Determination of Serum Thyroglobulin Concentration in Simple Diffuse Goiter Patients with Known Iodine Status

Background: Thyroglobulin (TG) seems to be a valuable indicator of thyroid function and iodine nutrition status. Aim of the study: The aim of the study was to observe the relationship between serum thyroglobulin and urinary iodine (UI) in simple diffuse goiter patients.Methods:This cross-sectional observational study was conducted at the Department of Endocrinology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh. The study duration was 2 years, starting from May 2014 to March 2016. Total 87 patients with simple diffuse goiter attending the OPD Department of Endocrinology of BSMMU had been recruited as study population. A purposive sampling technique was followed for sample selection.Results:Serum thyroglobulin (ng/mL, mean±SD and median) was lowest in the age group 12-16 years (6.0±4.5, 5.16 ng/mL) followed by age>31 years (8.8±8.1, 6.16 ng/mL), whereas other age groups showed level around 13.0 and 10.0 ng/mL (p= 0.520). Mean (±SD) Urinary Iodine was not statistically different among age groups (347.4± 226.5 vs. 337.08±188.9 vs. 300.5± 95.37 vs. 337.7± 225.42 vs. 278.3± 105.7, µg/L; F 0.451, p=0.771) while median values were 325.26 vs. 355.68 vs. 325.80 vs. 338.86 and 300.90 µg/L respectively. Neither thyroglobulin (5.76±5.72 vs. 11.60± 13.50; 3.47 vs. 8.9 ng/mL, m±SD and median; p=0.294) nor Urinary Iodine (373.5± 44.5 vs. 317.2± 180.32; 378.1 vs. 308.9 µg/L, m±SD and median; p=0.450) were statistically different between the gender groups. Similarly, thyroglobulin and Urinary Iodine were also statistically similar for grade-1 and grade-2 goiter (thyroglobulin: 6.79±4.33 vs. 11.67±13.69 and 6.74 vs. 8.02 ng/mL, m±SD and median, p=0.319; Urinary Iodine: 361.33± 51.60 vs. 317.09± 182.44, 362.69 vs. 305.35 µg/L, m±SD and median, p=0.498).Conclusion:Thyroglobulin seems to have an inverse association in iodine deficiency state and positive association in over sufficient state with UI. There was no statistically significant difference of TG concentration between males and females nor between Grade-1 and Grade-2 goiter.

The iodine knowledge of pregnant women in an endemic goiter area: a cross-sectional study

Purpose This study aims to determine the level of knowledge about iodine nutrition during pregnancy among pregnant women living in the area of Turkey where goiter is endemic. Design/methodology/approach A total of 150 pregnant women aged between 19 and 45 years, registered at the Gynaecology and Obstetrics Clinic in Trabzon were recruited. The data was collected through a voluntary face-to-face survey with pregnant women. The questionnaire comprising questions determining the sociodemographic characteristics of the participants, data concerning any previous pregnancy, iodized salt consumption habits and knowledge about iodine. Findings Although 68% of the women knew that iodine deficiency can cause serious consequences during pregnancy, the remainder did not. The three main dietary sources of iodine in Turkey are fish, cow’s milk and table salt; of the women, 68%, 20% and 77.3%, respectively, correctly identified these as good sources. The more educated of the pregnant women had significantly higher knowledge scores (p < 0.001). However, age, trimester, parity and previous receipt of information about iodine and iodine knowledge scores made no significant differences. Research limitations/implications This study may not be generalizable for all pregnant women. Originality/value To the best of the authors’ knowledge, this study is the first pilot study to evaluate the level of knowledge regarding iodine among pregnant women in Turkey.

The Role of Iodine for Thyroid Function in Lactating Women and Infants

Iodine is a micronutrient needed for the production of thyroid hormones, which regulate metabolism, growth, and development. Iodine deficiency or excess may alter the thyroid hormone synthesis. The potential effects on infant development depend on the degree, timing, and duration of exposure. The iodine requirement is particularly high during infancy because of elevated thyroid hormone turnover. Breastfed infants rely on iodine provided by human milk, but the iodine concentration in breast milk is determined by the maternal iodine intake. Diets in many countries cannot provide sufficient iodine, and deficiency is prevented by iodine fortification of salt. However, the coverage of iodized salt varies between countries. Epidemiological data suggest large differences in the iodine intake in lactating women, infants, and toddlers worldwide, ranging from deficient to excessive intake. In this review, we provide an overview of the current knowledge and recent advances in the understanding of iodine nutrition and its association with thyroid function in lactating women, infants, and toddlers. We discuss risk factors for iodine malnutrition and the impact of targeted intervention strategies on these vulnerable population groups. We highlight the importance of appropriate definitions of optimal iodine nutrition and the need for more data assessing the risk of mild iodine deficiency for thyroid disorders during the first 2 years in life.

Causes of different goiter rates with the same iodine deficiency among the pastoral and agricultural populations of Tibet: A geographical comparison

Background The residents of both the agricultural and pastoral areas of Tibet share the same iodine deficiency and iodine nutrition, but the rate of thyroid goiter was significantly higher in the agricultural areas than in the pastoral areas. This project sought to determine why the populations in the iodine-deficient pastoral areas show a lower rate of thyroid goiter. Methods Food frequency questionnaires (FFQs) and 24 h history recalls were adopted to investigate the dietary patterns of the residents of the agricultural and pastoral areas. Meat and milk samples were collected to measure their inorganic iodine, total iodine and thyroid hormone contents using ICP-MS, AsIII-Ce4+ catalytic spectrophotometry and the Siemens’ chemiluminescence method, respectively. The intake of protein, and the microelements, selenium and iron, was calculated according to their content in the food. Results The per capita daily intake of meat, dairy, and cereal in the pastoral areas was 116.7, 216.7, and 433.3 g, respectively, which are significantly higher than those in the agricultural areas (50.0, 72.2, and 375.0 g, respectively) (p < 0.05). The content of thyroid hormone in dried beef and milk in the pastoral areas was 62.6 and 13.5 µg/kg, respectively, which was significantly higher than those in the agricultural areas (25.1 and 4.1 µg/kg, respectively) (p < 0.05). The daily intake of thyroid hormone, protein and microelements, selenium and iron from foods by the residents of the pastoral areas were 10.5 µg, 99.6 g, 30.0 µg and 15.8 mg respectively, which was significantly higher than those in the agricultural areas (1.79 µg, 56.5 g, 23.8 µg and 13.2 mg, respectively) (p < 0.05). Conclusions The significantly high intake of the food-borne thyroid hormone by the residents of the pastoral area could be the main reason the residents in the pastoral areas show a lower rate of thyroid goiter than those in the agricultural area. Moreover, the relatively high intake of protein and trace elements, selenium and iron by residents in the pastoral area could be another important factor for reducing the goiter rates.

Low Iodine Intake May Decrease Women’s Fecundity: A Population-Based Cross-Sectional Study

Salt iodization is one of the most cost-effective strategies to eliminate iodine deficiency disorders (IDD). However, China’s dismantling of salt monopoly has reduced the availability of iodized salt in the susceptible population in pregnancy, which might cause IDD and have adverse health effects on both themselves and their offspring. The aim of our study was therefore to explore the association between IDD and women’s reproductive health. This is a population-based cross-sectional study conducted in 2018 in Zhejiang Province, China. A total of 1653 pregnant women participated in this study. Median urinary iodine concentration (UIC) in the population was used to assess iodine intake. Cox regression analyses were used to estimate the association between iodine intake and time to pregnancy, which was indicated with fecundability ratio (FR) and 95% confidence interval (CI). The percentage of participants with iodine deficiency who had been waiting longer than 13 months to get pregnant (20%; median UIC 119.6 μg/L) was significantly higher than those with iodine sufficiency (14%; median UIC 147.1 μg/L). A significant decrease in fecundity was observed in participants with iodine deficiency (FR, 0.820; 95% CI, 0.725−0.929) than those with iodine sufficiency. These findings indicate the importance of ongoing monitoring of iodine nutrition in women of reproductive age. Keeping a safe and optimal level of iodine nutrition during pregnancy should be emphasized.

Thyroid Function and Thyroglobulin Level in Iodine-Deficient Children of Eastern Nepal

Iodine deficiency during childhood affects physical and mental development. Iodine deficiency or excess both can negatively impact thyroid function. We conducted this study to assess iodine nutrition and thyroid function in children with insufficient urinary iodine concentration. A community-based cross-sectional study was conducted among the selected schools of Udayapur district. Urinary iodine concentration (UIC) was measured in 1012 school children (6-14 years). Based on UIC data, 83 blood samples were collected to measure serum thyroglobulin (Tg), thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4). UIC was measured by ammonium persulfate digestion method, and Tg, TSH, fT4, and fT3 were measured using ELISA kits. The median UIE was 236 µg/L, and 11.1% of the children had insufficient UIC. The mean fT3, fT4, and TSH in children with insufficient UIC were 2.55±0.43 pg/mL, 0.96±0.28 ng/dL, and 3.60±1.44 mIU/L respectively. Among children with low UIC levels, the median Tg was 17.5 ng/mL. Overt hypothyroidism was seen in 6%, and subclinical hypothyroidism in 3.6%. The children had sufficient iodine nutrition, and the frequency of thyroid dysfunction was low among the children with insufficient UIC.

High Iodine Nutrition May Be a Risk Factor for Cervical Lymph Node Metastasis in Papillary Thyroid Cancer Patients

<b><i>Purpose:</i></b> The aim of this study was to retrospectively identify the effect of iodine on the papillary thyroid cancer (PTC) process and investigate the risk clinicopathologic characteristics of cervical lymph node metastasis (CLNM) for achieving a better preventive strategy of PTC. <b><i>Methods:</i></b> Totally 187 patients with CLNM and 279 without CLNM (NCLNM) were enrolled, and their urinary iodine concentration (UIC) and serum iodine concentration (SIC) were measured. Logistic regressions were used to reveal the effects of iodine nutrition on the CLNM status of PTC. <b><i>Results:</i></b> The levels of thyroid-stimulating hormone (TSH) and thyroglobulin (TG) were higher in the CLNM group than in the NCLNM group. UIC and SIC were positively correlated, and both of them were correlated with TSH, free thyroxine, and TG. The proportions of UIC &#x3e;300 μg/L and of SIC &#x3e;90 μg/L were higher in the CLNM than in the NCLNM. Logistic analysis showed that SIC &#x3e;90 μg/L was an independent predictor for CLNM in PTC. Additionally, age ≥45, female, TG, multifocality, and diameter of cancer invasion &#x3e;1 cm also affected CLNM status in PTC, and their logistic regression model showed a certain diagnostic accuracy (area under the receiver-operating characteristic curve = 0.72). <b><i>Conclusions:</i></b> Relatively high iodine nutrition seemed to be a significant risk factor for the occurrence of CLNM in PTC and may promote lymphatic metastasis in PTC.

Iodine nutrition among the adult population of the Faroe Islands – a population-based study

The World Health Organization recommends monitoring iodine status in all populations with median urinary iodine concentration below 100 µg/L suggesting iodine deficiency. There are no data on the iodine intake among the population of the Faroe Islands. This study aimed to provide data on iodine nutrition in a representative sample of the general adult population from the Faroe Islands. We conducted a population-based cross-sectional survey in 2011-2012 and measured iodine in urine from 491 participants (294/197 men/women) using the ceri/arsen method after alkaline ashing. Participants include around 100 subjects in each of four adult decades and included participants from both the capital city and villages. The median urinary iodine concentration was low within the recommended range 101 µg/L (range 21-1870 µg/L). No samples were in the range suggesting severe iodine deficiency, but half of the samples were in the range of just adequate or mildly insufficient iodine intake with urinary iodine concentration markedly lower in women than in men (86 versus 115 µg/L; P<0·001). Intake of fish and whale meals affected the urinary iodine concentrations. In conclusion, nearly half of the population had an iodine excretion in the range of borderline or mild iodine deficiency. The lowest iodine nutrition level among Faroese women is a concern as it may extend to pregnancy with increased demands on iodine nutrition. In addition, we found large variations and the intermittently excessive iodine intakes warrants follow-up on thyroid function in the population of the Faroe Islands.