Urinary Iodine Concentration Levels Research Articles

Salt Iodization and Urinary Iodine Concentration Levels among Primary School Children in Mt. Elgon Sub-County, Kenya

Aims: Iodine plays a key role in thyroid hormone production and functioning. Inadequate iodine intake results in iodine deficiency (ID) which impairs the normal functioning of the thyroid. The deficiency is responsible for damage to brain development, growth retardation, cretinism, and thyroid dysfunction. Millions of people have been condemned to a life of few prospects and continued underdevelopment due to ID. The study was conducted to assess iodine status among primary school children in the Mt. Elgon region and the impact of salt iodization on this status.
 Study Design: A school-based cross-sectional descriptive study to assess iodine status among primary school children was employed in the study.
 Study Area and Duration: The study was carried out in Kenya, Bungoma County, Mount Elgon Sub-County. The study period was between 27th November 2018 and 26th November 2019.
 Methodology: Healthy primary school children aged 6 to 12 years who met the inclusion criteria were included in the study. Spot urine samples were collected in schools, while water samples were collected from different water sources. Salt was collected from households (HH) and at distribution outlets. The Sandell Kolthoff reaction was used to analyse urine and water samples while salt was analysed using iodometric titration.
 Results: The median urinary iodine concentration (UIC) was 200.7 µg/l. Out of which 0.55% were severely deficient, 5.25% moderately deficient, 18.23% with a mild deficiency, 25.69% had adequate iodine levels, 22.38% had more than adequate, and 27.90% had excess iodine levels. Household and salt samples from different distribution outlets that conformed to set standards of iodization were 49.4% and 63.64%, respectively. Iodine was not detected in all the water samples collected.
 Conclusion: The study population was found to have adequate iodine based on the median UIC of 200.7 µg/l. However, there was a coexistence of both deficiency and excessive UIC and salt iodization within the population. No iodine was detected in the water samples in the region.

The Relationship between Iodine and Selenium Levels with Anxiety and Depression in Patients with Euthyroid Nodular Goiter.

ObjectivesSelenium and iodine are essential microelements for normal body functions. These two elements play important roles in thyroid metabolism. The potential relationship between thyroid diseases and mental disorders have been demonstrated. We aimed to investigate the relationship between selenium and iodine levels with anxiety and depression in patients with euthyroid nodular goiter (ENG).MethodsIn this cross-sectional study, we enrolled 102 consecutive patients with ENG who attended the endocrine outpatient clinic between January 2018 and June 2018. We noted the patient’s demographics, thyroid ultrasound imaging, thyroid hormones, and urinary iodine concentration (UIC) results. We also obtained venous blood samples for serum selenium measurement. The same psychiatrist completed the Beck Anxiety Inventory (BAI) and Hamilton Depression Rating Scale (HDRS) for all participants. The study population was dichotomized according to the median values of selenium levels and UIC.ResultsBAI and HDRS scores were significantly higher in the low selenium group than the high selenium group (p = 0.032 and p = 0.042, respectively). BAI scores were significantly higher in the low UIC group than the high UIC group (p = 0.007).ConclusionsLow selenium and UIC levels may contribute to the development of anxiety and depression, independent of thyroid functions, in patients with ENG. In these patients, selenium and iodine replacement may be useful for the prevention of anxiety and depression, especially in deficient regions.

Maternal Urinary Iodine Concentration and Pregnancy Outcomes in Euthyroid Pregnant Women: a Systematic Review and Meta-analysis.

Iodine is an essential macronutrient for feto-maternal growth and development. Emerging evidence suggests that maternal iodine deficiency during pregnancy is potentially associated with both maternal and fetal adverse outcomes. The aim of this systematic review and meta-analysis was to investigate the association between maternal iodine status in euthyroid pregnant women and adverse pregnancy outcomes. A comprehensive literature search was performed in PubMed, Web of Science and Scopus up to October 2019 for retrieving related published articles in English. World Health Organization maternal median urinary iodine concentration (UIC) classification was used as follows: median UIC of less than 100, 100-149, 150-249, and more than 250μg/L, for moderate-to-severe iodine deficiency, mild iodine deficiency, iodine adequate and more than adequate-to-excessive iodine, respectively. The primary outcomes of interest in this meta-analysis were the pooled prevalence and pooled odds ratio of the preterm birth, low birth weight (LBW), and one composite outcome of hypertensive disorders of pregnancy comprising pregnancy hypertension and preeclampsia. The secondary outcome was pooled mean of neonatal characteristics including birth weight, head circumference, Apgar score, and gestational age at birth. A total of 6 studies involving 7698 participants were included in this meta-analysis. The pooled prevalence of preterm birth, LBW, and hypertensive disorders of pregnancy were not statistically significantly different in the four groups of UIC levels. The pooled prevalence of preterm birth was 0.05, 0.04, 0.04, and 0.03 in UIC < 100, 100-149, 150-249, and > 250μg/L, respectively. No evidence of an association was observed among the odds of preterm birth, LBW, and hypertensive disorders of pregnancy in euthyroid pregnant women with UIC between 100 and 149, 150-249, and > 250μg/L compared with UCI < 100μg/L. Likewise, there were not any statistical significant differences between the neonatal characteristics in different UIC groups. The results remained unchanged after subgroup analysis based on UIC less than 150μg/L as abnormal UIC level. The present meta-analysis showed that the UIC of euthyroid pregnant women is not generally associated with the pregnancy outcomes and it per se is an insufficient indicator for prediction of pregnancy complications. The results of this study are important for reproductive healthcare providers and policymakers in providing appropriate healthcare service for pregnant women. However, further studies are needed to confirm these findings.

Urinary Iodine Concentration is Inversely Associated with Thyroglobulin Antibodies

Objective: Epidemiologic studies on the relationship between iodine and thyroid antibodies are inconsistent. Iodine nutrition, genetic, and environmental factors have been shown to modify the effects of iodine on thyroid autoimmunity. We investigated the relationship between urinary iodine concentration (UIC) and thyroglobulin antibodies (TgAbs) in individuals living in iodine-sufficient areas in this cross-sectional study. Methods: A total of 15,008 participants were recruited according to the age range of the population of China in our study. An oral questionnaire was administered to collect basic demographic information. Serum thyrotropin (TSH), thyroid peroxidase antibodies (TPOAbs), TgAbs, and UIC were measured, and thyroid ultrasonography was performed in all subjects. Participants were further divided according to the level of UIC and the status of TgAb, and logistic regression was applied to determine the relationship between UIC and TgAbs. Results: The median UIC of the study population was 205.23 (95% confidence interval [CI], 65.7 to 537.67) μg/L. A total of 17.6% of participants had UIC <100 μg/L. With the increase in UIC, the prevalence of positive TgAbs decreased gradually. UIC level was lowest in subjects with high TgAb titer (median, 182.36 μg/L; 95% CI, 52.88 μg/L to 506.71 μg/L) and highest in the TgAb-negative group (median, 207.16 μg/L; 95% CI, 66.94 μg/L to 538.72 μg/L). Multilinear correlation analysis showed that gender (β = 37.632; P<.001), age (β = 0.467; P = .038), TSH (β = 13.107; P<.001), TPOAb (β = 1.150; P<.001), thyroid volume (β = 2.883; P<.001), and UIC (β = -0.047; P = .032) were independent predictors of TgAb variations. Low UIC (<100 μg/L) was associated with increased risk of positive TgAbs (adjusted odds ratio = 1.255 [1.004 to 1.568]). Conclusion: Low UIC is an independent risk factor for positive TgAb in individuals living in iodine-sufficient areas. Abbreviations: CI = confidence interval; CV = coefficient of variation; FT3 = free triiodothyronine; FT4 = free thyroxine; OR = odds ratio; TgAb = thyroglobulin antibody; TPOAb = thyroid peroxidase antibody; TSH = thyrotropin; UIC = urinary iodine concentration; USI = universal salt iodization.

Regional Influences on Nutritional Iodine Status of Pregnant Women in Pakistan.

Pregnant women are particularly vulnerable to iodine deficiency. Considering the rural-urban disparities in nutritional status in Pakistan, this study aimed to assess regional influences on nutritional iodine status of pregnant women in Pakistan. Data were collected from 1246 pregnant women in all trimesters of pregnancy who visited antenatal clinics for routine checkups in five Khyber Pakhtunkhwa province districts. Information concerning iodized salt intake and knowledge of iodine deficiency disorders (IDD) was obtained through an interview questionnaire. Goiter and urinary iodine concentration (UIC) levels were assessed by the palpation method and Sandell-Kolthoff reaction, respectively. Logistic regression analysis was used to quantify associations between residence (rural-urban), pregnancy trimester, and previous pregnancy outcomes with knowledge about IDD, iodized salt intake, presence of goiter, and UIC <150 μg/L. Among study participants, 87.7% had no knowledge about IDD, and only 21.0% were consuming iodized salt. Goiter was present in 25.5% of the women. The median UIC level was 131 μg/L, and 41.3% of study participants had a UIC ≥150 μg/L. There were no significant differences between pregnant women from rural and urban settings in regions with a solid socioeconomic status with respect to knowledge about IDD, iodized salt intake, iodine deficiency, and goiter prevalence. Urban-rural differences were observed only in socioeconomically disadvantaged districts. Only pregnant women living in the Lakki Marwat district had higher odds of having knowledge of IDD and iodized salt intake than those from rural regions. Trimesters of pregnancy and previous pregnancy outcomes had no significant effect on the outcome measures. Relative to a national nutrition survey conducted in Pakistan in 2011, the results from this study indicate that UIC levels remained stable with mild iodine deficiency, whereas rates of goiter and iodized salt intake remained high and low, respectively, especially in rural areas. Rural-urban disparities were observed only in socioeconomically disadvantaged districts, and these disparities limit the effectiveness of the IDD prevention program in rural areas in Pakistan. Thus, implementation of mandatory salt iodization requires improvement, and program effectiveness should be continuously monitored to prevent adverse health effects of iodine deficiency during pregnancy.

Median urinary iodine concentration reflected sufficient iodine supply in neonates from Northeast Germany in 2005-2006.

Data from recent adult studies suggest a decline of median urinary iodine concentrations (UIC) in Germany, but since 1996 no German study investigated UIC in neonates. The aim of our study was to investigate UIC and serum thyroid-stimulating hormone (TSH) levels in neonates from Germany. We used data from 399 neonates, which were born between April 2005 and November 2006 in the Northeast of Germany. UIC were evaluated by a photometric procedure with Sandell and Kolthoff reaction and afterwards corrected to be comparable with an ICP-MS method. TSH was determined from capillary blood, which was taken within 5days after birth, by DELFIA. Median UIC were 150µg/L (25th percentile: 104µg/L; 75th percentile: 196µg/L) and differed between boys (153.3µg/L) and girls (131.5µg/L; p = 0.012). The prevalence of serum TSH levels > 5 mIU/L was 14%. Neonates from mothers with intake of iodine supplementation (150µg/L) had significantly higher median UIC than neonates from mothers without iodine supplementation (132µg/L; p = 0.011). Multivariable linear regression adjusted for sex and iodine supplementation of the mother revealed a significant association between UIC and log-transformed serum TSH levels (β = 0.003: 95% confidence interval (CI) = 0.0001-0.005; p = 0.028). Neonates in Northeast Germany did show a sufficient supply of iodine. This points towards the possibility of a sufficient iodine supply of neonates also in other regions of Germany, even though recent studies in adults may indicate mild iodine deficiency.

New Statistical Approach to Apportion Dietary Sources of Iodine Intake: Findings from Kenya, Senegal and India.

Progress of national Universal Salt Iodization (USI) strategies is typically assessed by household coverage of adequately iodized salt and median urinary iodine concentration (UIC) in spot urine collections. However, household coverage does not inform on the iodized salt used in preparation of processed foods outside homes, nor does the total UIC reflect the portion of population iodine intake attributable to the USI strategy. This study used data from three population-representative surveys of women of reproductive age (WRA) in Kenya, Senegal and India to develop and illustrate a new approach to apportion the population UIC levels by the principal dietary sources of iodine intake, namely native iodine, iodine in processed food salt and iodine in household salt. The technique requires measurement of urinary sodium concentrations (UNaC) in the same spot urine samples collected for iodine status assessment. Taking into account the different complex survey designs of each survey, generalized linear regression (GLR) analyses were performed in which the UIC data of WRA was set as the outcome variable that depends on their UNaC and household salt iodine (SI) data as explanatory variables. Estimates of the UIC portions that correspond to iodine intake sources were calculated with use of the intercept and regression coefficients for the UNaC and SI variables in each country’s regression equation. GLR coefficients for UNaC and SI were significant in all country-specific models. Rural location did not show a significant association in any country when controlled for other explanatory variables. The estimated UIC portion from native dietary iodine intake in each country fell below the minimum threshold for iodine sufficiency. The UIC portion arising from processed food salt in Kenya was substantially higher than in Senegal and India, while the UIC portions from household salt use varied in accordance with the mean level of household SI content in the country surveys. The UIC portions and all-salt-derived iodine intakes found in this study were illustrative of existing differences in national USI legislative frameworks and national salt supply situations between countries. The approach of apportioning the population UIC from spot urine collections may be useful for future monitoring of change in iodine nutrition from reduced salt use in processed foods and in households.

Iodine status of pregnant women and children age 6 to 12 years feeding from the same food basket in Mopani district, Limpopo province, South Africa

Objectives: The aim of the study was to assess the iodine status of pregnant women and children age 6 to 12 years feeding from the same food basket in Mopani District.Design: A cross-sectional study was conducted.Setting: The setting was primary health care clinics and households from five municipalities of Mopani District in Limpopo province.Subjects: A total of 565 conveniently selected pregnant women and 116 children aged 6 to 12 years were recruited, of which 116 were mother–child pairs.Methods: The demographic information, iodine nutrition knowledge and salt consumption patterns were obtained using a validated questionnaire. Spot urine, household drinking water and salt samples were collected and analysed for iodine using standard procedures. A professional nurse, using filter paper to determine thyroid stimulating hormone (TSH) levels, collected spot finger-stick blood samples from pregnant women.Results: The findings showed that only 52.5% of household salt had an iodine concentration level of more than and equal to 15 ppm. The median iodine concentration of household drinking water was 46.2 μg/l (interquartile range [IQR] 10.8–73.4 μg/l). The TSH levels of the majority of pregnant women were normal and the maternal overall median urinary iodine concentration (UIC) was 164 μg/l (IQR 92–291 μg/l), indicating maternal iodine sufficiency. However, median UIC in the first and third trimesters was below 150 μg/l, indicating iodine insufficiency. The UIC level of children in the study was 386 μg/l (IQR 200–525 μg/l), signifying iodine excess.Conclusion: Iodine status of pregnant women in this study was sufficient, with UIC for children excessively high, more than two times higher than the iodine status of pregnant women. The reasons for the excessive UIC in school-age children need to be elucidated.

Iodized Salt Intake and Its Association with Urinary Iodine, Thyroid Peroxidase Antibodies, and Thyroglobulin Antibodies Among Urban Chinese.

Whether iodized salt increases the risk of thyroid disease has been strongly debated in China, especially in the urban areas of coastal regions, in recent years. This study aimed to investigate the status of iodized salt in terms of urinary and serum iodine concentration in urban coastal areas, and to explore further whether consumption of iodized salt or non-iodized salt is associated with autoimmune thyroid disease (AITD). The data source was SPECT-China, a cross-sectional study in East China. A total of 1678 subjects were enrolled from 12 communities in downtown Shanghai. The type of salt consumed, the urinary iodine concentration (UIC), serum iodine, thyroid peroxidase antibodies (TPOAb), and thyroglobulin antibodies (TgAb) levels were obtained. AITD was defined as serum TPOAb and/or TgAb >60 kIU/L (TPO/TgAb [+]). The prevalence of AITD was 10.5% in men and 21.4% in women. The median UIC and serum iodine concentration were 106.4 μg/L and 60.9 μg/L, respectively. Among all the subjects, 46.4% consumed non-iodized salt; the prevalence of iodine deficiency among those subjects was significantly higher than that of the subjects who consumed iodized salt (54.2% vs. 40.1%; p < 0.001). Consumption of non-iodized salt was positively associated with AITD in all participants (odds ratio [OR] = 1.49 [confidence interval (CI) 1.15-1.95]; p = 0.003) and in women (OR = 1.63 [CI 1.20-2.21]; p < 0.01) after multivariable adjustment. Additionally, the association between low UIC and AITD was observed among all subjects (OR = 1.50 [CI 1.10-2.05]; p = 0.01) and in women (OR = 1.45 [CI 1.02-2.07]; p = 0.038). In coastal areas, which are believed to be rich in iodine, consuming non-iodized salt still led to lower UIC levels and a higher prevalence of iodine deficiency. The consumption of non-iodized salt and low UICs might be a risk factor for AITD, especially for women, which should be further confirmed by longitudinal studies.

Interlaboratory variability of urinary iodine measurements.

The iodine status of populations is usually assessed by median urinary iodine concentrations (UIC) in population-based studies, but it is unclear to which extent UIC are comparable across different laboratories. The aim of our study was to investigate the variability of UIC measurements across three well-established German laboratories with long-term clinical-chemical expertise in iodine measurements and to compare these results to the gold standard inductively coupled plasma mass spectrometry (ICP-MS). UIC levels were measured from 303 urine samples derived from the "Dortmund Nutritional and Anthropometric Longitudinally Designed Study" and from volunteers of the University Medicine Greifswald at four different German laboratories. Three of these laboratories used Sandell-Kolthoff reaction with different digestion methods for UIC measurement (Lab1-Lab3), whereas one laboratory used ICP-MS as gold standard. Median UIC levels were significantly different across the four laboratories (ICP-MS: 77 μg/L; Lab1: 69 μg/L; Lab2: 73 μg/L; Lab3: 111 μg/L). Linear regressions associating UIC levels of Lab1-Lab3 with UIC levels of ICP-MS showed intercepts significantly different from 0 and slopes significantly different from 1. Intraclass correlations (ICC) in comparison to ICP-MS were 0.91 for Lab1, 0.98 for Lab2, and 0.69 for Lab3. Using the digestion method of Lab2 in Lab3 improved the comparison of UIC levels of Lab3 with those from the ICP-MS (ICC=0.89). We have demonstrated larger interlaboratory variations across high-quality laboratories with long-lasting experience in iodine measurements indicating a relevant non-comparability of UIC measurements in iodine monitoring studies. Therefore, standardization of UIC measurements has to be expedited.

The Relationship Between Iodine Serum Levels on The Thyroid Function and Iodine Status on Women Of Childbearing Age with The Risk of Hypothyroid

Background. Iodine micronutrients are required by the body to generate thyroid hormones. Thyroid hormone deficiency can cause hypothyroidism. Thyroid hormone is produced by the thyroid gland, which the function of the thyroid can be perceived in the levels of TSH and free T4, while iodine status can be appreciated from the iodine content of serum, iodine content of urine and thyroglobulin levels. The aim of this study was to describe the relationship between iodine serum level with thyroid function and iodine status on women of childbearing age with the risk of hypothyroid Method. This was cross sectional study in Purworejo district with a sample of women of childbearing aged 15-45 years with high levels of TSH> 2.5 μIU /mL. The sample size of this study were 88 people. Indicators quantified were the levels of TSH, free T4, iodine serum thyroglobulin levels and urinary iodine concentration (UIE). FreeT4 and TSH and thyroglobulin were measured by ELISA, while iodine serum and UIE were gauged by spectrophotometer method. Results. This study shows the average level of TSH 3.83 μIU / mL±1.5 FreeT4 levels of 1.33 ng / dL 0.25; thyroglobulin levels of 1.20 ng /mL ±0.41; serum iodine content 75.25 μg /L± 41.71 as well as the iodine substance of urine 96.14 μg / L± 65.04. UIE level of was less than 100 μg/L at 64.8%. There was a significant correlation between serum thyroglobulin with the iodine content with a correlation coefficient of 0.352 and p <0.05. Conclusion. For women of childbearing age with the risk of hypothyroidism had a urinary iodine concentration (UIE) less than the normal of 64.8% (problematic IDD) and there was a positive significant correlation between serum levels of iodine with thyroglobulin.

Thyroid status of iodine deficient newborn infants living in central region of Turkey: a pilot study.

Iodine deficiency (ID) during the fetal and neonatal periods can lead to neonatal hypothyroidism. This study was conducted to evaluate the effect of ID on the thyroid hormone level of newborns living in Turkey. Between 1998 and 2013, 71 newborns with a urinary iodine concentration <100 μg/L were recruited into the study. Data on thyroid volume, free triiodothyronine (fT3), free thyroxine (fT4), thyroid stimulating hormone (TSH), and thyroglobulin (Tg) were collected from all newborns, and on breast milk iodine from their mothers. Infants who were classified as having congenital hypothyroidism (TSH >40 mU/L and fT4 <8.5 pmol/L) were treated with levothyroxine (n=26, T group), while the remaining infants remained untreated (n=45, UT group). Thyroid hormones were subsequently measured 7-14 days later in a sub-sample of both treated and untreated infants. The average values at the time of admission were as follows [median (min-max)]. fT3: 5.0 (2.8-7.1) pmol/L, fT4: 7.7 (0.13-19.1) pmol/L, TSH: 75 (14-426) mU/L, Tg: 464 (226-1100) ng/mL, urinary iodine concentration (UIC): 30 (0-61) μg/L, breast milk iodine levels: 21 (10-150) μg/L, thyroid ultrasound (USG): 1.10 (0.24-1.95) mL for the T group; and fT3: 5.7 (1.7-12.7) pmol/L, fT4: 16.2 (9.9-33.5) pmol/L, TSH: 5.4 (0.63-41.8) mU/L, Tg: 171 (15-2124) ng/mL, UIC: 39 (0-90) μg/L, breast milk iodine levels: 47 (10-120) μg/L, thyroid USG: 0.75 (0.35-1.72) mL for the UT group. A significant difference was found between groups in respect to fT3, fT4, TSH and Tg levels. No significant difference in thyroid ultrasonography, UIC, and breast milk iodine levels was found between the two groups. The Tg levels of 50 out of 71 patients were measured, 40 (80%) of whom had Tg levels above the normal range (101 ng/mL). In our country, despite the use of iodized salt, congenital hypothyroidism due to ID remains a problem. The Tg level of newborns can be used as a good indicator of ID.

An Increase in Consuming Adequately Iodized Salt May Not Be Enough to Rectify Iodine Deficiency in Pregnancy in an Iodine-Sufficient Area of China.

Universal salt iodization (USI) has been implemented for two decades in China. It is crucial to periodically monitor iodine status in the most vulnerable population, such as pregnant women. A cross-sectional study was carried out in an evidence-proved iodine-sufficient province to evaluate iodine intake in pregnancy. According to the WHO/UNICEF/ICCIDD recommendation criteria of adequate iodine intake in pregnancy (150–249 µg/L), the median urinary iodine concentration (UIC) of the total 8159 recruited pregnant women was 147.5 µg/L, which indicated pregnant women had iodine deficiency at the province level. Overall, 51.0% of the total study participants had iodine deficiency with a UIC < 150 µg/L and only 32.9% of them had adequate iodine. Participants living in coastal areas had iodine deficiency with a median UIC of 130.1 µg/L, while those in inland areas had marginally adequate iodine intake with a median UIC of 158.1 µg/L (p < 0.001). Among the total study participants, 450 pregnant women consuming non-iodized salt had mild-moderate iodine deficiency with a median UIC of 99.6 µg/L; 7363 pregnant women consuming adequately iodized salt had a lightly statistically higher median UIC of 151.9 µg/L, compared with the recommended adequate level by the WHO/UNICEF/ICCIDD (p < 0.001). Consuming adequately iodized salt seemed to lightly increase the median UIC level, but it may not be enough to correct iodine nutrition status to an optimum level as recommended by the WHO/UNICEF/ICCIDD. We therefore suggest that, besides strengthening USI policy, additional interventive measure may be needed to improve iodine intake in pregnancy.

Assessment of Nutritional Status of Iodine Through Urinary Iodine Screening Among Local Children and Adolescents After the Fukushima Daiichi Nuclear Power Plant Accident.

Iodine deficiency is an important modifier of the risk of thyroid cancer following irradiation. However, little information is available on the prevalence of iodine deficiency in Fukushima and its surroundings after the Fukushima Daiichi nuclear power plant accident that occurred in March 2011. In order to assess urinary iodine concentrations (UIC) and the prevalence of iodine deficiency and to elucidate any associations between demographic characteristics and UIC levels among children and adolescents aged ≤18 years at the time of the accident in Fukushima Prefecture and its surroundings, the data on voluntary UIC testing conducted by Hirata Central Hospital, Fukushima, were evaluated. A total of 4410 children and adolescents with a median age of 10 years at examination underwent UIC testing between October 2012 and October 2015. Calculated for all the participants, the median UIC level was 204 μg/L (range 25-21,100 μg/L). There were 133 (3.0%), 732 (16.6%), and 1472 (33.4%) participants with UIC levels of <50, <100, or ≥300 μg/L, respectively. Based on the World Health Organization criteria for nutritional iodine status, no participants were severely iodine deficient (<20 μg/L), but 16.6% of the population were mildly (50-100 μg/L) or moderately (20-50 μg/L) iodine deficient. While no significant difference in UIC was noted between those who did and did not increase dietary iodine intake after the accident (p = 0.93), there were significant differences by year (p < 0.01), school level (p < 0.001), and residential area at the time of the accident (p < 0.001). This study demonstrates that the children and adolescents examined had a sufficient amount of iodine during the period 1.5-4.5 years after the nuclear accident. In addition to the differences in the scale and the countermeasures undertaken between the Fukushima and Chernobyl accidents, differences in dietary iodine intake might have played an additional role in resulting in the reportedly different radiation doses to the thyroid between the two nuclear accidents.

Iodine nutrition status and thyroid disorders: a cross-sectional study from the Xinjiang Autonomous Region of China.

Iodine nutritional status and its influence on thyroid function have been thoroughly investigated in many places in China, but little is known about Xinjiang province, where multiple minorities are living in a special geographical location and have different lifestyles compared with people from other parts of China. The aim of this study was to evaluate iodine status and thyroid disorders in two major ethnic groups living in the Xinjiang region of China. A total of 2253 residents over the age of 18 years who had lived in Xinjiang for more than 3 years were enrolled. Urinary iodine concentration (UIC), serum thyroid hormone concentrations and thyroid autoantibodies were measured, and thyroid ultrasonography was performed. The median UIC was 130.7 μg/l in adults. Among the subjects, those with deficient UIC levels were 34.4%. The prevalence of overt hyper- and hypothyroidism in the iodine-deficient group was higher than in the iodine-sufficient group (1.3% vs 0%, χ2=3.891, P=0.049; 4.8% vs 2.8%, χ2=8.715, P=0.003, respectively), and subclinical hypothyroidism was more frequent in the iodine-deficient group than in the iodine-excess group (19.6% vs 12.5%, χ2=4.529, P=0.033). One-third of the population is still iodine deficient in Xinjiang. Uyghur females are more susceptible to hypothyroidism and thyroid autoimmune diseases. Thyroid disorders, especially hyper/hypothyroidism and subclinical hypothyroidism, are more likely to be prevalent in an iodine-deficient population.

Iodine nutritional status in Uttarakhand State, India.

Introduction:Uttarakhand (UK) state is a known endemic region to iodine deficiency (ID).Objective:To assess the current status of iodine nutrition in a population of UK.Methodology:Three districts, namely Udham Singh Nagar (USN), Nainital (N), and Pauri Garhwal (PG) were selected. In each district, 30 clusters were identified by utilizing the population proportional to size cluster sampling methodology. Total of 6143 school age children (SAC) (USN; 1807, N; 2269, PG: 2067), 5430 adolescent girls (AGs) (USN; 1823, N; 1811, PG: 1796), 1727 pregnant mothers (PMs) (USN; 632, N; 614, PG: 481), and 2013 Neonates (USN; 649, N; 670, PG: 694), were included in the study. Clinical examination of thyroid of each child, AG and PM was conducted. Spot urine and salt samples were collected from children, AGs and PMs. Cord blood samples were collected from neonates for estimation of thyroid stimulating hormone (TSH).Results:In SAC, total goiter rate (TGR) was 13.2% (USN), 15.9% (N), and 16.8% (PG). Median urinary iodine concentration (UIC) level was 150 μg/l (USN), 125 μg/l (N), and 115 μg/l (PG). In AGs, TGR was 6.8% (USN), 8.2% (N) and 5.6% (PG). Median UIC level was 250 μg/l (USN), 200 μg/l (N), and 183 μg/l (PG). In PMs, TGR was 16.1% (USN), 20.2% (N), and 24.9% (PG). Median UIC level was 124 μg/l (USN), 117.5 μg/l (N) and 110 μg/l (PG), respectively. In Neonates, TSH levels of >5 mIU/L were found in 55.3 (USN), 76.4 (N) and 72.8 (PG) percent of neonates.Conclusion:UIC level in PMs and TSH levels among neonates indicate the prevalence of ID in three districts surveyed.

The Rise and Fall of Universal Salt Iodization in Vietnam: Lessons Learned for Designing Sustainable Food Fortification Programs With a Public Health Impact.

In 2005, more than 90% of Vietnamese households were using adequately iodized salt, and urinary iodine concentration among women of reproductive age was in the optimal range. However, household coverage declined thereafter to 45% in 2011, and urinary iodine concentration levels indicated inadequate iodine intake. To review the strengths and weaknesses of the Vietnamese universal salt iodization program from its inception to the current day and to discuss why achievements made by 2005 were not sustained. Qualitative review of program documents and semistructured interviews with national stakeholders. National legislation for mandatory salt iodization was revoked in 2005, and the political importance of the program was downgraded with consequential effects on budget, staff, and authority. The Vietnamese salt iodization program, as it was initially designed and implemented, was unsustainable, as salt iodization was not practiced as an industry norm but as a government-funded activity. An effective and sustainable salt iodization program needs to be reestablished for the long-term elimination of iodine deficiency, building upon lessons learned from the past and programs in neighboring countries. The new program will need to include mandatory legislation, including salt for food processing; industry responsibility for the cost of fortificant; government commitment for enforcement through routine food control systems and monitoring of iodine status through existing health/nutrition assessments; and intersectoral collaboration and management of the program. Many of the lessons would apply equally to universal salt iodization programs in other countries and indeed to food fortification programs in general.

Iodine Nutritional Status among Adolescent Girls in Uttarakhand, India.

Uttarakhand (UK) state is a known endemic region for Iodine deficiency. To assess iodine nutritional status among adolescent girls in districts: Udham Singh Nagar (USN), Nainital (N) and Pauri (P) of UK state. In each district, 30 clusters (schools) were identified by using population proportionate to size cluster sampling. In each school, 60 girls (12-18 years) attending the schools were included. Total of 5430 girls from USN (1823), N (1811) and P (1796) were studied. Clinical examination of thyroid of each girl was conducted. From each cluster, spot urine and salt samples were collected. Total goiter rate was found to be 6.8% (USN), 8.2% (N) and 5.6% (P). Median urinary iodine concentration levels were 250 μg/l (USN), 200 μg/l (N) and 183 μg/l (P). Findings of the study documented that adolescent girls had adequate iodine nutritional status in the three districts of UK.

Marginal Iodine Status and High Rate of Subclinical Hypothyroidism in Washington DC Women Planning Conception

Subclinical hypothyroidism during pregnancy has been associated with adverse maternal and fetal outcomes. A subset of pregnant women in the United States have been shown to have mild iodine deficiency. No study has evaluated the thyroid and iodine status of women who are planning to become pregnant in the near future. Thyroid function tests, thyroid antibodies, and urine iodine levels were evaluated in women presenting for preconception screening and counseling. A thyrotropin (TSH) level above 3.0 mIU/L was considered abnormal. One hundred and forty one women enrolled in the study. The median TSH level was 1.70 mIU/L (range 0.43-5.3 mIU/L). Sixteen women (11%) had a TSH above the upper limit of normal (>3.0 mIU/L). Eleven women (8%) were positive for TPO-Ab and 21 women (15%) for TgAb. Twenty-three women (16%) were positive for at least one thyroid antibody (TPOAb and/or TgAb). Median serum TSH concentrations were higher in women with detectable antithyroid antibodies than in women who were antibody negative (2.2 mIU/L vs. 1.7 mIU/L; p=0.005). The median urinary iodine concentration was 100.5 μg (range 19-843 μg/L). The present cohort exhibited the lowest median urinary iodine concentration levels to date reported in the United States for women in their childbearing years. One out of every nine women (11%) had thyroid function tests consistent with subclinical hypothyroidism.

Iodine status in healthy pregnant women in Korea: a first report.

Proper iodine intake is important during pregnancy for both fetal neurodevelopment and maternal thyroid function. Korea is known as a high iodine intake area. However, there are no data regarding iodine status in pregnant Korean women. Therefore, we evaluated the iodine status of pregnant women in Korea by measuring urine iodine concentration. This study had an observational, prospective design. We enrolled 344 healthy pregnant women who visited Samsung Medical Center in Korea for a routine antenatal checkup between April 2012 and September 2013. We measured iodine and creatinine concentration (Cr) in spot urine samples and TSH level in serum at the time of enrollment. The median urinary iodine concentration (UIC) and UIC adjusted by Cr were 427.3 μg/L and 447.9 μg/gCr, respectively. There was no difference in median UIC according to trimester of pregnancy (P value = 0.953). Serum TSH level was not different according to UIC level when subjects were grouped according to WHO iodine recommendations (P value = 0.401). The median UIC of healthy pregnant women in Korea was 427.3 μg/L and 447.9 μg/gCr, which are more than adequate according to WHO criteria. Considering the wide range of UIC, we recommend active education about adequate iodine intake during pregnancy in areas where iodine intake is more than adequate according to WHO criteria.