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.

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Iron and Iodine Status in Pregnant Women from A Developing Country and Its Relation to Pregnancy Outcomes

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16224414 ◽

2019 ◽

Vol 16 (22) ◽

pp. 4414 ◽

Cited By ~ 4

Author(s):

Sehar Iqbal ◽

Petra Rust ◽

Lisbeth Weitensfelder ◽

Inayat Ali ◽

Michael Kundi ◽

...

Keyword(s):

Pregnant Women ◽

Developing Country ◽

Pregnancy Complications ◽

Iron Status ◽

Urinary Iodine ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

Urinary Iodine Concentration ◽

Spot Urine ◽

Total Thyroxine

Birth related complications and comorbidities are highly associated with a poor nutritional status of pregnant women, whereas iron and iodine are among especially important trace elements for healthy maternal and fetal outcomes. The study compares the status of iron, iodine, and related functional parameters in pregnant and non-pregnant women from a developing country and associates the data with pregnancy complications. The concentrations of ferritin, hemoglobin (Hb), total triiodothyronine (TT3), total thyroxine (TT4), and thyroid-stimulating hormone (TSH) were determined in the blood serum of 80 pregnant women at the time of delivery and compared with 40 non-pregnant healthy controls. Spot urine samples were taken to evaluate the urinary iodine concentration (UIC). In pregnant women, ferritin, Hb concentrations, and UIC were significantly lower, and TT4 values were significantly higher compared to controls. Higher Hb levels were tendentially associated with a reduced risk for pregnancy complications (OR = 0.747, CI (95%) 0.556–1.004; p = 0.053). Regarding covariates, only previous miscarriages were marginally associated with pregnancy complications. High consumption of dairy products was associated with lower Hb and ferritin values. Our results suggest that pregnant women from a developing country have lower iron status with Hb levels being possibly associated with pregnancy complications.

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Association between Iodine Nutrition Status and Thyroid Disease-Related Hormone in Korean Adults: Korean National Health and Nutrition Examination Survey VI (2013–2015)

Nutrients ◽

10.3390/nu11112757 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2757 ◽

Cited By ~ 3

Author(s):

Kim ◽

Kwon ◽

Kim ◽

Hong ◽

Park

Keyword(s):

National Health ◽

Thyroid Disease ◽

Urinary Iodine ◽

Iodine Intake ◽

Thyroid Stimulating Hormone ◽

Nutrition Status ◽

Urinary Iodine Concentration ◽

Nutrition Examination Survey ◽

Iodine Nutrition ◽

Health And Nutrition

This study aimed to observe the relationship between iodine nutrition status (dietary iodine intake and estimated iodine intake based on urinary iodine concentration (UIC)) and thyroid disease-related hormones. This study involved 6090 subjects >19 years old with valid UIC, assessed between 2013 and 2015 by the Korean National Health and Nutrition Examination Survey, using a stratified, multistage, clustered probability-sampling design. The estimated iodine intake in participants was measured using UIC and urine creatinine. To examine the effect of iodine intake on thyroid disease, the iodine intake was divided into Korean Dietary Reference Intakes groups, and logistic regression analysis was performed via the surveylogistic procedure to obtain odds ratios (ORs) and 95% confidence intervals (CIs). The estimated iodine intake showed a significant positive correlation with dietary iodine intake (r = 0.021, p < 0.001), UIC (r = 0.918, p < 0.001), and thyroid-stimulating hormone (TSH) (r = 0.043, p < 0.001), but a significant negative correlation with free thyroxine (FT4) (r = −0.037, p < 0.001). Additionally, as the estimated iodine intake increased, age, TSH, and UIC increased, but FT4 decreased (p for trend < 0.0001). The risk of thyroid disease was higher in the “≥tolerable upper intake level (UL ≥ 2400 µg/day)” group than in the “<estimated average requirement (EAR < 150 µg/day)” group in females (OR: 2.418; 95% CI: 1.010–5.787). Also, as iodine intake increased, the risk of thyroid disease increased (p for trend < 0.038).

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Two Sources of Maternal Iodine Intake and Their Effect on Maternal and Infant Iodine Status and Thyroid Function and Infant Information Processing in Southern Ethiopia (P11-007-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz048.p11-007-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Author(s):

Tafere Gebreegziabher ◽

Barbara Stoecker

Keyword(s):

Information Processing ◽

Thyroid Function ◽

Visual Information ◽

Urinary Iodine ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

Iodized Salt ◽

Southern Ethiopia ◽

Urinary Iodine Concentration ◽

Iodine Supplementation

Abstract Objectives The objective of this study was to assess the effects of two sources of iodine supplementation on maternal and infant thyroid function and on visual information processing (VIP) of infants in southern Ethiopia Methods A community-based, randomized, supplementation trial was conducted. Mother infant dyads (n = 106) were recruited within the first week after delivery to participate in this study. Mothers were randomly assigned either to receive a potassium iodide capsule (225 µg iodine) daily for 26 weeks or appropriately iodized salt weekly for 26 weeks for household consumption. Maternal thyroxine (T4), triiodothyronine (T3), thyroid stimulating hormone (TSH), thyroglobulin (Tg), urinary iodine concentration (UIC), breast milk iodine concentration (BMIC) and infant T4, TSH, UIC and VIP were measured as outcome variables. Results At baseline, neither mothers nor infants in the two groups (capsule and iodized salt groups) were significantly different in any of the biomarkers and anthropometry measurements. Maternal TSH and goiter rate significantly decreased following iodine supplementation but T3, T4 and Tg didn't change. Maternal UIC and BMIC and infant UIC were not different among groups. Conclusions A maternal dose of 225 µg iodine daily or adequately iodized salt initiated within a week after delivery decreased goiter and TSH but did not impact infant T4, TSH or VIP. The two treatment groups didn't differ in any of the outcome variables. Funding Sources The study was funded by Nestlé Foundation and Oklahoma State University.

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Thyroid stimulating hormone isn’t a sensitive indicator of iodine nutritional status in schoolchildren

Revista de Ciências Médicas e Biológicas ◽

10.9771/cmbio.v14i3.14990 ◽

2016 ◽

Vol 14 (3) ◽

pp. 350

Author(s):

Renata De Oliveira Campos ◽

Joaquim Custódio Silva Júnior ◽

Elton Estrela Ramos

Keyword(s):

Public Schools ◽

Nutritional Status ◽

Filter Paper ◽

Urinary Iodine ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Cross Sectional ◽

Stimulating Hormone

Introduction: iodine deficiency disorders (IDD) are most common cause of preventable brain damage, mental retardation and stunted growth in children worldwide. Several indicators are complementary to urinary iodine concentration (UIC) for assessing iodine nutritional status, as thyroid size, thyroglobulin (Tg) and thyroid stimulating hormone (TSH) concentrations in the blood. Objective: analyze TSH in filter paper blood values and correlate with UIC in schoolchildren from public school at state of Bahia, Brazil. Methodology: cross-sectional study was conducted in 880 schoolchildren aged 6-14 years, randomly selected, of public schools in five cities of four micro-regions of Bahia between October 2013 and September 2014. TSH was analyzed in filter-paper blood and UIC were measured by adapted Sandell-Kolthoff reaction. Results: 880 blood samples on filter-paper were analyzed for TSH. The reference range previously established is 0.72 to 6.0 μUI/mL. Results of this research TSH dosage ranged from 0.24 μIU/L to 7.71 μIU/L, with a mean of 1.01±0.55 μUI/L and median 0.89 μUI/L. Only one child presented TSH greater than 6.0 (7.71 μIU/L); however, results of urinary iodine were consistent with a more than adequate nutrition iodine (243.70μg/L). There’ no correlation between TSH and UIC (r= 0.115; p= 0.002). Conclusion: in the present study, schoolchildren showed low values of TSH, but the mean UIC was indicative of adequate iodine nutrition.

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Thyroid dysfunction in region of excess iodine intake of Eastern Nepal

International Journal of Scientific Reports ◽

10.18203/issn.2454-2156.intjscirep20181848 ◽

2018 ◽

Vol 4 (5) ◽

pp. 114

Author(s):

Saroj Thapa ◽

Madhab Lamsal ◽

Rajendra K. Chaudhari ◽

Basanta Gelal ◽

Saroj Kunwar ◽

...

Keyword(s):

Primary School ◽

Subclinical Hypothyroidism ◽

Thyroid Dysfunction ◽

Urinary Iodine ◽

Iodine Concentration ◽

Primary School Children ◽

Nutrition Status ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Excess Iodine

Background: Iodine deficiency as well as iodine excess can result in an increased prevalence of thyroid disorders. The prevalence of excess iodine nutrition is increasing all over the world. The aim of the present study was to find the occurrence of iodine nutrition status in primary school children of Eastern Nepal and find the prevalence of associated thyroid dysfunction among those with excess urinary iodine concentration.Methods: A community based cross sectional study was conducted in Udayapur district which is located in Eastern part of Nepal. Primary school aged children (6 years to 12 years) were enrolled in this study from three schools. Blood and urine samples were collected and assayed for urinary iodine concentration (UIC), free thyroid hormones (fT3 and fT4), and thyroid stimulating hormone (TSH). Results: The median UIC was 232.27 µg/L. The iodine status showed that 15.5% (n=31) had low UIC, 21% (n=42) had above requirement and 36% (n=72) had excessive iodine nutrition status. The mean concentration of fT3 and fT4 was 2.87 pg/ml and 1.21 ng/dl respectively, while the median TSH concentration was 3.03 mIU/L. The prevalence of thyroid dysfunction was 10% (n=20) with subclinical hypothyroidism being the most common. Majority of participants with subclinical hypothyroidism had excess UIC.Conclusions: Above requirement and excess iodine nutrition is more common in region where there is unregulated consumption and improper monitoring of iodized salt. Subclinical hypothyroidism is common in regions of excess iodine nutrition.

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A study on the influencing factors of urinary iodine concentration and the relationship between iodised salt concentration and urinary iodine concentration

British Journal Of Nutrition ◽

10.1017/s0007114514003377 ◽

2014 ◽

Vol 113 (1) ◽

pp. 142-146 ◽

Cited By ~ 4

Author(s):

Yan Zou ◽

Gangqiang Ding ◽

Xiaoming Lou ◽

Zhe Mo ◽

Wenming Zhu ◽

...

Keyword(s):

Logistic Regression ◽

Regression Analysis ◽

Influencing Factors ◽

Urinary Iodine ◽

Iodine Concentration ◽

Nutrition Status ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Salt Iodine ◽

The Relationship

The aim of the present study was to explore the influencing factors of urinary iodine concentration (UIC) and the relationship between iodised salt concentration and UIC in order to give suggestions for the surveillance of iodine nutrition status. For this purpose, a multi-stage cluster sampling technique was employed in the present cross-sectional study. Correlations between UIC and salt iodine concentration were evaluated by Spearmen's correlation analysis. Risk factors of having a lower UIC were identified by logistic regression analysis, and the equations of UIC and salt iodine concentration were fitted by curve regression analysis. The median UIC was found to be 162·0 (25th–75th percentile 98·2–248·6) μg/l. The UIC was correlated with salt iodine concentration (Spearman's ρ = 0·144, P< 0·05). The multiple logistic regression analysis found the following influencing factors for having a lower UIC: age (OR 0·98, 95 % CI 0·98, 0·98, P< 0·05); sex (OR 0·81, 95 % CI 0·71, 0·92, P< 0·05); education level (OR 0·87, 95 % CI 0·83, 0·90, P< 0·05); status of occupation (OR 0·91, 95 % CI 0·86, 0·96, P< 0·05); occupation (OR 1·03, 95 % CI 1·00, 1·05, P< 0·05); pickled food (OR 1·24, 95 % CI 1·08, 1·42, P< 0·05); salt iodine concentration (OR 1·03, 95 % CI 1·02, 1·03, P< 0·05). The curve regression analysis found that UIC (y) and salt iodine concentration (x) could be expressed by the following equation: y= 1·5772x1·4845. In conclusion, the median UIC of individuals in Zhejiang Province falls within optimal status as recommended by the WHO/UNICEF/International Council for Control of IDD. To maintain optimal iodine nutrition status, salt iodine concentration should be in the range of 16·4 to 34·3 mg/kg.

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Iodine nutrition status in clinically euthyroid pregnant women attending in BSMMU

Bangabandhu Sheikh Mujib Medical University Journal ◽

10.3329/bsmmuj.v9i1.28942 ◽

2016 ◽

Vol 9 (1) ◽

pp. 38

Author(s):

Md. Anowar Hossain ◽

M. Abul Hasanat ◽

Murshed Ahamed Khan ◽

Jobaida Naznin ◽

Kazi Ashraful Alam ◽

...

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Iodine Content ◽

Iodine Concentration ◽

Nutrition Status ◽

Urinary Iodine Concentration ◽

Digestion Method ◽

Iodine Nutrition ◽

Cross Sectional ◽

Nutritional Problem

Background: Iodine deficiency disorders (IDD) are common nutritional problem globally. All groups of people are affected by it, but the pregnant women and their neonates are most vulnerable.Objectives: This study was carried out to see the iodine status of pregnant women using median urinary iodine concentration (MUI) as a measure of outcome. Methods: This cross sectional observational study assessed the MUI in casual urine samples from 225 pregnant women (75 pregnants from each trimester) and 75 non-pregnant healthy controls. The urinary iodine content was estimated in urine sample using the method of Dunn et al. with the modification of Sandell & Kolthoff (wet digestion method).Results: Median value of urinary iodine in pregnant women was 48.21Ug/L compared to 52.27

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TSH Mediated the Effect of Iodized Salt on Child Cognition in a Randomized Clinical Trial

Nutrition and Metabolic Insights ◽

10.1177/11786388211025352 ◽

2021 ◽

Vol 14 ◽

pp. 117863882110253

Author(s):

Husein Mohammed ◽

Grace S Marquis ◽

Frances Aboud ◽

Karim Bougma ◽

Aregash Samuel

Keyword(s):

Effect Size ◽

Market Access ◽

Iron Status ◽

Urinary Iodine ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

Iodized Salt ◽

Urinary Iodine Concentration ◽

Child Cognition ◽

Iodine Level

Objectives: This study examines the hormonal mediators of the effect of iodized salt in pregnancy on child cognition. Methods: Sixty districts across 6 zones in the Amhara region of Ethiopia were randomly allocated to a control or intervention arm of early market access to iodized salt. Twenty-two villages per arm were randomly selected for this sub-study. A total of 1220 pregnant women who conceived after the intervention began were enrolled and assessed for their iodine and iron status. Data were collected once on the household socio-demographic status and iodized salt use, and maternal urinary iodine during pregnancy. Then, infants’ diet, urinary iodine level, cognitive development (Bayley III), serum hormonal levels, iron status, and inflammation markers were measured between 2 and 13 months of age. Results: The median maternal urinary iodine concentration was adequate and significantly higher in the intervention mothers than that of the controls (163 vs 121 µg/L, P < .0001). Intervention children compared to the control children had lower thyroid-stimulating hormone (TSH) (mean: 2.4 ± 1.0 µIU/mL vs 2.7 ± 1.0 µIU/mL, effect size = 0.18, P < .01) and thyroglobulin (Tg) (41.6 ± 1.0 ng/mL vs 45.1 ± 1.0 ng/mL, effect size = 0.14, P < .05). There was an interaction between the intervention and iron stores such that cognition was higher with iron (effect size = 0.28, 100 vs 94 IQ points). TSH was a partial mediator (12%) of the effect of the intervention on child cognition (Sobel z-score = 2.1 ± 0.06, P < .05). Conclusion: TSH partially mediated the effect of the iodized salt intervention on child cognition.

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Iodine Status and Thyroid Function in a Group of Seaweed Consumers in Norway

Nutrients ◽

10.3390/nu12113483 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3483

Author(s):

Inger Aakre ◽

Lidunn Tveito Evensen ◽

Marian Kjellevold ◽

Lisbeth Dahl ◽

Sigrun Henjum ◽

...

Keyword(s):

Thyroid Function ◽

Urinary Iodine ◽

Iodine Content ◽

Iodine Concentration ◽

Iodine Intake ◽

Thyroid Stimulating Hormone ◽

Urinary Iodine Concentration ◽

Free Triiodothyronine ◽

Iodine Status ◽

Excessive Iodine

Seaweeds, or macroalgae, may be a good dietary iodine source but also a source of excessive iodine intake. The main aim in this study was to describe the iodine status and thyroid function in a group of macroalgae consumers. Two urine samples were collected from each participant (n = 44) to measure urinary iodine concentration (UIC) after habitual consumption of seaweed. Serum thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and peroxidase autoantibody (TPOAb), were measured in a subgroup (n = 19). A food frequency questionnaire and an iodine-specific 24 h recall were used to assess iodine intake and macroalgae consumption. The median (p25–p75) UIC was 1200 (370–2850) μg/L. Median (p25–p75) estimated dietary iodine intake, excluding macroalgae, was 110 (78–680) μg/day, indicating that seaweed was the major contributor to the iodine intake. TSH levels were within the reference values, but higher than in other comparable population groups. One third of the participants used seaweeds daily, and sugar kelp, winged kelp, dulse and laver were the most common species. Labelling of iodine content was lacking for a large share of the products consumed. This study found excessive iodine status in macroalgae consumers after intake of dietary seaweeds. Including macroalgae in the diet may give excessive iodine exposure, and consumers should be made aware of the risk associated with inclusion of macroalgae in their diet.

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Agreement between markers of population iodine status in classifying iodine status of populations: a systematic review

American Journal of Clinical Nutrition ◽

10.1093/ajcn/nqz118 ◽

2019 ◽

Vol 110 (4) ◽

pp. 949-958 ◽

Cited By ~ 2

Author(s):

Molla Mesele Wassie ◽

Philippa Middleton ◽

Shao Jia Zhou

Keyword(s):

Systematic Review ◽

Urinary Iodine ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

School Age Children ◽

Urinary Iodine Concentration ◽

School Age ◽

Iodine Status ◽

Goiter Prevalence ◽

Reference Markers

ABSTRACT Background Population iodine deficiency is indicated by >3% of the population with newborn thyroid-stimulating hormone (TSH) concentration >5 mIU/L, median urinary iodine concentration (MUIC) <100 µg/L, or >5% prevalence of goiter in school-age children. However, the agreement between these population markers has not been systematically investigated. Objective To assess the agreement between TSH, MUIC, and goiter as markers of population iodine status. Methods We performed a systematic search for studies published on PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, and PsycINFO up to 29 October, 2018. Studies assessing iodine status in the population using the TSH marker and either MUIC or goiter prevalence in school-age children were included. The agreement between markers in classifying iodine status of the population was assessed. The sensitivity and specificity of the TSH marker was determined against MUIC and goiter prevalence as the reference markers. Results Of 17,435 records identified by the search strategy, 57 eligible studies were included in the review. The agreement between markers in classifying the iodine status of populations into the same category was 65% for TSH and MUIC, and 83% for TSH and goiter prevalence. The TSH marker had a sensitivity of 0.75 and specificity of 0.53 when compared with MUIC, and 0.86 and 0.50 when compared with goiter prevalence. Conclusions The TSH marker has a better agreement with goiter prevalence than MUIC when classifying the iodine status of populations. Re-evaluation of the current criteria for classifying the iodine status of populations using the TSH marker is warranted. This systematic review was registered at PROSPERO (http://www.crd.york.ac.uk/prospero/) as CRD42018091247.

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