to confirm the appropriate nutritional iodine status and to analyse the influence of the ingestion of iodine on maternal urinary iodine concentration (UIC) and thyroid function. Methods: An observational study was carried out between May and June 2017 on women in the first trimester of pregnancy from Health Area IV in Asturias. The women completed a questionnaire related to their consumption of iodine and samples were taken to analyse UIC and thyroid function. Results: Three hundred and eighteen pregnant women were involved. Of these, 51.10% used iodised salt, 48.90% consumed ≥ 2 servings of dairy products daily and 87.08% took iodine supplements. The median UIC was 171.5 μg/L (116–265 μg/L) and 60.41% of women had UIC ≥ 150 μg/L. Multivariate logistic regression analysis demonstrated that iodised salt had a protective effect on UIC < 150 μg/L (odds ratio (OR) 0.404 (0.237–0.683), p = 0.001), but not iodine supplements (OR 0.512 (0.240–1.085), p = 0.080). The average level of thyroid stimulating hormone (TSH) was 2.26 ± 0.94 mIU/L; 68.40% of pregnant women taking iodine supplements had TSH < 2.5 mIU/L compared to 30.00% of those who were not taking supplements (p = 0.031). Conclusions: The pregnant women in our health area are maintaining appropriate nutritional iodine levels. The consumption of iodised salt protects against iodine deficiency; thus, iodine supplements should be taken on an individualised basis.

[Nutrition and gastronomy in the Principality of Asturias]

Introduction

Introduction: Asturias is renowned for its beautiful and diverse nature and landscapes and for its rich gastronomic tradition. Objectives: to understand the traditional gastronomic identity of Asturias and its relationship with food and nutritional intake and health indicators of the population. Methods: bibliographic search (PubMed, Google Scholar) with different combinations of keywords. Results: the gastronomic tradition of Asturias is characterized by a great variety of foods and dishes, with emblematic culinary preparations. Different reports and studies agree that it is one of the Spanish Regions with the highest food consumption, except for vegetables and cereals and derivatives. The energy intake is also among the highest, but with the highest rates of diet quality indexes. The high consumption of food and the high energy intake, together with an aged population with a high prevalence of sedentary lifestyles, could explain that the prevalence of obesity in the adult population of Asturias is the highest of all the Spanish Regions, with an increasing incidence of diabetes. Conclusions: it is necessary to implement public health policies aimed at improving food selection and health indicators. Furthermore, the study of the contribution of traditional dishes to the dietary habits, the nutritional intake and the health indicators of the population of Asturias would help in improving food selection.

Thyroid Volume Assessment in 3-14 Year-Old Spanish Children from an Iodine-Replete Area

BACKGROUND/AIMS

Few data exist on reference thyroid volumes (Tvols) for Spanish children. The standard tables of the World Health Organization (WHO) are only for children older than 6 years. The present cross-sectional study reports the normal Tvols of 3-14 year-old girls and boys living in Madrid (Spain).

METHODS

The study subjects were 217 children aged 3-14 years. Urinary iodine was determined, and, on the same day, cervical ultrasound examinations were performed by a single, experienced paediatric radiologist. The sex-specific, upper normal limits for Tvol were then determined, based on age and body surface area (BSA).

RESULTS

The median urinary iodine concentration was 120 µg/L (interquartile range 80-184); the population was therefore deemed to fall within the optimum range for iodine nutritional status. Eight children with heterogeneous glandular parenchyma were detected, as were 6 with increased vascularity, and 22 with intrathyroid cysts. Tvol increased with age and BSA in both sexes from the age of 3 years. In girls aged 11-12 years, Tvol was significantly larger than that in boys of the same age. When comparing children 6 years old and above, the 97th percentile Tvols with respect to gender/BSA were similar to WHO reference values, but by gender/age they were 30% larger.

CONCLUSIONS

This work proposes reference ultrasound-determined Tvols for 3-14-year-old children living in Madrid.

Nutritional status of iodine in children: When appropriateness relies on milk consumption and not adequate coverage of iodized salt in households

BACKGROUND & AIMS

Iodine deficiency inhibits the normal development of human beings and is the leading cause of preventable mental retardation. Our study aims to update the urinary iodine concentrations and the intake of iodized salt in children in Madrid (Spain).

METHODS

A cross-sectional study was designed where 217 children aged 3-14 years old were studied. A nutritional survey including the intake of iodized salt and other iodine-rich foods was performed. In addition, the urinary concentration of iodine was determined in each patient.

RESULTS

Near 60% of the surveyed households routinely used iodized salt. Significant differences in age, sex, country of birth, or country of birth and parents educational levels and iodized salt consumption were not found. The median of the urinary iodine level (120 μg/L; interquartile range 80-184) was significantly higher in boys than girls and more elevated in younger children. Iodized salt and milk consumption significantly increased the concentration of urinary iodine. Children who drank less than two glasses of milk per day and did not consume iodized salt have four times the risk of iodine deficiency compared to children who daily drank at least two glasses of milk and consumed iodized salt (P < 0.001).

CONCLUSIONS

The nutritional level of iodine in the children studied is appropriate despite the low consumption of iodized salt. This is due to the consumption of dairy products and milk. The younger the child, the better his/her iodine nutritional level. Teenagers studied are at higher risk of iodine deficiency.

Is iodine nutrition in the Spanish pediatric population adequate? Historical review and current situation

Iodine is an essential component of thyroid hormones, and iodine deficit is the leading cause of preventable mental retardation worldwide. Spain was considered iodine-deficient until 2003. Although iodine urinary levels have been in the optimal range in Spain since 2004, the WHO recognizes that our country does not meet the necessary requirements to ensure that the whole population is not at risk of an iodine deficiency disorder. The aim of this article is to review the current iodine status in Spain. Data from several studies emphasize the low consumption of iodized salt at home. Despite the progress made in recent decades, Spanish children are not exempt from suffering an iodine deficiency disorder. Policies that allow for controlling iodine nutrition and promote universal consumption of iodized salt should therefore be implemented.

Iodine nutritional status in Asturian schoolchildren

INTRODUCTION

Iodine deficiency is a public health problem, and iodine nutritional status should therefore be regularly measured.

OBJECTIVE

To ascertain iodine nutritional status in Asturias and its relation to use of iodized salt and to other sociodemographic and nutritional parameters.

MATERIAL AND METHODS

A descriptive, observational study was conducted in a random sample of schoolchildren aged 5 to 14 years, in whom urinary iodine levels were measured by high-performance liquid chromatography. Families completed a survey on use of iodized salt, consumption of dairy products and fish, and sociodemographic data.

RESULTS

The study sample consisted of 705 schoolchildren (51.1% females) with a mean age of 9.9 years (SD 2.6). In a total of 620 valid measurements, mean urinary iodine level was 204.1 μg/L (SD 120.6), while the median value was 180.7 μg/L (P₂₅-P₇₅: 124-252.3 μg/L, interquartile range 128.3 μg/L). Urinary iodine levels were <100 μg/L in 16.6% of children, and very low (<20 μg/L) in 0.2%. Iodized salt was used in 69.3% of all households, and in all school canteens. Consumption of dairy products was significantly associated to urinary iodine levels (P<.0005).

CONCLUSION

Iodine nutrition of Asturian schoolchildren is adequate, although the target of use of iodized salt in 90% of households is still far away. Adequate iodine nutrition may be due to other sources, such as dairy products. Public health campaigns are required to promote iodized salt consumption. Regular assessment of iodine nutritional status is also needed.

Iodine nutritional status of women in their first trimester of pregnancy in Catalonia

Background

Sufficient iodine intake is needed during pregnancy to ensure proper fetal development. The iodine levels of women in their first trimester of pregnancy in Catalonia are currently unknown. This data would help to determine whether our public health services should establish recommendations or interventions in this line. The aim of this study was to investigate the iodine nutritional status, prevalence of urinary iodine <150 μg/L, and tobacco use in the first trimester of pregnancy in our setting.

Methods

Cross-sectional study. Data were collected during 2008–2009 from women in their first trimester at the primary care centers of the province of Barcelona (Spain). Pregnant women included in the study completed a questionnaire on eating habits and underwent urinary iodine concentration (UIC) assessment.

Results

Nine hundred forty five women completed the dietary questionnaire and urinary iodine testing. Median UIC was 172 μg/L, with 407 participants (43.1%) showing levels <150 μg/L. On multivariate logistic regression analysis, intake of 1–2 glasses of milk per day, OR = 0.636 95% CI (0.45–0.90) or >2 glasses, OR = 0.593 95% CI (0.37–0.95); iodized salt consumption, OR = 0.678 95% CI (0.51–0. 90); and use of iodine supplementation, OR = 0.410 95% CI (0.31–0.54), protected against the risk of UIC <150 μg/L. Simultaneous consumption of iodized salt and milk (≥1 glass/day) showed a larger protective effect: OR = 0.427, 95% CI (0.31–0.54).

Conclusion

The median UIC of the pregnant women surveyed indicated an acceptable iodine nutritional status according to the criteria established by the WHO and ICCIDD. The risk of urinary iodine <150 μg/L decreased with simultaneous consumption of milk and iodized salt, similar to the decrease seen with iodine supplementation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-017-1423-4) contains supplementary material, which is available to authorized users.

[Urinary iodine levels and dairy consumption in pre-school children in Southwest Asturias (Spain)]

INTRODUCTION

For decades dairy products have been a major source of iodine for decades. The purpose of this study was to determine the iodine nutritional status and its relationship with dairy consumption in pre-schooler children between 2 to 5 years old in a rural area with 27,847 inhabitants.

PATIENTS AND METHODS

It was planned to study 200 participants, selected by random sampling, proportional to the size of the municipality, age, and sex. Parents provided urine samples to analyse urinary iodine, as well as the nutritional information through an interview. A glass of milk or a slice of cheese was considered as a ration, and a portion of other milk derivatives were considered as half rations. The nutritional status of iodine was interpreted with the median (P[percentile]₅₀) of the urinary iodine levels, and iodine intake was estimated using the mean of ration/day of milk and dairy products, fish, and eggs.

RESULTS

Of the total of 198 subjects that took part, 193 provide urine specimens for the determination of iodine levels. The mean dairy ration/day was 3.8 (SD:1.4). More than two-thirds (69.9%) drank ≥ 2 glasses of milk/day, and 88.1% consumed a dairy ration of another dairy product. The median urinary iodine level was 184 μg/l, but was dependent on glasses of milk/day (282.5 μg/l ≥ 4 glasses) and/or the type of milk (233.0 μg/l in semi-skimmed). An intake of 115.1 μg/day to 170.2 μg/day of iodine was estimated, and that milk was the food which provided more iodine (89.9 μg/day).

CONCLUSIONS

Iodine intake was adequate, although higher than necessary when four or more glasses of milk were consumed, and/or when the milk was skimmed. The consumption of dairy products should be monitored to prevent both excessive and deficient intake of iodine.

Prevalence of thyroid dysfunction in women in early pregnancy: does it increase with maternal age?

OBJECTIVE

Recent studies report high rates of thyroid disorders in pregnant women. However, the need for universal thyroid screening remains controversial. Our aim was to estimate the prevalence of thyroid dysfunction (TD) during pregnancy and to analyse the association with maternal age.

DESIGN AND METHODS

We conducted a cross-sectional study in a referral centre in collaboration with the primary care units from April 2010 to March 2011. The study included 2509 consecutive pregnant women resident in an iodine-sufficient area, mean age 32 years (range 16-47) who were universally screened for TD in their first trimester (median gestation 8 weeks, range 4-13 weeks). Thyroid-stimulating hormone (TSH) and free T4 (FT4) were analysed during the first antenatal visit. We applied first trimester-specific population-based TSH and FT4 reference ranges.

RESULTS

We identified 416 women with positive TD screening [16·6%, 95% confidence interval (95% CI) 15·1-18·0]. Of these, 47 had overt hypothyroidism (1·9%), 90 subclinical hypothyroidism (3·6%), 23 overt hyperthyroidism (0·9%), 20 subclinical hyperthyroidism (0·8%) and 236 had isolated hypothyroxinaemia (9·4%). Applying a logistic regression model, age ≥30 years was not associated with a higher risk of TD [odds ratio (OR) 0·85, 95% CI 0·67-1·08] or hypothyroidism (OR 0·72, 95% CI 0·50-1·06).

CONCLUSIONS

TD affects one in six pregnant women in an iodine-sufficient population. Maternal age ≥30 years do not increase the risk of TD.

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.

Evolution of urinary iodine excretion over eleven years in an adult population

BACKGROUND & AIMS

Few prospective cohort studies have evaluated dietary iodine intake and urinary iodine concentrations in the general adult population. We assess the evolution of urinary iodine excretion and factors that may influence it in an adult population followed for 11 years.

METHODS

A population-based cohort study was undertaken in Pizarra (Spain). In the three study phases (baseline (n = 886), and 6 (n = 788) and 11 years later (n = 501)), participants underwent an interview and a standardized clinical examination that included a food questionnaire, and thyroid hormone and urinary iodine determinations. Subjects with thyroid dysfunction, palpable goiter or urinary iodine excretion >400 μg/L were excluded.

RESULTS

Urinary iodine increased over the years (100.6 ± 70.0 μg/L at baseline vs. 125.4 ± 95.2 μg/L at 6 years and 141.6 ± 81.4 μg/L at 11 years; p < 0.0001). Urinary iodine was significantly higher in subjects who reported iodized salt consumption and in subjects with a higher intake of dairy products (p < 0.05). Consumption of iodized salt (Risk ratio (RR) = 1.23, 95% CI [1.01-2.05]) and dairy products (RR = 2.07, 95% CI [1.01-4.23]), and a baseline urinary iodine concentration ≥100 μg/L (RR = 1.26, 95% CI [1.04-1.53]) were significantly associated with urinary iodine concentrations ≥100 μg/L at 11 years. There is no correlation between thyroid function (TSH, free triiodothyronine or free thyroxine levels) and urinary iodine concentrations in conditions of iodine sufficiency.

CONCLUSIONS

The increase in urinary iodine concentrations over eleven years is associated with an increase in iodized salt intake and with the dairy products intake, and possibly with a higher iodine content of dairy products. However, individual variability in urinary iodine excretion was not fully explained by dietary iodine intake alone; previous urinary iodine concentrations were also important.

Changes in iodine nutrition status in schoolchildren from the Basque Country

BACKGROUND

An epidemiologic survey showed in 1992 iodine deficiency and endemic goiter in schoolchildren from the Basque Country.

OBJECTIVES

(1) To determine the percentage of homes of schoolchildren where iodized salt (IS) is used; (2) to assess iodine nutrition status in schoolchildren and to compare the data collected to those available from previous epidemiological studies.

DESIGN AND METHODS

A cross-sectional study in 720 randomly selected schoolchildren. Urinary iodine concentration (UIC) was measured using high-performance liquid chromatography(HPLC) with electrochemical detection.

RESULTS

IS was used at 53.0% of the homes (95% confidence interval [CI], 49.2-56.7%). Median UIC has increased by 226%, from 65 μg/L in 1992 to 147 μg/L (percentile [P], P(25), 99 μg/L; P(75), 233 μg/L) today. Both schoolchildren consuming IS and those using unfortified salt at their homes had UICs corresponding to adequate iodine intakes (165 and 132 μg/L respectively). UICs experienced great seasonal fluctuations, being 55% higher during the November-February period than in June-September period (191 μg/L vs 123 μg/L; p<0.001)

CONCLUSIONS

Schoolchildren from the Basque Country have normalized their iodine nutrition status. The strong seasonal pattern of UICs suggests that consumption of milk and iodine-rich dairy products coming from cows feed iodized fodder is one of the most significant factors involved in the increase in iodine intake since 1992.

Situación nutricional de yodo en la población escolar de Alicante

BACKGROUND

According to the World Health Organization (WHO), goiter is endemic in Spain. The main cause of endemic goiter is iodine deficiency, which is also the principal cause of mental retardation and avoidable cerebral palsy throughout the world.

MATERIAL AND METHODS

We conducted an observational study to determine the prevalence of endemic goiter and nutritional iodine status in the province of Alicante. Urinary iodine excretion was measured in a morning urine sample, and thyroid volume was measured by means of a thyroid ultrasound scan. A case of goiter was diagnosed if thyroid volume was above the 97th percentile adjusted by age, as published by the WHO.

RESULTS

No cases of goiter were found. In addition, the median urinary iodine excretion levels adjusted by age were within the normal range, as defined by the WHO's criteria.

CONCLUSIONS

Endemic goiter was not found in the province of Alicante and urinary iodine excretion values demonstrated adequate iodine intake. Further ultrasound studies are needed to establish reference thyroid volumes for our population.

Estudio de la yoduria en la población adulta de Cataluña

BACKGROUND AND OBJECTIVE

In 1983 goitre prevalence in Catalonia (Spain) was 21% and average urinary iodine (UI) 88.5 microg/l (SD 47.5). Surveys carried out in the nineties, after a campaign promoting the use of iodized salt, showed a significant improvement in UI. In the framework of Catalan Health Examination (2002), the assessment of iodine deficiency was included. The aim of this study was to determine UI and its distribution among a representative sample of population aged 18-74 in Catalonia.

SUBJECTS AND METHOD

A sample of 2,100 people were stratified in accordance with the eight Catalan health areas (CHA). A questionnaire was prepared and urinary samples were collected for iodine testing.

RESULTS

1,115 urinary samples were collected (in 7 of the 8 CHA). Median UI was 147 microg/l and average UI 182.8 (SD 140). UI < 50 microg/l was found in 5% (95% CI, 3.8-6.5) of the sample. No difference in average UI was found between sexes. In fertile women (< 45 years) the 25th percentile of UI was 98 microg/l. Among CHA, average UI ranges from 141 to 159 microg/l. No difference in social class, education or employment was found in average UI.

CONCLUSIONS

Our results show a significant improvement in iodine level of the Catalan population. Average UI is within the levels recommended by the WHO. However, it must be taken into account that 25% of fertile women have UI < 98 microg/l. This implies a risk in the event of pregnancy.