Urinary Iodine Concentration Values Research Articles

Iodized Salt May Not Be Sufficient to Guarantee an Adequate Iodine Intake in Pregnant Women.

Adequate iodine intake is of crucial importance in pregnancy to meet the thyroid hormone needs of both mother and fetus. In the present study, undertaken as a part of the surveillance actions following the introduction in Italy of a national salt iodination program in 2005, the iodine intake was investigated in 123 pregnant women and 49 control women living in the same area of central Italy. All the participants were screened for urinary iodine concentration (UIC), serum level of thyrotropin, free-thyroxine, free-triiodothyronine, and thyroid volume. Moreover, they were provided with a questionnaire on the use of iodine-containing salt or supplements. Control women had a median UIC of 102 µg/L, consistent with an iodine sufficiency, while in pregnant women the median UIC value was 108 µg/L, lower than the endorsed UIC of 150 µg/L. In addition, pregnant women showed a significantly increased median thyroid volume compared to controls. Interestingly, the median UIC did not differ between pregnant women not using iodine-containing salt or supplements and those regularly consuming iodized salt alone, while pregnant women with a daily intake of iodine-containing supplements had an adequate median UIC (168 µg/L). In conclusion, the data reported here showed that pregnant women and their fetuses are still exposed to the detrimental effects of iodine deficiency and that the consumption of iodine-containing supplements should be recommended in pregnancy.

Urinary iodine concentration and its associations with thyroid function in pregnant women of Shanghai.

To assess the iodine status and its associations with thyroid function in pregnant women of Shanghai. In this cross-sectional study, a total of 562 pregnant women were enrolled from January to December 2021. Both serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAB), thyroglobulin antibody (TGAB), and urinary iodine concentration (UIC) were detected. Participants were divided into four groups based on their UIC values. Correlation analysis was used to investigate the association between UIC and thyroid function-associated parameters. The median UIC of the pregnant women studied was 158.25µg/L (interquartile range [IQR] 90.15, 245.65µg/L). Among all the subjects, 45.55% had iodine deficiency according to the World Health Organization (WHO) criteria, and 15.65% had thyroid autoimmunity. FT3, FT4, TSH, TPOAB and TGAB levels were not different among different UIC groups (P > 0.05). UIC and TSH were negatively correlated (r=-0.127, p=0.043) in UIC<150 µg/L group. In the group with UIC 250- 499 µg/L, UIC was positively correlated with total T4 (TT4), total T3 (TT3) and TPOAB (r= 0.228, p=0.022, r=0.208, p= 0.039, r=0.190, p=0.042, respectively). A negative correlation between UIC and TPOAB values was observed in TPOAB-positive (+) pregnant women (r=-0.384, p=0.012). The prevalence of isolated hypothyroxinemia in UIC<150 µg/L group was significantly higher than that of other groups(p=0.033). The relationship between the prevalence of thyroid diseases and UIC embodied a U-shaped curve. Pregnant women on Chongming Island of Shanghai were iodine sufficient during the second trimester, but iodine deficiency was still prevalent. Both low and high gestational iodine status was related to thyroid function and autoimmunity. Optimal iodine nutrition status during gestation was important.

Assessment of the Iodine Status of Lactating Women and Infants in Shanghai, China.

There is a risk of iodine deficiency among pregnant women in China. However, research on the iodine status of lactating women and infants is scarce. In this study, we aimed to evaluate the iodine status of lactating women and their infants and explore the relationship between breast milk iodine concentrations (BMICs) and urinary iodine concentrations (UICs). In total, 257 lactating women and their infants were recruited from the Shanghai Sixth People's Hospital East campus between May 2018 and May 2019. The BMIC and UIC were measured by inductively coupled plasma‒mass spectrometry (ICP‒MS). One-day 24-h dietary recall was used to determine the dietary intake of iodine. The mean dietary intake of iodine among the lactating women was 145.1μg/day, and 97.83% (n = 225) of the lactating women had a dietary iodine intake below 240μg/day. The median BMIC and UIC of the lactating women was 150.7μg/L (interquartile range, IQR 102.9, 205.5) and 110.0μg/L (IQR 65.8, 171.4), respectively, and the median UIC of the infants was 212.7μg/L (IQR 142.1, 320.6). The BMIC of lactating women who consumed iodized salt was significantly higher than that of lactating women who did not consume iodized salt (p = 0.015). The infants' UIC values were significantly correlated with the BMIC values (r = 0.597**, p < 0.001). The iodine nutritional status of lactating women and infants in Shanghai was generally sufficient according to the WHO's iodine nutritional status recommendation. The use of iodized salt was related to increasing dietary iodine intake and the BMIC. Improvements in BMICs have positive effects on the nutritional levels of iodine in infants.

Sodium, Potassium and Iodine Intake in an Adult Population of Lithuania.

Hypertension is a leading risk factor for cardiovascular events and death. A reduction in salt intake is among the most cost-effective strategies to reduce blood pressure and the risk of cardiovascular diseases. Increasing potassium lowers blood pressure and is associated with lower cardiovascular risk. Adequate iodine intake is important to prevent iodine deficiency disorders. Salt iodization is a key strategy to prevent such deficiency. In Lithuania, no surveys have been performed to directly assess sodium, potassium and iodine consumption. The aim of the present study was to measure sodium, potassium and iodine intake in a randomly selected adult Lithuanian adult population using 24 h urine collections, and to assess knowledge, attitudes and behavior towards salt consumption. Salt and potassium intakes were estimated in 888 randomly selected participants by 24 h urine sodium and potassium excretion and 679 individuals provided suitable 24 h urine samples for the analysis of iodine excretion. Average salt intake was 10.0 (SD 5.3) g/24 h and average potassium intake was 3.3 (SD 1.3) g/24 h. Only 12.5% of participants consumed less than 5 g/24 h of salt. The median value of urinary iodine concentration (UIC) was 95.5 μg/L. Our study showed that average salt intake is twice as high as the maximum level recommended by the World Health Organization while potassium and iodine intakes in Lithuania are below the recommended levels.

Mandatory Versus Voluntary Implementation of Salt Iodization Program for the Last Two Decades in Ethiopia: A Comparative Review of Existing Literatures.

Ethiopian government was implementing mandatory salt iodization program for the last decade to eliminate iodine deficiency disorders, but several recent studies reported mixed findings. This review aimed to assess the difference in implementation of iodized salt program 10 years before and after mandatory salt iodization being implemented in Ethiopia since 2011. In Ethiopia, legislation that enforces salt producers to iodize all salts used for human consumption started in February 2011. All studies about iodine deficiency and iodized salt conducted in Ethiopia in the last 2 decades were searched. Searches were performed in PubMed database. Google Scholar, Iodine Global Network, and Ethiopian Public Health Institute websites were also searched. A total of 235 titles and abstracts were identified. After scanning the abstracts and full papers, 43 articles were remained for final data synthesis. In this review, all studies conducted before 2011 reported a urinary iodine concentration (UIC) value of < 100 μg/L and 66.7% of them reported a goiter prevalence of > 30%. On the other hand, among studies conducted after 2011, 88.9% reported UIC value < 100 μg/L and 73.7% reported goiter prevalence of > 30%. Household availability of adequately iodized salt increased from nearly 20% in pre 2011 to more than 50% in post 2011 period. Despite the efforts made by the Ethiopian government on mandatory salt iodization for the last decade, iodine deficiency is sustained in the country. Moreover, the goal of universal salt iodization program is offtrack and needs urgent revision. Registered on PROSPERO register with reg. no CRD42021251124.

Noncompliance to iodine supplementation recommendation is a risk factor for iodine insufficiency in Portuguese pregnant women: results from the IoMum cohort.

After a recommendation for iodine supplementation in pregnancy has been issued in 2013 in Portugal, there were no studies covering iodine status in pregnancy in the country. The aim of this study was to assess iodine status in pregnant women in Porto region and its association with iodine supplementation. A cross-sectional study was conducted at Centro Hospitalar Universitário São João, Porto, from April 2018 to April 2019. Pregnant women attending the 1st trimester ultrasound scan were invited to participate. Exclusion criteria were levothyroxine use, gestational age < 10 and ≥ 14weeks, non-evolutive pregnancy at recruitment and non-signing of informed consent. Urinary iodine concentration (UIC) was measured in random spot urine by inductively coupled plasma-mass spectrometry. Median UIC was 104μg/L (IQR 62-189) in the overall population (n = 481) of which 19% had UIC < 50µg/L. Forty three percent (n = 206) were not taking an iodine-containing supplement (ICS) and median UIC values were 146µg/L (IQR 81-260) and 74µg/L (IQR 42-113) in ICS users and non-users, respectively (p < 0.001). Not using an ICS was an independent risk factor for iodine insufficiency [adjusted OR (95% CI) = 6.00 (2.74, 13.16); p < 0.001]. Iodised salt use was associated with increased median iodine-to-creatinine ratio (p < 0.014). A low compliance to iodine supplementation recommendation in pregnancy accounted for a mild-to-moderately iodine deficiency. Our results evidence the need to support iodine supplementation among pregnant women in countries with low household coverage of iodised salt. Trial registration number NCT04010708, registered on the 8th July 2019.

Current Iodine Status in Japan: A Cross-sectional Nationwide Survey of Schoolchildren, 2014-2019.

Japan has been regarded as a long-standing iodine-sufficient country without iodine fortification; however, data on nationwide iodine status are lacking. This study aimed to characterize the iodine status in Japan. From 2014 through 2019, a nationwide school-based survey was conducted across all districts in Japan. Urinary iodine concentration (UIC), creatinine (Cr) concentration, and anthropometry were assessed in healthy school-aged children (SAC) aged 6 to 12 years. Their iodine status is regarded as generally representative of the nation's iodine status. A total of 32 025 children participated. The overall median UIC was 269 μg/L, which was within the World Health Organization's adequacy range. There was a regional difference in UIC values within 14 regions, and the lowest and highest median UICs were found in Tanegashima Island (209 μg/L) and Nakashibetsu, Hokkaido (1071 μg/L), respectively. The median UIC ≥ 300 μg/L was observed in 12 of 46 regions. By using estimated 24-hour urinary iodine excretion (UIE), the prevalence of SAC exceeding the upper tolerable limit of iodine for Japanese children was from 5.2% to 13.7%. The UIC values did not change with age, body surface area and body mass index percentile, whereas the Cr concentration simultaneously increased suggesting the effect of urinary creatinine on UI/Cr and estimated 24-hour UIE values. The iodine intake of Japanese people is adequate, but in some areas it is excessive. The incidence and prevalence of thyroid disorders associated with iodine intake should be obtained, especially in the areas where high amounts of iodine are consumed.

High Iodine Urinary Concentration Is Associated with High TSH Levels but Not with Nutrition Status in Schoolchildren of Northeastern Mexico

According to the Iodine Global Network, Mexico is considered a country with adequate national iodine intake (297 mg/L), but some regions have not been studied. We aimed to evaluate urinary iodine concentration (UIC) and its association with thyroid stimulating hormone (TSH) levels and the nutritional status in 307 children (aged 5 to 11 years) from three elementary schools of Monterrey, northern Mexico. UIC in spot urine samples and capillary TSH levels were measured to assess thyroid function, in addition to weight, height, body mass index (BMI), and waist circumference (WC). We found a median UIC of 442 mg/L and a significant association between UIC and TSH levels by logistic regression when data were adjusted for (1) age and sex; (2) age, sex, and WC; and (3) age, sex, and weight status. UIC values were higher in 7-year-old children compared to 11-year-old children. High prevalences of overweight/obesity (41%) and WC >90 pctl (22%) were observed. This study identified higher UIC levels in children than those previously reported in the country. The UIC showed a positive and significant correlation between TSH levels in the three models evaluated. More studies are needed to assess the causes and possible outcomes of high UIC levels.

Obesity and Monitoring Iodine Nutritional Status in Schoolchildren: is Body Mass Index a Factor to Consider?

Background: The frequency of overweight (OW) and obese (OB) children has increased worldwide, particularly in economically developed countries. No studies have been conducted to verify whether the increasing frequency of OW and obesity in schoolchildren may affect the evaluation of iodine nutritional status in populations. The aim of this study was to verify whether urinary iodine concentration (UIC), thyroid volume (TV), and thyroid hypoechoic pattern may be affected by body mass index (BMI) in schoolchildren. Methods: The children included in this study (aged 11-13 years) were a part of the schoolchildren recruited in the second nationwide survey (period 2015-2019) conducted in Italy to monitor by law (Atto di Intesa Stato-Regioni February 26, 2009) the nationwide iodine prophylaxis program. Specifically, 1281 schoolchildren residing in iodine-sufficient areas (IS group) and 384 children residing in a still mildly iodine-deficient area (ID group) were recruited between January and March 2015 in the first-degree secondary state schools. In all the children, spot UIC was measured, thyroid ultrasound was performed to evaluate TV, and hypoechogenicity was assessed to indirectly evaluate iodine-associated thyroid autoimmunity. Results: The frequency of OW, OB, and adequate weight (AW) children was similar in the IS and ID groups at any age. After adjusting for sex and age, the regression analysis showed lower UIC values in OB children than in AW children of the IS group (beta coefficient = -34.09 [95% confidence interval -65.3 to -2.8]), whereas no significant differences were observed in the ID group. In both the IS and ID groups, the distribution of TV in AW children was significantly shifted toward lower values in comparison to the distribution of OB children (p < 0.001 in the IS group; p = 0.012 in the ID group). Furthermore, the frequency of thyroid hypoechogenicity was higher in the ID group than in the IS group (10.9% vs. 6.6%, p = 0.005); however, in both groups, it was significantly lower in AW children than in OB children (p < 0.01). Conclusions: This study for the first time demonstrates that BMI may be a confounding factor in monitoring iodine nutritional status in schoolchildren. Since in Italy as in other Western countries the number of OW and OB children is high, BMI is a factor to consider in monitoring salt iodization programs worldwide.

Urinary Iodine Concentrations in Pregnant Women and Offspring Brain Morphology.

Background: Severe maternal iodine deficiency during pregnancy leads to marked intellectual disability in the offspring. Although recent studies showed that even mild-to-moderate maternal iodine deficiency is associated with lower intelligence quotient and attention deficit hyperactivity disorder in offspring, the underlying neurobiological mechanism of these associations remains unknown. The aim of this study was to investigate the association of maternal iodine excretion during pregnancy with offspring brain morphology during pre-adolescence. Methods: This study was embedded within Generation R, a prospective population-based birth cohort in Rotterdam, the Netherlands. We included 990 mother-child pairs with data on urinary iodine concentration (UIC) and creatinine during pregnancy. The UIC was assessed at <18 and/or 18-25 weeks of gestation and offspring brain imaging data were acquired with magnetic resonance imaging (MRI) at age 10 years. We used linear regression to study the association of the iodine-to-creatinine ratio (UI/Creat) with offspring brain MRI outcomes. Results: Maternal UI/Creat during pregnancy was not consistently associated with offspring brain morphology. A low UI/Creat (<150 μg/g) during pregnancy was nominally associated with smaller total gray matter volume, but this did not survive correction for multiple testing. Also, we could not identify a linear association between continuous iodine excretion and offspring brain morphology. Instead, our results suggest a curvilinear association between UI/Creat and brain morphology. In sensitivity analyses using the World Health Organization categorization for UIC values, both low and high UI/Creat were associated with smaller total gray matter volume. Conclusions: The current study provides some but no conclusive evidence for an association of maternal iodine excretion during pregnancy with offspring brain morphology. Our results suggest that the exact definition of the reference group is important because of potential non-linear associations, which could be leveraged in future studies.

Concentration-dependent Differences in Urinary Iodine Measurements Between Inductively Coupled Plasma Mass Spectrometry and the Sandell-Kolthoff Method

A large amount of historical data regarding urinary iodine concentration (UIC) were measured with the Sandell-Kolthoff (S-K) method for iodine nutrition surveillance. The congruence in urinary iodine measurements between inductively coupled plasma mass spectrometry (ICP-MS) and the S-K method has been debated. A total of 2064 adult urine samples were included in the present study. The UIC measurement results obtained simultaneously by standardized ICP-MS and the S-K method were analyzed. The UIC obtained with ICP-MS was significantly higher than that obtained with the S-K method (158 μg/L vs. 148 μg/L, p < 0.001). The Bland-Altman difference plot showed a small but significant mean difference of 6.12 μg/L between the two methods. The stratified analysis showed that the correlation coefficient was higher in the UIC < 300 μg/L group than the UIC ≥ 300 μg/L group (0.93 vs. 0.88, p = 0.0001). The mean difference between the S-K and ICP-MS methods was positively correlated with the UIC. The ICP-MS and S-K methods were comparable when the UIC was less than 300 μg/L; however, UIC values between 300 and 600 μg/L should be compared with caution after considering the research objective. We do not suggest comparing UICs obtained from the ICP-MS and S-K methods in iodine monitoring studies if the UIC is greater than 600 μg/L.

Changing Dietary Habits in Veneto Region over Two Decades: Still a Long Road to Go to Reach an Iodine-Sufficient Status.

Background: Fifteen years after a nationwide voluntary iodine prophylaxis program was introduced, the aims of the present study were: (a) to obtain an up-to-date assessment of dietary iodine intake in the Veneto region, Italy; and (b) to assess dietary and socioeconomic factors that might influence iodine status. Methods: Urinary iodine concentration (UIC) was obtained in 747 school students (median age 13 years; range: 11–16 years). Results: The median UIC was 111 μg/L, with 56% of samples ≥ 100 μg/L, but 26% were < 50 μg/L, more frequently females. Iodized salt was used by 82% of the students. The median UIC was higher among users of iodized salt than among non-users, 117.0 ug/L versus 90 ug/L (p = 0.01). The median UIC was higher in regular consumers of cow’s milk than in occasional consumers, 132.0 μg/L versus 96.0 μg/L (p < 0.01). A regular intake of milk and/or the use of iodized salt sufficed to reach an adequate median UIC, although satisfying only with the combined use. A trend towards higher UIC values emerged in regular consumers of cheese and yogurt. Conclusion: Iodine status has improved (median UIC 111.0 μg/L), but it is still not adequate as 26% had a UIC < 50 μg/L in the resident population of the Veneto region. A more widespread use of iodized salt but also milk and milk product consumption may have been one of the key factors in achieving this partial improvement.

Goitre Prevalence and Urinary Iodine Concentration in School-Aged Children in the Ashanti Region of Ghana.

Background Iodine deficiency is a public health problem. The universal salt iodization (USI) program is the main, simple, and cost-effective intervention strategy to control iodine deficiency. The study examined the iodine status in school-aged children in Ashanti region, Ghana, using thyroid volumes along with urinary iodine concentrations, the methods recommended by the WHO/ICCIDD for monitoring the sustained impact of USI programs. Methods This cross-sectional study was conducted among school-aged children (6–12 years) from randomly selected schools in the central and northern part of the Ashanti region, Kumasi Metropolis, and Ejura-Sekyedumase Municipality, respectively. A total of 852 children were enrolled in the study. Thyroid volume and urinary iodine concentrations of the children were determined using the standardized methods recommended by WHO/ICCIDD. Anthropometric measurements were also evaluated. Results The mean values of thyroid volume in female and male school-aged children were 3.53 ± 0.09 and 3.32 ± 0.07, respectively. The thyroid size was significantly associated with age (P < 0.0001), weight (P < 0.0001), height (P < 0.0001), BMI (P < 0.05), and BSA (P < 0.0001) by Pearson's correlation in both males and females. The P50 (median) thyroid volumes of school children investigated in this study were generally larger compared to the WHO/ICCIDD reference data by age and body surface area. The median value of urinary iodine concentration was 201.85 μg/L, which showed significant sex difference (P value <0.0001). Excessive iodine nutrition (≥300 μg/L) was observed among 34.4% of male children and 27.6% of female children. Also, 12.8% of the male and 19.5% of the female children had UIC below requirement (<100 μg/L). The criteria of thyroid volume per age yielded a goitre prevalence of 2.2%. In contrast, the criteria of thyroid volume by body surface area yielded a goitre prevalence of 0.9%. Conclusion The study clearly indicated that adequate iodine nutrition exists generally among the school children. However, insufficient and excessive iodine intakes still persist among some of the children. The establishment of local reference values for thyroid volume that might be applicable to precisely define goitre prevalence in the Ghanaian context is highly recommended.

Thyroglobulin Concentration and Maternal Iodine Status During Pregnancy: A Systematic Review and Meta-Analysis.

Background: Literature to date has been inconclusive regarding the value of thyroglobulin (Tg) as a marker of iodine status in pregnant women. This systematic review and meta-analysis is one of the first to assess whether Tg concentration accurately reflects iodine status among pregnant women. Methods: We searched MEDLINE, the Web of Science, the Cochrane Library, Scopus, and other relevant databases to identify relevant studies published in the English language, between January 1988 and December 2018. The criteria for study inclusion in the systematic review were human studies, healthy pregnant women as participants, and available data for maternal urinary iodine concentration (UIC) and Tg level. Each study was assessed for quality and risk of bias. The pooled mean Tg values, and 95% confidence intervals were estimated in a population of women with UIC <150 and UIC ≥150 μg/L during pregnancy. Potential linear or nonlinear dose-response associations between maternal UIC and Tg concentration were examined. Results: Of 814 identified studies, 25 were eligible for inclusion in the meta-analysis. Studies included were conducted in Africa, Asia, Europe, South America, and the Oceania. The pooled mean (95% confidence interval [CI]) Tg concentration in iodine-deficient pregnant women was higher than that in iodine-sufficient pregnant women (10.73 μg/L [5.65-15.82] vs. 7.34 μg/L [2.20-12.47]); a comparison of the 95% CI showed that none of these values was significantly different. No significant differences were observed in Tg concentration between the two groups in each trimester of pregnancy. Dose-response meta-analyses revealed a significant nonlinear association between maternal UIC and Tg concentration during pregnancy. Among populations of pregnant women, an inverse association was found between UIC values <100 μg/L and Tg concentration (p-linearity = 0.007; p-nonlinearity = 0.027); however, higher values of UIC were not associated with Tg concentration. Conclusions: Our meta-analysis showed that Tg concentration can be a sensitive indicator of iodine deficiency, specifically in populations of pregnant women with median UIC <100 μg/L. Further studies are warranted to determine the sensitivity of Tg at different degrees of iodine deficiency during pregnancy.

MON-584 Iodine Nutrition Status in Pregnancy: Is the Situation in Poland Improving?

Iodine deficiency is considered the most common preventable cause of brain damage worldwide. It is particularly important during pregnancy, as it influences not only mothers but their fetuses as well. The Polish model of iodine prophylaxis is based on the obligatory household salt iodization and recommendation of iodine-containing supplements use by pregnant women. The aim of the study was to assess the current iodine status of pregnant women in Poland, and to compare it with earlier results. Material and methods: 1208 pregnant women aged 16-46 years (median 29 years) were included. 911 of them (75.4%) were investigated between 2007 and 2011, remaining 297 (24.6%) were studied in 2017. A signed informed consent was obtained from every participating woman. The urinary iodine concentration (UIC) in a casual morning sample was assessed by Sandell-Kolthoff reaction. Thyroid volume was measured by ultrasound. Iodine supplements intake was assessed by a questionnaire. The study protocol was approved by the Local Ethics Board. Results: The studied population of pregnant women proved to be iodine insufficient: median UIC was 94.9 mcg/l (lower quartile - 61.85 mcg/l, upper quartile - 149.0 mcg/l). The UIC significantly increased between 2007-2011 and 2018 (median 92.47 mcg/l and 111.45 mcg/l, respectively; p=008), but still did not meet the iodine sufficiency criterion (median UIC between 150 and 249 mcg/l). In only 17.4% of investigated women, UIC value was within the optimal range of 150 to 249 mcg/l: in 17.3% between 2007 and 2011, and 17.5% in 2018. 62.2% of pregnant women were taking iodine supplements: 63.3% of women investigated between 2007 and 2011, and 58.6% in 2011 (p=0.14). The median thyroid volume in the investigated group was 11.8 mL (lower quartile 9.2 mL, upper quartile 15.0 mL). There was no significant difference in thyroid volume between two groups: 11.9 mL in women investigated between 2007 and 2011, and 11.6 mL in 2017. Conclusions. Although during last years iodine status of Polish pregnant women has improved, it has not reached a sufficiency level. Therefore the current Polish iodine prophylaxis model should be adjusted to provide pregnant women with adequate iodine intake.

Iodine status five years after the mandatory salt iodization legislation indicates above requirement: a cross sectional study in Northwest Ethiopia

BackgroundIodine deficiency is one of a major nutritional problem. The study aimed to assess the iodine status of populations in Dabat district using median urinary iodine concentration (UIC) in school-age children (6–12 years) and compared the results with goiter prevalence.MethodsThe study used a cross-sectional study design. The study was conducted in Dabat district, northwest Ethiopia in May 2016. Spot urine samples were used for the determination of UIC. Manual examination of the thyroid gland was performed to assess presence of goiter. The MBI international Rapid Test Kits (RTK) were used to determine the level of salt iodine content. Children aged 6–12 years were recruited from schools using a multistage stratified sampling. One-way Analysis of Variance (ANOVA) was used to compare mean of log-transformed UIC values among key variables. Significant was determined at P-value less than 0.05.ResultsA total of 358 school age children enrolled to the study. The mean age of children was 10.8((Standard Deviation (SD) = 1.45) years and 56.7% were males. The median UIC was 235 μg/l ((Inter Quartile Range (IQR): 161, 320]. Excessive iodine intake and inadequate iodine intake was observed on 29.1 and 8.7% of school aged children, respectfully. The coverage of iodized salt use in school-age children were 66.8%. The UIC was higher in urban children than rural counterparts and in those used adequately iodised salt than inadequately iodized salt (P < 0.05). Thirty-four percent of school-age children had a goiter. The prevalence of grade 1 and grade 2 goiter was 26.5 and 7.5%, respectively. There was a poor agreement between UIC and goiter (k = 0.1) in classifying iodine status of populations.ConclusionsThe study population is classified as above requirements by median UIC in school-age children but severe iodine deficiency by goiter prevalence. Further research investigating the agreement between UIC and goiter prevalence in classifying iodine status of populations with various iodine status is warranted.

Iodine status of Saint Petersburg adult residents

Обоснование. В мире около двух миллиардов человек имеют недостаточное потребление йода.&#x0D; Цель. Оценить обеспеченность йодом и эффективность профилактики йодного дефицита у взрослого населения Санкт-Петербурга.&#x0D; Методы. В ретроспективной части работы проведен анализ распространенности гипертиреотропинемии новорожденных Санкт-Петербурга за период 2013–2014 гг. В одномоментное поперечное когортное исследование были включены 542 жителя Санкт-Петербурга в возрасте 18–77 лет. Все участники были разделены на три группы согласно возрасту. Беременные женщины были выделены в отдельную группу. У всех участников проведено анкетирование и проанализированы значения йодурии.&#x0D; Результаты. Количество новорожденных, имевших концентрацию тиреотропного гормона более 5 мЕД/л, составило 6,9%, отражая дефицит йода легкой степени тяжести у населения. Йодированную соль использовали в пищу только 41,1% всех обследованных и 52,2% беременных женщин. Препараты йода принимала половина беременных женщин. Медиана йодурии (МЙУ) всех участников составила 91,2 мкг/л и соответствовала дефициту йода легкой степени тяжести. Значение МЙУ у беременных женщин составило 112,4 мкг/л и соответствовало недостаточному потреблению йода.&#x0D; Заключение. Население Санкт-Петербурга проживает в регионе легкого дефицита йода. Профилактика дефицита йода, проводимая в Санкт-Петербурге в 2013–2015 гг., недостаточно эффективна. Лица репродуктивного возраста и беременные женщины имеют дефицит йода легкой степени тяжести.

Biomonitoring Equivalents for interpretation of urinary iodine

Iodine is an essential nutrient whose deficiency or excess exposure can cause adverse health effects. The primary sources of iodine exposure in the general population are iodized salt, dairy products, bread and sea food. Urinary iodine concentrations (UIC) have been measured by Canadian Health Measures Survey (CHMS) and US National Health and Nutrition Examination Survey (NHANES). The Institute of Medicine (IOM), the US Agency for Toxic Substances and Disease Registry (ATSDR) and World Health Organization (WHO) have established exposure guidance values for nutrition (IOM Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), WHO Recommended Nutrient Intake (RNI)) and toxicity (IOM Tolerable Upper Intake Level (UL); ATSDR Minimal Risk Level (MRL), WHO International Programme on Chemical Safety (IPCS) Tolerable Daily Intake (TDI)). Using a urinary excretion fraction of 0.9, Biomonitoring Equivalents (BE) for the EAR, RDA, UL and MRL were derived for adults (60, 100, 730 and 450 μg/L, respectively) and children (50, 80, 580 and 360 μg/L, respectively). The population median UIC values from NHANES and CHMS for adults (140–181, 122–126 μg/L, respectively) and children (232, 189 μg/L, respectively) were above the criteria for assessing iodine nutrition, indicating that US and Canadian populations are likely to have adequate population iodine nutrition. The median UIC from NHANES and CHMS do not exceed BE values derived from exposure guidance values for toxicity.

First Israeli National Iodine Survey Demonstrates Iodine Deficiency Among School-Aged Children and Pregnant Women

National data on iodine status in Israel are lacking. Reliance on iodine-depleted desalinated water, the absence of a salt iodization program, and reports of increased use of thyroid medication in Israel suggest that the population's iodine intake is likely inadequate. The aims of this study were therefore to determine the iodine status of Israeli school-age children (SAC) and pregnant women (PW) in a nationally representative sample obtained by a novel approach of using pre-discard urinalysis samples collected from a centralized national laboratory. Spot urine samples from 1023 SAC and 1074 PW, representing all regions and major sectors in Israel, were collected during 2016 at the Maccabi Healthcare Services central laboratory. Urinary iodine concentration (UIC) was measured, and the results were analyzed by trimester, sex, region, and sector. SAC were iodine deficient, with a median (interquartile range [IQR]) UIC of 83 μg/L (52-127 μg/L); 62% of SAC UICs were below the World Health Organization adequacy range for SAC (100-199 μg/L). PW were also iodine deficient, with a median (IQR) UIC of 61 μg/L (36-97 μg/L); 85% of PW UICs were below the adequacy range for PW (150-249 μg/L). For both SAC and PW, the median UIC was below the World Health Organization's adequacy range across all sectors, sexes, and districts. Among SAC, the median (IQR) UIC was lower among females (75 μg/L; 48-119 μg/L) than males (92 μg/L; 59-133 μg/L; p < 0.05). Median UIC values of PW correlated significantly with the median UIC for SAC by sub-district (R2 = 0.3, p < 0.05). Urine sampling via a centralized national laboratory was efficient and cost-saving. Iodine deficiency in Israeli SAC and PW is a serious public-health concern. A national program of salt iodization and iodine supplementation of PW should be urgently considered.

Urinary iodine concentration (UIC) could be a promising biomarker for predicting goiter among school-age children: A systematic review and meta-analysis.

ObjectivesTo evaluate whether urinary iodine concentration (UIC) can predict goiter among school-age children, and to assess the association between UIC and goiter prevalence.MethodsWe searched the MEDLINE, EMBASE, Cochrane Library (Cochrane Database of Systematic Reviews), Web of Science, CNKI, VIP, and Wan Fang databases for relevant reports in both English and Chinese up to August 25, 2016. The mean differences (MD) and 95% confidence intervals (CI) were calculated for the UIC and goiter prevalence assessments. Pooled odds ratios and 95% CIs were used to compare the prevalences of goiter in the different UIC groups.ResultsWe identified 11 case-control studies, and found that children with goiter had lower UIC values, compared to children without goiter (MD: –1.82, 95% CI: –3.24, –0.40, p < 0.05). An increased risk of goiter was associated with UIC values of < 20 μg/L or > 200 μg/L.ConclusionThe results of our meta-analysis suggest that lower UIC values were associated with an increased risk of goiter, and that iodine deficiency may lead to an increased risk of goiter. Furthermore, we observed U-shaped relationships between UIC and the prevalence of goiter, which suggests that both severe iodine deficiency and excessive iodine intake may lead to increased risks of goiter.