Iodine-deficient Countries Research Articles

Approach to Newborns with Elevated TSH: A Different Perspective from the International Guidelines for Iodine-Deficient Countries.

Lowering of thyroid-stimulating hormone (TSH) cutoffs in newborn screening programs has created a management dilemma by leading to more frequent detection of neonates with elevated TSH concentrations due to false-positive results, transient neonatal hyperthyrotropinemia (NHT), and milder forms of congenital hypothyroidism. Current consensus guidelines recommend starting treatment if the venous TSH level is >20 mU/l in the face of a normal free thyroxin (FT4) level, which is an arbitrary threshold for treatment decisions. In countries such as Türkiye, where transient NHT may be more common due to iodine deficiency and/or overload, putting this recommendation into daily practice may lead to unnecessary and over treatments, long-term follow-ups, and increased workload and costs. In this review, we addressed alternative approaches for infants with elevated TSH concentrations detected at newborn screening. Our management approach can be summarized as follows: Infants with mild NHT (TSH<20 mU/l) should be followed without treatment. In moderate NHT (TSH 20-30 mU/l), treatment or monitoring decisions can be made according to age, TSH trend and absolute FT4 level. Moderate cases of NHT should be treated if age at confirmatory testing is >21 days or if there is no downward trend in TSH and FT4 level is in the lower half of age-specific reference range in the first 21 days. In in-between cases of moderate NHT, thyroid ultrasound can guide treatment decision by determining mild cases of thyroid dysgenesis that require life-long treatment. Otherwise, monitoring is a reasonable option. Infants with compensated hypothyroidism (TSH>30 mU/l) and persistent hyperthyrotropinemia (>6-10 mU/l after neonatal period) should receive L-thyroxine treatment. But all treated cases of isolated TSH elevation should be closely monitored to avoid overtreatment, and re-evaluated by a trial off therapy. This alternative approach will largely eliminate unnecessary treatment of infants with transient NHT, mostly caused by iodine deficiency or excess, and will reduce workload and costs by preventing unwarranted investigation and long-term follow-up.

Iodine deficiency and prevalence of nodular goitre in Ukraine

More than one tenth of the world population is to some degree affected by goitre and most of these harbour nodules. The large differences in thyroid disease prevalence between populations may be caused by genetic and environmental factors. Among the latter, iodine deficiency seems by far to be the most important risk factor. Thus, nodular goitre is a condition predominantly seen in iodine deficient areas of the world. Large thyroid volumes and high frequencies of goitres have been reported in countries affected by iodine deficiency. In the present review, we evaluated prevalences of thyroid nodules in iodine-deficient countries. In 2016 in Ukraine the prevalence of nodular goiter was 707.8 per 100 thousand population, then after 5 years the figure slowly increased to 891.5 cases, respectively (+25.9%). The existing high indices of newly diagnosed patients with nodular goitre in the country in 2016 were 71.9, and at the end of 2020— 90.2 initially established cases per 100 thousand population, with a positive increase of +25.5%. In the Whickham survey, 20% of women and 5% of men who had goitres in the initial survey showed no evidence of goitre in a follow-up survey. An average growth rate in the multinodular goitre of 5–20% was reported in iodine-sufficient areas. On the basis of the results of the Framingham survey, the estimated lifetime risk for developing a nodule is 5–10%. Thyroid nodule size can increase, decrease, or remain stable, and thyroid nodules may eventually also disappear over time. Solid nodules more frequently increase, whereas cystic nodules can shrink or disappear. If the goitre has been present for some time, autonomous function of the nodules and eventually hyperthyroidism develop. The rate of progression from euthyroidism to subclinical and overt hyperthyroidism is about 10%.

2013 Iodine Nutrition in Africa: An Update for 2014

The elimination of iodine deficiency and its serious consequences, called the iodine deficiency disorders (IDD), are among the health priorities of most countries in the world. These IDDs include impaired mental development, adverse effects on growth, infant mortality, hypothyroidism, reproductive failure, and endemic goitre, which may lead to decreased educability, apathy, and reduced work capacity and may ultimately result in impaired social and economic development. Salt iodization programs in approximately 150 countries have markedly improved the global iodine nutritional status over the past decade. This is reflected in the decrease in the number of iodine-deficient countries worldwide fr om 54 in 2003 to 47 in 2007 and then to 32 in 2011.3 Despite remarkable progress, the successes have been regionally variable, with some regions showing little progress. Against the background of a general global improvement in iodine status and a marked improvement in four of the six WHO regions since 2003, the trend in Africa indicated a small decrease in the proportion of school-age children (SAC) with insufficient iodine intake as judged by urinary iodine concentration (UIC) below 100 μg/L, while the number of African SAC with insufficient iodine intake remained the same between 2007 and 2011.

Exploration of the optimal range of urinary iodine concentration in Chinese pregnant women in mildly iodine-deficient and -sufficient areas.

There is some uncertainty about the optimal ranges for urinary iodine concentration (UIC) during pregnancy. This study aimed to explore associations between maternal UIC and thyroid function in iodine sufficient and mildly iodine deficient areas. It was a cross-sectional study in which 1461 healthy pregnant women were enrolled to collect their blood and urine samples during their routine antenatal care in Tianjin and Wuqiang, China. Wuqiang was a mildly iodine-deficient region, while Tianjin was iodine sufficient. UIC, free triiodothyronine (FT3), free thyroid hormone (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), serum iodine concentration (SIC) including total serum iodine concentration (tSIC) and non-protein bound serum iodine concentration (nbSIC) were assessed during the routine antenatal care visits. The median UIC in pregnant women was 174 (113, 249) μg/L in Tianjin and 111 (63, 167) μg/L in Wuqiang, respectively. Compared with Tianjin, UIC, FT3 and TSH were lower, and FT4, tSIC, nbSIC, rates of TPOAb and TgAb positivity and the thyroid dysfunction rate (TDR) were higher in Wuqiang (P < 0.001). FT3, FT4, tSIC and nbSIC increased during pregnancy in Tianjin with increasing UIC, while only FT3 and nbSIC increased in Wuqiang (P < 0.05). In Tianjin, the TDR increased with UIC and peaked at UIC ≥ 500μg/L (P = 0.002), while in Wuqiang, the TDR showed a weak "U-shaped" relationship with UIC and the rate was lowest with UIC 100-149μg/L. In iodine-deficient areas, there was a lower TDR in pregnant women with UIC 100-149μg/L. We suspected that the optimal UIC criteria recommended by WHO may be a little high for pregnant women in mild-to-moderate iodine-deficient countries.

Low urinary iodine is a protective factor of central lymph node metastasis in papillary thyroid cancer: a cross-sectional study

BackgroundAn abrupt increase of thyroid cancer has been witnessed paralleling the supplemented iodine intake in formerly iodine-deficient countries. And increased iodine intake has been linked to the rising incidence rate of papillary thyroid cancer (PTC). However, the correlation between iodine and clinicopathological features of PTC has not been well-characterized. This study aimed to investigate the associations between iodine intake and the clinicopathological features of PTC patients.MethodsThree hundred and fifty-nine PTC patients who received surgical treatment in Peking Union Medical College Hospital from May 2015 to November 2020 were retrospectively reviewed. The associations between urinary iodine (UI), urinary iodine/creatinine ratio (UI/U-Cr), and the clinicopathological features of PTC were analyzed. Univariate and multivariate analysis were performed to investigate the relationship between UI level and central lymph node metastasis (CLNM).ResultsThere were no significant differences in UI in different groups according to the variables studied, except that patients with CLNM had higher UI level than CLNM(−) patients. No associations were found between UI/U-Cr and clinicopathological features except variant subtypes (classic/follicular). After dividing patients into high-iodine group and low-iodine group, more patients were found to have CLNM in the high-iodine group (p = 0.02). In addition, younger age, larger tumor size, and classic variant were positively correlated with CLNM (p < 0.05). Univariate analysis showed that insufficient iodine intake (≤ 99 μg/L) was associated with decreased CLNM risk in PTC. And after defining insufficient iodine intake as ≤ 109 μg/L and above requirements as ≥ 190 μg/L, multivariate analysis showed that lower iodine was associated with CLNM in total population of PTC (OR 0.53, 95% CI 0.31–0.91) and in PTC < 1 cm (papillary thyroid microcarcinoma, PTMC) (OR 0.43, 95% CI 0.21–0.87).ConclusionsLow iodine was a protective factor for CLNM in papillary thyroid cancer, particularly in those < 1 cm. These results indicated that iodine may not only be an initiator of tumorigenesis, but also a promoter of the development of PTC.

GLOBAL ENDOCRINOLOGY: Global perspectives in endocrinology: coverage of iodized salt programs and iodine status in 2020

Iodine deficiency has multiple adverse effects on growth and development. Diets in many countries cannot provide adequate iodine without iodine fortification of salt. In 2020, 124 countries have legislation for mandatory salt iodization and 21 have legislation allowing voluntary iodization. As a result, 88% of the global population uses iodized salt. For population surveys, the urinary iodine concentration (UIC) should be measured and expressed as the median, in μg/L. The quality of available survey data is high: UIC surveys have been done in 152 out of 194 countries in the past 15 years; in 132 countries, the studies were nationally representative. The number of countries with adequate iodine intake has nearly doubled from 67 in 2003 to 118 in 2020. However, 21 countries remain deficient, while 13 countries have excessive intakes, either due to excess groundwater iodine, or over-iodized salt. Iodine programs are reaching the poorest of the poor: of the 15 poorest countries in the world, 10 are iodine sufficient and only 3 (Burundi, Mozambique and Madagascar) remain mild-to-moderately deficient. Nigeria and India have unstable food systems and millions of malnourished children, but both are iodine-sufficient and population coverage with iodized salt is a remarkable 93% in both. Once entrenched, iodine programs are often surprisingly durable even during national crises, for example, war-torn Afghanistan and Yemen are iodine-sufficient. However, the equity of iodized salt programs within countries remains an important issue. In summary, continued support of iodine programs is needed to sustain these remarkable global achievements, and to reach the remaining iodine-deficient countries.

Iodine nutrition optimization: are there risks for thyroid autoimmunity?

Iodine deficiency is still the main cause of preventable thyroid disorders, worldwide. To optimize iodine intake, programs of voluntary or mandatory iodization of salt have been implemented in several iodine-deficient countries and iodine sufficiency has been achieved in many. Despite the clear beneficial effects on thyroid health, some concerns have been raised on the presumed detriment of iodine prophylaxis on thyroid autoimmunity. Very recent studies aimed at evaluating the long-term consequences of iodine supplementation on thyroid autoimmunity and related dysfunction, have clearly demonstrated that the early post-iodization increase in thyroid antibody positivity is largely transient and not clinically relevant, since the prevalence of overt thyroid dysfunction has remained reassuring low over two decades. The recommended iodine intake is therefore safe with regard to thyroid autoimmunity, the benefits largely outweighing the risks in a population with a stable median iodine concentration not exceeding 300μg/L. Thus, a possible increase in thyroid autoimmunity should not represent a limitation to promoting iodine supplementation in the general population, also taking into account the steady rise in prevalence of autoimmune disorders which has occurred in the last few decades because of environmental factors other than iodine.

Metastatic Follicular Thyroid Carcinoma Presenting as Thoracic Cord Compression

Follicular thyroid carcinoma (FTC) is an uncommon cancer and the incidence of FTC is higher in endemic areas of iodine deficiency or endemic goiter. Up until the 1990s Fiji was listed as an iodine deficient country. We report a rare case of a 53-year-old native Fijian man who presented to our hospital with spinal cord compression due to a metastatic deposit of an undiagnosed FTC. He underwent emergent neurosurgical treatment for his cord compression, with histology of the lesion at the level of T5 identifying metastatic FTC. Despite the emergent surgery, he did not have any neurological recovery. Total thyroidectomy confirmed the presence of a large left-sided FTC and the patient was assessed for radioactive iodine treatment. Nuclear medicine imaging revealed extensive distant bony metastatic disease. Unfortunately due to his significant distant disease burden, he was unable to undergo radioactive iodine ablation therapy. After significant allied health input he was discharged home with community palliative care input. J Med Cases. 2021;12(5):177-180 doi: https://doi.org/10.14740/jmc3658

Iodine deficiency disorders as a non-infectious epidemic: a look at the problem at the tome of COVID-19 pandemic

Radioactive iodine, flying out of the destroyed reactor of the Chernobyl nuclear power plant, like a corona virus quickly spread throughout Europe. Iodine deficiency in the regions of Ukraine, Belarus and Russia adjacent to nuclear power plants became a factor in increased uptake of radioactive iodine by the thyroid gland in children and after 5 years led to an epidemic of thyroid cancer. Optimal iodine intake could become a kind of vaccination, which sharply reduces the risk of developing thyroid cancer, as has happened after the accident at the Fukushima nuclear power plant in Japan. Endemic goiter was eliminated 50 years ago, but returned to the country in the early 1990s after the collapse of iodized salt production and has not been eliminated to this day due to the lack of a legislative framework for mandatory salt iodization. The actual average consumption of iodine by residents of Russia is from 40 to 80 mcg per day, which is 23 times less than the recommended norm. Mild and moderate iodine deficiency was detected throughout the Russian Federation, and it is more typical for the the rural population. The iodine deficiency has the greatest negative effect on the psychomotor development of the child during the critical period the first 1000 days of life from the moment of conception to the end of the second year of life. According to WHO, over the past 20 years, iodine deficiency has been eliminated in 115 countries of the world, and the number of iodine-deficient countries has dropped to 25, but Russia is still among them. We believe that after the COVID-19 pandemic, it will no longer be necessary to prove the need for effective support for the prevention of both infectious and non-infectious diseases, and the declared preventive direction of Russian medicine will indeed become such.

Determinants of iodine deficiency among school age children in Guraghe Zone, Southwest Ethiopia

Globally, insufficient iodine intake is found to be the most common preventable cause of mental retardation that results in diminished immunity, decreased school performance and infant and young child death. Ethiopia is the first of the top iodine deficient countries in the world. About 12 million children (school age) get inadequate iodine. Community based cross sectional study was conducted on 792 school age children in Guraghe Zone, Ethiopia to assess the determinants of iodine deficiency. Multistage sampling technique was used to select the study subjects. Data were collected by using pretested questionnaire. Clinical examinations were taken following standard procedures. The collected data were entered into Epi-data and exported to SPSS for analysis. Descriptive statistics was calculated and presented accordingly. Bivariate and multivariable Logistic regression with odds ratios along with the 95% confidence interval was computed and interpreted accordingly. A P-value &amp;lt;0.05 was declared as statistically significant association. Total goiter rate was 8.7%. Factors that had significant association with goiter were: School age children who utilized non iodized salt (AOR=3.12, 95% CI=1.73-5.63), those who consumed cabbage &amp;gt;2 times per week (AOR=1.94, 95% CI=1.10-3.52), and children who got elder (AOR=1.22, 95% CI=1.10-1.41). The study area had mild iodine deficiency disorder. Non iodized salt utilization; frequent cabbage consumption and increased age of children were found to be predictors of goiter. Thus, Interventions should focus on universal salt iodization, besides familiarizing goiterogens to the community at large.

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

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.

Breast-Milk Iodine Concentrations and Iodine Levels of Infants According to the Iodine Status of the Country of Residence: A Systematic Review and Meta-Analysis.

Iodine, an essential micronutrient, plays a critical role in normal growth and development, especially during the first two years of life. This systematic review and meta-analysis is among the first to evaluate breast-milk iodine concentrations and infant iodine status in countries characterized by iodine sufficiency or deficiency. PubMed, Web of Science, Cochrane Library, Google Scholar, and other relevant databases, as well as reference lists of previous reviews, were searched for relevant studies published between 1986 and 2016. Mean or median breast-milk and infant urinary iodine concentrations, along with other relevant data, were extracted from eligible studies. Each study was assessed for quality and risk of bias. Of the 496 identified studies, 57 met the criteria for inclusion in the meta-analysis. The mean (confidence interval [CI]) iodine concentrations in maternal colostrum were 152.0 μg/L [CI 106.2-198.7 μg/L] and 57.8 μg/L [CI 41.4-74.1 μg/L] in iodine-sufficient and -deficient countries, respectively, indicating a significant difference between the two iodine statuses. By contrast, the corresponding values in mature milk did not differ significantly between mothers in iodine-sufficient and -deficient countries (71.5 μg/L [CI 51.0-92.0 μg/L] and 28.0 μg/L [CI -13.8 to 69.9 μg/L], respectively]. The weighted urinary iodine levels [CIs] of breast-fed infants in iodine-sufficient countries were significantly higher than those in iodine-deficient countries (164.5 μg/L [CI 116.4-212.7 μg/L] vs. 70.4 μg/L [CI 46.2-94.6 μg/L]). Similarly, a significant difference was observed in the pooled estimates of urinary iodine levels [CIs] among formula-fed infants in iodine-sufficient versus iodine-deficient countries (310.3 μg/L [CI 287.4-342.1 μg/L] vs. 38.3 μg/L [CI 23.4-53.2 μg/L]). The meta-analysis reveals that in iodine-sufficient countries, the mean iodine concentrations in colostrum and mature breast milk corresponded to iodine sufficiency among infants. The results are thus compatible with the international recommendation that lactating women and infants younger than two years of age who reside in iodine-sufficient countries do not require iodine supplementation.

Iodisation of Salt in Slovenia: Increased Availability of Non-Iodised Salt in the Food Supply.

Salt iodisation is considered a key public health measure for assuring adequate iodine intake in iodine-deficient countries. In Slovenia, the iodisation of all salt was made mandatory in 1953. A considerable regulatory change came in 2003 with the mandatory iodisation of rock and evaporated salt only. In addition, joining the European Union’s free single market in 2004 enabled the import of non-iodised salt. The objective of this study was to investigate the extent of salt iodising in the food supply. We examined both the availability and sale of (non-)iodised salt. Average sales-weighted iodine levels in salt were calculated using the results of a national monitoring of salt quality. Data on the availability and sales of salts were collected in major food retailers in 2014. Iodised salt represented 59.2% of the salt samples, and 95.9% of salt sales, with an average (sales-weighted) level of 24.2 mg KI/kg of salt. The average sales-weighted KI level in non-iodised salts was 3.5 mg KI/kg. We may conclude that the sales-weighted average iodine levels in iodised salt are in line with the regulatory requirements. However, the regulatory changes and the EU single market have considerably affected the availability of non-iodised salt. While sales of non-iodised salt are still low, non-iodised salt represented 33.7% of the salts in our sample. This indicates the existence of a niche market which could pose a risk of inadequate iodine intake in those who deliberately decide to consume non-iodised salt only. Policymakers need to provide efficient salt iodisation intervention to assure sufficient iodine supply in the future. The reported sales-weighting approach enables cost-efficient monitoring of the iodisation of salt in the food supply.

Genetic alterations of differentiated thyroid carcinoma in iodine-rich and iodine-deficient countries.

BRAF V600E mutation, RET rearrangements, and RAS mutations are the common genetic alterations in differentiated thyroid carcinomas derived from follicular thyroid cells. However, the relationship between these alterations and iodine intake is still controversial. To clarify the influence of iodine intake on the occurrence of differentiated thyroid carcinomas, we performed molecular analyses for two differentiated carcinomas, papillary thyroid carcinomas (PTCs) and follicular thyroid carcinomas (FTCs), from an iodine‐rich country (Japan) and an iodine‐deficient country (Vietnam). We examined 120 PTCs (67 Japanese and 53 Vietnamese) and 74 FTCs (51 Japanese and 23 Vietnamese). We carried out allele‐specific polymerase chain reaction (AS‐PCR) for BRAF V600E, PCR and direct sequencing for RAS mutations (codon 12, 13, and 61 in NRAS,HRAS, and KRAS), and RT‐PCR for RET/PTC1 and RET/PTC3. BRAF V600E was present in 55/67 (82.1%) Japanese PTCs and 44/53 (83%) Vietnamese PTCs. RET/PTC1 was identified in only one PTC from each country, and no samples had RET/PTC3. NRAS mutation was found in 17/51 (33.3%) Japanese FTCs and 4/23 (17.4%) Vietnamese FTCs. NRAS mutation was cited in codon 61 (20 cases) and codon 12 (one case). None of FTCs had KRAS or HRAS mutations. There were no significant differences in the prevalence of BRAF V600E,RET/PTC, or RAS mutations between the two countries. Our study showed no differences in genetic alterations of thyroid cancers from iodine‐rich and iodine‐deficient countries, possibly suggesting that iodine intake might not affect the genetic alterations of differentiated thyroid cancer.

Epidemiological trends of iodine-related thyroid disorders: an example from Slovenia.

The epidemiology of thyroid disorders is significantly associated with iodine supply. In 1999, Slovenia increased iodine content in kitchen salt from 10 mg to 25 mg of potassium iodide per kg of salt. According to the WHO criteria, Slovenia shifted from a mildly iodine-deficient country to a country with adequate iodine intake. Ten years after the increase in iodine intake, the incidence of diffuse goitre and thyroid autonomy decreased. Now patients with diffuse goitre and thyroid autonomy reach older age than the patients before the increase in iodine intake. In addition, patients with thyroid autonomy are less frequently hyperthyroid than ten years ago and iodine-induced hyperthyroidism is less severe. The incidence of highly malignant thyroid carcinoma has also dropped. However, the incidence of Hashimoto's thyroiditis increased, most probably in genetically predisposed individuals. Over the last ten years, many animal and in vitro studies evaluated the effects of endocrine disrupting chemicals (EDC) on various aspects of the thyroid function. They mostly studied the effects of polychlorinated biphenyls (PCBs) and dioxins, brominated flame retardants, phthalates, bisphenol A, perfluorinated chemicals, and perchlorate. However, human studies on the effects of EDCs on the thyroid function are very scarce, especially the long-term ones. What they do suggest is that PCBs and dioxins interfere with the transport of thyroid hormones and adversely affect the thyroid function. Many authors agree that iodine deficiency predisposes the thyroid gland to harmful effects of EDCs. Therefore the effects of EDCs in iodine-deficient areas could be more severe than in areas with adequate iodine intake.

Progress and challenges in eliminating iodine deficiency in Ethiopia: a systematic review

Iodine deficiency disorders (IDD) and their attendant effects on human development, perinatal mortality and intellectual dysfunction are a major nutrition and public health problem worldwide, with Ethiopia counted among the top iodine-deficient countries. Despite the passing of new legislation in 2011 under the National Nutrition Programme and subsequent increase in the availability of iodized salt, the eradication of IDD in Ethiopia remains a significant challenge. This paper critically reviews the recent published data on iodine-status in Ethiopia as a basis for formulating future research and policy initiatives. We performed a structural search for IDD studies in Ethiopia for all population groups published after the year 2000. Twenty four studies reported national and regional data giving a national total goiter rate above 35.8 % in women, with rates close to 60 % in four regional states, and an estimated prevalence of IDD ranging from 0.4 to 66.3 % depending on region. The prevalence of goiter in children was 35 %, but was as high as 71 % in the South Nations Nationalities and Peoples Region. The problem persists despite the widespread availability of iodized salt. Eradicating IDD in Ethiopia will require concerted efforts including the close evaluation of intervention programs through regular, nation-wide monitoring of IDD and salt-iodization coverage. Salt iodization became mandatory in Ethiopia in 2011 and despite significant progress, the current level of eradicating IDD could be improved. Prospective and controlled intervention studies to evaluate biomarkers of thyroid function and cognitive outcomes will help to monitor and improve eradication efforts. Ascertaining and improving health and development in the most vulnerable populations of women and children is a priority that may be advanced through a greater investment in outreach and education.

Iodine deficiency induces a VEGF-dependent microvascular response in salivary glands and in the stomach.

Despite efforts to optimize iodine supply in iodine deficient countries, iodine deficiency (ID) remains a global problem worldwide. Activation of the local microvasculature by ID in the thyroid gland aims at improving the local supply of iodide. For this purpose, the thyrocytes secrete vascular endothelial growth factor (VEGF) that acts on adjacent capillaries, via a reactive oxygen species (ROS)/Hypoxia Inducible factor (HIF)-dependent pathway. Beside the thyroid, other organs including salivary glands and the stomach do express the sodium/iodide symporter (NIS) and are able to take iodide up, potentially rendering them sensitive to ID. To verify this hypothesis, ID-induced effects on the local microvasculature were studied in salivary glands and in the stomach. ID was induced by feeding young mice with an iodide-deficient diet and NIS inhibitor perchlorate in the drinking water. In salivary glands, ID induced a transient increase in HIF-1α protein expression accompanied by a transient, VEGF-dependent increase in blood flow. In the gastric mucosa, ID transiently increased VEGF expression in the mucin-secreting epithelium and in ghrelin-secreting endocrine cells. These observations suggest that microvascular changes in response to ID occur in NIS-expressing tissues other than the thyroid. NIS expressing cells could be viewed as iodide sensors that respond to ID by inducing vascular changes, probably to optimize iodide bioavailability at regional or systemic levels.

Prevalence of goiter and iodine status among 6-12 years school age children in district Kohat, Pakistan

Pakistan is considered to be one of the most severely iodine deficient countries in the region. A decade earlier, 70% of the population was estimated to be at risk of iodine deficiency. However, the recent use of iodized salt has reduced the intensity of the problem. Earlier studies regarding iodine deficiency in Pakistan were restricted to the northern mountainous regions, but have now been extended to the sub-Himalaya areas and the plains of Punjab. The aim of the present study was to investigate the prevalence of goiter and iodine status among school children in district Kohat, Pakistan. The 30 cluster approach was adopted for the study. From each cluster, 40 samples were collected from school going children. The palpation method was used to measure goiter grade, whereas, for urinary iodine estimation, the wet digestion method was used. The prevalence of goiter in the district was found to be 35% (37.16% in boys and 33% in girls). The median urinary iodine concentration was found to be 56±31.19?g/L. Estimation of iodine content in salt illustrated that 56.8% people were consuming non-iodized salt and 43.5% were using iodized salt. The current study suggests a severe iodine deficiency in school children of district Kohat and regular iodine supplementation is required on an instant basis.South East Asia Journal of Public Health Vol.4(2) 2014: 42-46

Effect of household storage practices on iodine content of iodized salt

Iodine deficiency is amongst the most widely prevalent nutritional problems of Indian peninsula. India is one of the major iodine deficient countries in the world. Iodine deficiency is the most common cause of preventable mental retardation and brain damage. It causes goitre and decreases the production of hormones vital to growth and development. In India it is estimated that about 200 million people are at risk for iodine deficiency disorders. Iodized salt is undoubtedly the strategy for the country still iodine is not fully utilized by the people because of improper handling, usage and storage practices and the data regarding its losses in iodized salt during storage at household level are not available. Keeping the above facts in consideration, the present study was planned with the objective to determine the effect of storage place, duration, type of storage vessel on the iodine content of the salt.

High Prevalence of Thyroid Disorders in Pregnant Women in a Mildly Iodine-deficient Country: A Population-Based Study

Many countries in Europe remain mildly iodine deficient but relatively few country-level data exist on mild iodine deficiency (MID) and its impact on thyroid function in pregnant women. To determine the prevalence of thyroid disorders in pregnant women in Belgium and to assess the association between iodine status and serum thyroglobulin (Tg). We conducted a national survey of pregnant women in 55 obstetric clinics. Urinary iodine concentration corrected for creatinine (UIC/Cr) and thyroid function were measured. The frequency of elevated serum TSH was 7.2%, indicating either subclinical hypothyroidism (6.8%) or overt hypothyroidism (0.4%). Among those women, 13.8% were thyroid peroxidase antibodies (TPO-Ab) positive. The frequency of low serum TSH was 4.1%, indicating either subclinical hyperthyroidism (3.6%) or overt hyperthyroidism (0.5%). In the entire population, the frequency of positive TPO-Ab and/or Tg antibodies positive women was 4%. Globally, the prevalence of thyroid disorders (abnormally high or low TSH) or thyroid autoimmunity features was 15.3% and 18.6% in first-trimester pregnant women. Women with an adequate iodine status (UIC/Cr = 150-249 μg/g) had a significantly lower median Tg concentration compared to moderately iodine deficient women (UIC/Cr ≤ 49 μg/g), 19 μg/L and 25 μg/L, respectively. The prevalence of thyroid disorders was high, affecting one in six pregnant women in Belgium. Therefore, the iodine status in women needs to be improved and screening for thyroid disease should be performed early in pregnancy. In addition, our data suggest that a median Tg of <20 μg/L may indicate iodine sufficiency in pregnant women.