Iodine Sufficiency Research Articles

Thyroid-Stimulating Hormone Reference Ranges in the First Trimester of Pregnancy in an Iodine-Sufficient Country.

BackgroundThyroid dysfunction is associated with negative neonatal and obstetric outcomes. Large differences in thyroid function reference intervals exist across different populations. These differences can be explained by population-specific factors, such as iodine status. Many countries in Latin America report iodine sufficiency, but relatively few countries have published up-to-date data on iodine levels and thyroid function in the overall population, and especially in pregnant women. We evaluated the iodine status of pregnant women in Chile and determined thyroid hormone reference ranges in this population.MethodsThis was a prospective observational study of healthy Chilean women at their first prenatal visit before week 14. Thyroid-stimulating hormone (TSH), total thyroxine (T4), free T4, antithyroid peroxidase antibody (TPOAb), and iodine levels from spot urine samples were measured. Iodine status and the reference ranges for TSH were calculated.ResultsA total of 1,022 pregnant women in the first trimester were selected. Urinary iodine levels were measured in 302 randomly-selected women. The median urinary iodine concentration was 173.45 µg/L (interquartile range, 108.11 to 249.35).The reference ranges of TSH were calculated in 670 patients selected according to the National Academy of Clinical Biochemistry guidelines. The median TSH level was 1.88 µIU/mL (2.5th percentile: 0.13 to 97.5th percentile: 5.37). Using the reference range in the 1,022 women, the prevalence of clinical hypothyroidism was 1.76%, and that of subclinical hypothyroidism was 3.92%. TPOAb positivity was more common in women with TSH levels above 3.5 µIU/mL.ConclusionWe found adequate iodine intake and a right-shifted distribution of serum TSH levels in pregnant women in Chile. The prevalence of hypothyroidism in our sample of pregnant women was higher than has been described in the literature.

Reduced Educational Outcomes Persist into Adolescence Following Mild Iodine Deficiency in Utero, Despite Adequacy in Childhood: 15-Year Follow-Up of the Gestational Iodine Cohort Investigating Auditory Processing Speed and Working Memory.

There is increasing evidence that even mild gestational iodine deficiency (GID) results in adverse neurocognitive impacts on offspring. It’s unclear, however, if these persist long-term and whether they can be ameliorated by iodine sufficiency in childhood. We followed a unique cohort (Gestational Iodine Cohort, n = 266) where gestation occurred during a period of mild population iodine deficiency, with children subsequently growing-up in an iodine replete environment. We investigated whether associations between mild GID and reductions in literacy outcomes, observed at age 9-years, persisted into adolescence. Comparisons were made between offspring of mothers with gestational urinary iodine concentrations (UICs) ≥ 150 μg/L and < 150 μg/L. Educational outcomes were measured using Australian National Assessment Program—Literacy and Numeracy (NAPLAN) tests. Children whose mothers had UICs < 150 μg/L exhibited persistent reductions in spelling from Year 3 (10%, −41.4 points (95% Confidence Interval −65.1 to −17.6, p = 0.001)) to Year 9 (5.6%, −31.6 (−57.0 to −6.2, p = 0.015)) compared to children whose mothers had UICs ≥ 150 μg/L. Associations remained after adjustment for biological factors, socioeconomic status and adolescent UIC. Results support the hypothesis that mild GID may impact working memory and auditory processing speed. The findings have important public health implications for management of iodine nutrition in pregnancy.

Urinary Iodine, Perchlorate, and Thiocyanate Concentrations in U.S. Lactating Women.

Iodine is an essential micronutrient for thyroid hormone production. Adequate iodine intake and normal thyroid function are important during early development, and breastfed infants rely on maternal iodine excreted in breast milk for their iodine nutrition. The proportion of women in the United States of childbearing age with urinary iodine concentration (UIC) <50 μg/L has been increasing, and a subset of lactating women may have inadequate iodine intake. UIC may also be influenced by environmental exposure to perchlorate and thiocyanate, competitive inhibitors of iodine transport into thyroid, and lactating mammary glands. Data regarding UIC in U.S. lactating women are limited. To adequately assess the iodine sufficiency of lactating women and potential associations with environmental perchlorate and thiocyanate exposure, we conducted a multicenter, cross-sectional study of urinary iodine, perchlorate, and thiocyanate concentrations in healthy U.S. lactating women. Lactating women ≥18 years of age were recruited from three U.S. geographic regions: California, Massachusetts, and Ohio/Illinois from November 2008 to June 2016. Demographic information and multivitamin supplements use were obtained. Iodine, perchlorate, and thiocyanate levels were measured from spot urine samples. Correlations between urinary iodine, perchlorate, and thiocyanate levels were determined using Spearman's rank correlation. Multivariable regression models were used to assess predictors of urinary iodine, perchlorate, and thiocyanate levels, and UIC <100 μg/L. A total of 376 subjects (≥125 from each geographic region) were included in the final analyses [mean (SD) age 31.1 (5.6) years, 37% white, 31% black, and 11% Hispanic]. Seventy-seven percent used multivitamin supplements, 5% reported active cigarette smoking, and 45% were exclusively breastfeeding. Median urinary iodine, perchlorate, and thiocyanate concentrations were 143 μg/L, 3.1 μg/L, and 514 μg/L, respectively. One-third of women had UIC <100 μg/L. Spot urinary iodine, perchlorate, and thiocyanate levels all significantly positively correlated to each other. No significant predictors of UIC, UIC <100 μg/L, or urinary perchlorate levels were identified. Smoking, race/ethnicity, and marital status were significant predictors of urinary thiocyanate levels. Lactating women in three U.S. geographic regions are iodine sufficient with an overall median UIC of 143 μg/L. Given ubiquitous exposure to perchlorate and thiocyanate, adequate iodine nutrition should be emphasized, along with consideration to decrease these exposures in lactating women to protect developing infants.

Dual-Energy CT: Balance Between Iodine Attenuation and Artifact Reduction for the Evaluation of Head and Neck Cancer.

Dual-energy computed tomography high energy virtual monochromatic images (VMIs) can reduce artifact but suppress iodine attenuation in enhancing tumor. We investigated this trade-off to identify VMI(s) that strike the best balance between iodine detection and artifact reduction. The study was performed using an Alderson radiation therapy phantom. Different iodine solutions (based on estimated tumor iodine content in situ using dual-energy computed tomography material decomposition) and different dental fillings were investigated. Spectral attenuation curves and quality index (QI: 1/SD) were evaluated. The relationship between iodine attenuation and QI depends on artifact severity and iodine concentration. For low to average concentration solutions degraded by mild to moderate artifact, the iodine attenuation and QI curves crossed at 95 keV. High energy VMIs less than 100 keV can achieve modest artifact reduction while preserving sufficient iodine attenuation and could represent a useful additional reconstruction for evaluation of head and neck cancer.

The Impact of Iodine Status on the Recall Rate of the Screening Program for Congenital Hypothyroidism: Findings from Two National Studies in Iran.

Back ground: Iodine deficiency is one of the important factors in increasing the recall rate in congenital hypothyroidism (CH) screening programs. The present study assessed whether the iodine status of the general population may predict the recall rate or vice versa. Methods: In the current national study, among 1,382,229 live births delivered between March 2010 and March 2011, 1,288,237 neonates were screened for detecting CH by TSH (thyroid stimulating hormone) measurement via heel prick sampling. Simultaneously, a total of 11,280 school-aged children, aged 7–8 years, were selected using random multi-cluster sampling for measurement of urinary iodine. Results: A negative correlation was found between median urinary iodine (MUI) and the recall rate (r = −0.33, p = 0.03). No correlation was found between MUIC (median urinary iodine concentration) and the incidence rate of CH. Linear regression analysis showed a 0.1% increase in the recall rate for a one unit decrease in MUIC (β = −0.11, 95% CI: −0.2, −0.1, p = 0.03). MUIC, at a cut-off point of 144.7 µg/L, was predictive for a recall rate < 3% (p = 0.05). Conclusion: Frequencies of TSH ≥ 5 mU/L may be a more sensitive indicator for iodine status during pregnancy rather than in the general population. As higher recall rates reflect inadequate iodine nutrition, sufficient iodine supplementation is needed to reduce the recall rate in such communities.

Review of Iodine Nutrition in Iranian Population in the Past Quarter of Century.

ContextIodine deficiency is one of the most important health problems worldwide. The overall aim of this study was a narrative review of the past and present status of iodine nutrition in the Iranian population to gather and provide valuable background data in this field for future studies.Evidence AcquisitionFor this narrative literature review study, published internal (SID, Iran doc, Iran medex) and international (Web of knowledge, Pubmed, SCOPUS) source studies were searched using the following medical subject heading terms: Iodine, IDD (iodine deficiency disorders), UIC (urinary iodine concentration), Goiter, IQ (intelligence quotient), thyroid hormone, Iodine and pregnancy, Iodine and breast feeding, as well as Iodized salt, reporting the prevalence of iodine deficiency and iodine nutrition status of different target populations in Iran over 25 years, between 1988 - 2014, were assessed. We found 185 abstracts by literature search, of which, 161 papers that were as case reports, animal study, with lack of regional or national data were excluded after full text evaluation. Finally 24 full papers covering regional or national data on iodine nutrition of the study population were eligible for our review.ResultsIodine deficiency, as a nutritional problem, had been identified in Iran since 1968. In the years 1987 - 1989, a few studies were done to define the prevalence of iodine deficiency in the country. The first nation-wide survey was performed in 14 provinces. Based on this survey all provinces were suffering of endemic goiter. In 1989, iodine deficiency was recognized as a major problem for community health. In 1990, salt factories began to produce iodized salt and in 1996, the second national survey was performed in 26 provinces. This survey indicated that 40% of boys and 50% of girls have goiter, with a median urinary iodine excretion of 205 µg/L. The 3rd national survey in 2001 showed that the total goiter rate is 9.8% and median UIC of 165 μg/L. In 2007, the 3th national survey was conducted 17 years after iodized salt consumption by Iranian households. In this study the total goiter rate and median urinary iodine was 5.7% and 145 μg/L, respectively. The 5th national survey conducted in 2013, showed household consumption of iodized salt for all provinces was 98% and the median urinary iodine of school children was 161 μg/L. Following the 5th national survey, the 1st national survey of the iodine status and thyroid function of pregnant women, conducted in 10 provinces in the different region of the country, documented a median UIC for pregnant women of 87.3 µg/L, results of this national survey clarified that despite iodine sufficiency of school children in Iran, pregnant women have moderate iodine deficiency and need iodine supplementation.ConclusionsThe success of iodine deficiency control program depends on well designed programmatic steps and mandatory iodized salt consumption in certain situations. The iodine intake of school children is sufficient, however, Iranian pregnant women are suffering from moderate iodine deficiency and need iodine supplementation.

Evaluation of serum ferritin and thyroid function in the second trimester of pregnancy.

Ferritin is a universal intracellular protein that acts as an iron carrier. Several studies have indicated that iron deficiency affects thyroid function in non-pregnant women. Our objective was to assess the relationship between serum ferritin levels and thyroid function in pregnant women during the second trimester. Pregnant women with sufficient iodine intake and normal antithyroid antibodies during the second trimester were recruited from the obstetric outpatient department of the Fifth People's Hospital of Fudan University. Serum ferritin (SF) levels, thyroid function, anti-thyroid antibodies and vitamin B12 were determined by electrochemiluminescence immunoassay kit. Maternal serum iron (Fe), unsaturated iron binding capacity (UIBC), hemoglobin (Hb), creatinine (Cr), fasting blood glucose (FBG), and alanine aminotransferase (ALT) were also evaluated. Stepwise regressions performed to evaluate the associations between SF and other maternal parameters. In the second trimester, 11.4% pregnant women had a SF concentration less than 12 μg/L, and 7.6% pregnant women were anemic. SF levels were negatively correlated with serum TSH levels (r = -0.219, p < 0.05), and positively correlated with FT4 levels (r = 0.203, p < 0.05). Linear regression analysis showed only SF, age, week of gestation were significant predictors of regression with TSH as the dependent variable (β: -0.007, -0.059, and 0.118 respectively; all p < 0.05). However consistent relation between the SF levels and FT4 was not observed in stepwise linear regression. Maternal iron status is a determinant of TSH concentrations during pregnancy in pregnant women during the second trimester.

Hypothyroidism among females and differences in their dietary patterns and urinary iodine concentrations compared to normal subjects

Thyroid disorders are among the most common endocrine disorders in India. Hypothyroidism is a very common condition. The condition is more common in women than in men, and its incidence increases with age. For the present study 150 females of 21 to 50 years of age were selected via random sampling from Pantnagar area of Udham Singh Nagar District, Uttarakhand and were interviewed using a predesigned proforma. The subjects mainly belonged to middle and upper income groups. Among 150 subjects, 30 were found to be suffering from hypothyroidism of which six were the newly diagnosed cases who had not started medications. Subjects were assessed for their dietary intakes and differences in the food habits based on food avoidance, food preferences, dietary habits and dietary diversity scores. Based on the analysis of the dietary intakes of normal (n=120) and hypothyroid (n=30) subjects not much difference was found, as was also evident from the dietary diversity scores (where non-significant difference was observed) except for in case of some dietary habits which showed significant differences. The mean dietary diversity scores of hypothyroid and normal subjects were 5.8±0.88 and 6.0±0.90 respectively. Urine samples were also collected for the measurement of urinary iodine concentration of only 30 subjects which included six of the newly detected hypothyroid cases not on medication and the remaining 24 normal subjects. Only 2 hypothyroid subjects and 3 normal subjects were found to be suffering from mild iodine deficiency with values of urinary iodine ranging from 76.5 to 94.6µg/l. Median urine iodine excretion in the present study was 172 µg/l (mean 186.5±58.4 µg/l) indicating iodine sufficiency.

Evaluating of significance of thyroglobulin (Tg) level in blood as a biomarker of iodine deficiency disorders severity in Uzbekistan

Iodine deficiency has serious adverse effects on growth and development of humans, such as mental impairment. It is known, that thyroglobulin level in blood is promising biomarker that can determine iodine deficiency disorders severity in a given region.&#x0D; The Aim of study: Evaluating of significance of thyroglobulin level in blood as a biomarker of iodine deficiency disorders severity in Uzbekistan..&#x0D; Materials and Methods: We evaluated thyroglobulin level in blood in schoolchildren of Uzbekistan. In this purpose we studied 366 schoolchildren in 8-12 age group, of that 163 boys and 203 girls living in Tashkent city, Fergana, Samarkand, Bukhara, Kashkadarya, Khoresm and Republic of Karakalpakistan. Such parameters as urinary iodine concentration, diffuse goiter plasma TSH, fT4 were analyzed too.&#x0D; Results: Diffuse goiter prevalence was 27 % among children, the overall mean thyroglobulin concentration was 12,8 ± 10.4 ng/ml, the overall median urinary iodine concentration (UIC) was 120.27 μg/L indicating iodine sufficiency. Plasma TSH was 2.75 ± 1.69 mIU/l and plasma fТ4 14.48 ± 3,96 pmol/l. Thyroglobulin level depended on goiter size, so that in children without goiter (grade 0) mean thyroglobulin concentration was 11,9 ± 7.9 ng/ml, in children with goiter grade 1 mean thyroglobulin concentration was 14,24 ± 13.5 ng/ml and in children with goiter grade 2 mean thyroglobulin concentration was 18,82±18,3 ng/ml. Overall mean thyroglobulin concentration of goitrous children (grade 1 and 2) was 16,4±10,5 ng/ml.&#x0D; Conclusions: Though international studies in school-aged children showed that iodine-sufficient children typically had a median Tg &lt;13 ng/ml, our investigation showed that while study group’s UIC was 120.27 μg/L and overall mean thyroglobulin concentration was 12,8 ± 10.4 ng/ml, that is equal to median thyroglobulin concentration – 11,73 ng/ml, 39% of children in this group still have UIC below 100 μg/L.

Micronutrient status of population of the Russian Federation and possibility of its correction. State of the problem

Vitamin status of the working population (about 950 subjects) from Moscow region, Samara, Nizhny Novgorod, Arkhangelsk, Yamalo-Nenetsky Avtonomny Okrug has been evaluated in 2015-2016. The lack of vitamin D assessed by means of blood serum level determination was detected in 57.5% of the adults, B vitamins - in 12.6-34.5%, vitamins A and E - in 5.3-10.8%, carotene - in 67.3%. Multivitamin insufficiency (the lack of 3 or more vitamins) was found in 22-38% of adults. Micronutrient fortification of foods of mass consumption is a promising way to improve vitamin status of the population. The needs for vitamins in medical, food industry and agriculture are satisfied only by imports. Calculation of the quantity of imported vitamins substances, carried out on the basis of databases of the Federal Customs Service of Russia, showed that import volume of vitamins increased and amounted to 9920 tons (125 980 000 dollars) in 2016. The estimated total demand of food industry in vitamins (substances) for the production of vitamin-mineral supplements (at the rate of 1-month course per person per year), the inclusion of vitamin and mineral supplements in health nutrition in hospitals and the production of fortified foodstuffs (at the rate of 24 kg of flour per year per one person and milk - 50 kg/year per person) was about 2.5 thousand tons per year. The absence of vitamin synthesis in the Russian Federation is a problem for increasing of nutritive value and quality of food products. The urgent need to revive domestic production (synthesis) of vitamin substances has appeared. The use of iodized salt instead of noniodized salt in bread and bakery production automatically converted it into enriched foods, which could improve the iodine sufficiency of the population.

Suboptimal Iodine Concentration in Breastmilk and Inadequate Iodine Intake among Lactating Women in Norway.

Breastfed infants depend on sufficient maternal iodine intake for optimal growth and neurological development. Despite this, few studies have assessed iodine concentrations in human milk and there is currently no published data on iodine status among lactating women in Norway. The aim of this study was to assess iodine concentrations in breast milk (BMIC) in lactating women and estimate iodine intake. Five Mother and Child Health Centres in Oslo were randomly selected during 2016, and 175 lactating women between 2nd and 28th weeks postpartum participated. Each of the women provided four breastmilk samples which were pooled and analysed for iodine concentrations. Participants also provided information on iodine intake from food and supplements covering the last 24 h and the habitual iodine intake (food frequency questionnaire). The median (p25, p75 percentiles) BMIC was 68 (45, 98) µg/L and 76% had BMIC <100 µg/L. Only 19% had taken an iodine-containing supplement during the last 24 h. The median 24 h iodine intake from food (p25, p75) was 121 (82, 162) µg/day and the total intake (food and supplements) was 134 (95, 222) µg/day. The majority of lactating women had suboptimal BMIC and inadequate intake of iodine from food and supplements.

Iodine Deficiency Disorder Among Filipino School Children, Pregnant and Lactating Women and the Elderly 20 Years After the Act for Salt Iodization Nationwide Law

Background: Iodine deficiency disorder (IDD) is still a public health problem globally. In response to this, universal salt iodization (USI) has been implemented. This is the most cost-effective strategy to prevent and control it. In the Philippines, an Act for Salt Iodization Nationwide (ASIN Law) was passed in 1995, in response to the increasing goiter rates. This paper describes the prevalence and severity of IDD among Filipino school-aged children (SAC), pregnant and lactating women and the elderly, 20 years after the implementation of the ASIN Law. Methods: Casual urine samples were collected from SAC, pregnant and lactating women and elderly of 1998, 2003, 2008 and 2013, of selected households of the National Nutrition Survey (NNS). Urinary iodine (UI) levels were determined using the acid digestion method. UI levels and prevalence of IDD in the 2013 NNS were compared with those in previous NNSs. Results: Iodine nutrition among the SAC has improved from mild deficiency with a median of 71 ug/L in 1998 to 201 ug/L in 2003. It has remained “optimal” till the 2013 NNS, almost 20 years after ASIN Law. UI was 107 ug/L among the elderly in 2008, but decreased to 80 ug/L in 2013, also indicating “mild” iodine deficiency. Among the lactating women, UI was 111 ug/L in 2003, indicating iodine sufficiency, but decreased to 81 and 77 ug/L in 2008 and 2013 NNS, respectively, indicating “mild” iodine deficiency. Median UI among the pregnant women was 142, 105 and 105 ug/L, also indicating the presence of IDD for the 2003, 2008 and 2013 NNS, respectively. Conclusion: Twenty years after ASIN Law, Filipino SAC have achieved optimum iodine status while the pregnant and lactating women and the elderly remain to be iodine deficient. Strict monitoring of iodization of salt at the production site should be implemented, since iodine levels in salt have remained at levels below the standard. J Endocrinol Metab. 2017;7(3):86-93 doi: https://doi.org/10.14740/jem414w

Iodine Storage and Metabolism of Mild to Moderate Iodine-Deficient Pregnant Rats.

Severe iodine deficiency during pregnancy results in neurodevelopmental disorders in children, while the consequences of mild to moderate iodine deficiency (MMID) are uncertain. The concentration of iodine in the thyroid is the most accurate indicator of iodine nutrition. This study aimed to evaluate whether the iodine stores in the thyroid cover the needs of the mother and the fetus in iodine-sufficient and MMID conditions by inductively coupled plasma-mass spectrometry. One hundred four-week-old female Wistar rats were randomly divided into MMID (low iodine intake [L]) and normal (normal iodine intake [N]) groups. The rats were fed for the next three months, and after pregnancy they were further divided into two subgroups, respectively: low iodine pregnancy (LP) and low iodine pregnancy with iodine supplement (LP+), and normal iodine intake pregnancy (NP) and normal iodine intake pregnancy with iodine supplement (NP+). The iodine intake of pregnant rats in the NP+ and LP+ groups was twice as much as in the NP and LP groups. The rats were sacrificed on gestational day 15 and postnatal day 7. The iodine concentration in the thyroid of the maternal and newborn rats, maternal serum, placenta, and amniotic fluid were determined by inductively coupled plasma-mass spectrometry. The concentration of iodine in the thyroid of the N group was significantly higher than that in the L group before pregnancy. The concentration of iodine in the maternal thyroids of the LP group decreased during pregnancy, whereas that of the NP group did not change significantly. There was no significant difference in the iodine concentration in the thyroid of mothers and offspring between the NP and NP+ groups, but it was significant between LP and LP+ groups. The concentration of iodine in amniotic fluid was significantly different between the four groups. There is sufficient iodine storage in the thyroid of maternal rats with normal iodine intake during pregnancy, and there is no need for iodine supplementation. However, iodine stores are insufficient in rats with MMID. Iodine supplementation can increase the iodine concentration in the thyroid of maternal rats with MMID and their offspring, as well as in the amniotic fluid during pregnancy.

Urinary iodine in early pregnancy is associated with subclinical hypothyroidism in Tianjin, China: an observational study

BackgroundSubclinical hypothyroidism (SH) is associated with adverse obstetric outcomes and neurodevelopment disorders. Both iodine deficiency and excess are associated with SH; however, few data regarding iodine nutrition status of pregnant women with SH are available. This study aimed to clarify whether iodine deficiency or excess is associated with SH, especially, when test results for anti-thyroid autoantibodies are negative.MethodsA total of 115 women with SH and 104 women with euthyroidism (EH) in early pregnancy in Tianjin, China were investigated, and their serum thyroid-stimulating hormone, free thyroxine, free triiodothyronine, anti-thyroid peroxidase antibody (TPOAb), anti-thyroid globulin antibody (TGAb), urinary iodine (UIC), and urinary creatinine (UCr) concentrations were measured. Thyroid ultrasonography was performed to determine thyroid echogenicity and volume. The UIC, UIC/UCr ratio, prevalence of TPOAb and TGAb positivity, and thyroid gland volume were compared between the EH and SH groups. UIC and ultrasonographic features were analysed in subjects in the SH group who were negative for TPOAb and TGAb.ResultsMedian UIC of SH (154.0 μg/L) and EH (150.1 μg/L) met the World Health Organization criterion for iodine sufficiency in pregnant women. Neither UIC nor the UIC/UCr ratio differed significantly between groups. The prevalence of TPOAb and TGAb positivity in the SH group was significantly higher than that in the EH group (P < 0.01). The percentage of subjects with UIC ≥ 250 μg/L in the SH group was significantly higher than that in the EH group (p = 0.004). The percentage of subjects negative for autoantibodies and UIC ≥ 250 μg/L in the SH group tended to be higher than that in subjects in the EH group negative for autoantibodies, but the difference was not statistically significant (p = 0.025, adjusted test level α = 0.0167). Eight of 18 subjects in the SH group with negative results for TPOAb and TGAb were diagnosed with Hashimoto thyroiditis by means of thyroid ultrasonography.ConclusionsWomen in early pregnancy with SH in Tianjin were iodine sufficient, but still at risk of iodine deficiency as pregnancy progressed. UIC ≥ 250 μg/L was associated with increased risk of SH. Serological negative autoimmune thyroiditis and UIC ≥ 250 μg/L may play a role in pathogenesis of SH cases with negative results for autoantibodies.

Application of povidone-iodine at delivery significantly increases maternal urinary iodine but not neonatal thyrotropin in an area with iodine sufficiency.

The aim of the present study was to investigate the effect of povidone-iodine (PVP-I) application at delivery on maternal urinary iodine concentration (UIC) and neonatal thyrotropin concentration. In this cross-sectional study, urine samples were collected from each pregnant woman after admission to the hospital and before routine application of the PVP-I for delivery preparation and after delivery at time of screening for congenital hypothyroidism. A heel-prick blood sample was taken from all newborns. A total of 394 pregnant women at time of delivery participated in this study. Median (interquartile range [IQR]) maternal UIC values were 120 (105-157) and 253 (126-470) μg/L before and after delivery, respectively (p<0.001). No significant correlations were observed between maternal UIC before and after delivery and neonatal thyrotropin levels. Application of PVP-I significantly increased UIC in postpartum mothers; however, thyrotropin concentration in neonates, whose mothers had adequate UIC, was within the normal range.

Monitoring the effects of iodine prophylaxis in the adult population of southern Italy with deficient and sufficient iodine intake levels: a cross-sectional, epidemiological study.

I prophylaxis is the most effective strategy to eradicate I deficiency disorders, but it has been shown to affect the thyroid disease pattern. In this study, we assessed the frequency of thyroid disorders in an adult population living in two areas of southern Italy after implementing I prophylaxis. To this aim, a cross-sectional, population-based study including 489 subjects from an I-deficient rural and an I-sufficient urban area of southern Italy was conducted. Thyroid ultrasound was performed on all participants, and urine and blood samples were collected from each subject. The levels of thyroid-stimulating hormone (TSH), thyroglobulin (TgAb) and thyroperoxidase antibodies (TPOAb), urinary I excretion (UIE), and thyroid volume and echogenicity were evaluated. We found that the median UIE was higher in the urban than in the rural area (P=0·004), whereas the prevalence of subjects affected by goitre was higher in the rural compared with the urban area (P=0·003). Positive TgAb rather than TPOAb were more frequent in subjects from the urban area compared with the rural area (P=0·009). The hypoechoic pattern at thyroid ultrasound (HT-US) was similar between the two areas, but TgAb were significantly higher (P=0·01) in HT-US subjects from the urban area. The frequency of elevated TSH did not differ between the two screened populations, and no changes were found for TgAb positivity in subjects with high TSH in the urban compared with the rural area. Our findings support that the small risks of I supplementation are far outweighed by the substantial benefits of correcting I deficiency, although continued monitoring of populations is necessary.

Iodine Deficiency Disorder Among Filipino School Children, Pregnant and Lactating Women and the Elderly 20 Years After the Act for Salt Iodization Nationwide Law

Background: Iodine deficiency disorder (IDD) is still a public health problem globally. In response to this, universal salt iodization (USI) has been implemented. This is the most cost-effective strategy to prevent and control it. In the Philippines, an Act for Salt Iodization Nationwide (ASIN Law) was passed in 1995, in response to the increasing goiter rates. This paper describes the prevalence and severity of IDD among Filipino school-aged children (SAC), pregnant and lactating women and the elderly, 20 years after the implementation of the ASIN Law. Methods: Casual urine samples were collected from SAC, pregnant and lactating women and elderly of 1998, 2003, 2008 and 2013, of selected households of the National Nutrition Survey (NNS). Urinary iodine (UI) levels were determined using the acid digestion method. UI levels and prevalence of IDD in the 2013 NNS were compared with those in previous NNSs. Results: Iodine nutrition among the SAC has improved from mild deficiency with a median of 71 ug/L in 1998 to 201 ug/L in 2003. It has remained “optimal” till the 2013 NNS, almost 20 years after ASIN Law. UI was 107 ug/L among the elderly in 2008, but decreased to 80 ug/L in 2013, also indicating “mild” iodine deficiency. Among the lactating women, UI was 111 ug/L in 2003, indicating iodine sufficiency, but decreased to 81 and 77 ug/L in 2008 and 2013 NNS, respectively, indicating “mild” iodine deficiency. Median UI among the pregnant women was 142, 105 and 105 ug/L, also indicating the presence of IDD for the 2003, 2008 and 2013 NNS, respectively. Conclusion: Twenty years after ASIN Law, Filipino SAC have achieved optimum iodine status while the pregnant and lactating women and the elderly remain to be iodine deficient. Strict monitoring of iodization of salt at the production site should be implemented, since iodine levels in salt have remained at levels below the standard. J Endocrinol Metab. 2017;7(3):86-93 doi: https://doi.org/10.14740/jem414w

Histologic pattern of thyroid disorders in Southern Kerala

Since the implementation of universal salt iodization in 1986, India is said to be in the transition phase from iodine deficiency to iodine sufficiency, and this is expected to change the spectrum of thyroid disorders in the country. Materials and Methods: A retrospective study of 246 biopsy specimens of subtotal/total/hemi thyroidectomy cases done during a period of 6 years from 2007 to 2012 at a tertiary hospital in Trivandrum, Kerala, is analyzed. Results: Thyroidectomy specimens accounted for 3.2% of the total surgical specimens received during the study period. Among the 246 thyroidectomy specimens, nodular colloid goiter (NCG) with or without other associated thyroid lesions outnumbered other disorders accounting for a total of 142 cases (58%) followed by 90 cases of autoimmune thyroiditis (AIT) with or without other thyroid lesions (37%). Dual lesions such as AIT with colloid goiter (7 cases, 3%), AIT with tumors (45 cases, 18%), and NCG with tumors (40 cases 16%) were also noted. The presence of tumors was found in 106 cases (43%). The overall incidence of malignancy was 36%. Forty-one cases of AIT and 36 cases of NCG were associated with papillary thyroid carcinoma (PTC) (46% and 25%, respectively); the difference was statistically significant ( P = 0.01). Conclusions: This study showed that the incidence of AIT and associated PTC is high, and the role of iodine or any other goitrogens in triggering or enhancing the onset and development of AIT in this area deserves further study.

Iodine status of pregnant women in South Australia after mandatory iodine fortification of bread and the recommendation for iodine supplementation.

Mandatory iodine fortification of bread was introduced in 2009 in Australia in response to the reemergence of iodine deficiency. The aim of this study was to assess iodine intake, urinary iodine concentration (UIC) and their correlation in pregnant women (n=783) recruited from South Australia 2years following mandatory iodine fortification. Total iodine intake (food and supplements) and UIC were assessed at study entry (<20weeks') and at 28weeks' gestation. Mean (±SD) total iodine intake at study entry and 28weeks' gestation was 307±128μg/day and 300±127μg/day, respectively. Overall, 85.9% of women met the estimated average intake (≥160μg/day) for iodine in pregnancy, but only 44.5% met the estimated average intake from food alone. The main food sources of iodine were dairy foods and iodine-fortified bread. Median (interquartile range) UIC at study entry and 28weeks' gestation was 189μg/L and 172μg/L, respectively. At study entry, median UIC was higher in women taking supplements containing iodine ≥150μg/day compared with those containing iodine <150μg/day (221μg/L vs. 163μg/L, p=.003) and those not taking supplements containing iodine (221μg/L vs. 159μg/L, p<.001). At 28weeks' gestation, the median UIC for the groups was 187, 152 and 141μg/L, respectively (each of the two comparisons yielded p<.001). Total iodine intake (food and supplements) from all women was positively, though weakly, correlated with UIC (r=.23, p<.001). In conclusion, pregnant women in South Australia are iodine sufficient postmandatory iodine fortification of bread. However, without iodine supplementation, it may be difficult to achieve a UIC >150μg/L.

Neonatal thyrotropin concentration and iodine nutrition status of mothers: a systematic review and meta-analysis

Background: Low maternal iodine intake disturbs the thyroid function of neonates transiently or permanently.Objective: To our knowledge, we conducted one of the first systematic reviews and meta-analyses aimed at exploring the association of neonatal thyrotropin concentrations and iodine status of mothers during pregnancy and early postpartum periods.Design: Data were collected through literature searches for studies published between 1969 and 2015 with the use of electronic databases. Mean or median maternal urinary iodine and neonatal thyrotropin concentrations, along with other relevant data, were extracted from eligible studies. The quality and risk of bias of each study was assessed.Results: A random-effects model was used for the analysis. Of 110 studies identified, 25 trials were shown to be eligible for inclusion in the meta-analysis. Mean (95% CI) thyrotropin concentrations of neonates born to mothers with iodine deficiency were higher than in neonates born to mothers with iodine sufficiency during pregnancy in both heel blood samples [1.79 mIU/L (95% CI: 1.61, 1.97 mIU/L) compared with 1.75 mIU/L (95% CI: 1.68, 1.82 mIU/L), respectively] and cord blood samples [11.91 mIU/L (95% CI: 6.67, 17.14 mIU/L) compared with 6.15 mIU/L (95% CI: 4.30, 8.01 mIU/L), respectively]. There were no significant differences in neonatal thyrotropin concentrations of heel samples between mothers with iodine deficiency and those with sufficiency during the early postpartum period; however, the values of thyrotropin in cord samples of neonates born to mothers with iodine deficiency were significantly higher than in neonates born to mothers with iodine sufficiency [11.62 mIU/L (95% CI: 10.47, 12.77 mIU/L) compared with 7.40 mIU/L (95% CI: 6.21, 8.59 mIU/L)].Conclusion: Our findings reveal that, compared with heel blood samples, neonatal thyrotropin in samples collected from the cord are more sensitive to the iodine status of mothers; however, further investigations are required in this regard.