Associations between thyroid dysfunction and developmental status in children with excessive iodine status

Gestational Age and Neurodevelopmental Delay in Term Births at 6 and 12 Months: The Japan Environment and Children's Study (JECS)

BACKGROUND

In the recent years, a high risk of developmental delay not only in very low birth weight infants and late preterm infants but also in early term infants (37-38 weeks) have increasingly been reported. However, in Japan, there are virtually no studies regarding the development delays in early term infants.

METHODS

This study used the data from the Japan Environment and Children's Study (JECS), a birth cohort study conducted in Japan. Data were selected for analysis from the records of 104,065 fetal records. The risk of neurodevelopmental delays at 6 months and 12 months after birth was evaluated using multivariate analysis for infants of various gestational ages, using the 40th week of pregnancy as a reference value. Neurodevelopment was evaluated at 6 months and 12 months after birth using the Ages and Stages Questionnaires, Japanese translation (J-ASQ-3).

RESULTS

The proportion of infants born at a gestational age of 37 to 38 weeks who did not reach the J-ASQ-3 score cutoff value was significantly higher in all areas at both 6 months and 12 months after birth, when compared to that of infants born at 40 weeks. The odds ratio decreased at 12 months after birth compared to that at 6 months after birth.

CONCLUSION

Early term infants in Japan are at an increased risk of neurodevelopmental delay at 12 months after birth.

Excessive iodine in iodized household salt in Nepal

Iodine is an essential trace element required for the regulation of physiological processes involving the thyroid gland. However, inadequate and excessive intake of iodine are responsible for health problems, such as iodine deficiency disorders, hypothyroidism, hyperthyroidism, thyroiditis, thyroid papillary cancer, and thyrotoxicosis. The Universal Salt Iodization (USI) program has become successful in providing supplemental iodine at the population level globally. Packaging quality, fortification level, and transportation and storage conditions of iodized salt determine the availability of iodine. Previous studies have reported severe health issues caused by excessive iodine intake after the implementation of the USI program. To understand the levels of iodine, we collected 2117 household salt samples from seven districts of Nepal and tested them for iodine content; among them, 98.1% were iodized. Overall median concentration of iodine was 53.9 ppm (range: 43.5-61.4 ppm). The majority (67.2%) of samples had iodine in the range of 45-75 ppm. Approximately 0.9% of samples had inadequate, 13.3% contained adequate, and 83.9% had excessive iodine than the World Health Organization-recommended value. Iodine content varied among the sampling districts and seasons, to some extent. Our study confirmed that iodized salt is widely used in Nepal and is excessively iodized. Excessive intake of iodine through iodized salt requires further attention by policy makers. The iodine level may need adjustment to address the health impact.

Impact of urinary iodine concentration on blood glucose levels and blood pressure: a nationwide population-based study

PURPOSE

Iodine is a vital trace element for systemic metabolic control as well as thyroid hormone synthesis. Though iodine has significant antioxidant and anti-inflammatory effects, reports on its effects on metabolic disorders are limited and inconsistent.

METHODS

Impact of urinary iodine concentrations (UICs) on fasting blood glucose (FBG) levels and blood pressure (BP) in the general Korean population was evaluated adjusting for covariates including thyrotropin level and presence of thyroid diseases.

RESULTS

The median UIC was 302.3 μg/L in all participants and was significantly lower in those with dysglycemia (303.6 μg/L in normal participants, 285.1 μg/L in participants with FBG levels of 100-125 mg/dL, and 261.8 μg/L in participants with FBG levels ≥ 126 mg/dL; p = 0.002). Similarly, the UIC was lower in participants with higher BP (311.6 μg/L in normal participants, 288.7 μg/L in prehypertensive participants, and 265.8 μg/L in hypertensive participants; p < 0.001). The multiple linear regression model showed a negative correlation between the UIC and FBG levels (p = 0.002), and the UIC and systolic BP (p < 0.001). One standard deviation increase in the UIC showed odds ratios of 0.84 (95% confidence interval [CI] = 0.73-0.98) for elevated FBG levels (≥ 100 mg/dL) and 0.94 (95% CI = 0.88-0.99) for elevated SBP (≥ 120 mm Hg) after full adjustment.

CONCLUSION

Higher UICs were associated with lower FBG and BP levels, independent of thyroid function and other confounding factors in Korea, an iodine-replete country.

A Meta-Analysis of the Effect of Iodine Excess on the Intellectual Development of Children in Areas with High Iodine Levels in their Drinking Water

The purpose of this meta-analysis is to comprehensively investigate the effect of iodine excess on children's intellectual development in areas with high iodine levels in their drinking water. We systematically searched the electronic databases and identified 17 publications (16 in Chinese and 1 in English) on the effect of iodine excess on children's intelligence published between January 31, 1985, and January 31, 2020. This meta-analysis included 14,794 children from 28 studies. The results showed that compared with the control group, the intelligence level of children in the high iodine group reduced significantly by 1.64 points (WMD=-1.64; 95% CI (-3.225, -0.049), Z=2.02, P<0.05). Subgroup analyses were performed according to the water iodine concentration, water iodine concentration of the control group, the intelligence test method, and regions of China (i.e., north and south). We noted that when the water iodine concentration was <300μg/L, 301-600μg/L, 600.1-900μg/L, and >900μg/L, the intelligence level of the high iodine groups decreased by varying degrees, although not statistically significant (all P>0.05). The water iodine concentration of the control group was divided into two groups (<150 μg/L and <100 μg/L) and the heterogeneity analysis showed that the heterogeneity of the control group decreased significantly when the concentration of water iodine was <150 μg/L, I² = 67.3%, P<0.001, which indicated a potential source of heterogeneity. The analyses by test method showed that among the studies which used the China Joint Raven's test, the intelligence level of children in the high iodine group was 0.86 points lower than in the control group (P>0.05). Conversely, we observed that among the studies which used the China Binet intelligence test and the binaphthalene intelligence test of Tanzhida in Japan to evaluate children's intelligence level, the intelligence level of children in the high iodine groups was significantly lower (3.65 points and 8.0 points, respectively) compared with the control groups (P<0.05). The analysis of the regions of China demonstrated that whereas the reduction in children's intelligence level from excess iodine in the north of China was not statistically significant (WMD=-0.16, 95% CI (-2.18, 1.85), P>0.05), the association was statistically significant in the southern part of China (WMD=-1.86, 95% CI (-3.57, -0.09), P<0.05). This study found that high iodine concentration was statistically significantly associated with a decline in intelligence level in children. Comparatively, the intelligence level of children who were exposed to high iodine concentrations reduced significantly by 1.64 points. These findings have public health implications.

Translation and Cultural Adaptation of the Ages and Stages Questionnaires (ASQ) Worldwide: A Scoping Review

OBJECTIVE

This scoping review aims to provide a data mapping and narrative synthesis of the available peer-reviewed scientific literature on the translation and cultural adaptation processes relative to the Ages and Stages Questionnaires (ASQ) as reported by the authors. It also seeks to paint an overall portrait of the implementation of the translated and culturally adapted ASQ worldwide.

METHODS

Articles published between 1995 and May 11, 2018, were identified via systematic searches of peer-reviewed literature carried out using CINAHL, Scopus, MEDLINE, Education Source, PsycINFO, and ERIC. The articles included in the qualitative synthesis were coded based on an extraction form developed for the study.

RESULTS

In the 46 articles surveyed, 37 different cultural adaptations were identified in 29 languages and 27 countries. Translations were included in 33 cultural adaptations, and language modifications were reported in 18 adaptations. The forward-backward translation method was reported in 25 cases. The authors declared having made cultural content, language, visual, and/or conceptual modifications in 26 adaptations. Cultural content modifications were reported in 24 adaptations. At least one method (pilot study, individual interview, survey or focus group with respondents) was reported in 24 adaptations.

CONCLUSION

Cultural modifications were relatively minor and were, in general, made to establish equivalence with the source version. As well, the processes used to translate and culturally adapt the ASQ varied widely based on the types of methods. Additional work should be conducted to document the process of this crucial phase.

Does maternal iodine supplementation during the lactation have a positive impact on neurodevelopment of children? Three-year follow up of a randomized controlled trial

PURPOSE

The aim of this study was to examine, for the first time, the neurodevelopmental outcomes in children whose mothers received different doses of iodine supplements during lactation.

METHODS

We conducted a follow-up study on children whose mothers participated in a randomized clinical trial to receive placebo, 150 µg/day or 300 µg/day of iodine until 12 months postpartum. Child neurocognitive development was assessed at 36 months of age using the Bayley Scales of Infant and Toddler Development Third Edition. Linear mixed-model analysis was preformed to assess iodine supplement dose effects on child cognitive, language, and motor functions.

RESULTS

A total of 122 children provided neurodevelopmental data as follows: 300 µg/d iodine group: 45; 150 µg/d iodine group: 35; and placebo group: 42. Cognitive scores were higher in children whose mothers received 150 µg iodine/d compared to children whose mothers received placebo [102.8 (SD 13.2) vs. 99.2 (SD 10.5); β = 4.43, P = 0.032]. However, supplementation with 150 µg iodine/d had no effect on language or motor development. No significant differences were observed in cognitive, language, or motor functions between children whose mothers received 300 µg iodine/d and those whose mothers received 150 µg iodine/d or placebo.

CONCLUSION

Maternal iodine supplementation with 150 µg/d during lactation may have a beneficial effect on child cognitive development; however, we found no evidence of either improved or delayed neurodevelopmental outcomes in children whose mothers received iodine supplements at doses higher than recommended. Further randomized controlled trials with larger sample sizes are needed to confirm these results.

CLINICAL TRIAL REGISTRY

IRCT201303164794N8; registration date: 2013-05-20.

A Scoping Review of the Health of African Immigrant and Refugee Children

Migration is a growing phenomenon around the world, including within the African continent. Many migrants, especially African children, face challenges related to health and social inclusion and can face increased health risks. A systematic scoping review of available literature on the health of African migrant children across the globe was conducted to offer insight into these health risks. The review was conducted over a 15-month period from January 2019 to April 2020, yielding 6602 articles once duplicates were removed. This search included electronic databases, reference lists of articles reviewed, and searches of libraries of relevant organisations. A total of 187 studies met the inclusion criteria, of which 159 were quantitative, 22 were qualitative, and 6 used mixed methods. The findings reveal decreased health in this population in areas of nutrition, infectious diseases, mental health, birth outcomes, sexual and reproductive health, physical and developmental health, parasitic infections, oral health, respiratory health, preventative health, endocrine disorders, health care services, and haematological conditions. The findings offer insights into factors influencing the health of African immigrant and refugee children. Further studies, especially qualitative studies, are needed to determine barriers to service access after migration and to investigate other underexplored and overlooked health concerns of African migrant children, including pneumonia and child maltreatment.

Acetylcholinesterase activity and thyroid hormone levels in Ecuadorian adolescents living in agricultural settings where organophosphate pesticides are used

BACKGROUND

Organophosphates are frequently applied insecticides that inhibit acetylcholinesterase (AChE) activity resulting in cholinergic overstimulation. Limited evidence suggests that organophosphates may alter thyroid hormone levels, although studies have yielded inconsistent findings. We aimed to test the associations between AChE activity, a physiological marker of organophosphate exposure, and thyroid function in adolescents.

METHODS

We included information of 80 adolescent participants (ages 12-17y in 2016, 53% male) growing up in agricultural settings in Ecuador. We measured fingerstick erythrocytic AChE activity and hemoglobin concentration, and concurrent serum thyroid stimulating hormone (TSH) and free-T4 (fT4) concentrations. General linear models were used to test associations which adjusted for demographic and anthropometric variables. TSH associations were further adjusted for fT4.

RESULTS

The mean (SD) AChE, TSH and fT4 levels were 3.77 U/mL (0.55), 2.82 μIU/ml (1.49) and 1.11 ng/dl (0.13), respectively. Lower AChE activity, indicating greater organophosphate exposure, was marginally associated with greater fT4 concentrations (difference per SD decrease in AChE activity (β) = 0.03 ng/dL, [90% CI: 0.00, 0.06]) but not with TSH (β = -0.01 μIU/ml, [-0.38, 0.36]). Gender modified the AChE-TSH association (p = 0.03). In girls, lower AChE activity was associated with higher fT4 levels (β=0.05 ng/dL [0.01, 0.10]) and lower TSH concentrations (β = -0.51 μIU/ml, [-1.00, -0.023]). No associations were observed in boys.

DISCUSSION

These cross-sectional findings suggest that alterations in the cholinergic system from organophosphate exposures can increase fT4 levels coupled with a beyond-compensatory downregulation of TSH in female adolescents. This is the first study to characterize these associations in adolescents.

Thyroid Function Changes and Pubertal Progress in Females: A Longitudinal Study in Iodine-Sufficient Areas of East China

BACKGROUND

The onset of puberty is influenced by thyroid function, and thyroid hormones (THs) fluctuate substantially during the period of pubertal development. However, it needs to be further clarified how THs change at specific puberty stages and how it influences pubertal development in girls. So far, longitudinal data from China are scarce.

METHODS

A cohort study was conducted among girls during puberty in iodine-sufficient regions of East China between 2017 to 2019. Serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were determined for each participant. Thyroid homeostasis structure parameters (THSPs), including the ratio of FT4 to FT3 (FT4/FT3), Jostel's TSH index (TSHI), and thyroid feedback quantile-based index (TFQI), were calculated. Puberty category scores (PCS), calculated based on the Puberty Development Scale (PDS), was used to assess the stage of puberty. Girls were grouped into three categories according to PCS changes (△PCS) and six categories according puberty stage (B_PF_P: pre-pubertal at both baseline and follow-up; B_PF_L: pre-pubertal at baseline and late-pubertal at follow-up, respectively; B_PF_T: pre-pubertal at baseline and post-pubertal at follow-up, respectively; B_LF_L: late-pubertal at both baseline and follow-up; B_LF_T: late-pubertal at baseline and post-pubertal at follow-up, respectively; B_TF_T: post-pubertal at both baseline and follow-up). Multiple linear regression analyses were used to evaluate the associations of THs changes with pubertal progress.

RESULTS

The levels of serum TSH and FT3 decreased while serum FT4 increased during the study period (P<0.001). In multiple linear regression analyses, after adjustment for covariables, FT3 decreased by an additional 0.24 pmol/L (95% CI: -0.47 to -0.01) in the higher △PCS group than the lower △PCS group. Compared with the B_LF_L group, the B_PF_T group showed an additional decline in FT3 (β= -0.39 pmol/L, 95%CI: -0.73 to -0.04), the B_TF_T group showed a lower decline in TSH (β=0.50 mU/L, 95% CI: 0.21 to 0.80) and a lower decline in TSHI (β=0.24, 95%CI: 0.06 to 0.41), respectively. There was no association of △FT4 or △TFQI with △PCS or the puberty pattern.

CONCLUSIONS

Serum TSH and FT3 decreased while serum FT4 increased among girls during puberty. Both the initial stage and the velocity of pubertal development were related to thyroid hormone fluctuations.

The Relationship between High Iodine Consumption and Levels of Autoimmune Thyroiditis-Related Biomarkers in a Chinese Population: a Meta-Analysis

To comprehensively evaluate the relationship between high iodine concentration and biomarker abnormalities related to autoimmune thyroiditis in a Chinese population. Medline, PubMed, and Embase electronic databases were searched for articles published domestically and internationally on the relationship between high iodine concentrations and thyroid hormone antibodies and thyroid-stimulating hormone in China before March 2019. Articles published in Chinese were searched in the China Biology Medicine (CBM) disc, Wanfang Database, and China National Knowledge Infrastructure (CNKI). A total of 16 cross-sectional articles were included in this study, including 9061 participants. A meta-analysis was conducted in Stata 14.0. The binary categorical and continuous variables used odds ratios (ORs) and standardized mean differences (SMDs) with the corresponding 95% confidence intervals (CIs) as the effect statistics, respectively. The results showed that high iodine concentrations had a minimal association with the abnormal rates of thyroid peroxidase antibody (TPOAb) (OR = 1.274, 95% CI (0.957, 1.695), P > 0.05) and thyroglobulin antibody (TGAb) (OR = 1.217, 95% CI (0.911, 1.626), P > 0.05) in the entire population. The thyroid-stimulating hormone (TSH) level in the high iodine group was greater than that in the adaptive iodine group (SMD = 0.202, 95% CI (0.096, 0.309), P < 0.05). The results of the subgroup analysis showed that the abnormal TPOAb rate in pregnant women (OR = 1.519, 95% CI (1.007, 2.291), P < 0.05) and children (OR = 3.365, 95% CI (1.966, 5.672), P < 0.05) in the high iodine group was greater than that in the adaptive iodine group, and the abnormal TGAb rate of children in the high iodine group was greater than that in the adaptive iodine group. The TSH levels of lactating women (SMD = 0.24, 95% CI (0.053, 0.427), P < 0.05), pregnant women (SMD = 0.301, 95% CI (0.176, 0.426), P < 0.05), and children (SMD = 0.25, 95% CI(0.096, 0.309), P < 0.05) in the high iodine group were higher than those in the adaptive iodine group. Egger's and Begg's tests showed no significant (P > 0.1) publication bias. High iodine can increase the risk of abnormal levels of TPOAb, TGAb, and TSH related to autoimmune thyroiditis in pregnant women, lactating women, and children in China.

Iodine nutritional status of pregnant women in an urban area of northern Taiwan in 2018

Pregnant women are considered as one of the most vulnerable groups for iodine deficiency. The Nutrition and Health Survey in Taiwan 2013 revealed that the median urinary iodine concentration (UIC) of non-pregnant women of child-bearing age of 15-44 years was 124 μg/L, which was adequate in general, but insufficient according to pregnancy criteria. The aim of this study was to determine the iodine nutritional status of pregnant women in an urban area of Northern Taiwan. A hospital-based cross-sectional survey was conducted in Taipei Veterans General Hospital. Random spot urine samples were collected from January to October, 2018 and UIC was determined by inductively coupled plasma mass-spectrometry. A food frequency questionnaire was also delivered to the participants. The overall median UIC was 225.3 μg/L (IQR: 109.1-514.2 μg/L) for 257 pregnant women ranging from 21-47 years-old. The distribution of UIC was as follows: 35.4% with UIC <150 μg/L, 17.1% with UIC within 150-249 μg/L, 21.8% with UIC within 250-499 μg/L, and 25.7% with UIC ≥500 μg/L. The use of prenatal multivitamin was very common among the participants: 79.4% (n = 204) took multivitamin either every day or less frequently, with 52.5% (n = 135) taking one pill every day, and only 20.6% (n = 53) never took multivitamin during their pregnancy. Other commonly consumed iodine-containing foods were dairy products and fish. Our results indicate that the iodine status in the studied women is adequate. However, efforts are still needed to avoid iodine deficiency as well as iodine excess.

Effects of Excessive Iodine Intake on Blood Glucose, Blood Pressure, and Blood Lipids in Adults

To understand the effects of excess iodine intake on blood glucose, blood pressure, and blood lipids in adults. We selected three villages from Shanxi Province to conduct cross-sectional survey: Maxi [median water iodine concentration (MWIC) 6.3 μg/L, median urinary iodine concentration (MUIC) 126.6 μg/L, 320 adults]; Xiwenzhuang (MWIC 79.8 μg/L, MUIC 221.2 μg/L, 264 adults); and Gaoche (MWIC 506.0 μg/L, MUIC 421.3 μg/L, 241 adults). According to the urinary iodine levels in adults, the three villages were defined as iodine-adequate, iodine-sufficient, and iodine-excess. Urinary iodine, water iodine, thyroid function, blood glucose, blood pressure, and blood lipids were measured. Compared with the iodine-adequate area, blood glucose and systolic and diastolic pressure of adults in iodine-sufficient and iodine-excess areas increased and high-density lipoprotein-cholesterol decreased (all P < 0.001). Urinary iodine, thyroid-stimulating hormone, and free thyroxine have a nonlinear correlation with blood glucose (R² = 0.8174, 0.8264, and 0.8520, respectively). Excessive iodine intake may result in elevated blood glucose and blood pressure and has some influence on blood lipids, and may increase the risk of hypertension and diabetes.

Production, milk iodine, and nutrient utilization in Jersey cows supplemented with the brown seaweed Ascophyllum nodosum (kelp meal) during the grazing season

Kelp meal (KM) is a supplement made from the brown seaweed Ascophyllum nodosum, known to bioaccumulate iodine (I) and to be the richest source of phlorotannins, which can inhibit ruminal proteolysis and microbial growth. The objective of this study was to investigate the effects of KM on production, milk I, concentrations of blood metabolites, apparent total-tract digestibility of nutrients, and CH4 emissions in grazing dairy cows. Eight multiparous Jersey cows averaging (mean ± SD) 175 ± 60 d in milk and 12 primiparous Jersey cows averaging 142 ± 47 d in milk at the beginning of the study were assigned to either 0 g/d of KM (control diet, CTRL) or 113 g/d of KM (brown seaweed diet, BSW) in a randomized complete block design. Diets were formulated to yield a 70:30 forage-to-concentrate ratio and consisted of (dry matter basis): 48% cool-season perennial herbage and 52% partial TMR (pTMR). Each experimental period (n = 3) lasted 28 d, with data and sample collection taking place during the last 7 d of each period. Cows had approximately 16.5 h of access to pasture daily. Herbage dry matter intake increased, and total dry matter intake tended to increase in cows fed BSW versus the CTRL diet. Milk yield and concentrations and yields of milk components were not affected by diets. Similarly, blood concentrations of cortisol, glucose, fatty acids, and thyroxine did not change with feeding CTRL or BSW. However, a diet × period interaction was observed for milk I concentration; cows offered the BSW diet had greater milk I concentration during periods 1, 2, and 3, but the largest difference between BSW and CTRL was observed in period 2 (579 vs. 111 µg/L, respectively). Except for period 2, the concentration of milk I in cows fed KM did not exceed the 500 µg/L threshold recommended for human consumption. Diet × period interactions were also found for serum triiodothyronine concentration, total-tract digestibilities of crude protein and acid detergent fiber, CH4 production, and urinary excretion of purine derivatives. Overall, the lack of KM effects on milk yield and concentrations and yields of milk components indicate that dairy producers should consider costs before making KM supplementation decisions during the grazing season. Future research is needed to evaluate the concentration of I in retail organic milk because of the high prevalence of KM supplementation in northeastern and midwestern US organic dairies and possibly in other regions of the country.

Reference values for fasting serum concentrations of thyroid-stimulating hormone and thyroid hormones in healthy Danish/North-European white children and adolescents

Thyroid-stimulating hormone (TSH) and thyroid hormones influence the functions of many organ systems, as well as child development and growth. Several studies have reported an association between ethnicity and thyroid hormones. This study aims to explore pediatric serum concentrations of TSH, free triiodothyronine (fT3), and free thyroxine (fT4) and their relation to age and sex and subsequently to present pediatric reference intervals from healthy Danish/North-European white children. A population-based cohort in Denmark of 2411 (1435 girls) healthy school children and adolescents aged 6.0-18.9 years were included. Fasting concentrations of serum TSH, fT3, and fT4 were determined from venous blood samples using immunologic chemiluminescent assays. Age- and sex-dependent percentiles were generated using the GAMLSS function. Median values of fT3 and fT4, but not TSH, were lower in the older age group compared with the youngest age group for both sexes (all p < .05). A significant difference for fT3 was found between the sexes for all age groups (all p < .001). fT4 was negatively correlated with body mass index standard deviation scores in boys. In conclusion, serum concentrations of thyroid hormones vary during childhood and adolescence and differ with age and sex.

High iodine content in local animal milk and risk of exceeding EFSA upper intake level for iodine among Saharawi women

Excessive iodine intake is a major public health problem in the Saharawi refugee camps in Algeria, where animal milk is an important source of iodine. The purpose of this study was to assess the association between iodine concentrations in locally produced animal milk and in animal drinking water and further to assess the risk of exceeding European Food Safety Authority (EFSA) tolerable upper intake level for iodine (600 μg/d) among Saharawi women. In 2009 and 2010, 202 milk samples from goats and sheep and 52 milk samples from camel were collected. Iodine in milk was determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In addition, iodine in 56 water samples from the general water system and 54 water samples from wells, was determined by modified Sandell-Kolthoff reaction. Animal milk is generally consumed mixed with water. The median (min, max) iodine intake from goat/sheep milk mixed with water in camps with high iodine content in human drinking water was 284 (57, 2889) μg/d and 19% of participants exceeded EFSA upper intake level for iodine. The median (min, max) iodine intake from camel milk mixed with water in all camps was 2100 (210, 11100) and 47% of participants exceeded the EFSA upper intake level. The median (min, max) iodine content in goat/sheep milk from camps with moderate and high iodine content in water was 507 (101, 4791) μg/L and 1612 (487, 9323) μg/L, respectively (p < 0.001). The iodine content in goat/sheep milk was positively associated with iodine content in animal drinking water (regression coefficient, B 5.71, 95% CI 4.03, 7.39). In conclusion, consumption of camel milk and living in camps with high water iodine content increased the risk of exceeding the EFSA upper intake level for iodine. We suggest that purified water for both human and animal consumption should be provided.

Provision of micronutrients in coexisting public health programs and risk of excessive intake: regulatory considerations

Countries around the world have been implementing public health interventions to provide vitamins and minerals. There is a concern that the cumulative micronutrient contribution of coexisting programs, when targeting the same population, may exceed their safe levels of intake, thus potentially challenging the primum non nocere principle. We assessed the regulatory framework of such interventions and determined qualitatively whether there were provisions in the regulations that called for coordination among programs to ensure their innocuousness. Country cases from various WHO regions were selected for the study: (1) the Americas: Chile, Costa Rica, and Guatemala; (2) Africa: Malawi, Uganda, and Zambia; (3) South Asia: Bangladesh; and (4) the Western Pacific Region: China and the Philippines. We did not identify any provisions in the existing regulations requiring coordination mechanisms among interventions. However, in some countries, governments have established national micronutrient fortification commissions or alliances aimed to foster interprogram coordination. Their focus, however, has been mostly on the efficacy of the programs and less on their safety. A regulatory framework for coexisting micronutrient interventions should be comprehensive, accounting for all micronutrient sources and including regulatory provisions for coordination among programs.

Effect of Excess Iodine Intake from Iodized Salt and/or Groundwater Iodine on Thyroid Function in Nonpregnant and Pregnant Women, Infants, and Children: A Multicenter Study in East Africa

BACKGROUND

Acute excess iodine intake can damage the thyroid, but the effects of chronic excess iodine intake are uncertain. Few data exist for pregnant and lactating women and infants exposed to excessive iodine intake.

METHODS

This was a multicenter cross-sectional study. At study sites in rural Kenya and urban Tanzania previously reporting iodine excess in children, urinary iodine concentration (UIC), thyrotropin, total thyroxine, and thyroglobulin (Tg) were measured in school-age children (SAC), women of reproductive age, pregnant (PW) and lactating women, and breast-feeding and weaning infants. In a national study in Djibouti, UIC was measured in SAC and PW. At all sites, daily iodine intake was estimated based on UIC, and iodine concentration was measured in household salt and drinking water.

RESULTS

The total sample size was 4636: 1390, 2048, and 1198 subjects from Kenya, Tanzania, and Djibouti, respectively. In Kenya and Tanzania: (i) median UIC was well above thresholds for adequate iodine nutrition in all groups and exceeded the threshold for excess iodine intake in SAC; (ii) iodine concentrations >40 mg of iodine/kg were found in approximately 55% of household salt samples; (iii) iodine concentrations ≥10 μg/L were detected in 9% of drinking water samples; (iv) Tg was elevated in all population groups, but the prevalence of thyroid disorders was negligible, except that 5-12% of women of reproductive age had subclinical hyperthyroidism and 10-15% of PW were hypothyroxinemic. In Djibouti: (i) the median UIC was 335 μg/L (interquartile range [IQR] = 216-493 μg/L) in SAC and 265 μg/L (IQR = 168-449 μg/L) in PW; (ii) only 1.6% of Djibouti salt samples (n = 1200) were adequately iodized (>15 mg/kg); (iii) the median iodine concentration in drinking water was 92 μg/L (IQR = 37-158 μg/L; n = 77). In all countries, UIC was not significantly correlated with salt or water iodine concentrations.

CONCLUSIONS

Although iodine intake was excessive and Tg concentrations were elevated, there was little impact on thyroid function. Chronic excess iodine intake thus appears to be well tolerated by women, infants, and children. However, such high iodine intake is unnecessary and should be avoided. Careful evaluation of contributions from both iodized salt and groundwater iodine is recommended before any review of iodization policy is considered.

Trace Element Concentrations in Drinking Water and Urine among Saharawi Women and Young Children

Poor water quality has been reported along with a variety of negative health outcomes in the Saharawi refugee camps in Algeria. We assessed the concentration of elements in drinking water and urine in refugee women and children. Twenty-four samples of distributed public drinking water were collected, along with urine samples from 77 women and 296 children. Using inductively coupled plasma mass spectrometry, we analyzed water and urine for 31 and 10 elements, respectively. In addition, the water samples were analyzed for five anions by ion-exchange chromatography. Data were described according to two areas: zone 1 with purified water and water with naturally better quality, and zone 2 with only partially purified water. Most elements in drinking water had significantly higher concentration in zone 2 compared with zone 1. Sodium, chloride, nitrite, and nitrate were the parameters that exceeded the WHO Guidelines for Drinking Water Quality. Among both women and children, urinary concentration of vanadium, arsenic, selenium, lead, iodine, and uranium exceeded reference values, and most of the elements were significantly higher in zone 2 compared to zone 1. Even though water purification in the Saharawi refugee camps has increased during the last years, some elements are still exceeding the WHO guidelines for drinking water quality. Moreover, urinary exposure of some elements exceeded reference values from the literature. Further effort should be made to improve the water quality among the Saharawi refugees.