Low Iodine Levels Research Articles

Is low iodine a risk factor for cardiovascular disease in Americans without thyroid dysfunction? Findings from NHANES

Background and aimsLow body iodine levels are associated with cardiovascular disease, in part through alterations in thyroid function. While this association suggested from animal studies, it lacks supportive evidence in humans. This study examined the association between urine iodine levels and presence of coronary artery disease (CAD) and stroke in adults without thyroid dysfunction. Methods and resultsThis cross-sectional study included 2440 adults (representing a weighted n = 91,713,183) aged ≥40 years without thyroid dysfunction in the nationally-representative 2007–2012 National Health and Nutrition Examination Survey. The age and sex-adjusted urine iodine/creatinine ratio (aICR) was categorized into low (aICR<116 μg/day), medium (116 μg/day ≤ aICR < 370μg/day), and high (aICR ≥ 370μg/day) based on lowest/highest quintiles. Stroke and CAD were from self-reported physician diagnoses. We examined the association between low urine aICR and CAD or stroke using multivariable logistic regression modeling. The mean age of this population was 56.0 years, 47% were women, and three quarters were non-Hispanic whites. Compared with high urine iodine levels, multivariable adjusted odds ratios aOR (95% confidence intervals) for CAD were statistically significant for low, aOR = 1.97 (1.08–3.59), but not medium, aOR = 1.26 (0.75–2.13) urine iodine levels. There was no association between stroke and low, aOR = 1.12 (0.52–2.44) or medium, aOR = 1.48 (0.88–2.48) urine iodine levels. ConclusionThe association between low urine iodine levels and CAD should be confirmed in a prospective study with serial measures of urine iodine. If low iodine levels precede CAD, then this potential and modifiable new CAD risk factor might have therapeutic implications.

The Cognitive Effects of Micronutrient Deficiency: Evidence from Salt Iodization in the United States.

Iodine deficiency is the leading cause of preventable mental retardation in the world today. The condition, which was common in the developed world until the introduction of iodized salt in the 1920s, is connected to low iodine levels in the soil and water. We examine the impact of salt iodization on cognitive outcomes in the US by taking advantage of this natural geographic variation. Salt was iodized over a short period of time beginning in 1924. We use military data collected during WWI and WWII to compare outcomes of cohorts born before and after iodization in localities that were naturally poor and rich in iodine. We find that for the one quarter of the population most deficient in iodine this intervention raised IQ by approximately one standard deviation. Our results can explain roughly one decade's worth of the upward trend in IQ in the US (the Flynn Effect). We also document a large increase in thyroid-related deaths following the countrywide adoption of iodized salt, which affected mostly older individuals in localities with high prevalence of iodine deficiency.

Efficacy of a high free iodine barrier teat disinfectant for the prevention of naturally occurring new intramammary infections and clinical mastitis in dairy cows

Using a natural exposure trial design, the goal of our study was to evaluate the clinical efficacy of an iodine teat disinfectant with barrier properties and a high level of free iodine relative to a conventional iodine teat disinfectant with no barrier properties and low levels of free iodine. During the 18 wk of the trial, quarter milk samples were collected every 2 wk from 385 dairy cows from 2 herds. Cows on both farms were assigned in a balanced way according to milk yield, number of lactation, days in milk, somatic cell count (SCC) and microbiology culture pretrial into one of following groups: nonbarrier post milking teat disinfectant (NBAR; n = 195 cows; 747 quarters) or barrier postmilking teat disinfectant (BAR; n = 190 cows; 728 quarters). Afterward, at each scoring date every 2 wk, milk SCC was quantified in samples from all mammary quarters and microbiologic culture was only performed on milk samples with SCC >200,000 cells/mL for multiparous cows and SCC >100,000 cells/mL for primiparous cows. A new intramammary infection (NIMI) was defined when a quarter had milk SCC <200,000 cells/mL for multiparous cows and <100,000 cells/mL for primiparous without microorganism isolation, and in a subsequent sampling visit had milk SCC >200,000 cells/mL for multiparous cows and >100,000 cells/mL for primiparous cows, and positive microorganism isolation. A quarter could have several NIMI, but only 1 case per specific pathogen was considered. The most frequently isolated microorganism group on both farms was Streptococcus spp. (6.25% of total mammary quarters), followed by coagulase-negative staphylococci (3.6%) and Corynebacterium spp. (1.5%). In the present study, an interaction occurred between treatment and week of trial on the incidence risk of NIMI. Quarters disinfected with BAR had 54 and 37% lower odds of NIMI than quarters disinfected with NBAR at 8 and 16 wk of the trial, respectively; whereas at other weeks of the study both products had similar incidence risks of NIMI. Overall, teats disinfected with BAR had 46% lower odds of acquiring a clinical mastitis than those disinfected with NBAR. We concluded that the postmilking teat disinfectant with barrier properties and higher free iodine content reduced the risk of clinical mastitis, although differences in new infections were detected at only weekly time points.

Perspectives on Proterozoic surface ocean redox from iodine contents in ancient and recent carbonate

The Proterozoic Eon hosted the emergence and initial recorded diversification of eukaryotes. Oxygen levels in the shallow marine settings critical to these events were lower than today's, although how much lower is debated. Here, we use concentrations of iodate (the oxidized iodine species) in shallow-marine limestones and dolostones to generate the first comprehensive record of Proterozoic near-surface marine redox conditions. The iodine proxy is sensitive to both local oxygen availability and the relative proximity to anoxic waters. To assess the validity of our approach, Neogene–Quaternary carbonates are used to demonstrate that diagenesis most often decreases and is unlikely to increase carbonate-iodine contents. Despite the potential for diagenetic loss, maximum Proterozoic carbonate iodine levels are elevated relative to those of the Archean, particularly during the Lomagundi and Shuram carbon isotope excursions of the Paleo- and Neoproterozoic, respectively. For the Shuram anomaly, comparisons to Neogene–Quaternary carbonates suggest that diagenesis is not responsible for the observed iodine trends. The baseline low iodine levels in Proterozoic carbonates, relative to the Phanerozoic, are linked to a shallow oxic–anoxic interface. Oxygen concentrations in surface waters would have at least intermittently been above the threshold required to support eukaryotes. However, the diagnostically low iodine data from mid-Proterozoic shallow-water carbonates, relative to those of the bracketing time intervals, are consistent with a dynamic chemocline and anoxic waters that would have episodically mixed upward and laterally into the shallow oceans. This redox instability may have challenged early eukaryotic diversification and expansion, creating an evolutionary landscape unfavorable for the emergence of animals.

Association of Iodine and Iron with Thyroid Function

Iodine and iron are essential elements for healthy thyroid function. However, little is known about the association of iron and iodine with thyroid function in the general US population. We investigated iron and iodine status in relation to concentrations of thyroid hormones. We included 7672 participants aged 20 and older from three surveys (2007-2008, 2009-2010, and 2011-2012) of the National Health and Nutrition Examination Survey. Serum thyroid measures (including free and total T3 and T4, and TSH), serum iron concentration, and urinary iodine concentrations were measured. Multivariate linear regression models were conducted with serum thyroid measures as dependent variables and combinations of serum iron concentration and urinary iodine concentration as predictors with covariate adjustment. Logistic regression models were performed with TSH levels (low, normal, and high) and combinations of serum iron concentration and urinary iodine concentration. Overall, 10.9% of the study population had low iron; 32.2 and 18.8% had low or high iodine levels, respectively. Compared with normal levels of iron and iodine, normal iron and high iodine were associated with reduced free T3 and increased risk of abnormal high TSH. Combined low iron and low iodine was associated with reduced free T3 and increased TSH. In addition, high iodine was associated with increased risk of abnormal high TSH in females but not in males. Thyroid function may be disrupted by low levels of iron or abnormal iodine, and relationships are complex and sex-specific. Large prospective studies are needed to understand the mechanisms by which iron interacts with iodine on thyroid function.

Prevalence of iodine deficiency among multinodular goiter patients: a South Indian study

Background: Mass iodization of table salt was introduced by the Government of India to treat as well as prevent iodine deficiency problems including goitres. However, even after so many years of introduction of iodized salt, the number of patients reporting with multi nodular goiter to the hospitals in Kerala seems to be high. The coastal districts of Trivandrum and Kollam report especially high prevalence of goitres and subsequently thyroidectomies. The aim of this study was to find the prevalence of iodine deficiency among patients with multi nodular goiter in South Kerala.Methods: This was a cross sectional study of 300 patients admitted with multinodular goitre in the general surgical wards of Government Medical College Trivandrum, Kerala, India. From June 2013 to June 2014, these patients were evaluated clinically and with the investigatory facilities available at this institution. Their urine spot iodine excretion levels were measured at the laboratory of state iodine deficiency control cell, Trivandrum, Kerala, India.Results: Out of the 300 cases, 6 patients were found to have mild iodine deficiency. Mean iodine level was normal at 170 microgram per decilitre. The prevalence of iodine deficiency in multinodular goiter cases studied was found to be 2%.Conclusions: The high prevalence of multinodular goiter cases in Kerala cannot be sited per se as due to iodine deficiency as only 2% of the total number of cases studied had low urine iodine levels. This raises a question whether the salt iodization programme needs to be re-analyzed and possibly re-structured for the state of Kerala.

Iodine deficiency and associated factors among school children: a cross-sectional study in Ethiopia.

BackgroundIodine deficiency remains a public health problem in the world. It is the leading cause of preventable mental retardation and brain damage worldwide. Though 12 million school age children are at risk of developing iodine deficiency, there is a scarcity of literature showing the magnitude of iodine deficiency in Ethiopia. Therefore, this study aimed to determine the prevalence and associated factors of iodine deficiency among school children in Robe District, southeast Ethiopia.MethodsA school based cross–sectional study was conducted from February to June, 2015. A structured interviewer-administered questionnaire was used to collect data. A systematic random sampling technique was employed to select 422 children. A multivariate logistic regression analysis was carried out to identify factors associated with iodine deficiency. In the multivariate analysis, variables with a P-value of <0.05 were considered statistically significant.ResultsA total of 393 school children participated in the study. The median urinary iodine level was 78 μg/l. About 57 and 43.5 % of the children were found with low urinary iodine level and goiter, respectively. Only 29 % of the households utilized adequately iodized salt. The result of the multivariate analysis revealed that the odds of iodine deficiency were higher among female [AOR = 2.23; 95 % CI: 1.54, 3.55] and older (10–12 years) [AOR = 2.21; 95 % CI: 1.44, 3.42] children.ConclusionIn this community, the prevalence of goiter and low urine iodine level is high. Thus, iodine deficiency exists as severe public health problem. In addition, there is a low utilization of iodized salt in the setting. Therefore, it is crucial to intensify efforts in the implementation of iodized salt. Moreover, attention should be given to school children to address ID.

Iodine concentration in cooking salt consumed in Lubumbashi and the iodine status of vulnerable people: case study of pregnant women living in underprivileged areas

IntroductionLa consommation du sel faiblement iodé peut engendrer des troubles divers liés à la carence iodée Ce travail a pour objectif d’évaluer la teneur en iode du sel consommé à Lubumbashi et de déterminer le statut iodé des femmes enceintes, cible privilégiée de la carence iodée.MéthodesUne étude transversale descriptive a été consacrée à une analyse iodométrique d'iode dans 739 échantillons de sel collectés dans les ménages et marchés de Lubumbashi en 2014. Précédemment, l'iode urinaire a été déterminé par la technique de minéralisation au persulfate d'ammonium chez 225 femmes enceintes reçues en consultation du 15 mars 2009 au 25 avril 2011.RésultatsNotre enquête a révélé 47,5% des échantillons de sels de cuisine adéquatement iodés (15 à 40 ppm), 36,9% d’échantillons faiblement iodés, 7,4% d’échantillons trop riches en iode et 8,1% des échantillons non iodés. La disponibilité en iode du sel de cuisine analysé était globalement de 54,9%, se trouvant nettement en dessous des normes OMS (90%). En mesurant l'iode urinaire chez la femme enceinte, la carence iodée (iode urinaire <150 µg/l) a été observée dans une proportion de 52%.ConclusionLa faible disponibilité en iode du sel consommé à Lubumbashi pourrait être responsable d'une grande proportion de la carence iodée observée chez la femme enceinte, ce qui expose celle-ci aux risques majeurs des troubles dus à la carence en iode.

Increased oxidative stress parameters in children with moderate iodine deficiency.

Iodine is a part of thyroid hormones and has been reported to act directly as an antioxidant or induce indirectly antioxidant enzymes. This study aimed to assess the urinary iodine concentration and its relationship between the antioxidant and oxidative stress capacity in healthy school-aged children. In total, 196 students from five primary schools, randomly selected between 9 and 12 years (mean age: 10.2±1.2 years), were enrolled in the study. Urinary iodine levels were measured by spectrophotometry with the Sandell-Kolthoff reaction. Total antioxidant status (TAS) and total oxidant status (TOS) were analysed from urine samples. The ratio of TOS to TAS was regarded as an oxidative stress index (OSI), an indicator of the degree of oxidative status. Fifty-four percentage (107) of the children had iodine deficiency (ID) and the majority of them (30%) had mild ID. There was no severe-ID child in the population (<20 μg/L). Urine TAS levels were significantly lower in the moderate-ID group than in the mild-ID group (6.5±4.1 vs. 11.3±4.1 mmol, p<0.001) and the iodine-sufficient group (11.0±5.3 μmol, p<0.001). TOS levels and OSI were found higher in the moderate-ID group than in the mild-ID group (4.8±2.1 vs. 3.7±2.1 μmol, p<0.001) and the iodine-sufficient group (4.8±2.1 vs. 3.4±2.5 mmol, p<0.001). In the moderate-ID group, low urine iodine levels exhibited significant negative correlations with OSI (r=-0.660) and TOS (r=-0.248) and a positive correlation with TAS (r=0.475). We found that children with moderate ID were exposed to more oxidative burden than children with mild ID or iodine sufficiency. Increased systemic oxidative stress induced by moderate ID could cause development of ID-related complications and diseases. Iodine supplementation could have a beneficial role in the prevention of oxidative stress.

Iodine status of Taiwanese children before the change in national salt iodization policy: a retrospective study of the nutrition and health survey in Taiwan 2001-2002.

Taiwan was an iodine deficiency area and endemic goiter was common in 1940's. Mandatory salt iodization started in 1967, and a 1971 survey indicated that goiter rates in children decreased from 21.6% to 4.3%. To understand iodine status before the change of national salt iodization program in 2003, from mandatory to voluntary salt iodization, we retrospectively measured urinary iodine concentrations of samples collected from children in the Nutrition and Health Survey in Taiwan 2001-2002. The median UI level for children aged 6-12 years was 123 μg/L (no differences between males and females). Females aged 10-12 years had the lowest urinary iodine levels. The percentages of this population with urinary iodine levels below 100, 50, and 20 μg/L were 35.2% ± 1.0%, 4.4% ± 0.4%, and 0.2% ± 0.1%, respectively. Older children were more likely to have low urinary iodine levels. People living in different areas of Taiwan had a median urinary iodine levels ranged from 113 μg/L to 164 μg/L (males: 113-153 μg/L; females: 105-174 μg/L), with the highest level in Penghu islands, and the lowest level in the eastern and southern (Southern area 2) areas. According to international criteria, iodine status in 2001-2002 was adequate, comparable to the surveyed goiter rates (4.3%, classified as iodine sufficiency) in 1971, inferring that iodine nutrition remained adequate and stable during this period. The present study is of great importance in documenting the iodine status of Taiwan before the change from mandatory to voluntary salt iodization to serve as a baseline data for future trend analysis in iodine nutrition.

SEAWEED AS MICRONUTRIENTS INGREDIENT FOR FOOD SUPPLEMENT

In some part of Indonesia seaweed has been used as vegetables dish. The most important component of seaweed isiodine and iron. Gracillariasp is one species of seaweed that can be used as a source of the mikronutrients such as iron, iodine and calcium. Iron Deficiency Anemia and Iodine Deficiency Disorder can cause several diseases also known low haemoglobin level and iodine level in the blood. This preparation of Gracillariasp could supplement micro-nutrients in the diet. This study was to develop appropriate local technology of Gracillariaspcontainedas an ingredient in the making of food supplement for imorovement of micronutrients intake.The experimental study uses optimum formulated comosition from seaweed.Based on the practical in the area (Bali), the formula of seaweed compose of seaweed of Gracillaria with additional of 20 % salty fish extract, 5 % dextrin. The seaweeds contains high of carbohydrate, iodine, calcium and iron but low in protein and lipid. Appropriate technology of dried seaweed supplement could be prepared at home. Theseseaweed supplements could be advocated in rural arealevel or posyandufor combating under nutrition status of the children.The formula of direct seaweed inclusion inthe supplement is preferred due to green colour and acceptable taste compared to dried seaweed. The serving sice of 25 g of this product could be cover children’s need about 23 % in iodine, 100 % in iron and 22- 35 % in calcium. Keywords: seaweed, Gracillariasp, iodine, iron, food supplement

Maternal urinary iodine concentration in pregnancy and children's cognition: results from a population-based birth cohort in an iodine-sufficient area

ObjectiveReports from populations with an insufficient iodine intake suggest that children of mothers with mild iodine deficiency during pregnancy are at risk for cognitive impairments. However, it is unknown whether,...

Reference values and variability study of thyroid hormones in pregnant women from El Bierzo

Abstract Background and objectives El Bierzo area is characterized by low urinary iodine levels in the pregnant population. Guidelines recommend that local reference values are established for the diagnosis of thyroid dysfunction in pregnancy. Our objectives were to establish reference values for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) in women in the first trimester of pregnancy and to explore the factors influencing variability in these hormones. Patients and methods A retrospective study of 412 women in the first trimester of pregnancy who were measured serum levels of TSH, FT4, and FT3; 163 women with conditions with a potential influence on thyroid function were excluded. Thirty smoking pregnant women were also excluded from the study of reference values. Factors examined in the variability study included age, body mass index (BMI), and smoking. A multifactorial analysis of covariance was performed. Results Reference values in first-trimester pregnant women were: TSH: 0.497–3.595 mIU/L; FT4: 0.90–1.42 ng/dL; FT3: 2.49–3.56 pg/mL. TSH levels depended on mother age and on interaction between age and smoking. FT3 levels depended on the mother's BMI and smoking, and there was also an interaction between both factors. Conclusion The reference values found may be used to assess thyroid dysfunction in pregnant women from El Bierzo. TSH and FT3 levels are influenced by age and BMI of the mother and by smoking, in addition to the interaction of these factors.

Iodine contributes to osmotic acclimatisation in the kelp Laminaria digitata (Phaeophyceae).

Iodide (I⁻) retained by the brown macroalga Laminaria digitata at millimolar levels, possesses antioxidant activities, but the wider physiological significance of its accumulation remains poorly understood. In its natural habitat in the lower intertidal, L. digitata experiences salinity changes and osmotic homeostasis is achieved by regulating the organic osmolyte mannitol. However, I⁻ may also holds an osmotic function. Here, impacts of hypo- and hypersaline conditions on I⁻ release from, and accumulation by, L. digitata were assessed. Additionally, mannitol accumulation was determined at high salinities, and physiological responses to externally elevated iodine concentrations and salinities were characterised by chl a fluorometry. Net I⁻ release rates increased with decreasing salinity. I⁻ was accumulated at normal (35 S A) and high salinities (50 S A); this coincided with enhanced rETRmax and qP causing pronounced photoprotection capabilities via NPQ. At 50 S A elevated tissue iodine levels impeded the well-established response of mannitol accumulation and prevented photoinhibition. Contrarily, low tissue iodine levels limited photoprotection capabilities and resulted in photoinhibition at 50 S A, even though mannitol was accumulated. The results indicate a, so far, undescribed osmotic function of I⁻ in L. digitata and, thus, multifunctional principles of this halogen in kelps. The osmotic function of mannitol may have been substituted by that of I⁻ under hypersaline conditions, suggesting a complementary role of inorganic and organic solutes under salinity stress. This study also provides first evidence that iodine accumulation in L. digitata positively affects photo-physiology.

Suplementação de iodo na pré-concepção, gravidez e amamentação: a recomendação e a Medicina baseada na inferência

In August 2013, the Portuguese Directorate General of Health published a recommendation for supplementation with potassium iodide (150-200 µg/day) before and during pregnancy and breastfeeding. This recommendation joins to the recommendations of the World Health Organization, the American Thyroid Association, and the results of observational studies. One of these studies was conducted in Portugal with 3631 pregnant women. It found a low level of urinary iodine, especially in pregnant women living in the Azores, Madeira and in the hinterland. It is believed that low urinary iodine levels reflect a low level of serum iodine. This in turn can lead to low levels of thyroid hormones and consequently neurocognitive disorders. The question arises whether iodine supplementation for these women will reduce morbidity in the fetus and the newborn related to low levels of thyroid hormones. We discuss this recommendation in the light of evidence-based and patient-oriented medicine

The effects of perchlorate, nitrate, and thiocyanate on free thyroxine for potentially sensitive subpopulations of the 2001–2002 and 2007–2008 National Health and Nutrition Examination Surveys

Among women with urinary iodine concentration <100 μg/l in the 2001-2002 National Health and Nutrition Examination Survey (NHANES), urinary perchlorate was associated with significant changes in thyroid stimulating hormone and total thyroxine (T4). Although perchlorate, nitrate, and thiocyanate all potentially act to inhibit iodide uptake, free T4 was not found to be associated with exposure to these chemicals in the same data. Fetuses of pregnant mothers with iodine deficiency are thought to be a sensitive subpopulation for perchlorate exposure, but the potential associations between free T4 and exposure to these chemicals among pregnant mothers in NHANES 2001-2002 and 2007-2008 have not been specifically evaluated to date. This study investigates the potential associations between urinary perchlorate, nitrate, and thiocyanate and serum free T4 in individuals with low urinary iodine levels and pregnant women. Multivariate regression models of free T4 were conducted and included urinary perchlorate, nitrate, thiocyanate, and covariates known to have an impact on the thyroid (anti-thyroid peroxidase (TPO) antibodies, age, race/ethnicity, body mass index, and hours of fasting). Meta-analyses were also conducted on non-pregnant and on pregnant women from the two survey cycles. Urinary nitrate was associated with serum free T4 in non-pregnant women of NHANES 2001-2002 who had urinary iodine ≥100 μg/l. In the meta-analysis, urinary perchlorate, nitrate, and thiocyanate were significant predictors of serum free T4 in non-pregnant women. No association was found in men and pregnant women. TPO antibodies were significant predictors of free T4 among non-pregnant women only when the models included urinary perchlorate, nitrate, or thiocyanate. Risk assessment for perchlorate exposure should consider co-exposure to nitrate and thiocyanate.

Autoimmune Thyroiditis and Iodine Therapy

The incidence of Hashimoto’s thyroiditis, also referred to as goitrous autoimmune thyroiditis, is estimated to be equivalent to that of Grave’s disease. Although first discovered one hundred years ago, the pathophysiology of this disease has not yet been completely defined. Patients present with varying degrees of symptoms and may present euthyroid. Studies have found associations between genetic predisposition, environmental factors and co-occurrence of other autoimmune disorders within patients with autoimmune thyroiditis. This has further impeded advances to clearly define the mechanisms associated with autoimmune thyroiditis as there are a number of potential confounding factors which are not shared by all patients. Concern has been raised suggesting that iodination of salt led to the emergence or increase in prevalence of autoimmune thyroiditis. In regions where chronic excess consumption of iodine occurs, studies have not found an association between iodine intake and prevalence of this disorder. Furthermore, autoimmune thyroiditis patients with low thyroid levels of iodine are at risk of developing hypothyroidism. Therefore iodine therapy is indicated in patients with autoimmune thyroiditis to preserve normal function of the thyroid, unless the patient has goiter. Patients receiving iodine therapy must be monitored closely to ensure the condition does not exacerbate.

Valores de referencia y estudio de la variabilidad de hormonas tiroideas en gestantes de El Bierzo

Background and objectivesEl Bierzo area is characterized by low urinary iodine levels in the pregnant population. Guidelines recommend that local reference values are established for the diagnosis of thyroid dysfunction in pregnancy. Our objectives were to establish reference values for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) in women in the first trimester of pregnancy and to explore the factors influencing variability in these hormones. Patients and methodsA retrospective study of 412 women in the first trimester of pregnancy who were measured serum levels of TSH, FT4, and FT3; 163 women with conditions with a potential influence on thyroid function were excluded. Thirty smoking pregnant women were also excluded from the study of reference values. Factors examined in the variability study included age, body mass index (BMI), and smoking. A multifactorial analysis of covariance was performed. ResultsReference values in first-trimester pregnant women were: TSH: 0.497-3.595mIU/L; FT4: 0.90–1.42ng/dL; FT3: 2.49–3.56pg/mL. TSH levels depended on mother age and on interaction between age and smoking. FT3 levels depended on the mother's BMI and smoking, and there was also an interaction between both factors. ConclusionThe reference values found may be used to assess thyroid dysfunction in pregnant women from El Bierzo. TSH and FT3 levels are influenced by age and BMI of the mother and by smoking, in addition to the interaction of these factors.

An animal model of Kashin–Beck disease induced by a low-nutrition diet and exposure to T-2 toxin

We investigated the combined roles of a low-nutrition diet (low levels of protein, iodine, and selenium) and T-2 toxin in bone development and to establish an experimental animal model of Kashin-Beck disease (KBD) that reliably mimics the disease's pathological changes for further study of the pathogenesis and prevention of the disease. Sprague-Dawley rats were randomly divided among four groups: group A, normal diet; group B, normal diet plus T-2 toxin; group C, low-nutrition diet; and group D, low-nutrition diet plus T-2 toxin exposure. The radiographic and histopathological changes in the tibial growth zone, plate cartilage and metaphysis were examined. In group D, all epiphyseal plates were blurred, thin, and irregular. Tibias were significantly shorter in group D than in groups A and B. After 4 weeks, epiphyseal plates showed chondrocyte necrosis, with the more obvious necrosis appearing in groups C and D. The positive rate of lamellar necrosis was significantly higher in group D than in groups B and A (P<0.01). In group D, metaphyseal trabecular bone was sparse, disordered, and disrupted, and massive transverse trabecular bone appeared in the metaphysis at 12 weeks. A rat model of KBD induced by a low-nutrition diet and T-2 toxin exposure demonstrated radiographic and histopathological abnormalities of the proximal epiphyseal plate and the tibial metaphysis that are very similar to the bone changes found in patients with KBD. This animal model will be helpful for further study of the pathogenesis and prevention of KBD.

Iodine nutritional status of the vulnerable population in Henan province in 2011

To investigate the iodine nutritional status of the vulnerable population in Henan in 2011. From March to December 2011, 44 049 urinary samples of newly married women of childbearing age (363), pregnant women (31 874), lactating women (4893) and children under 2 years (6919) collected from hospitals, maternal and child care hospitals and outpatient department of family planning organizations from 8 cities of Henan province (only including the areas where water iodine was less than 100 µg/L) were tested for urine iodine concentration. The iodine nutritional status of different groups was analyzed. The median of urinary iodine for newly married women, pregnant women, lactating women and children under 2 years was 204.5, 190.9, 145.5 and 185.4 µg/L, respectively (χ(2) = 874.16, P < 0.01). The proportion of urinary iodine below 150 µg/L of pregnant women and below 100 µg/L of lactating women and children under 2 years was 33.0% (10 519/31 874), 24.9% (1218/4893) and 12.4% (855/6919), respectively. The proportion of urinary iodine above 300 µg/L of newly married women was 33.6% (122/363). The median of urinary iodine for pregnant women in the first, second and third trimester was 186.7, 193.8 and 182.5 µg/L, respectively (χ(2) = 55.19, P < 0.01). The median of urinary iodine for the breast-feeding, formula-feeding and mixed-feeding infant under the age of 1 year was 194.8, 85.6 and 176.0 µg/L, respectively (χ(2) = 179.25, P < 0.01). The overall iodine nutrient levels of the vulnerable population in Henan in 2011 were appropriate, but there were still some proportions of pregnant and lactating women with low iodine level. The iodine intake of the formula-feeding infants was not sufficient.