The disorders induced by iodine deficiency

Autoimmune thyroiditis incidence in a large population-based study in northeastern Italy

PURPOSE

An improvement in iodine status in the Veneto region (Italy) in the last decade has been documented. Our aim was to estimate the incidence of autoimmune thyroiditis (AT) in this region over the period 2012-2022.

METHODS

A retrospective population-based study conducted in Veneto using the population registry and administrative health databases. We documented incident hyperthyroidism from 2013 to 2022 to exclude prevalent cases and calculated standardised incidence rates (IR) per 10,000 person-years by age and sex.

RESULTS

We identified 65,379 incident cases (IR: 13.38), 5.44-fold higher in females than in males. IR decreased from 15.86 (95% CI: 15.50, 16.21) in 2013 to 12.35 (95% CI: 12.04, 12.67) in 2022. The decline was evident only in females, with a documented reduction in IR from 27.26 (95% CI: 26.61, 27.91) in 2013 to 20.49 (95% CI: 19.92, 21.07) in 2022 (P = 0.002). The decrease was sharper in females aged 15-54 years (IR from 37.86 (95%CI: 36.79, 38.94) in 2013 to 27.40 (95% CI: 26.44, 28.36) in 2022; P < 0.001) than in those aged ≥55 years (IR from 20.06 (95% CI: 19.13, 20.99) in 2013 to 16.56 (95% CI: 15.78, 17.35) in 2022; P = 0.034). In 2020, an out-of-trend decrease in AT incidence was documented, corresponding with the SARS-CoV-2 pandemic, with a realignment to the trend in the subsequent years.

CONCLUSIONS

A decline in AT was documented in the Veneto region in the last decade, paralleling improvement in the iodine status. The reduction was significant only among females, particularly in reproductive age.

Mechanically interlocked host systems for ion-pair recognition

The ever-increasing interest directed towards the construction of host architectures capable of the strong and selective recognition of various ionic species of biological, medical and environmental importance has identified mechanically interlocked molecules (MIMs), such as rotaxanes and catenanes, as potent host systems, owing to their unique three-dimensional topologically preorganised cavity recognition environments. Ion-pair receptors are steadily gaining prominence over monotopic receptor analogues due to their enhanced binding strength and selectivity, demonstrated primarily through acyclic and macrocyclic heteroditopic host systems. Exploiting the mechanical bond for ion-pair recognition through the strategic design of neutral heteroditopic MIMs offers exciting opportunities to accomplish potent and effective binding while mitigating competing interactions from the bulk solvent and counter-ions. This review details the design and ion-pair recognition capabilities of rotaxanes and catenanes employing hydrogen bonding (HB) and halogen bonding (XB) motifs, providing valuable insight into the burgeoning field and inspiration for future research.

A Comparative Study on the Dietary Iodine Intake and the Contribution Rates of Various Foods to the Dietary Iodine Intake among Residents in Zhejiang in 2010 and 2022

We aim to analyze the changes in dietary iodine intake and the contribution rates of various foods to it after the reduction in salt iodine concentration in Zhejiang. We used data from two cross-sectional nutrition surveillance surveys conducted by the Zhejiang Provincial Center for Disease Control and Prevention in 2010 (9798 residents) and 2022 (5980 residents). In both surveys, multi-stage stratified and systematic sampling were adopted, and uniformly trained investigators conducted the dietary surveys using a 24 h dietary review and weighing record methods for 3 consecutive days. From 2010 to 2022, the median salt iodine concentration and the consumption rate of qualified iodized salt in Zhejiang households dropped from 28.80 to 22.08 mg/kg and from 76.65% to 64.20%, respectively. Moreover, the residents' median dietary iodine intake decreased from 277.48 to 142.05 μg/d. Significant interregional differences in dietary iodine intake were found in 2010 and 2022 (H = 639.175, p < 0.001; H = 588.592, p < 0.001, respectively); however, no significant differences existed between urban and rural areas (p > 0.05). From 2010 to 2022, the proportion of residents with dietary iodine intake below the estimated average requirement increased from 15.10% to 34.80%, while that of residents with intake above the tolerable upper limit decreased from 15.00% to 2.90%. The contribution rate of salt to dietary iodine intake among residents in Zhejiang decreased from 74.92% to 48.54%, showing an apparent overall downward trend despite the dietary intake being generally adequate (markedly inadequate in coastal regions). The salt iodine concentration and the consumption rate of qualified iodized salt in households in Zhejiang showed downward trends. Salt remained the main source of dietary iodine; however, its contribution decreased significantly. Zhejiang may need to reverse the trend of the continuous decline in the consumption rate of qualified iodized salt to protect the health of its residents.

Lithium chloride selective ion-pair recognition by heteroditopic [2]rotaxanes

The first heteroditopic [2]rotaxane host systems capable of strong and selective binding of lithium chloride ion-pair species are described. Importantly, a cooperative 'switch on' mechanism was found to operate, in which complexation of a lithium metal cation enhances the halide anion affinity of the rotaxanes via a combination of favourable proximal electrostatic and preorganised allosteric effects. The mechanically bonded rotaxane host design features a macrocycle component possessing a 2,6-dialkoxy pyridyl cation binding motif and an isophthalamide anion binding group, as well as an axle component functionalised with either a halogen bonding (XB) iodotriazole or hydrogen bonding (HB) prototriazole moiety. Extensive quantitative 1H NMR titration studies in CD3CN/CDCl3 solvent mixtures determined enhanced ion-pair binding affinities for lithium halides over the corresponding sodium or potassium halide salts, with the axle prototriazole-containing HB rotaxane in particular demonstrating a marked selectivity for lithium chloride. Solid-state X-ray crystallographic studies and computational DFT investigations provide evidence for a [2]rotaxane host axle-separated ion-pair binding mode, in which complementary cation and anion binding motifs from both the macrocycle and axle components act convergently to recognise each of the charged guest species.

Paediatric thyroid disease

The spectrum of thyroid disorders presenting to paediatricians is different to that seen by adult physicians. Referrals reflect cases detected by the neonatal screening programme for congenital hypothyroidism and many of the inherited defects of thyroid hormone generation or action will be manifest in early life. Autoimmune thyroid disease can be particularly challenging to manage in the young and the potential impact of thyroid status on neurodevelopment and schooling are key considerations throughout childhood and adolescence.

The correlation between urinary iodine levels and gallstone risk: elevated iodine intake linked to gallstone occurrence

Background

Essential trace elements are vital for human growth and development. Nevertheless, excessive intake can pose risks. As of yet, no research has looked at the possibility of a relationship between the prevalence of gallstones and urinary concentrations of nickel, molybdenum, and iodine.

Objectives

The purpose of this study was to examine the correlation between urinary levels of iodine, molybdenum, and nickel and the occurrence of gallstones in a U.S. population and to verify whether excessive iodine intake is associated with the occurrence of gallstones.

Methods

Data from 2,734 participants that were gathered between 2017 and 2020 were examined. Employing inductively coupled plasma mass spectrometry (ICP-MS), the levels of nickel (Ni), iodine (I), and molybdenum (Mo) in the urine were determined. Gallstones presence was determined using a standardized questionnaire. Restricted cubic spline analysis, subgroup analysis, and logistic regression analysis were used to evaluate the relationship between the occurrence of gallstones and urinary essential trace elements.

Results

The logistic regression analysis indicated an increased risk of gallstone development in Quartiles 2, Quartiles 3, and Quartiles 4 groups in comparison to the Quartiles 1 group, based on urinary iodine levels (OR = 1.69, 95% CI: 1.11-2.56; OR = 1.68, 95% CI: 1.10-2.55; OR = 1.65, 95% CI: 1.09-2.51). Urinary iodine levels were nonlinearly positively linked with the development of gallstones, according to restricted cubic spline analysis (P-Nonlinear = 0.032). Subgroup analyses showed that high levels of urinary iodine were associated with a high risk of gallstones in different populations, and were more pronounced in adults aged 60 years and older, in women, with a BMI ≥ 25, and in diabetic patients.

Conclusion

Our research revealed a correlation between an increased risk of gallstones and increasing urinary iodine levels. Urinary iodine levels serve as indicators of the body's iodine status, thus suggesting that excessive iodine intake may be linked to an elevated risk of gallstone formation.

Dietary Iodine Intake and Sources among Residents in Zhejiang Province 10 Years after Reducing Iodine Concentration in Iodized Salt

We aimed to assess dietary iodine intake and sources in Zhejiang Province a decade after a reduction in iodine concentration in iodized salt. Three-day 24 h dietary recall and household weighing were used, complemented by "Chinese Food Composition" data. Household water and salt samples were collected from 5890 residents and analyzed. Differences in iodized salt consumption rates were observed across the following regions: inland (84.20%), subcoastal (67.80%), and coastal (37.00%) areas. The median (P25, P75) iodine concentration in water and diet were 2.2 (0.9, 4.0) μg/L and 142.05 (58.94, 237.11) μg/d, respectively, with significant regional differences in dietary concentration (inland [185.61 μg/d], subcoastal [153.42 μg/d], and coastal [75.66 μg/d]). Males (149.99 μg/d) and iodized salt consumers (191.98 μg/d) had a significantly higher dietary iodine intake than their counterparts. Regions were ranked as follows based on the proportions of individuals meeting the recommended dietary iodine intake: inland (69.40%), subcoastal (56.50%), and coastal (34.10%) areas. Dietary sources included salt (48.54%), other foods (32.06%), drinking water (8.84%), laver (4.82%), kelp (3.02%), and other seafood (2.32%). The qualified iodized salt consumption rate was significantly lower than the national standard. Zhejiang Province should continue implementing measures to control iodine deficiency through salt iodization, education efforts, and increasing the qualified iodized salt consumption rate.

Changing trends in the global, regional, and national burden of iodine deficiency among adolescents and young adults: population-based study

Iodine is a micronutrient required for the production of thyroid hormones, which regulate metabolism, growth, and neurodevelopment. Iodine deficiency among adolescents and young adults is a major global health issue. We analyzed data from the Global Burden of Disease 2019 database to calculate the prevalence, incidence, and disability-adjusted life-year (DALY) rates of iodine deficiency among adolescents and young adults. We explored the specific year with the most substantial changes in the trends of iodine deficiency among adolescents with annual percentage change (APC) by Joinpoint Regression analysis. Descriptive analyses were conducted to characterize the iodine deficiency burden according to age, sex, location, and sociodemographic index (SDI) quintiles. All measures are listed with 95% uncertainty intervals (UIs), and all rates are reported per 100,000 individuals. From 1990 to 2019, the iodine deficiency prevalence rate among adolescents decreased from 3082.43 (95% uncertainty interval [UI], 2473.01-3855.86) to 2190.84 (95% [UI], 1729.18-2776.16) per 100,000 population, with an AAPC of -1.15 (95% confidence interval [CI], -1.29 to -1.02). Regarding the SDI in 2019, the highest prevalence and DALY rates of iodine deficiency were reported in low-SDI countries. In 1990, Southeast Asia had the highest prevalence and DALYs rates for iodine deficiency among adolescents, while in 2019, Africa had the highest prevalence rate (3330.12).

CONCLUSION

Globally, the iodine deficiency burden among adolescents has substantially decreased since 1990; however, low-SDI countries still bear a great burden. Implementation measures and monitoring systems should be strengthened to reduce the iodine deficiency burden, especially among adolescents.

WHAT IS KNOWN

• Iodine deficiency can cause severe or irreversible developmental disorders, particularly in adolescents and young adults. • Universal Salt Iodization was implemented for ensuring appropriate iodine intake.

WHAT IS NEW

• We found substantial declines in the prevalence rates of iodine deficiency among adolescents during the past three decades. Globally, the disability-adjusted life-year rate of iodine deficiency among adolescents decreased from 56.17 in 1990 to 35.38 in 2019. • Iodine deficiency among adolescents in low- sociodemographic index countries still bear a great burden.

Exploring the potential of genetic analysis in historical blood spots for patients with iodine-deficient goiter and thyroid carcinomas in Switzerland and Germany (1929-1989)

Iodine deficiency-induced goiter continues to be a global public health concern, with varying manifestations based on geography, patient's age, and sex. To gain insights into clinical occurrences, a retrospective study analyzed medical records from patients with iodine deficiency-induced goiter or thyroid cancer who underwent surgery at the Community Hospital in Riehen, Switzerland, between 1929 and 1989. Despite today's adequate iodine supplementation, a significant risk for iodine-independent goiter remains in Switzerland, suggesting that genetic factors, among others, might be involved. Thus, a pilot study exploring the feasibility of genetic analysis of blood spots from these medical records was conducted to investigate and enhance the understanding of goiter development, potentially identify genetic variations, and explore the influence of dietary habits and other environmental stimuli on the disease.Blood prints from goiter patients' enlarged organs were collected per decade from medical records. These prints had been made by pressing, drawing, or tracing (i.e., pressed and drawn) the removed organs onto paper sheets. DNA analysis revealed that its yields varied more between the prints than between years. A considerable proportion of the samples exhibited substantial DNA degradation unrelated to sample collection time and DNA mixtures of different contributors. Thus, each goiter imprint must be individually evaluated and cannot be used to predict the success rate of genetic analysis in general. Collecting a large sample or the entire blood ablation for genetic analysis is recommended to mitigate potential insufficient DNA quantities. Researchers should also consider degradation and external biological compounds' impact on the genetic analysis of interest, with the dominant contributor anticipated to originate from the patient's blood.

A Halogen Bonding [2]Rotaxane Shuttle for Chloride-Selective Optical Sensing

The first example of a [2]rotaxane shuttle capable of selective optical sensing of chloride anions over other halides is reported. The rotaxane was synthesised via a chloride ion template-directed cyclisation of an isophthalamide macrocycle around a multi-station axle containing peripheral naphthalene diimide (NDI) stations and a halogen bonding (XB) bis(iodotriazole) based station. Proton NMR studies indicate the macrocycle resides preferentially at the NDI stations in the free rotaxane, where it is stabilised by aromatic donor-acceptor charge transfer interactions between the axle NDI and macrocycle hydroquinone moieties. Addition of chloride ions in an aqueous-acetone solvent mixture induces macrocycle translocation to the XB anion binding station to facilitate the formation of convergent XB⋅⋅⋅Cl- and hydrogen bonding HB⋅⋅⋅Cl- interactions, which is accompanied by a reduction of the charge-transfer absorption band. Importantly, little to no optical response was induced by addition of bromide or iodide to the rotaxane, indicative of the size discriminative steric inaccessibility of the interlocked cavity to the larger halides, demonstrating the potential of using the mechanical bond effect as a potent strategy and tool in chloride-selective chemo-sensing applications in aqueous containing solvent environments.

Clinical and magnetic resonance imaging findings in a French bulldog puppy with genetically confirmed congenital hypothyroidism

A 7-month-old male French bulldog was referred for abnormal mentation and gait. Physical examination revealed a dome shaped calvarium and persistent bregmatic fontanelle. Neurological examination revealed proprioceptive ataxia, pelvic limb paraparesis and strabismus with moderate ventriculomegaly, thinning of the cerebral parenchyma, and widened cerebral sulci on magnetic resonance imaging. Masses were identified in the region of the thyroid, which appeared heterogeneous and hyperintense in T1-weighted and T2-weighted compared with the adjacent muscle signal masses were identified. Radiological diagnosis was hydrocephalus "ex vacuo" and goiter. Blood test revealed abnormally low total thyroxine (TT4), free thyroxine (FT4), and normal thyrotropin concentration. A diagnosis of congenital hypothyroidism was confirmed by positive genetic test for thyroid peroxidase mutation. Thyroxine supplementation treatment rapidly improved clinical signs.

Neutral MOF Anion Receptor: Radical-Promoted Precise Anion Recognition

Precise ion recognition plays a key role in the anionic decontamination in water. However, the established anionic recognition based on neutral or cationic anion receptor is still restricted by the inherent limitation, such as narrow application scope in organic solvent rather than water for neutral anion receptor and poor selectivity due to non-directional electrostatic interaction for cationic anion receptor. Herein, for the first time, a neutral metal-organic framework (MOF) anion receptor is shown, enabling precise anion recognition, for example, the presence of a variety of 1000-fold competitive anions does not affect the selective adsorption of the target anion at all. A radical-dominating anion-recognition mechanism is proposed for rationalizing the efficacy of the neutral MOF.

Prevalence of iodine deficiency among vegan compared to vegetarian and omnivore children in the Czech Republic: cross-sectional study

BACKGROUND

The intake and homeostasis of iodine, an essential micronutrient that plays a vital role in thyroid physiology, is of particular concern with the increasing popularity of vegetarian (VG) and vegan (VN) diets. Children on these restrictive diets may be at risk of possible adverse effects on growth and development, but there is currently a lack of recent epidemiological studies on this topic.

METHODS

We gathered clinical, anthropometric, and blood/urine data on iodine status and thyroid function from children aged 0-18 years who followed either a VG diet (n = 91), VN diet (n = 75), or omnivore diet (OM, n = 52). Cross-sectional comparison of the groups and linear regression was used. Stratified analyses were performed based on age (according to WHO): 0-5 years and 6-18 years.

RESULTS

Our study revealed no significant differences in levels of thyroid-stimulating hormone (TSH), triiodothyronine (fT3), thyroglobulin (TG) or anti-thyroid peroxidase antibody (ATPOc) between the VG, VN, and OM groups. However, thyroxine (fT4) levels were found to be higher in the VN group compared to the OM group (15.00 ± 1.73 vs. 16.17 ± 1.82 pmol/l, p < 0.001). The presence of anti-thyroglobulin antibodies (AhTGc) was notably more common in the VG (18.2%)/VN (35.0%) groups than in the OM group (2.1%) (p < 0.001). Regarding iodine status, the concentration of iodine in spot urine (UIC) was found to be highest in the OM group (197.28 ± 105.35 vs. VG: 177.95 ± 155.88 vs. VN: 162.97 ± 164.51 µg/l, p < 0.001). Notably, the lowest (5.99 µg/l) and highest (991.80 µg/l) levels were measured in the VN group. Of the participants, 31 VN, 31 VG and 10 OM children met the criteria for iodine deficiency (i.e., UIC < 100 µg/l). We found that children with regular iodine supplementation had higher UIC (p < 0.001). Importantly, the median UIC was above 100 µg/l in all three groups, through the recommended intake (RDI) of iodine was rarely met throughout the groups.

CONCLUSION

We have observed a trend to lower UIC values in VN as compared to OM. This trend is also reflected in the median UIC values, even though the median UIC values were above the WHO cut-off (e.g., 100 µg/l) for iodine deficiency in all dietary groups. These results suggest that VN and VG children may be more at higher risk of iodine deficiency, this theory is also supported by higher prevalence of AhTGc positivity. Further research is needed to investigate the long-term impact of these dietary patterns on iodine status and thyroid function in children. Given our findings, it may also be necessary to consider new guidelines for supplementing children following VG and VN diets to ensure their iodine needs are met.

Squaramide-Based Heteroditopic [2]Rotaxanes for Sodium Halide Ion-Pair Recognition

A series of squaramide-based heteroditopic [2]rotaxanes consisting of isophthalamide macrocycle and squaramide axle components are synthesized using an alkali metal cation template-directed stoppering methodology. This work highlights the unprecedented sodium cation template coordination of the Lewis basic squaramide carbonyls for interlocked structure synthesis. Extensive quantitative 1 H NMR spectroscopic anion and ion-pair recognition studies reveal the [2]rotaxane hosts are capable of cooperative sodium halide ion-pair mechanical bond axle-macrocycle component recognition, eliciting up to 20-fold enhancements in binding strengths for bromide and iodide, wherein the Lewis basic carbonyls and Lewis acidic NH hydrogen bond donors of the squaramide axle motif operate as cation and anion receptive sites simultaneously in an ambidentate fashion. Notably, varying the length and nature of the polyether cation binding unit of the macrocycle component dramatically influences the ion-pair binding affinities of the [2]rotaxanes, even overcoming direct contact NaCl ion-pair binding modes in polar organic solvents. Furthermore, the cooperative ion-pair binding properties of the squaramide-based heteroditopic [2]rotaxanes are exploited to successfully extract solid sodium halide salts into organic media.

BINOL and triazole-containing Janus rings and 29-8-29-membered tricyclic ladder-type hybridized siloxane: application in the fluorescence sensing of anions

Tetrachloro- and tetraazide-substituted all-cis-tetraphenylcyclotetrasiloxanes (all-cis-T₄) 2 and 3 were synthesized in high yields and were fully characterized. Then the precursor 3 underwent CuAAC click reaction with monopropargyl BINOL 4 and dipropargyl BINOL 6 to give the novel BINOL and triazole-containing all-cis-T₄ cyclic siloxane 5 and the 29-8-29-membered-ring ladder-type hybrid siloxane 7. The sensing ability of compounds 5 and 7 towards anions was studied as well, and it was observed that 7 could selectively recognize iodides through synergistic C-H⋯I hydrogen bonding, resulting in an impressive fluorescence quenching with a K_sv of 8.10 × 10⁴ M^-1.

Goiter prevalence and iodine deficiency disorder among school-age children (6-12 years) in district Ganderbal of Kashmir valley

BACKGROUND

Iodine deficiency is a major cause of brain damage in childhood which can be prevented. Dietary deficiency of iodine is mainly responsible for iodine deficiency. This study was done to determine the prevalence of goiter among school-aged group of 6-12 years in district Ganderbal.

MATERIALS AND METHODS

This was a cross-sectional study done among children of 6-12 years in district Ganderbal.

RESULTS

Out of 2700 children examined, Grade 1 goiter was found in 90 (3.3%) children and Grade 2 goiter was found in 6 (0.3%) with a total goiter rate (sum of grade first and grade second) of 3.6%. On analyzing the urine samples, about 19.1% of the children had mild to moderate iodine deficiency.

CONCLUSION

The study showed mild goiter prevalence in school-aged children of 6-12 years in the Ganderbal district of Kashmir valley. Continuous periodic surveys to assess the magnitude of the iodine deficiency disorders (IDD) should be undertaken to ensure that we achieve sustainable elimination of IDD in India.

Methyl orange as a novel colorimetric iodide indicator with in situ generation of H2O2 by etching uncoated Ag-Ti3C2 nanohybrids

Iodine intake remains a major public health concern, as both iodine excess and deficiency are related to adverse effects on health. Therefore, developing simple and economical methods to detect I^- is still in great demand. Herein, we constructed a visual I^- sensing platform based on the uncoated Ag-Ti₃C₂ nanohybrids using methyl orange (MO) as a colorimetric indicator. Plasmonic nanostructures are frequently employed in colorimetric analysis, but uncoated Ag nanoparticles (NPs) are unstable because their surface energies are usually high. Considering that Ag NPs can be etched by I^- via forming Ag-I bond, we introduce Ag-Ti₃C₂ nanohybrids because uncoated Ag NPs with immaculate surfaces are more conducive to binding with I^- and being etched. Dissolved O₂ molecules adsorbed on Ti³⁺ of Ti₃C₂ MXenes enable the in situ generation of H₂O₂ by iodine-etching of uncoated Ag-Ti₃C₂ nanohybrids. ∙OH radicals promote the degradation of MO through a self-driven Fenton-like process, exhibiting the color variation from orange to transparent. Under optimal conditions, the absorbance of MO at 465 nm decreases linearly with the concentration of I^- in the range of 0.5-300 μM, with a limit of detection as low as 0.31 μM. This work opens the feasibility of iodine-etching of Ag in developing novel probes for facile colorimetric determination of I^-.

Optimizing Growth: The Case for Iodine

Iodine is an essential micronutrient and component of thyroid hormone. An adequate dietary iodine intake is critical to maintain and promote normal growth and development, especially during vulnerable life stages such as pregnancy and early infancy. The role of iodine in cognitive development is supported by numerous interventional and observational studies, and when iodine intake is too low, somatic growth is also impaired. This can be clearly seen in cases of untreated congenital hypothyroidism related to severe iodine deficiency, which is characterized, in part, by a short stature. Nevertheless, the impact of a less severe iodine deficiency on growth, whether in utero or postnatal, is unclear. Robust studies examining the relationship between iodine and growth are rarely feasible, including the aspect of examining the effect of a single micronutrient on a process that is reliant on multiple nutrients for optimal success. Conversely, excessive iodine intake can affect thyroid function and the secretion of optimal thyroid hormone levels; however, whether this affects growth has not been examined. This narrative review outlines the mechanisms by which iodine contributes to the growth process from conception onwards, supported by evidence from human studies. It emphasizes the need for adequate iodine public health policies and their robust monitoring and surveillance, to ensure coverage for all population groups, particularly those at life stages vulnerable for growth. Finally, it summarizes the other micronutrients important to consider alongside iodine when seeking to assess the impact of iodine on somatic growth.

Halogen-Bonding Heteroditopic [2]Catenanes for Recognition of Alkali Metal/Halide Ion Pairs

The first examples of halogen bonding (XB) heteroditopic homo[2]catenanes were prepared by discrete Na+ template-directed assembly of oligo(ethylene glycol) units derived from XB donor-containing macrocycles and acyclic bis-azide precursors, followed by a CuI -mediated azide-alkyne cycloaddition macrocyclisation reaction. Extensive 1 H NMR spectroscopic studies show the [2]catenane hosts exhibit positive cooperative ion-pair recognition behaviour, wherein XB-mediated halide recognition is enhanced by alkali metal cation pre-complexation. Notably, subtle changes in the catenanes' oligo(ethylene glycol) chain length dramatically alters their ion-binding affinity, stoichiometry, complexation mode, and conformational dynamics. Solution-phase and single-crystal X-ray diffraction studies provide evidence for competing host-separated and direct-contact ion-pair binding modes. We further demonstrate the [2]catenanes are capable of extracting solid alkali-metal halide salts into organic media.

The Thyroid Hormone and Immunoglobulin Concentrations in Blood Serum and Thyroid Gland Morphology in Young Hens Fed with Different Diets, Sources, and Levels of Iodine Supply

The aim of this study was to examine the influence of the level (1, 3, and 5 mg I/kg) and source of iodine (KI, Ca(IO₃)₂, and KIO₃) on thyroid hormone and immunoglobulin concentrations in the blood serum of laying hens alongside a histological picture of the thyroid. In the first, birds were fed grain-soybean meal mixtures, and in the second, two kinds of diets based on corn-soybean or corn-soybean-rapeseed meal were applied. In the experiments, we determined the levels of the blood serum thyroid hormones fT₃ and fT₄, as well as the morphological structure of the thyroid gland. In the second experiment, the concentration of immunoglobulins in blood serum was assayed. In both experiments, no influence of iodine source on thyroid hormone concentration was observed. However, increasing the iodine level in the full mixture and adding rapeseed meal in both experiments caused an increase in fT₃ concentration. Increasing I-addition in both experiments led to a decrease in thyroid gland follicle diameter. Rapeseed meal inclusion (at a level of 10%) to the complete hen mixture led to an increase in thyroid gland follicle diameter. Applying KIO₃ as an iodine source in both experiments caused a decrease in the thyroid gland height of follicle epithelial cells. Immunoglobulin concentrations in the serum were not affected by experimental factors. The results suggest that the methodologies of studies on the bioavailability of minerals and the corresponding analytical methods require unification. The lack of such standardization makes it impossible to engage in a satisfactory discussion of the results and exchange experiences.

Iodine and Iodine Deficiency: A Comprehensive Review of a Re-Emerging Issue

Iodine is a mineral nutrient essential for the regulation of a variety of key physiological functions including metabolism and brain development and function in children and adults. As such, iodine intake and status within populations is an area of concern and research focus. This paper will review recently published studies that focus on the re-emerging issue of iodine deficiency as a global concern and declining intake among populations in developed countries. Historically, the implementation of salt-iodization programs worldwide has reduced the incidence of iodine deficiency, but 30% of the world’s population is still at risk. Iodine nutrition is a growing issue within industrialized countries including the U.S. as a result of declining iodine intake, in part due to changing dietary patterns and food manufacturing practices. Few countries mandate universal salt iodization policies, and differing agriculture and industry practices and regulations among countries have resulted in inconsistencies in supplementation practices. In the U.S., in spite of salt-iodization policies, mild-to-moderate iodine deficiency is common and appears to be increasing. European countries with the highest incidence of deficiency lack iodization programs. Monitoring the iodine status of at-risk populations and, when appropriate, public health initiatives, appear to be warranted.

A comprehensive review of flaxseed (Linum usitatissimum L.): health-affecting compounds, mechanism of toxicity, detoxification, anticancer and potential risk

Flaxseed consumption (Linum usitatissimum L.) has increased due to its potential health benefits, such as protection against inflammation, diabetes, cancer, and cardiovascular diseases. However, flaxseeds also contains various anti-nutritive and toxic compounds such as cyanogenic glycosides, and phytic acids etc. In this case, the long-term consumption of flaxseed may pose health risks due to these non-nutritional substances, which may be life threatening if consumed in high doses, although if appropriately utilized these may prevent/treat various diseases by preventing/inhibiting and or reversing the toxicity induced by other compounds. Therefore, it is necessary to remove or suppress the harmful and anti-nutritive effects of flaxseeds before these are utilized for large-scale as food for human consumption. Interestingly, the toxic compounds of flaxseed also undergoes biochemical detoxification in the body, transforming into less toxic or inactive forms like α-ketoglutarate cyanohydrin etc. However, such detoxification is also a challenge for the development, scalability, and real-time quantification of these bioactive substances. This review focuses on the health affecting composition of flaxseed, along with health benefits and potential toxicity of its components, detoxification methods and mechanisms with evidence supported by animal and human studies.

MECHANISMS IN ENDOCRINOLOGY: The pathophysiology of transient congenital hypothyroidism

Transient congenital hypothyroidism (TCH) refers to congenital hypothyroidism which spontaneously resolves in the first few months or years of life. Currently, there is a paucity of reliable markers predicting TCH at diagnosis, and the diagnosis is established following the withdrawal of levothyroxine therapy around 3 years of age. The incidence of TCH is increasing, and it is a major contributor to the overall increase in the incidence of CH in recent studies. Both genetic factors, in particular mutations affecting DUOX2 and DUOXA2, and environmental factors, for example, iodine deficiency and excess, anti- TSHR antibodies and exposure to antithyroid or iodine-rich medications, may cause TCH. Resolution of TCH in childhood may reflect both normal thyroid physiology (decreased thyroid hormone biosynthesis requirements after the neonatal period) and clearance or cessation of environmental precipitants. The relative contributions and interactions of genetic and environmental factors to TCH, and the extent to which TCH may be prevented, require evaluation in future population-based studies.

Case Report: Technetium-99m Pertechnetate Scintigraphy Findings in a Dog With Iodine Deficiency-Induced Goitrous Hypothyroidism

There is only one previous report of canine goitrous hypothyroidism caused by iodine deficiency from 1986. The present case report describes the novel diagnostic methods and long-term outcomes of a dog diagnosed with goitrous hypothyroidism caused by iodine deficiency. A 4-year-old neutered, female Pomeranian dog presented with a cervical mass, lethargy, and inactivity. The dog had a history of eating home-cooked diets sold by a private seller for 1 year. The physical examination and ultrasonography showed two bilaterally symmetric masses in the mid-cervical area (left, 1.8 × 1.4 cm; right, 2.3 × 1.8 cm), and they were suspected to be the thyroid glands. To identify the function of the thyroid gland, the basal concentrations of thyroid hormones [total T4 (tT4) and thyroid-stimulating hormone (TSH)] were measured and a TSH stimulation test was performed: baseline tT4, 0.5 μg/dL (reference interval, 1–4 μg/dL), baseline TSH, 0.81 μg/dL (reference interval, 0.05–0.42 μg/dL), and post-tT4, 1 μg/dL (6 h after the injection of TSH). The values indicated primary hypothyroidism. The urinary iodine concentration was 302 μg/L, which was markedly lower than that of normal dogs (1,289 μg/L). Thyroid scintigraphy with technetium-99m pertechnetate was also performed to quantify the activity of the thyroid gland, and the thyroid-to-salivary ratio was 3.35. Based on the results of these examinations and patient history, the dog was diagnosed with diet-induced (iodine deficiency) goitrous hypothyroidism. The dog was treated with iodine (62.5 μg/day). At 31 days after treatment, clinical signs and thyroid hormones were normalized (tT4, 1.3 μg/dL; TSH, 0.24 μg/dL). One year after treatment, the dog was well with normal concentrations of thyroid hormones (tT4, 1.8 μg/dL; TSH, 0.27 μg/dL) and a partially reduced goiter (left, 1.6 × 1.1 cm; right, 1.2 × 0.9 cm). This is the first case to describe novel diagnostic methods and long-term outcomes of a dog diagnosed with goitrous hypothyroidism caused by iodine deficiency.

OUP accepted manuscript

Context

Adequate iodine intake is essential throughout life. Key dietary sources are iodized salt and animal products, but dietary patterns in Europe are changing, for example toward lower salt intake and a more plant-based diet.

Objective

To review iodine intake (not status) in European populations (adults, children, and pregnant women) to identify at-risk groups and dietary sources.

Data sources

PubMed, Embase, and Cochrane databases, as well as European national nutrition surveys were searched for data on had iodine intake (from dietary assessment) and sources of iodine, collected after 2006.

Data selection

In total, 57 studies were included, comprising 22 national surveys and 35 sub-national studies. Iodine intake data were available from national surveys of children aged <10 years (n = 11), 11–17 years (n = 12), and adults (n = 15), but data from pregnancy were only available from sub-national studies.

Results

Iodine intake data are lacking—only 17 of 45 (38%) European countries had iodine-intake data from national surveys. Iodine intake reported from national surveys was below recommendations for: (1) children aged <10 years in 2 surveys (18%), (2) boys and girls aged 11–17 years in 6 (50%) and 8 (68%) surveys, respectively, and (3) adult men and women in 7 (47%) and 12 (80%) surveys, respectively. In pregnant women, intake was below recommendations except where women were taking iodine-containing supplements. Just 32% of national surveys (n = 7) included iodized salt when estimating iodine intake. Milk, dairy products, fish, and eggs were important contributors to intake in many countries, suggesting limited sources in plant-based diets.

Conclusion

Results are limited by the challenges of dietary assessment for measuring iodine intake. Future national surveys should include iodine intake. Policy makers should consider dietary sources alongside any iodized salt policies when considering methods for improving population iodine intake.

Systematic Review Registration

PROSPERO 2017 CRD42017075422.

Assessment of iodine nutrition of schoolchildren in Gonda, India, indicates improvement and effectivity of salt iodisation

OBJECTIVE

To study the total goitre rate (TGR), urinary iodine concentration (UIC) and salt iodine content among schoolchildren in a previously endemic area for severe iodine deficiency disorder (IDD).

DESIGN

Cross-sectional epidemiological study.

SETTING

The study was carried out in the Gonda district (sub-Himalayan region) of North India.

PARTICIPANTS

Nine hundred and seventy-seven schoolchildren (6-12 years) were studied for parameters such as height, weight, UIC and salt iodine content. Thyroid volume (TV) was measured by ultrasonography to estimate TGR.

RESULTS

The overall TGR in the study population was 2·8 % (95 % CI 1·8, 3·8). No significant difference in TGR was observed between boys and girls (3·5 % v. 1·9 %, P = 0·2). There was a non-significant trend of increasing TGR with age (P = 0·05). Median UIC was 157·1 μg/l (interquartile range: 94·5-244·9). At the time of the study, 97 % of salt sample were iodised and nearly 86 % of salt samples had iodine content higher than or equal to 15 part per million. Overall, TGR was significantly lower (2·8 % v. 31·0 %, P < 0·001), and median UIC was significantly higher (157·1 v. 100·0 μg/l, P < 0·05) than that reported in the same area in 2009.

CONCLUSIONS

A marked improvement was seen in overall iodine nutrition in the Gonda district after three and a half decades of Universal Salt Iodisation (USI). To sustainably control IDD, USI and other programmes, such as health education, must be continuously implemented along with putting mechanisms to monitor the programme at regular intervals in place.

Nutrition and Metabolism of Minerals in Fish

Simple Summary

Our aim is to introduce the mineral nutrition of fish and explain the complexity of determining requirements for these elements, which are absorbed and excreted by the fish into the surrounding water. To date, only the requirements for nine minerals have been investigated. The review is focused on the absorption and the dietary factors that reduce their absorption from feed ingredients of plant and animal origin. Some diseases, such as cataracts, anemia and bone deformity, have been linked to dietary deficiency of minerals.

Abstract

Aquatic animals have unique physiological mechanisms to absorb and retain minerals from their diets and water. Research and development in the area of mineral nutrition of farmed fish and crustaceans have been relatively slow and major gaps exist in the knowledge of trace element requirements, physiological functions and bioavailability from feed ingredients. Quantitative dietary requirements have been reported for three macroelements (calcium, phosphorus and magnesium) and six trace minerals (zinc, iron, copper, manganese, iodine and selenium) for selected fish species. Mineral deficiency signs in fish include reduced bone mineralization, anorexia, lens cataracts (zinc), skeletal deformities (phosphorus, magnesium, zinc), fin erosion (copper, zinc), nephrocalcinosis (magnesium deficiency, selenium toxicity), thyroid hyperplasia (iodine), muscular dystrophy (selenium) and hypochromic microcytic anemia (iron). An excessive intake of minerals from either diet or gill uptake causes toxicity and therefore a fine balance between mineral deficiency and toxicity is vital for aquatic organisms to maintain their homeostasis, either through increased absorption or excretion. Release of minerals from uneaten or undigested feed and from urinary excretion can cause eutrophication of natural waters, which requires additional consideration in feed formulation. The current knowledge in mineral nutrition of fish is briefly reviewed.

Effects of isolated maternal hypothyroxinemia on adverse pregnancy outcomes

PURPOSE

There are conflicting results about the effects of maternal hypothyroidism (IMH) on adverse pregnancy outcomes. This study aimed to investigate the relationship between IMH identified in the first trimester of gestation and adverse pregnancy outcomes.

METHODS

In this prospective cohort study, we used data from the Tehran Thyroid and Pregnancy study (TTPs). To diagnose IMH, we considered a threshold of 2.04 for FTI, which was based on the 10th percentile of this marker identified in the 1st trimesters. A generalized linear regression (GLM) model adjusted for the gravidity, urine iodine, and TPOAb status was applied to assess the effects of IMH on adverse pregnancy outcomes, compared to the controls group.

RESULTS

Penalized logistic regression analysis indicated that the adjusted odds ratio (aOR) of Preterm premature rupture of the membranes (PPROM) in women with IMH was 5.43-folder higher than euthyroid group [aOR 5.43, 95% CI (1.40, 21.1), p = 0.01]. Besides, the adjusted odds ratio of low birth weight (LBW) in the IMH group was 2.53-folder higher than the healthy group [aOR 2.53, 95% CI (1.01, 6.33), p = 0.047]. Furthermore, the results of the GLM adjusted model revealed that the mean of neonatal head circumference and weight in the IMH group was around 0.43 cm (95% CI - 0.80, - 0.07, p = 0.02) and 145.4 g (95% CI - 242.6, - 48.1, p = 0.003) lower than euthyroid group, respectively.

CONCLUSIONS

This study demonstrated that women with IMH identified in early pregnancy have a higher odds ratio for developing some adverse pregnancy outcomes, including PPROM and LBW compared to their euthyroid counterparts. Also, the neonatal head circumference and weight in the IMH group were lower than in the euthyroid group.

Comparison between an Emerging Point-of-Care Tool for TSH Evaluation and a Centralized Laboratory-Based Method in a Cohort of Patients from Southern Italy

Endocrine and metabolic disorders are a common condition in Europe and worldwide, and, among these, thyroid dysfunction still remains a problem. The measurement of thyroid stimulating hormone (TSH) levels represents the first-line assay for the assessment of thyroid function. In the present study, we compared serum concentrations of TSH, measured using a commercially available point-of-care test (POCT) method (FastPack^® IP) and an established "conventional" laboratory-based method (Beckmann Access 2) in a cohort of patients from Foggia in Southern Italy. A strong correlation (r = 0.994) was found between both methods and was also confirmed by receiver operating characteristic (ROC) curve analysis (0.82). The within-run coefficient of variation (CV) using FastPack^® ranged from 4.03% and 8.57% at the TSH concentrations of 39.49 and 0.70 mIU/L, respectively. The between-run CV was 10.34% and 6.33% at the TSH concentrations of 0.87 and 26.55 mIU/L, respectively. The ratios of within- to between-assay CV were 0.83 and 1.06 at the TSH levels of 0.70 and 52.59 mIU/mL, respectively. In this study, we showed that serum TSH levels can be measured in a few minutes and at low-cost in terms of materials and equipment required. We observed that this approach is user-friendly, accurate, reproducible, and suitable for use in the clinic, while also meeting the criteria for effectiveness, impact, efficiency, and sustainability.

The association of lactating mothers' urinary and breast milk iodine levels with iodine nutrition status and thyroid hormone levels of newborns

Objective

To explore the iodine status of lactating mother-newborn pairs, and whether neonatal serum thyroid-stimulating hormone (TSH) can be used for estimation of iodine status of the population.

Materials and Methods

A total of 334 mothers and their healthy neonates were included. Urine, serum, and breast milk samples were obtained at 4th and 6th days of delivery. Urinary iodine concentration (UIC) was measured in urine samples of mothers and their neonates, as well as breast milk iodine concentration (BMIC) and serum thyroid hormone levels of neonates, were measured from the samples taken between the 4th and 6th days after birth.

Results

Median age of the mothers was 27 years (23-30). The median UIC of mothers and their newborns were 125 μg/L and 142 μg/L, respectively. The median BMIC was 138,0 μg/L. There was a significant positive correlation between the BMIC and UIC of neonates (r=0.276, p<0.001). The prevalence of neonatal serum TSH >10 mIU/L, which is suggestive of mild iodine deficiency (i.e. 3.0-19.9%), was 19.0%. However, there were no participants with iodine deficiency in lactating mothers and neonates according to UIC.

Conclusion

By previous reports, Aydın is iodine sufficient. Although 19% of the neonates had serum TSH levels >10 mU/L, which is suggestive of a mild iodine deficiency, iodine deficiency was observed in none of the neonates and their mothers. Therefore, it will be appropriate to investigate the role of neonatal TSH levels in a larger sample to assess the iodine status of the population.

Salt Used for the National School Nutrition Program (NSNP) in Rural Schools of Limpopo Province, South Africa, has Adequate Levels of Iodine

BACKGROUND

Salt iodisation is considered the most effective long-term public health intervention for achieving optimal iodine nutrition. Effective salt iodisation is a prerequisite for the sustainable elimination of iodine deficiency disorders. The aim of this study was to determine iodine concentration of salt used for the National School Nutrition Program (NSNP).

METHODS

A cross-sectional study was conducted in 359 food handlers from Vhembe and Mopani districts of Limpopo Province, South Africa. The questionnaire was administered to solicit data on demographic information, general questions on salt fortification, and iodine nutrition knowledge. After the interviews, two tablespoons of salt used for the NSNP food preparation was collected from 318 schools in small zip-lock plastic bags. The salt samples were coded and stored at room temperature and protected from light and moisture until the time of analysis. Salt iodine concentrations were determined at the North-West University (NWU) in Potchefstroom by means of the iCheck test method.

RESULTS

The median iodine concentration of both Mopani (31.65 ppm) and Vhembe (32.56 ppm) districts signified adequate iodine levels. Of 318 salt samples, 113 (71%) samples in Mopani and 104 (65%) in Vhembe had an iodine concentration of 15-64 ppm. A few (6%) food handlers in Mopani and almost half (45.9%) in Vhembe could correctly identify iodated salt as the main source of iodine. Almost half of the food handlers (%) in Mopani and 36.5% in Vhembe did not know which part of body needs iodine for functioning.

CONCLUSION

More than 20 years after the implementation of the USI program, the result of the study shows that the international goal of 90% coverage is still far from being realised.

Circulating concentrations of thyroid hormones and cortisol in wild and semi-natural Yangtze finless porpoise (Neophocaena asiaeorientalis)

Our understanding about how environmental and biological variables may influence circulating thyroid and adrenal hormones in free-ranging cetaceans is limited. As such, we used liquid chromatography-mass spectrometry to determine concentrations of circulating cortisol and thyroid hormones (THs; tT3, tT4) in 132 Yangtze finless porpoises (YFPs) located in Poyang Lake, (PL, n = 92) and Tian-E-Zhou Oxbow reserve (TZO, n = 40). For overall hormone comparisons, animals were partitioned by age [juvenile and adult (male and non-pregnant, non-lactating female)], sex, season (winter or spring) and geographical location. Geographically, during winter, circulating THs were significantly higher in the PL versus TZO population. Seasonally, within PL, THs were significantly higher in the winter versus spring season. Animals were further binned into groups as follows: juvenile male (JM) and juvenile female (JF), adult male (AM), non-pregnant adult female, pregnant female and non-pregnant lactating female. Intra-group comparisons between locations showed a significant increase in JM THs at PL. Significant increases in THs during winter compared to spring were detected between JM and JF groups. Mean comparisons of cortisol within and between locations for each group identified a significant increase for TZO AM versus TZO pregnant female and JM and JF. Seasonally, in PL, only JF has significantly higher cortisol in winter versus spring. Finally, we established reference values of THs and cortisol for YFPs in different geographical locations. These references are important baselines from which the effects of environmental and biological variables on THs and cortisol may be evaluated.

Effects of Two Weekly Servings of Cod for 16 Weeks in Pregnancy on Maternal Iodine Status and Infant Neurodevelopment: Mommy's Food, a Randomized-Controlled Trial

Background: Mild-to-moderate iodine deficiency is still present in many countries, particularly in pregnant women. Observational studies suggest that mild-to-moderate iodine deficiency during pregnancy may be associated with impaired thyroid function and child neurodevelopment. Randomized-controlled food trials to increase iodine status are scarce. We assessed the impact of an increased intake of cod during pregnancy on maternal iodine status and infant neurodevelopment. Methods: In this randomized-controlled trial, pregnant women in Bergen, Norway, recruited through Haukeland University Hospital, were randomly assigned (1:1) to an intervention of 200 g of cod twice a week for 16 weeks (gestational week 20-36) or to continue with their standard diet (control group). Randomization was done by lottery. Primary outcome was urinary iodine concentration (UIC) (spot samples from six consecutive days) measured postintervention. Secondary outcome was infant neurodevelopment assessed by the cognitive, language, and motor scales of the Bayley Scales of Infant and Toddler Developmental third edition (Bayley-III) at 11 months of age. In addition, maternal thyroid function was measured (thyrotropin [TSH], free triiodothyronine [fT3], free thyroxine [fT4]) at baseline and postintervention. Results: Between January 2016 until February 2017, 137 women were recruited. Postintervention UIC was higher in the intervention group (n = 61) [median (interquartile range, IQR) 98 (64-145) μg/L], compared with control (n = 61) [median (IQR) 73 (52-120) μg/L] (p = 0.028), also after adjusting for baseline UIC (p = 0.048). Infants of mothers in the intervention group had a lower cognitive composite score on the Bayley-III compared with the control group (p = 0.045). There were no group differences in the Bayley III language- or motor composite scores. Maternal thyroid hormones (TSH, fT3, fT4) did not differ between the groups postintervention. Conclusions: Increased cod intake during pregnancy improved the iodine status in women with mild-to-moderate iodine deficiency, however, did not affect thyroid function. The negative effect on cognition should be followed up to assess whether this is a stable effect over time. More studies are warranted to enable good health advice on iodine nutrition in pregnancy. ClinicalTrials.gov NCT02610959. Registered November 20, 2015.

Prevalence of Goiter Among School-Aged Children in Ethiopia: Update of Systematic Review and Meta-analysis

Background

Iodine deficiency is a major public health concern throughout the world. Goiter is the most visible sign of iodine deficiency. In Ethiopia, a study finding regarding the prevalence of goiter among school-age children is inconsistent and highly variable.

Objectives

To estimate the pooled prevalence of goiter among school-age children in Ethiopia.

Methods

Three international databases (MEDLINE/Pub-Med, Google Scholar and Science Direct) were systematically searched. Besides, the reference sections of identified articles were searched to increase the chance of detecting missed articles in gray literature. STATA Version 14 statistical software was used to conduct a meta-analysis. The pooled prevalence with a 95% confidence interval was displayed using the forest plot. A random-effect meta-analysis model was used to compute the pooled prevalence, and The Cochrane Q test statistics and I² test were used to assess the heterogeneity of the studies.

Results

A total of 14 studies fulfilled the inclusion criteria and included in this systematic review and Meta-analysis, with a total sample size of 26,282. The finding of this systematic review revealed that the pooled prevalence of goiter among school-age children was 42.9% (95% CI: 38.8–46.9). The highest prevalence of goiter (46.7%) was observed in Oromia region and the lowest (26.3%) was observed in Benishangul-Gumuz region.

Conclusions

This review finding revealed that more than two in five of the school children in Ethiopia suffer from iodine deficiency disorder as manifested by the goiter rate.

Thyroid function control among pregnant women following a therapeutic thyroidectomy

OBJECTIVES

The aim of this study was to assess the extent of thyroid function control among pregnant women who had previously undergone a therapeutic thyroidectomy.

DESIGN

Retrospective cohort study.

SETTING

The largest health maintenance organization in Israel.

PARTICIPANTS

All female patients who were pregnant between May, 2001 and September, 2012 and had a medical history of thyroid surgery.

MAIN OUTCOME MEASURE

The thyroid-stimulating hormone (TSH) levels throughout the pregnancy were compared to recommended trimestral values. A multivariate analysis was performed to determine risk factors for not attaining TSH recommended range.

RESULTS

A total of 477 females with a history of thyroid surgery had given 701 births during the study period. Forty-three percent (n = 203), had thyroidal malignancy. Nearly half of the women underwent total thyroidectomy (43.4%, n = 207). The women's TSH values were within the recommended range in only 60% (n = 350) of the pregnancies during the first trimester (0.1-2.5 mIU/L), in 61% (n = 335) during the second trimester (0.2-3 mIU/L), and in 70% (n = 338) during the third trimester (0.3-3 mIU/L). In multivariate analysis, women that underwent a total thyroidectomy due to a benign thyroid disease, were at the highest risk for not attaining target TSH levels.

CONCLUSIONS

This very large cohort of pregnant women with a past history of thyroid surgery demonstrated a significant percentage of pregnancies with TSH values above the recommended range. Women that underwent a total thyroidectomy due to benign thyroid disease were at the highest risk for gestational hypothyroidism.

Theoretical study of chloride complexes with hybrid macrocycles

Macrocycle receptors are investigated from DFT calculations to simultaneously recognize two Cl⁻ anions, which show several applications in the environment.

Optical sensing of anions by macrocyclic and interlocked hosts

This review summarises recent developments in the use of macrocyclic and mechanically-interlocked host molecules as optical sensors for anions.

National incidence, prevalence and disability-adjusted life years (DALYs) of common micronutrient deficiencies in Ethiopia from 1990 to 2017: estimates from the global burden of diseases study

BACKGROUND

Understanding the national burden and trend of micronutrient deficiencies helps to guide effective intervention strategies under various circumstances. There is, however, a lack of evidence on trends, age- and sex-specific variations in Ethiopia.

OBJECTIVE

This study aimed to provide evidence on the trends of common micronutrient deficiencies including, dietary iron, iodine, vitamin A and other nutritional deficiencies in Ethiopia, from 1990 to 2017, using findings from the Global Burden of Disease study.

METHOD

We used estimates from the GBD 2017 study to report the incidence, prevalence and disability-adjusted life years of micronutrient deficiencies in Ethiopia from 1990 to 2017. All estimates, both crude counts, as well as all-age and age-standardized rates per 100,000 population, are accompanied by 95% uncertainty intervals (UIs). We summarized the age- and sex-specific patterns and we compared the burden with the sub-Saharan Africa and global estimate.

RESULTS

From 1990 to 2017, the age-standardized prevalence rate of dietary iron, vitamin A and iodine deficiency decreased by 20.1%, 16.7%, and 91.6%, respectively. However, MNDs still account for a large number of DALYs in the country. In 2017, the all-age total DALYs due to dietary iron deficiency were estimated to be 448.4 thousand [95% UI: 298.9-640.7], accounting for 1.18% of the total DALYs. Similarly, the all-age total DALYs due to vitamin A deficiency were 397.8 thousand [256.1-589.2]. The total DALYs due to iodine deficiency were estimated to be 89.6 thousand [48.3-155.4].

CONCLUSIONS

Micronutrient deficiencies and associated morbidity and mortality are still high in Ethiopia compared with the sub-Saharan and global estimate. Adolescent and early adult females and children aged under-five are disproportionately affected segments of the population. Therefore, in collaboration with other sectors, the National Nutrition Program needs to place greater emphasis upon improving accessibility and utilization of nutrient-rich foods and supplementation, particularly for vulnerable groups of the population.

Prevalence of iodine deficiency among pregnant women in Gwembe and Sinazongwe districts of Southern Province, Zambia: a cross-sectional study

Background

Maternal iodine deficiency is one of the common causes of morbidity and mortality during pregnancy. Maternal iodine deficiency during pregnancy is associated with a number of adverse outcomes such as abortion, stillbirth, congenital anomalies, perinatal mortality and irreversible mental retardation. A study conducted in Zambia among pregnant women in 2013 on the prevalence of iodine deficiency showed that iodine deficiency was not a public health concern. The previous study used Urine Iodine concentration (UIC) as a marker of iodine deficiency among the pregnant women. Our study was conducted to assess the prevalence of iodine deficiency among pregnant women in Gwembe and Sinazongwe districts of Southern Province, Zambia, using urine iodine concentration and goitre presence by manual palpation.

Methods

We carried out a community based, cross sectional study in rural areas of Gwembe and Sinazongwe districts between April 2016 to March 2018. Data were collected from 412 pregnant women by a multistage cluster sampling technique. The presence of a goitre was examined by manual palpation and urinary iodine concentration was determined by the Ultra Violet Method using PerkinElmer Labda UV Spectrometer equipment made in Jena Germany (Model 107,745). As part of the existing baseline data, we used results of a 2013 countrywide study (n = 489) for household salt iodine content which showed a greater than 40 ppm at 76.2%, between 15 and 40 ppm at 19.21% and less than 15 ppm at 4.59%. Statistical analysis was done using Stata version 14.0. The outputs of analysis are presented as median and Interquartile range (IQR) as the urine data were not normally distributed. Further, the categorical and independent variables were presented as proportions (percentages) to describe the distribution and trends in the target sample population.

Results

The median Urine Iodine concentration (UIC) of the pregnant women was 150 μg/L (Interquartile Range (IQR): 100–200 μg/L). Based on the UIC, There were 49% pregnant women who had inadequate iodine intake with urine iodine concentration of less than 150 μg/L, 34.0% had UIC of 150–249 μg/L indicating adequate iodine intake, 13.0% with UIC of 250–499 μg/L indicating more than adequate iodine intake, and 5.0% with UIC of above 500 μg/L indicating excessive iodine intake. To determine whether the women had access to iodized salt, we used baseline data from 2013 Zambia national survey for iodine concentration in household salt samples as being an average of 40 ppm, which also showed that 95.41% households consumed adequately iodized salt (≥15 ppm). The prevalence of goitre in our study was very low at 0.02% among the pregnant women of all ages who participated in the study (18–49 years).

Conclusion

Iodine deficiency was still not a public health concern among the pregnant women of Gwembe and Sinazongwe districts of Southern Province in Zambia. Goitre prevalence has remained very low in this study area. The UIC and goitre observations were consistent with the Zambia National Food and Nutrition Commission findings in 2013 report. However, our study showed more pregnant women with insufficient than adequate iodine status indicating the risk of developing IDD is still high in this region. It also reinforces the argument that strengthening of the existing salt iodization program is needed in order to make a homogenous iodated salt available to the communities. The National Food and Nutrition Commission of Zambia needs to find innovative ways of sensitizing people about the adverse effects of IDDs and how these could be prevented. It is recommended that iodine supplementation be introduced as part of the package of Antenatal clinic care for all pregnant women.

Universal Salt Iodisation: Lessons learned from Cambodia for ensuring programme sustainability

Iodine deficiency is the leading cause of preventable intellectual disability in the world, but it has been successfully prevented in most countries through universal salt iodization (USI). In 2011, Cambodia appeared to be an example of this success story, but today, Cambodian women and children are once again iodine deficient. In 2011, Cambodia demonstrated high‐household coverage of adequately iodized salt and had achieved virtual elimination of iodine deficiency in school‐age children. However, this achievement was not sustained because the USI programme was dependent on external funding, and the national government and salt industries had not institutionalized their implementation responsibilities. Recent programmatic efforts, in particular the establishment of a regulatory monitoring and enforcement system, are turning the situation around. Although Cambodia has not yet fully regained the achievements of 2011 (only 55% of tested salt was adequately iodized in 2017 compared with 67% in 2011), the recent steps taken by the government and the salt industry point to greater sustainability of the USI programme and the long‐term prevention of iodine deficiency in children, women, and the general population.

Indications for treatment of subclinical hypothyroidism and isolated hypothyroxinaemia in pregnancy

Thyroid hormones are essential for maintaining a pregnancy and optimal fetal neurological development. Pregnancy places additional demands on the thyroid axis and around 5% of women who have their thyroid function checked during gestation will have borderline low thyroid function (subclinical hypothyroidism or isolated hypothyroxinemia) identified. These borderline low thyroid states are associated with adverse obstetric and offspring outcomes. Whilst it is well established that overt hypothyroidism requires treatment with levothyroxine, it is less clear whether there is any benefit of treating borderline low thyroid states. This review summarizes the potential indications for treatment of subclinical hypothyroidism and isolated hypothyroxinemia.

Physiologic Significance of Epigenetic Regulation of Thyroid Hormone Target Gene Expression

BACKGROUND

In previous publications, we have reported our findings demonstrating that exposure to high maternal levels of thyroid hormones (TH) has life-long effects on the wild-type (WT, without THRB mutation) progeny of mothers with resistance to thyroid hormone beta (RTHβ). The mechanism of this epigenetic effect remains unclear.

OBJECTIVES

We reviewed the mechanisms involved in the epigenetic regulation of TH target genes and understand how they may explain the reduced sensitivity to TH in the WT progeny of RTHβ mothers.

METHODS

The availability of a large, formerly genotyped Azorean population with many individuals harboring the THRB mutation, R243Q, provided us a model to study the influence of fetal exposure to high maternal TH levels.

RESULTS

The thyroid-stimulating hormone (TSH) response in WT adults was less suppressible following the administration of L-triiodothyronine (L-T₃). This finding suggests reduced sensitivity to TH that is induced by an epigenetic mechanism resulting from exposure to high maternal levels of TH during pregnancy. The persistence of this effect across 3 generations of WT subjects favors transgenerational epigenetic inheritance. Based on preliminary studies in mice, we identified the naturally imprinted gene encoding deiodinase type 3, i.e., DIO3, as a possible mediator of this epigenetic effect through increased inactivation of TH.

CONCLUSION

Increased D3 expression and consequently increased T₃ degradation appear to be responsible for the reduced sensitivity of the anterior pituitary to administered L-T₃. The imprinted DIO3 gene may be a candidate gene that mediates the epigenetic effect induced by exposure to high maternal levels of TH. However, we cannot exclude the role of other TH-responsive genes.

High prevalence of TPO-Abs and subclinical hypothyroidism in iodine-sufficient pregnant women in Northern Algeria

BACKGROUND

Iodine is a trace element whose adequate intakes are essential during gestation to promote the correct growth and development of the fetus. Historically, endemic goiter and cretinism affected northern regions of Algeria, and iodized salt was introduced in 1990. However, there has been no national study of iodine nutrition in Algeria since 1994. The aim of this study was to assess the iodine status and thyroid function of women of reproductive age (WRA) and pregnant women (PW) in northern Algeria.

METHODS

Healthy WRA and PW were recruited from an urban area (Algiers) and healthy WRA from a rural area (Tizi-Ouzou). Spot urine and venous blood samples were collected to assess iodine status (urinary iodine concentration, UIC) and serum thyroid hormones (TSH, FT4), thyroglobulin (Tg), and anti-thyroid peroxidase antibodies (TPO-Ab) concentrations.

RESULTS

The median UIC in WRA was 256 μg/L (IQR: 166-354 μg/L; n = 151) in Algiers and 253 μg/L (167-341 μg/L; n = 150) in Tizi-Ouzou. The median UIC for the PW in Algiers was 233 μg/L (IQR: 157-326 μg/L; n = 173).Thirty-five percent of WRA and 30% of PW had an UIC > 300 μg/L. Median TSH, FT4 and Tg concentrations were within reference ranges in all groups of women. Among PW, 72.7%, 75.4% and 75.5% in the first, second and third trimester were TPO-Ab+. Among TPO-Ab + PW in the first, second and third trimesters, 18.7%, 13% and 10.3% had subclinical hypothyroidism.

CONCLUSION

In northern Algeria, median UICs in PW indicate iodine sufficiency, and in WRA indicate more than adequate intakes. About 75% of PW are TPO-Ab + and the prevalence of subclinical hypothyroidism is high. Monitoring and surveillance of iodine fortification programs is vital to avoid both iodine deficiency and excess. There is an urgent need for a comprehensive national iodine status survey including school-age children and other vulnerable population groups in Algeria.

Impaired Gene Expression Due to Iodine Excess in the Development and Differentiation of Endoderm and Thyroid Is Associated with Epigenetic Changes

Background: Thyroid hormone (TH) synthesis is essential for the control of development, growth, and metabolism in vertebrates and depends on a sufficient dietary iodine intake. Importantly, both iodine deficiency and iodine excess (IE) impair TH synthesis, causing serious health problems especially during fetal/neonatal development. While it is known that IE disrupts thyroid function by inhibiting thyroid gene expression, its effects on thyroid development are less clear. Accordingly, this study sought to investigate the effects of IE during the embryonic development/differentiation of endoderm and the thyroid gland. Methods: We used the murine embryonic stem (ES) cell model of in vitro directed differentiation to assess the impact of IE on the generation of endoderm and thyroid cells. Additionally, we subjected endoderm and thyroid explants obtained during early gestation to IE and evaluated gene and protein expression of endodermal markers in both models. Results: ES cells were successfully differentiated into endoderm cells and, subsequently, into thyrocytes expressing the specific thyroid markers Tshr, Slc5a5, Tpo, and Tg. IE exposure decreased the messenger RNA (mRNA) levels of the main endoderm markers Afp, Crcx4, Foxa1, Foxa2, and Sox17 in both ES cell-derived endoderm cells and embryonic explants. Interestingly, IE also decreased the expression of the main thyroid markers in ES cell-derived thyrocytes and thyroid explants. Finally, we demonstrate that DNA methyltransferase expression was increased by exposure to IE, and this was accompanied by hypermethylation and hypoacetylation of histone H3, pointing to an association between the gene repression triggered by IE and the observed epigenetic changes. Conclusions: These data establish that IE treatment is deleterious for embryonic endoderm and thyroid gene expression.

Socio-demographic correlates of availability of adequate iodine in household salt: a community-based cross-sectional study

Objective

This study aimed to assess the availability of adequately iodized salt at a household level and associated factors in Arba Minch town, South Ethiopia using the gold standard technique, the iodometric titration.

Results

41.8% (95% CI (confidence interval) 38.6 to 45.1) of households had inadequately iodized salt, and 9.3% (95% CI 7.5 to 11.4) had an iodine content below 10 ppm (parts per million). Compared to households with a monthly income of greater than 2000 ETB (Ethiopian Birr), households with a monthly income between 1000 ETB to 2000 ETB (adjusted odds ratio (AOR) = 0.52, 95% CI 0.390.36 to 00.77) and main food handlers aged 30 years or above compared to those aged less than 20 years of age (aOR = 0.55, 95% CI 0.34 to 0.91) had higher odds of having adequately iodized salt. Food handler’s knowledge and practice were not found to be correlated with the availability of adequately iodized salt in household salt.