Iodine concentration and prevalence of thyroid disease in older people after salt iodization in Turkey

Background: Iodine uptake is a main factor affecting thyroid disease. In Turkey, mandatory salt iodization began in 1999–2000. Aims: This study in 2009 determined the prevalence of thyroid diseases in older people in Mamak district, Ankara after iodization to ascertain if salt iodization alone is sufficient to reach adequate iodine levels in the older population. Methods: All Mamak residents ≥ 65 years were eligible for inclusion in the study. Demographic data and medical history were recorded. All participants had a thyroid ultrasound. Blood samples were taken to assess thyroid function and autoantibodies, and urine samples to assess iodine concentration. Participants with low levels of thyroid stimulating hormone underwent scintigraphy to assess thyroid uptake. Fine-needle aspiration biopsy was done of nodules ≥ 1.5 cm where thyroid stimulating hormone was not suppressed. Results: Of 1200 eligible residents, 979 were included. Their mean age was 70.9 (standard deviation (SD) 5.7) years; 49.7% were women. Mean urinary iodine concentration was 98 (SD 81.29) µg/L. Goitre was found in 18.2% (89/487) of women and 6.7% (33/492) of men (P < 0.001) and 43.8% (428/979) had nodules. Subclinical hypothyroidism was found in 5.8% (57/979) of the participants, overt hyperthyroidism in 0.8% (8/979), subclinical hyperthyroidism in 2.2% (22/979) and T3 thyrotoxicosis in 0.3% (3/979). Toxic multinodular goitre and toxic adenoma caused 80% of hyperthyroidism cases. Biopsy detected no malignant pathology. Conclusion: After salt iodization, iodine levels have not yet reached favourable levels in older people. Iodization of salt seems insufficient to achieve these levels in older people; alternative iodine supplementation should be considered.

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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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Comparison of iodine status pre- and post-mandatory iodine fortification of bread in South Australia: a population study using newborn thyroid-stimulating hormone concentration as a marker

Public Health Nutrition ◽

10.1017/s1368980019001915 ◽

2019 ◽

Vol 22 (16) ◽

pp. 3063-3072 ◽

Cited By ~ 1

Author(s):

Molla Mesele Wassie ◽

Lisa N Yelland ◽

Lisa G Smithers ◽

Enzo Ranieri ◽

Shao Jia Zhou

Keyword(s):

Iodine Deficiency ◽

Urinary Iodine ◽

South Australia ◽

Interrupted Time Series ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

Transitional Period ◽

Urinary Iodine Concentration ◽

Iodine Status ◽

Stimulating Hormone

AbstractObjective:The present study aimed to evaluate the effect of mandatory iodine fortification of bread on the iodine status of South Australian populations using newborn thyroid-stimulating hormone (TSH) concentration as a marker.Design:The study used an interrupted time-series design.Setting:TSH data collected between 2005 and 2016 (n 211 033) were extracted from the routine newborn screening programme in South Australia for analysis. Iodine deficiency is indicated when more than 3 % of newborns have TSH > 5 mIU/l.Participants:Newborns were classified into three groups: the pre-fortification group (those born before October 2009); the transition group (born between October 2009 and June 2010); and the post-fortification group (born after June 2010).Results:The percentage of newborns with TSH > 5 mIU/l was 5·1, 6·2 and 4·6 % in the pre-fortification, transition and post-fortification groups, respectively. Based on a segmented regression model, newborns in the post-fortification period had a 10 % lower risk of having TSH > 5 mIU/l than newborns in the pre-fortification group (incidence rate ratio (IRR) = 0·90; 95 % CI 0·87, 0·94), while newborns in the transitional period had a 22 % higher risk of having TSH > 5 mIU/l compared with newborns in the pre-fortification period (IRR = 1·22; 95 % CI 1·13, 1·31).Conclusions:Using TSH as a marker, South Australia would be classified as mild iodine deficiency post-fortification in contrast to iodine sufficiency using median urinary iodine concentration as a population marker. Re-evaluation of the current TSH criteria to define iodine status in populations is warranted in this context.

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Iodine Status of Taiwanese Population in 2013: 10 Years After Changing From Mandatory to Voluntary Salt Iodization

Food and Nutrition Bulletin ◽

10.1177/0379572117738883 ◽

2017 ◽

Vol 39 (1) ◽

pp. 75-85 ◽

Cited By ~ 2

Author(s):

Fan-Fen Wang ◽

Kam-Tsun Tang ◽

Wen-Harn Pan ◽

Justin Ging-Shing Won ◽

Yao-Te Hsieh ◽

...

Keyword(s):

Age Groups ◽

Urinary Iodine ◽

Iodine Concentration ◽

World Health ◽

Urinary Iodine Concentration ◽

Taiwanese Population ◽

Iodine Nutrition ◽

Iodine Status ◽

Salt Iodization ◽

Health Organization

Background: In 2003, Taiwan’s iodine policy changed from mandatory to voluntary. The Nutrition and Health Survey in Taiwan (NAHSIT) 2001-2002 for schoolchildren showed adequate iodine nutrition, while NAHSIT 2005-2008 for adults showed the iodine status was at borderline adequacy. Objective: To investigate the iodine status of the Taiwanese population from schoolchildren to adulthood 10 years after the change of the salt iodization policy. Method: Urinary iodine was measured in samples from subjects in NAHSIT 2013. Results: The median urinary iodine concentration (UIC) of the Taiwanese population aged 6 years and above in 2013 was 96 μg/L, indicating mild iodine deficiency. The median UIC of 6- to 12-year-old schoolchildren was 124 μg/L (interquartile range [IQR]: 92-213 μg/L), and 115 μg/L (IQR: 80-166 μg/L), 125 μg/L (IQR: 74-161 μg/L), 73 μg/L (IQR: 52-131 μg/L), and 78 μg/L (IQR: 52-132 μg/L) in populations aged 13 to 18 years, 19 to 44 years, 45 to 64 years, and ≥65 years, respectively. Declining iodine nutrition in age groups ≥45 years old was noted that the median UIC of populations aged 45 to 64 years and ≥65 years was 99 and 88 μg/L, respectively, in NAHSIT 2005-2008. The median UIC of schoolchildren was not lower than that during the mandatory salt fortification period, but the distribution of urinary iodine levels signified a dietary pattern change. Conclusion: Wide-ranging variation in iodine nutrition levels was observed in different age groups. Universal salt iodization, as suggested by the World Health Organization, should be the best strategy to achieve adequate iodine nutrition.

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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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Urinary Iodine Concentration in a Cohort of Adult Outpatients with Thyroid Diseases in Liguria 14 Years after the Law on Salt Iodization

Nutrients ◽

10.3390/nu12010011 ◽

2019 ◽

Vol 12 (1) ◽

pp. 11

Author(s):

Conte ◽

Comina ◽

Monti ◽

Sidoti ◽

Vannozzi ◽

...

Keyword(s):

Medical Records ◽

Urinary Iodine ◽

Thyroid Volume ◽

Iodine Concentration ◽

Thyroid Diseases ◽

Outpatient Clinics ◽

Urinary Iodine Concentration ◽

Salt Iodization ◽

Clinical Records ◽

Iodine Sufficiency

Italy is considered a mildly iodine-deficient country. The aim of this study was to evaluate the iodine status of a cohort of adults living in Liguria after the 2005 salt iodization program. We searched all medical records of patients examined in two endocrine outpatient clinics in Genoa and Savona for data on urinary iodine. Subjects were under evaluation for thyroid diseases. Information on the type of salt used was found in few clinical records. Iodized salt use was reported in 29%, 20%, and 13% of records of people living in Genoa districts, the Savona district and nearby districts, respectively. The average urinary iodine concentration was 112.9 ± 62.3 µg/L (n = 415, median 101.0 µg/L). Non-significant differences (P > 0.05) were found between subjects with (median 103.5 µg/L) and without (median 97.5 µg/L) a thyroid gland, between the periods 2009–2013 (median 105.0 µg/L) and 2014–2018 (median 97.5 µg/L), and between Genoa (median 94.0 µg/L), Savona (median 105.0 µg/L) and the other districts (median 114.5 µg/L). No correlation with age, body mass index, creatinine, free thyroxine, thyroglobulin, levo-thyroxine dosage, or thyroid volume was observed. These data suggest a borderline status of iodine sufficiency in this cohort.

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

Asian Food Science Journal ◽

10.9734/afsj/2021/v20i130249 ◽

2021 ◽

pp. 10-17

Author(s):

Stephen N. Onteri ◽

Anselimo O. Makokha ◽

Beatrice Nyanchama Kiage Mokua ◽

Philip Ndemwa

Keyword(s):

Primary School ◽

School Children ◽

Water Samples ◽

Urinary Iodine ◽

Iodine Concentration ◽

Primary School Children ◽

Urinary Iodine Concentration ◽

Iodine Status ◽

Salt Iodization ◽

The Impact

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.

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