Iodine deficiency in Italy. Italian Study Group on Urinary Iodine of SIEDP

Iodine Deficiency: Consequences and Progress toward Elimination

While traditionally associated with cretinism and goiter, iodine deficiency has broad effects on central nervous system development that can occur in the absence of either condition. Any maternal iodine deficiency results in a range of intellectual, motor, and hearing deficits in offspring. This loss in intellectual capacity limits educational achievement of populations and the economic prowess of nations. Progress made since the historic World Summit for Children in 1990 has been outstanding. Approximately 70% of households in the world used iodized salt by 2000, compared with less than 20% in 1990. It is estimated that at least 85 million newborns out of 130 million annual births are protected from a loss in learning ability that would otherwise have occurred. The elimination of iodine deficiency, by expedient production, marketing, and universal consumption of iodized salt, represents a significant development effort in public nutrition. Although globally iodine nutrition has greatly improved, 20% to 30% of pregnancies and thus newborns still do not fully benefit from the use of iodized salt. Countries where success is in evidence could rapidly revert back to deficiency if vigilance is not maintained. Just as success came through concerted public-private-civic actions, making sure that this is expanded and will steadily go on requires continuous collaboration.

Validity and Reproducibility of the Iodine Dietary Intake Questionnaire Assessment Conducted for Young Polish Women

The aim of this study was to analyse a designed brief iodine dietary intake questionnaire based on a food frequency assessment (IOdine Dietary INtake Evaluation-Food Frequency Questionnaire—IODINE-FFQ), including the assessment of validity and reproducibility in a group of 90 Polish women aged 20–35 years. Participants collected 3-day dietary records and filled in the IODINE-FFQ twice (FFQ1—directly after the dietary record and FFQ2—6 weeks later). The analysis included an assessment of validity (comparison with the results of the 3-day dietary record) and of reproducibility (comparison of the results obtained twice—FFQ1 and FFQ2). In the analysis of validity, a Bland-Altman index of 5.5% and 4.4% was recorded, respectively for FFQ1 and FFQ2. In the analysis of reproducibility it was 6.7%, but the share of individuals correctly classified into tertiles was over 70% (weighted κ of 0.675). It was stated, that assessment of IODINE-FFQ revealed a satisfactory level of validity and reproducibility in the analysis of Bland-Alman plot. The IODINE-FFQ may be indicated as a tool for the assessment of iodine intake in the young women in Poland, however further studies should be considered in order to obtain the practical tool for public health specialists. Due to the lack of validated iodine-specific food frequency questionnaires for countries of Eastern Europe, the IODINE-FFQ may be adjusted for courtiers other than Poland including iodine-fortified products.

Iodine Deficiency: Consequences and Progress toward Elimination

While traditionally associated with cretinism and goiter, iodine deficiency has broad effects on central nervous system development that can occur in the absence of either condition. Any maternal iodine deficiency results in a range of intellectual, motor, and hearing deficits in offspring. This loss in intellectual capacity limits educational achievement of populations and the economic prowess of nations. Progress made since the historic World Summit for Children in 1990 has been outstanding. Approximately 70% of households in the world used iodized salt by 2000, compared with less than 20% in 1990. It is estimated that at least 85 million newborns out of 130 million annual births are protected from a loss in learning ability that would otherwise have occurred. The elimination of iodine deficiency, by expedient production, marketing, and universal consumption of iodized salt, represents a significant development effort in public nutrition. Although globally iodine nutrition has greatly improved, 20% to 30% of pregnancies and thus newborns still do not fully benefit from the use of iodized salt. Countries where success is in evidence could rapidly revert back to deficiency if vigilance is not maintained. Just as success came through concerted public-private-civic actions, making sure that this is expanded and will steadily go on requires continuous collaboration.

Pilot study of urinary iodine concentration and of biochemical thyroid parameters before and after cautious public health intervention on salt iodide content: The Swiss longitudinal 1996–2000 iodine study

OBJECTIVE AND DESIGN

Iodide concentration (IC) in salt was cautiously increased in Switzerland (15 --> 20 ppm iodide). We evaluated the dynamics of the effect of this intervention on urinary iodine concentration (UIC, microg/l) and on thyroid parameters.

SETTING

University Hospital in Bern, Switzerland.

SUBJECTS

A cohort of 36 subjects (12 children, 11 women, 13 men) out of 44 were recruited.

INTERVENTIONS

During the study periods PRE (May 1996-May 1998) and POST (October 1998-December 2000, subdivided into equal subperiods POST1 and POST2), that is, before and after the increase of IC in salt, subjects collected 6248 urine spots for analysis of UIC. Thyroid volumes (n=2/subject) and serum thyroid parameters (n=8/subject) were sequentially evaluated.

METHODS

Average PRE-POST data were compared (multiple regression analysis).

RESULTS

UIC increased overall by 5.1% (P=0.0003). Increase of UIC was highest in children (11.3%, P<0.0001), significant in women (8%, P=0.0016), but not significant in men (P=0.143). Comparison between periods POST1 and POST2 showed that UIC changed more gradually in women than in children. Thyroid volumes were normal, no nonphysiological change occurred. TSH indicated euthyroidism; it decreased in children (1.98 ==> 1.74 mU/l, P=0.04) and increased in men (1.65 ==> 1.91mU/l, P=0.025). FT3 decreased in children (P<0.004) and FT4 decreased in men (P=0.017), both within normal ranges. TSH, FT3 and FT4 were unchanged in women. FT3/FT4 ratios were stable. Anti-TPO-Ab titers were stable (P=0.9). Anti-Tg-Ab titers decreased (P=0.009).

CONCLUSION

The significant UIC effects were of uncertain metabolic relevance. No pathological side effects occurred. Differential delays and penetrances of UIC increase in children and adults were hitherto unknown. The unspectacular stepwise policy seems to be safe. Our pilot results in a population with moderate iodine deficiency in women should be confirmed in population-based cluster studies.

SPONSORSHIP

This work was supported by grants from the University Hospital in Bern, the Swiss Federal Office of Public Health (SFOPH), the 'Swiss National Foundation for Scientific Research' (32-49424.96), the 'Fondation Genevoise de Bienfaisance Valerie Rossi di Montelera', the 'Schweizerische Lebensversicherungs- und Rentenanstalt' and the 'Schüpbach Foundation of the University of Bern'.

[Iodine nutritional status and risk factors for iodine deficiency in infants and children of the french North department]

INTRODUCTION

Iodine deficiency is responsible for a higher mortality and morbidity in neonates and infants. It has not yet disappeared in European countries, especially in Southern and Eastern Europe.

OBJECTIVES

The present study aimed at evaluating the status of iodine nutrition of infants living in the North department (France) and at studying risk factors for iodine deficiency.

METHODS

The study was conducted in primary health care centres in 160 healthy infants aged ten days to six years (mean +/- SD: 17.7 +/- 2.5 months). Data included: familial thyroid disease history, type of feeding at inclusion, timing of introduction of complementary foods, nutritional status (weight, height, head and arm circumference), as well as maternal education level and family socio-economical status. Iodine status was assessed by urinary iodine excretion.

RESULTS

Urinary iodine concentration ranged from 4 to 1042 microg/l (median +/- SD: 195,5 +/- 21,6 microg/l). Thirty-eight (24%) of 160 children were iodine deficient (urinary iodine < 100 microg/l): mild iodine deficiency (50-99 microg/l: 17%), moderate iodine deficiency (20-49 microg/l: 5%), severe iodine deficiency (<20 microg/l: 2%). No relationship was found between iodine status and age, sex, geographic origin of the children, as well as social and occupational group of the parents. Breast-feeding did not prevent from iodine deficiency. Iodine status did not differ between the cow's milk fed group and the group that was not fed cow's milk. Formula feeding was associated with iodine deficiency (p = 0,02).

CONCLUSIONS

Prevalence of severe iodine deficiency was very low in this population. However, iodine status was not optimal.