Iodine-induced thyroid dysfunction

Risks of Iodine Excess

Iodine is a micronutrient that is required for thyroid hormone synthesis. The iodide cycle in thyroid hormone synthesis consists of a series of transport, oxidation, organification, and binding/coupling steps in thyroid follicular cells. Common sources of iodine include the consumption of an iodine-rich diet or iodine fortified foods, the administration of amiodarone, iodine-containing supplements, or iodinated contrast media, and other miscellaneous sources. Methods to assess population iodine status include the measurement of urinary iodine concentrations, blood thyroglobulin levels, prevalence of elevated neonatal TSH levels, and thyroid volume. Although excessive iodine intake or exposure is generally well tolerated, an acute iodine load may result in thyroid dysfunction (hypothyroidism or hyperthyroidism) in certain susceptible individuals due to the failure to escape from the Wolff-Chaikoff effect and to the Jod-Basedow phenomenon, respectively. In this review, we discuss the associations between excessive iodine intake or exposure, with particular focus on iodinated contrast media as a common source of excess iodine in healthcare settings, and risks of incident thyroid dysfunction. We also summarize the risks of iodine excess in vulnerable populations and review current guidelines regarding the screening and monitoring of iodinated contrast-induced thyroid dysfunction. Finally, we discuss the long-term potential nonthyroidal health risks associated with iodine excess and suggest the need for more data to define safe upper limits for iodine intake, particularly in high-risk populations.

Hypothyroidism Due to Seaweed Overconsumption

Hypothyroidism presents various symptoms, ranging from commonly observed signs, such as fatigue, cold sensation, and constipation, to rare features, such as rash and pancytopenia, resembling certain rheumatological and hematological diseases. Chronic, excessive iodine consumption causes primary hypothyroidism. However, when iodine overconsumption becomes a regular part of daily dietary habits, it becomes difficult for patients to associate their symptoms with daily iodine consumption. Therefore, clinicians cannot obtain information on excessive iodine intake from the patient. Here, we present a case of hypothyroidism that was subsequently identified as caused by excessive dairy seaweed consumption for health purposes. This case report highlights the importance of a detailed dietary history in patients diagnosed with primary hypothyroidism without thyroid autoantibodies.

Effects of iodine intake on gut microbiota and gut metabolites in Hashimoto thyroiditis-diseased humans and mice

Hashimoto thyroiditis (HT) is an organ-specific autoimmune disease linked to iodine intake. Emerging evidence highlights the gut microbiota's role in HT pathogenesis via the microbiota-gut-thyroid axis. However, the process through which iodine intake modifies the microbiota and triggers HT remains unclear. This study examines how iodine affects gut dysbiosis and HT, recruiting 23 patients with HT and 25 healthy individuals to assess gut microbiota composition and metabolic features. Furthermore, we establish a spontaneously developed thyroiditis mouse model using NOD.H-2h4 mice highlighting the influence of iodine intake on HT progression. The butanoate metabolism significantly differs between these two groups according to the enrichment results, and butyric acid is significantly decreased in patients with HT compared with those in healthy individuals. Gut dysbiosis, driven by excessive iodine intake, disrupts TH17/Treg balance by reducing butyric acid. In summary, iodine intake alters intestinal microbiota composition and metabolic changes influencing the microbiota-gut-thyroid axis.

Radiopharmaceuticals: A New Vista for Diagnosis and Treatment of Thyroid Cancer

Radiopharmaceuticals are in the diagnosis and treatment of cancerous and noncancerous diseases, and a hope for optimistic effort in the field of nuclear medicine. They play a crucial role in clinical nuclear medicine by providing a tool to comprehend human disease and create efficient treatments. A detailed analysis is provided regarding the crux of molecular imaging including PET and SPECT overview for the detection of cancers. For a specified understanding of radiation therapy, topics include ranging from the selection of radionuclide to its development and manufacture, and dosage requirements to establishing the importance of I- 131 Radiotherapy in thyroid cancer. In this review, we also discussed the current state of the art of nuclear medicine in thyroid cancer, including the role of radioiodine (RAI) therapeutic scans in the diagnosis of differentiated thyroid cancer. In addition, we established a brief outlook into the current status of the research in thyroid cancer and discussed the future directions in this field.

Iodine-induced hypothyroidism (IIH) in paediatric patients receiving peritoneal dialysis: Is risk mitigation possible?

Children with kidney failure who receive maintenance peritoneal dialysis (PD) are at increased risk for thyroid dysfunction. A poorly appreciated cause of hypothyroidism related to PD is iodine overload from exposure to iodine-containing cleaning solutions, iodinated contrast agents or povidone-iodine-containing PD caps, particularly in infants and small children. An international survey was conducted to understand current practices regarding iodine exposure in PD patients, the frequency of iodine-induced hypothyroidism (IIH) in patients receiving PD, and to assess awareness of this issue among paediatric nephrologists. Eighty-nine paediatric nephrology centres responded to the survey. Hypothyroidism in PD patients was diagnosed in 64% (n = 57) of responding centres, although only 19 of these centres (33%) suspected or diagnosed IIH. Aetiologies of IIH included exposure to povidone-iodine-containing PD caps (53%), cleaning solutions with iodine (37%) and iodinated contrast (10%). While most centres (58%, n = 52) routinely evaluate thyroid function, only 34% (n = 30) specifically aim to limit iodine exposure. Of centres not routinely evaluating for or utilising methods to prevent iodine exposure and hypothyroidism, 81% reported being unaware of the risk of IIH in PD patients. Hypothyroidism is diagnosed in a substantial percentage of paediatric PD programmes internationally. Increased education on the risk of iodine exposure in children receiving PD may decrease the incidence of IIH as an aetiology of hypothyroidism.

Thyroid dysfunction associated with iodine-contrast media: A real-world pharmacovigilance study based on the FDA adverse event reporting system

Objective

To comprehensively analyze characteristics of thyroid dysfunction associated with iodine contrast media (ICM) based on data from the FDA adverse event reporting system (FAERS).

Methods

Disproportionate analysis was employed to identify signals of thyroid dysfunction caused by ICM, and descriptive analysis was performed to examine the clinical characteristics of reported cases involving ICM-related thyroid dysfunctions.

Results

A total of 83 adverse event reports were identified, documenting thyroid dysfunctions associated with ICM agents. Treatment with ICM was significantly associated with higher reporting of hypothyroidism ([ROR] = 2.21, 95 % CI: 1.59-3.08; IC025 = 0.58) and hyperthyroidism (ROR = 3.49, 95 % CI: 2.37-5.13; IC025 = 1.14). Among the six ICM agents investigated, iodixanol demonstrated the highest signal strength in both hypothyroidism (ROR = 9.47) and hyperthyroidism (ROR = 5.44). Hypothyroidism and hyperthyroidism almost occurred in the first 30 days after ICM administration (76.9 % and 70 % of patients, respectively). Furthermore, the proportion of severe outcomes in hyperthyroidism was significantly higher than that in hypothyroidism (12/26 vs. 2/35, P = 0.009).

Conclusion

The present study highlights the varying risks of thyroid dysfunction associated with different ICM agents, with iodixanol exhibiting the highest signal intensity. Hypothyroidism and hyperthyroidism associated with ICM generally manifest within the first month following administration. Consequently, monitoring of thyroid function during this period is strongly recommended for ICM agents presenting higher risk profiles.

Over- and Undertreatment With Levothyroxine

BACKGROUND

Levothyroxine is a very commonly prescribed drug, and treatment with it is often insufficient or excessive. Nonetheless, there have been only a few reports on the determinants of inadequate levothyroxine treatment.

METHODS

Data from 2938 participants in the population-based Rhineland Study were analyzed. Putative determinants of inadequate levothyroxine treatment (overtreatment, thyrotropin level <0.56 mU/L; undertreatment, thyrotropin level >4.27 mU/L) were studied with logistic regression. The determinants of the levothyroxine dose were assessed with linear regression.

RESULTS

Overall, 23% of the participants (n = 662) stated that they were taking levothyroxine. Among these participants, 18% were overtreated and 4% were undertreated. Individuals over 70 years of age and above were four times as likely to be overtreated (OR = 4.05, 95% CI [1.20; 13.72]). Each rise in the levothyroxine dose by 25 μg was associated with an increased risk of overtreatment (OR = 1.02, 95% CI [1.02; 1.03]) and of undertreatment (OR = 1.02, 95% CI [1.00; 1.03]). Well-controlled participants (normal thyrotropin levels 0.56-4.27 mU/L) received a lower levothyroxine dose (1.04 ± 0.5 μg/kg/d) than overtreated (1.40 ±0.5 μg/kg/d) or undertreated (1.37 ±0.5 μg/kg/d) participants. No association was found between sociodemographic factors or comorbidities and the levothyroxine dose. Iodine supplementation was associated with a lower daily dose (β = -0.19, 95% CI [-0.28; -0.10]), while three years or more of levothyroxine exposure was associated with a higher daily dose (β = 0.24, 95% CI [0.07; 0.41]).

CONCLUSION

Levothyroxine intake was high in our sample, and suboptimal despite monitoring. Our findings underscore the need for careful dosing and for due consideration of deintensification of treatment where appropriate.

Iodine-induced thyroid dysfunction: a scientometric study and visualization analysis

Objective

Iodine is essential in thyroid hormone production. Iodine deficiency is associated with serious complications (i.e miscarriage and stillbirth), whereas excess can cause thyroid dysfunction (i.e hyperthyroidism, hypothyroidism, thyroid autoimmunity). We conducted this scientometric study to visualize hot spots and trends in iodine-induced thyroid dysfunction over past two decades. The aim of this paper was to help scholars quickly understand the development and potential trend in this field, and guide future research directions.

Methods

Articles on iodine-induced thyroid dysfunction from 2000 to 2022 were retrieved from the Web of Science Core Collection (WoSCC) using the following search terms: (((((TS=(hypothyroid*)) OR TS=(hyperthyroid*)) OR TS= ("TSH deficiency")) OR TS= ("thyroid stimulating hormone deficiency")) AND TS=(Iodine)) NOT TS=(radioiodine). Only publications in English were selected. CiteSpace, VOSviewer, Tableau, Carrot2, and R software were used to analyze the contribution and co-occurrence relationships of different countries, institutes, keywords, references, and journals.

Results

A total of 2986 publications from 115 countries and 3412 research institutions were included. From 2000 to 2022, research on iodine-induced thyroid dysfunction progressed over a three-stage development period: initial development (2000-2009), stable development (2010-2016), and rapid development (2016-2022) period. The Journal of Clinical Endocrinology and Metabolism had the most co-citations followed and China Medical University (n=76) had the most publications. The top three clusters of co-citation references were isolated maternal hypothyroxinemia, subclinical hyperthyroidism, and brain development. Various scientific methods were applied to reveal acknowledge structure, development trend and research hotspots in iodine-induced thyroid dysfunction.

Conclusion

Our scientometric analysis shows that investigations related to pregnant women, epidemiology surveys, and iodine deficiency are promising topics for future iodine-induced thyroid dysfunction research and highlights the important role of iodine on thyroid function.

Safety and efficacy of prophylactic treatment for hyperthyroidism induced by iodinated contrast media in a high-risk population

Introduction

The use of iodinated contrast media (ICM) can lead to thyrotoxicosis, especially in patients with risk factors, such as Graves' disease, multinodular goiter, older age, and iodine deficiency. Although hyperthyroidism may have clinically relevant effects, whether high-risk patients should receive prophylactic treatment before they are administered ICM is still debated.

Aim of the study

We aimed to demonstrate the safety and efficacy of prophylactic treatment with sodium perchlorate and/or methimazole to prevent ICM-induced hyperthyroidism (ICMIH) in a population of high-risk cardiac patients. We ran a cost analysis to ascertain the most cost-effective prophylactic treatment protocol. We also aimed to identify possible risk factors for the onset of ICMIH.

Materials and methods

We performed a longitudinal retrospective study on 61 patients admitted to a tertiary-level cardiology unit for diagnostic and/or therapeutic ICM-procedures. We included patients with available records of thyroid function tests performed before and after ICM were administered, who were at high risk of developing ICMIH. Patients were given one of two different prophylactic treatments (methimazole alone or both methimazole and sodium perchlorate) or no prophylactic treatment. The difference between their thyroid function at the baseline and 11-30 days after the ICM-related procedure was considered the principal endpoint.

Results

Twenty-three (38%) of the 61 patients were given a prophylactic treatment. Thyroid function deteriorated after the administration of ICM in 9/61 patients (15%). These cases were associated with higher plasma creatinine levels at admission, higher baseline TSH levels, lower baseline FT4 levels, and no use of prophylactic treatment. The type of prophylaxis provided did not influence any onset of ICMIH. A cost-benefit analysis showed that prophylactic treatment with methimazole alone was less costly per person than the combination protocol. On multivariate analysis, only the use of a prophylactic treatment was independently associated with a reduction in the risk of ICMIH. Patients not given any prophylactic treatment had a nearly five-fold higher relative risk of developing ICMIH.

Conclusion

Prophylactic treatment can prevent the onset of ICMIH in high-risk populations administered ICM. Prophylaxis is safe and effective in this setting, especially in cardiopathic patients. Prophylaxis with methimazole alone seems to be the most cost-effective option.

Severe Autoimmune Thyroiditis in Transgenic NOD.H2h4 Mice Expressing Interleukin-4 in the Thyroid

Background: Hashimoto's thyroiditis is a common autoimmune thyroid disorder characterized by thyroid lymphocytic infiltrates and autoreactive antibodies against thyroglobulin (TgAbs) and thyroperoxidase. Final evolution of the disease can lead to hypothyroidism with destruction of the thyroid architecture. Interleukin-4 (IL-4) is involved in the humoral immune response and B cell activation required in autoimmune thyroiditis (AT) progression. We used our mouse model overexpressing IL-4 by thyrocytes (Thyr-IL4) to study the impact of a local IL-4 expression in AT using transgenic nonobese diabetic (NOD.H2^h4) derived animals treated with iodide-supplemented water to increase the incidence of spontaneous AT (SAT). Methods: Thyr-IL4 NOD.H2^h4 and nonpathogenic C57BL/6 animals aged 8 weeks were exposed to 0.05% sodium iodide (NaI) in their drinking water for 8 and 16 weeks. Circulating TgAbs and expression of intrathyroidal cytokines were quantified. Thyroid inflammation was assessed by classical histological analyses, including identification of some immune cell populations. The most sensitive parameter to evaluate the thyroid function, serum thyrotropin (TSH), was also measured at the end of the treatment. Results: Relative to wild-type (WT) animals, Thyr-IL4 NOD.H2^h4 mice developed severe accelerated SAT with elevated serum TgAbs and numerous thyroid infiltrates mainly composed of CD4⁺/CD8⁺ T cells, B lymphocytes, and monocytes/macrophages. Thyroid expression of T helper (Th) Th1/Th2 cytokines was also enhanced, as well as IL-17. In contrast, excessive iodide supply did not induce TgAbs in WT and Thyr-IL4 SAT-resistant C57BL/6 animals. However, moderate leukocyte infiltrations in transgenic thyroids were evident compared to WT, but associated with a limited number of T and B cells and a different cytokine profile from Thyr-IL4 NOD.H2^h4 mice. Finally, and despite their diverse immune responses, both transgenic strains presented marked thyroid enlargement and elevated serum TSH at the end of the treatment in contrast to their WT littermates. Conclusions: These findings demonstrated that ectopic expression of IL-4 from thyrocytes enhanced the severity of accelerated SAT in disease-prone Thyr-IL4 NOD.H2^h4 animals and promoted thyroid leukocyte infiltration in SAT-resistant transgenic C57BL/6 mice. Moreover, impaired thyroid function emerged in both transgenic strains during the progression of the disease.

German Radiological Society and the Professional Association of German Radiologists Position Paper on Coronary computed tomography: Clinical Evidence and Quality of Patient Care in Chronic Coronary Syndrome

This position paper is a joint statement of the German Radiological Society (DRG) and the Professional Association of German Radiologists (BDR), which reflects the current state of knowledge about coronary computed tomography. It is based on preclinical and clinical studies that have investigated the clinical relevance as well as the technical requirements and fundamentals of cardiac computed tomography. CITATION FORMAT: · Langenbach MC, Sandstede J, Sieren M et al. DRG and BDR Position Paper on Coronary CT: Clinical Evidence and Quality of Patient Care in Chronic Coronary Syndrome. Fortschr Röntgenstr 2023; 195: 115 - 133.

[German Radiological Society and the Professional Association of German Radiologists position paper on coronary computed tomography: clinical evidence and quality of patient care in chronic coronary syndrome]

This position paper is a joint statement of the German Radiological Society (DRG) and the Professional Association of German Radiologists (BDR), which reflects the current state of knowledge about coronary computed tomography (CT). It is based on preclinical and clinical studies that have investigated the clinical relevance as well as the technical requirements and fundamentals of cardiac computed tomography.

Antiviral activity of amiodarone in SARS-CoV-2 disease

Amiodarone seems to exhibit some antiviral activity in the disease caused by SARS-CoV-2. Here we have examined the SARS-CoV-2 disease course in the entire population of the Czech Republic and compared it with the course of the disease in patients treated with amiodarone in two major Prague’s hospitals. In the whole population of the Czech Republic SARS-CoV-2 infected 1665070 persons (15.6 %) out of 10694000 (100 %) between 1 April 2020 and 30 June 2021. In the same time period only 35 patients (3.4 %) treated with amiodarone were infected with SARS-CoV-2 virus out of 1032 patients (100 %) who received amiodarone. It appears that amiodarone can prevent SARS-CoV-2 virus infection by multiple mechanisms. In in-vitro experiments it exhibits SARS-CoV-2 virus replication inhibitions. Due to its anti-inflammatory and antioxidant properties, it may have beneficial effect on the complications caused by SARS-CoV-2 as well. Additionally, inorganic iodine released from amiodarone can be converted to hypoiodite (IO-), which has antiviral and antibacterial activity, and thus can affect the life cycle of the virus.

Adverse effects of Lugol's iodine: Heart failure in a patient with subcutaneous phycomycosis from a resource-limited setting

Subcutaneous phycomycosis becomes a chronic, debilitating condition if left untreated. Treatment includes oral antifungal therapy, though oral potassium iodide has been used in resource-limited settings. Lugol's iodine has been an effective substitute, but little is known about its safety. We report a case of subcutaneous phycomycosis complicated by heart failure during treatment with Lugol's iodine. We review subcutaneous phycomycosis, iodine-mediated cardiotoxicity, as well as social determinants of health relevant to our case, suggesting that Lugol's iodine may only be an effective treatment with proper dosing and long-term monitoring.

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Lugol's iodine has been an alternative therapy in resource-limited settings.

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Proper dosing and long-term monitoring is essential to prevent toxicity.

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Excess iodine can cause heart failure through hyperthyroid and hypothyroid states.

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Social determinants of health may cause dosing errors and inadequate monitoring.

Evaluating the Image Quality of Neck Structures Scanned on Chest CT with Low-Concentration-Iodine Contrast Media

BACKGROUND

The purpose of this study was to investigate and compare the image quality of low-concentration-iodine (240 mgI/mL) contrast media (CM) and high-concentration-iodine (320 mgI/mL) CM according to the radiation dose.

METHODS

A total of 366 CT examinations were examined. Based on an assessment of quantitative and qualitative parameters by two radiologists, the quality was compared between Group A (low-concentration-iodine CM) and Group B (high-concentration-iodine CM) images of thyroid gland, sternocleidomastoid muscle (SCM), internal jugular vein (IJV), and common carotid artery (CCA). Another subgroup analysis compared Group a, (using ≤90 kVp in Group A), and Group b, (using ≥100 kVp in Group B) for finding the difference in image quality when the tube voltage is lowered.

RESULTS

Image quality did not differ between Groups A and B or between Groups a and b. The signal-to-noise ratio and contrast-to-noise ratio were significantly higher for Group B than Group A for the thyroid gland, IJV, and CCA. No statistical differences were found in the comparison of all structures between Groups a and b.

CONCLUSION

There was no significant difference in image quality based on CM concentration with variable radiation doses. Therefore, if an appropriate CT protocol is applied, clinically feasible neck CT images can be obtained even using low-concentration-iodine CM.

Antiviral activity of amiodarone in SARS-CoV-2 disease

Amiodarone seems to exhibit some antiviral activity in the disease caused by SARS-CoV-2. Here we have examined the SARS-CoV-2 disease course in the entire population of the Czech Republic and compared it with the course of the disease in patients treated with amiodarone in two major Prague's hospitals. In the whole population of the Czech Republic SARS-CoV-2 infected 1665070 persons (15.6 %) out of 10694000 (100 %) between 1 April 2020 and 30 June 2021. In the same time period only 35 patients (3.4 %) treated with amiodarone were infected with SARS-CoV-2 virus out of 1032 patients (100 %) who received amiodarone. It appears that amiodarone can prevent SARS-CoV-2 virus infection by multiple mechanisms. In in-vitro experiments it exhibits SARS-CoV-2 virus replication inhibitions. Due to its anti-inflammatory and antioxidant properties, it may have beneficial effect on the complications caused by SARS-CoV-2 as well. Additionally, inorganic iodine released from amiodarone can be converted to hypoiodite (IO-), which has antiviral and antibacterial activity, and thus can affect the life cycle of the virus.

In Situ Direct Monitoring of the Morphological Transformation of Single Au Nanostars Induced by Iodide through Dual-Laser Dark-Field Microscopy: Unexpected Mechanism and Sensing Applications

Single nanoparticle imaging is a significant technique to help reveal the reaction mechanism and provides insight into the nanoparticle transformation. Here, we monitor the in situ morphological transformation of Au nanostars (GNSs) induced by iodide (I⁻) in real time using dark-field microscopy (DFM) with 638 nm red (R) and 534 nm green (G) laser coillumination. The two lasers are selected because the longitudinal localized surface plasmon resonance of GNSs is located at 638 nm and that for GNSs after transformation is at 534 nm. Interestingly, I⁻ can interact with GNSs directly without the engagement of other reagents, and upon increasing I⁻ concentrations, GNSs undergo color changes from red to orange, yellow, and green under DFM. Accordingly, green/red channel intensities (G/R ratios) are extracted by obtaining red and green channel intensities of single nanoparticles to weigh the morphological changes and quantify I⁻. A single nanoparticle sensor is constructed for I⁻ detection with a detection limit of 6.9 nM. Finally, a novel mechanism is proposed to elucidate this shape transformation. I⁻ absorbed onto the surface of GNSs binds with Au atoms to form AuI⁻, lowering the energy of its bond with other Au atoms, which facilitates the diffusion of this atom across the nanoparticle surface to low-energy sites at the concaves, thus deforming to spherical Au nanoparticles.

Recommendation of the German Society of Hospital Hygiene (DGKH): Prevention of COVID-19 by virucidal gargling and virucidal nasal spray - updated version April 2022

The German Society of Hospital Hygiene develops guidelines, recommendations and standard operation procedures on a voluntary basis, published on the DGKH-website (https://www.krankenhaushygiene.de/). The original German version of this recommendation was published in April 2022 and has now been made available to the international professional public in English. Evaluating the current data on the efficacy of virucidal gargle/mouthwash solutions and nasal sprays against SARS-CoV-2 in vitro and in clinical trials, conducted with preventive or therapeutic objectives, recommendations are given for the prevention of COVID-19. The following areas are considered: Protection of the community when regional clusters or high incidences of infection become knownProtection of the community at low risk of infectionPre-exposure prophylaxis for the protection of healthcare workersPost-exposure prophylaxis.

Hypothyroidism

Hypothyroidism is the common clinical condition of thyroid hormone deficiency and, if left untreated, can lead to serious adverse health effects on multiple organ systems, with the cardiovascular system as the most robustly studied target. Overt primary hypothyroidism is defined as elevated thyroid-stimulating hormone (TSH) concentration in combination with free thyroxine (fT₄) concentration below the reference range. Subclinical hypothyroidism, commonly considered an early sign of thyroid failure, is defined by elevated TSH concentrations but fT₄ concentrations within the reference range. Hypothyroidism is classified as primary, central or peripheral based on pathology in the thyroid, the pituitary or hypothalamus, or peripheral tissue, respectively. Acquired primary hypothyroidism is the most prevalent form and can be caused by severe iodine deficiency but is more frequently caused by chronic autoimmune thyroiditis in iodine-replete areas. The onset of hypothyroidism is insidious in most cases and symptoms may present relatively late in the disease process. There is a large variation in clinical presentation and the presence of hypothyroid symptoms, especially in pregnancy and in children. Levothyroxine (LT4) is the mainstay of treatment and is one of the most commonly prescribed drugs worldwide. After normalization of TSH and fT₄ concentrations, a considerable proportion of patients treated with LT4 continue to have persistent complaints, compromising quality of life. Further research is needed regarding the appropriateness of currently applied reference ranges and treatment thresholds, particularly in pregnancy, and the potential benefit of LT4/liothyronine combination therapy for thyroid-related symptom relief, patient satisfaction and long-term adverse effects.

[Studies on the use of iodine-containing contrast agent diatrizoate in rabbits (Oryctolagus cuniculus)]

OBJECTIVE

The use of the iodine-containing contrast agent diatrizoate was investigated in healthy rabbits and in rabbits with gastric dilatation and intestinal obstruction. For this purpose, transit times through the gastrointestinal tract and clinical use were investigated during a one year period. In addition, a possible influence on thyroid hormone levels was evaluated.

MATERIAL AND METHODS

Transit times of contrast agent through the different intestinal sections were examined radiographically in 14 healthy rabbits. For this purpose, 7 ml/kg of a 300 mg iodine/ml and 600 mg diatrizoate/ml containing solution were administered. Radiographs were obtained at different time intervals. Three different doses (D1 2 ml/kg, D2 7 ml/kg, D3 10 ml/kg) were administered, and blood samples were collected at two time points (60 min, 24 h) to analyze thyroid hormone levels (TT4, fT4, TSH). In addition, 70 rabbits that had received the contrast agent diatrizoate because of gastric dilatation and suspected intestinal obstruction were retrospectively evaluated during a period of one year. Focus was placed on arrival of the contrast agent in the cecum, laboratory changes, and mortalities.

RESULTS

In all healthy rabbits, contrast medium was detectable in the cecum after a mean of 45-60 min. In the animals suffering from gastrointestinal obstruction, this was delayed to a mean of 121.2 min. These animals showed hypothermia in 92.4 % and hyperglycemia in 45.9 %. 56.1 % exhibited an increase in urea and 33.9 % an increase in creatinine. In 71.4 % of cases, medical treatment was possible, however 12 % of these individuals succumbed to the disease. 28.6 % of the cases were managed surgically which was associated with a mortality of 50 %. TT4, fT4, and TSH levels displayed significant alterations among the three contrast agent doses (p < 0.05). These changes were found to be transient when follow-up was performed two weeks later.

CONCLUSION AND CLINICAL RELEVANCE

When ileus is suspected in rabbits, diatrizoate may be helpful in evaluating the progression of the disease in addition to the use of native radiographs. Sufficient hydration and monitoring of renal function are advisable. Transient changes in thyroid hormones were evident but lacked clinical relevance.

Iodine Concentrations in Conventional and Organic Milk in the Northeastern U.S

Milk is a major source of dietary iodine in the United States. Due to a relatively low margin of safety for iodine intake, there are concerns for both deficiency and over-exposure. Iodine concentrations of raw milk samples from farms and retail milk in the Northeastern U.S. region were compared between seasons (winter vs. summer) and farming practices (conventional vs. organic). Overall, mean iodine concentration was 46.2% higher in raw milk from conventional farms vs. organic farms. An interaction effect between season and farming practices was observed. Organic raw milk had higher iodine content in the winter than in the summer (423 ± 54 μg/L vs. 273 ± 24 μg/L), whereas conventional raw milk had higher iodine content in the summer than in the winter (618 ± 75 μg/L vs. 398 ± 27 μg/L). Milk samples from conventional farms had 2.27-fold higher average iodine concentration compared to milk coming from organic farms in the summer but did not differ in the winter. Out of 68 and 98 raw milk samples originating from conventional and organic farms, 22 (32.4%) and 19 (19.4%) respectively, had iodine concentrations > 500 µg/L, reaching as high as 1928 μg/L. In contrast, the overall mean concentration of iodine in retail milk did not differ between conventional and organic milk (345 ± 23 vs. 320 ± 42 μg/L, respectively). The current study confirms dairy milk remains to be a good source of iodine to U.S. consumers. However, dairy farms should be aware of the potential adverse health effects of excess iodine intake. Careful considerations in dairy management may be necessary to not exceed the recommended level of iodine supplementation in both conventional and organic operations at the farm level—to maintain optimal iodine concentrations in retail fluid milk accessible to the consumers.

Impact of Iodinated Contrast Media in Patients Received Percutaneous Coronary Intervention: Focus on Thyroid Disease

BACKGROUND

With the rapid advance in percutaneous coronary intervention (PCI) technology, patients absorb large volume of iodinated contrast media (ICM). Recent studies suggested that ICM may lead to hyperthyroidism, but the association between ICM volume and thyroid is still unclear. We sought to evaluate the long-term influence of ICM on thyroid dysfunction and disease in patients received PCI.

METHODS

This single-center retrospective study included consecutive coronary artery disease (CAD) patients. A covariance (ANCOVA) model was performed to evaluate the change of serum TSH, FT3 and FT4 before and one-year after the PCI procedure. Restricted cubic splines and logistic regression were performed to evaluate the association between ICM volume and thyroid disease.

RESULTS

2062 patients met inclusion criteria (1381 patients in the low-volume group and 681 patients in the high-volume group). The high-volume group was 0.238 ± 0.092 pmol/L higher than the low-volume group (P = 0.010) in the serum FT4. Restricted cubic splines show that there were linear dose-response relationships for ICM volume and composite endpoint and hyperthyroidism. In all models, there were significant differences in composite endpoint between the two groups. (OR 1.75, 95% CI (1.05, 2.92), P = 0.032, OR 1.73, 95% CI (1.01-2.96), P= 0.032 and OR 1.83, 95% CI (1.09-3.06), P= 0.022, respectively). The positive results were also showed for hyperthyroidism in all models (OR 2.35, 95% CI (1.14-4.84), P = 0.021, OR 10.36, 95% CI (1.20-89.00), P = 0.033 and OR 2.35, 95% CI (1.13-4.87), P = 0.022, respectively).

CONCLUSION

The present analysis gives an overview that ICM volume is associated with an increased risk of thyroid dysfunction and thyroid disease.

MicroRNA expression profiles of the thyroid after goiter formation and involution in rats under different iodine regimens

BACKGROUND

Thyroid damage occurs during experimental iodine-deficient goiter and involution with iodine supplementation. This study investigated the dynamic microRNAs (miRNAs) expression profiles in iodine-deficient thyroids during adequate and excessive iodine supplementation.

METHODS

Twenty-four female Wistar rats were randomly divided into control, low-iodine (LI), LI-1I, and LI-2I groups. The LI-1I and LI-2I groups were fed a LI diet for 12 weeks, followed by a onefold (adequate) or twofold (excessive) physiological dose of iodine for 4 weeks to induce involution. The miRNA expression profiles were evaluated and the potential functions of the differentially expressed miRNAs identified were explored.

RESULTS

In the LI group, 20 miRNAs were downregulated and 8 were upregulated. After involution, 21 miRNAs recovered to the control group levels in the LI-1I group, which was more than the 17 that recovered in the LI-2I group. In addition, 8 new differentially expressed miRNAs were identified in the LI-1I group, which was less than the 13 found in the LI-2I group. Bioinformatics analyses indicated that all differentially expressed miRNAs were involved in different processes and pathways, such as autoimmune thyroid disease and the Ras signaling pathway.

CONCLUSION

Differentially expressed miRNAs are involved in iodine-deficient goiter formation and involution. Supplementation with adequate, not excessive, iodine may be more beneficial to restore homeostasis.

Review of Pre-Operative Skin Preparation Options Based on Surgical Site in Orthopedic Surgery

Background: Surgical site infections (SSIs) are a primary contributor to surgical morbidity and mortality, causing a substantial financial burden on the healthcare system. Specifically, Cutibacterium acnes contributes greatly to infections in the shoulder and spine regions. Prevention of infection is crucial to improve patient outcomes and reduce costs. This article reviews current surgical skin preparation solutions, the unique distribution of organisms at common orthopedic surgical sites, and recommends solutions based on surgical location. Methods: A search of electronic databases (PubMed, MEDLINE, and Embase) was conducted for relevant literature until December 2020. Sources were compiled based on title and abstract, then full texts were read for possible inclusion. This review summarizes the most recent publications in the field of SSIs and preparation solutions. Results: The mechanism and efficacy of alcohol-, iodine-, and chlorhexidine-based preparations were reviewed, along with experimental preparations. This article identifies common colonization patterns for the shoulder, elbow, hip, knee, spine, foot, and ankle, and discusses recommendations for preparations based on current evidence. Recommendations: For shoulder and elbow operations, we recommend ChloraPrep™ (CareFusion, BD, El Paso, TX), DuraPrep™ (3M Health Care, St. Paul, MN), or Betadine^® applied with 4 × 4 gauze sponge, three-day pre-operative benzyl peroxide, and application of 3% hydrogen peroxide before skin preparation. For the hip and knee, we recommend application of 2% chlorhexidine gluconate (CHG) cloth the night before and morning of surgery and either DuraPrep or iodine-alcohol skin prep prior to surgery. For spine surgeries, we recommended ChloraPrep. For foot and ankle, our recommendations are: ChloraPrep or DuraPrep, submersion of foot in 70% ethanol/10% isopropyl alcohol for five minutes prior to procedure, application with a bristled brush, and a second vigorous scrub with 4 × 4 soaked gauze. Conclusions: The current surgical skin preparations have both benefits and drawbacks. We recommend that orthopedic surgeons choose a skin preparation based on surgical site and prevalence of unique skin flora there.

The effect of galvanization and potassium iodide iontophoresis of the throat and larynx on thyroid parameters: a randomized controlled trial

Few studies have assessed the application and side effects of potassium iodide (KI) iontophoresis. Using a double-blinded randomized controlled trial with a 1:1 parallel-group, we investigated the effect of galvanization and the KI iontophoresis in the throat and larynx on three thyroid parameters. A total of 50 healthy volunteers with normal TSH, FT₃, and FT₄ levels and lacking focal changes in the thyroid ultrasonography were subjected to 10 electrotherapy treatments. The TSH, FT₃, and FT₄ levels were determined prior to the 10 electrotherapeutic treatments (T1), 2-weeks after treatment (T2) and 6-months after treatment (T3). At T2 and T3, both groups had normal levels of TSH, FT₃, and FT₄. Regarding the change of TSH, FT₃, and FT₄ levels between T1 vs. T2 and T1 vs. T3, no significant differences between the galvanization and iontophoresis groups were found. However, both groups had lower levels of all three hormones at T3. Together, these data indicate that KI iontophoresis does not affect thyroid hormone levels in the short- nor long-term. Additional follow-up studies with larger groups are required to better confirm the safety of galvanization and iontophoresis procedures in the pharynx and larynx.

Trial registration ClinicalTrials.gov (NCT04013308; URL: www.clinicaltrials.gov). Day of first registration 09/07/2019.

2021 European Thyroid Association Guidelines for the Management of Iodine-Based Contrast Media-Induced Thyroid Dysfunction

Given the fact that a large number of radiological examinations using iodine-based contrast media (ICM) are performed in everyday practice, clinicians should be aware of potential ICM-induced thyroid dysfunction (TD). ICM can induce hyperthyroidism (Hyper) or hypothyroidism (Hypo) due to supraphysiological concentrations of iodine in the contrast solution. The prevalence of ICM-induced TD varies from 1 to 15%. ICM-induced Hyper is predominantly found in regions with iodine deficiency and in patients with underlying nodular goiter or latent Graves' disease. Patients at risk for ICM-induced Hypo include those with autoimmune thyroiditis, living in areas with sufficient iodine supply. Most cases of ICM-induced TD are mild and transient. In the absence of prospective clinical trials on the management of ICM-induced TD, an individualized approach to prevention and treatment, based on patient's age, clinical symptoms, pre-existing thyroid diseases, coexisting morbidities and iodine intake must be advised. Treatment of ICM-induced Hyper with antithyroid drugs (in selected cases in combination with sodium perchlorate) should be considered in patients with severe or prolonged hyperthyroid symptoms or in older patients with underlying heart disease. It is debated whether preventive therapy with methimazole and/or perchlorate prior to ICM administration is justified. In ICM-induced overt Hypo, temporary levothyroxine may be considered in younger patients with symptoms of Hypo, with an underlying autoimmune thyroiditis and in women planning pregnancy. Additional clinical trials with clinically relevant endpoints are warranted to further aid in clinical decision-making in patients with ICM-induced TD.

Thyroid function in neonates conceived after hysterosalpingography with iodinated contrast

STUDY QUESTION

Does exposure to preconceptional hysterosalpingography (HSG) with iodinated oil-based contrast affect neonatal thyroid function as compared to iodinated water-based contrast?

SUMMARY ANSWER

Preconceptional HSG with iodinated contrast did not influence the neonatal thyroid function.

WHAT IS KNOWN ALREADY

HSG is a commonly applied tubal patency test during fertility work-up in which either oil- or water-based contrast is used. Oil-based contrast contains more iodine compared to water-based contrast. A previous study in an East Asian population found an increased risk of congenital hypothyroidism (CH) in neonates whose mothers were exposed to high amounts of oil-based contrast during HSG.

STUDY DESIGN, SIZE, DURATION

This is a retrospective data analysis of the H2Oil study, a randomized controlled trial (RCT) comparing HSG with the use of oil- versus water-based contrast during fertility work-up. After an HSG with oil-based contrast, 214 women had an ongoing pregnancy within 6 months leading to a live birth compared to 155 women after HSG with water-based contrast.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the 369 women who had a live born infant, 208 consented to be approached for future research and 138 provided informed consent to collect data on the thyroid function tests of their offspring (n = 140). Thyroid function tests of these children were retrieved from the Dutch neonatal screening program, which includes the assessment of total thyroxine (T4) in all newborns, followed by thyroid-stimulating hormone only in those with a T4 level of ≤ -0.8 SD score. Furthermore, amount of contrast medium used and time between HSG and conception were compared between the two study groups.

MAIN RESULTS AND THE ROLE OF CHANCE

Data were collected from 140 neonates conceived after HSG with oil-based (n = 76) or water-based (n = 64) contrast. The median T4 concentration was 87.0 nmol/l [76.0-96.0] in the oil group and 90.0 nmol/l [78.0-106.0] in the water group (P = 0.13). None of the neonates had a positive screening result for CH.The median amount of contrast medium used was 9.0 ml [interquartile range (IQR), 6.0-11.8] in the oil-group and 10.0 ml [IQR, 7.5-14.0] in the water group (P = 0.43). No influence of the amount of contrast on the effect of contrast group on T4 concentrations was found (P-value for interaction, 0.37).

LIMITATIONS, REASONS FOR CAUTION

A relatively small sample size and possible attrition at follow-up are limitations of this study. Although our results suggest that the use of iodinated contrast media for HSG is safe for the offspring, the impact of a decrease in maternal thyroid function on offspring neurodevelopment could not be excluded, as data on maternal thyroid function after HSG and during conception were lacking.

WIDER IMPLICATIONS OF THE FINDINGS

As HSG with oil-based contrast does not affect thyroid function of the offspring, there is no reason to withhold this contrast to infertile women undergoing HSG. Future studies should investigate whether HSG with iodinated contrast influences the periconceptional maternal thyroid function and, consequently, offspring neurodevelopment.

STUDY FUNDING/COMPETING INTEREST(S)

This study received no funding. The original H2Oil RCT was an investigator-initiated study that was funded by the two academic institutions (Academic Medical Center and VU University Medical Center) of the Amsterdam UMC. The funders had no role in study design, collection, analysis and intrepretation of the data. I.R. reports receiving travel fee from Guerbet. C.B.L. reports speakers fee from Ferring in the past and research grants from Ferring, Merck and Guerbet. K.D. reports receiving travel fee and speakers fee from Guerbet. B.W.M. is supported by a NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck KGaA and Guerbet and travel and research grants from Merck KGaA and Guerbet. V.M. reports receiving travel fee and speakers fee as well as research grants from Guerbet. The other authors do not report conflicts of interest.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register NTR 7526 (Neonates born after the H2Oil study), NTR 3270 (original H2Oil study), www.trialregister.nl.

Applications of nanoscale metal-organic frameworks as imaging agents in biology and medicine

Nanoscale metal-organic frameworks (NMOFs) are an interesting and unique class of hybrid porous materials constructed by the self-assembly of metal ions/clusters with organic linkers. The high storage capacities, facile synthesis, easy surface functionalization, diverse compositions and excellent biocompatibilities of NMOFs have made them promising agents for theranostic applications. By combination of a large variety of metal ions and organic ligands, and incorporation of desired molecular functionalities including imaging modalities and therapeutic molecules, diverse MOF structures with versatile functionalities can be obtained and utilized in biomedical imaging and drug delivery. In recent years, NMOFs have attracted great interest as imaging agents in optical imaging (OI), magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET) and photoacoustic imaging (PAI). Furthermore, the significant porosity of MOFs allows them to be loaded with multiple imaging agents and therapeutics simultaneously and applied for multimodal imaging and therapy as a single entity. In this review, which is intended as an introduction to the use of MOFs in biomedical imaging for a reader entering the subject, we summarize the up-to-date progress of NMOFs as bioimaging agents, giving (i) a broad perspective of the varying imaging techniques that MOFs can enable, (ii) the different routes to manufacturing functionalised MOF nanoparticles and hybrids, and (iii) the integration of imaging with differing therapeutic techniques. The current challenges and perspectives of NMOFs for their further clinical translation are also highlighted and discussed.

Fe3O4-Au Core-Shell Nanoparticles as a Multimodal Platform for In Vivo Imaging and Focused Photothermal Therapy

In this study, we report the synthesis of gold-coated iron oxide nanoparticles capped with polyvinylpyrrolidone (Fe@Au NPs). The as-synthesized nanoparticles (NPs) exhibited good stability in aqueous media and excellent features as contrast agents (CA) for both magnetic resonance imaging (MRI) and X-ray computed tomography (CT). Additionally, due to the presence of the local surface plasmon resonances of gold, the NPs showed exploitable "light-to-heat" conversion ability in the near-infrared (NIR) region, a key attribute for effective photothermal therapies (PTT). In vitro experiments revealed biocompatibility as well as excellent efficiency in killing glioblastoma cells via PTT. The in vivo nontoxicity of the NPs was demonstrated using zebrafish embryos as an intermediate step between cells and rodent models. To warrant that an effective therapeutic dose was achieved inside the tumor, both intratumoral and intravenous routes were screened in rodent models by MRI and CT. The pharmacokinetics and biodistribution confirmed the multimodal imaging CA capabilities of the Fe@AuNPs and revealed constraints of the intravenous route for tumor targeting, dictating intratumoral administration for therapeutic applications. Finally, Fe@Au NPs were successfully used for an in vivo proof of concept of imaging-guided focused PTT against glioblastoma multiforme in a mouse model.

Iodine Content in Meal Replacements in the United States

OBJECTIVE

Iodine is essential for thyroid hormone production. The recommended dietary allowance for iodine in nonpregnant adults is 150 μg/d. However, most product labels do not list the iodine content. Meal replacements are not required to contain specific vitamins and minerals. Nevertheless, they are often marketed as good and convenient sources of a balanced nutrition. In this study, we aimed to assess the iodine content in meal replacements to determine how they may contribute to iodine deficiency or excess.

METHODS

Twenty seven meal replacements from supermarkets in the Boston area were collected. The iodine concentration of each meal replacement was measured spectrophotometrically. Iodine content in meal replacements were compared according to form (liquid, bar, and powder) and type (vegan and nonvegan).

RESULTS

The overall mean ± SD iodine content was 49.7 ± 125.4 μg/serving. However, 1 meal replacement was an outlier and had 671.9 μg iodine per serving. Mean iodine content differed between forms and was highest for liquids (mean ± SD: 37.4 ± 6.5 μg/serving). Nonvegan meal replacements had a higher mean iodine content than vegan meal replacements (mean ± SD: 31.6 ± 15.78 μg/serving).

CONCLUSION

All of the meal replacements contained detectible amounts of iodine regardless of whether it was listed on their labels (41% did not list iodine). Overall, the meal replacements in this study were found to be good sources of iodine. However, consumers should be aware that packaging labels may not accurately reflect the amount of iodine present.

Is There an Ideal Diet to Protect against Iodine Deficiency?

Iodine deficiency is a global issue and affects around 2 billion people worldwide, with pregnant women as a high-risk group. Iodine-deficiency prevention began in the 20th century and started with global salt iodination programmes, which aimed to improve the iodine intake status globally. Although it resulted in the effective eradication of the endemic goitre, it seems that salt iodination did not resolve all the issues. Currently, it is recommended to limit the consumption of salt, which is the main source of iodine, as a preventive measure of non-communicable diseases, such as hypertension or cancer the prevalence of which is increasing. In spite of the fact that there are other sources of iodine, such as fish, seafood, dairy products, water, and vegetables, the high consumption of processed food with a high content of unionised salt, alternative diets or limited salt intake can still lead to iodine deficiency. Thus, iodine deficiency remains a relevant issue, with new, preventive solutions necessary. However, it appears that there is no diet which would fully cover the iodine requirements, and iodine food supplementation is still required.

Elemental Metabolomics for Prediction of Term Gestational Outcomes Utilising 18-Week Maternal Plasma and Urine Samples

A normal pregnancy is essential to establishing a healthy start to life. Complications during have been associated with adverse perinatal outcomes and lifelong health problems. The ability to identify risk factors associated with pregnancy complications early in gestation is vitally important for preventing negative foetal outcomes. Maternal nutrition has been long considered vital to a healthy pregnancy, with micronutrients and trace elements heavily implicated in maternofoetal metabolism. This study proposed the use of elemental metabolomics to study multiple elements at 18 weeks gestation from blood plasma and urine to construct models that could predict outcomes such as small for gestational age (SGA) (n = 10), low placental weight (n = 18), and preterm birth (n = 13) from control samples (n = 87). Samples collected from the Lyell McEwin Hospital in Adelaide, South Australia, were measured for 27 plasma elements and 37 urine elements by inductively coupled plasma mass spectrometry. Exploratory analysis indicated an average selenium concentration 20 μg/L lower than established reference ranges across all groups, low zinc in preterm (0.64 μg/L, reference range 0.66-1.10 μg/L), and higher iodine in preterm and SGA gestations (preterm 102 μg/L, SGA 111 μg/L, reference range 40-92 μg/L). Using random forest algorithms with receiver operating characteristic curves, low placental weight was predicted with 86.7% accuracy using plasma, 78.6% prediction for SGA with urine, and 73.5% determination of preterm pregnancies. This study indicates that elemental metabolomic modelling could provide a means of early detection of at-risk pregnancies allowing for more targeted monitoring of mothers, with potential for early intervention strategies to be developed.

Amiodarone-induced thyroid dysfunction in children: insights from the THYRAMIO study

BACKGROUND

Amiodarone treatment is effective against various types of arrhythmias but is associated with adverse effects affecting, among other organs, thyroid function. Amiodarone-induced thyroid dysfunction was not thoroughly evaluated in children as it was in adults, yet this affection may lead to irreversible neurodevelopmental complications. Our study aimed to define the incidence and risk factors of amiodarone-induced thyroid dysfunction in children.

METHODS

The study was designed as an observational study with a retrospective clinical series of 152 children treated by amiodarone in the Pediatric Cardiology Unit of our center from 1990 to 2019. All patients were divided into three groups according to their thyroid status: euthyroid, AIH (amiodarone-induced hypothyroidism) or AIT (amiodarone-induced thyrotoxicosis). Patients from these three groups were compared in terms of key clinical and therapeutic features.

RESULTS

Amiodarone-induced thyroid dysfunction was present in 23% of patients. AIT (5.3%) was three times less common than AIH (17.7%), and its occurrence increased with older age (p < 0.05), treatment dosage (p < 0.05), treatment duration (p < 0.05) and the number of loading doses administered (p < 0.05). There were no distinctive clinical features between euthyroid and AIH groups. A multivariable prediction model of AIT was built, with a yield of 66.7% as positive predictive value and 96.7% as negative predictive value.

CONCLUSION

We observed that one in five children developed amiodarone-induced thyroid dysfunction. Special attention is required for older children with a high dosage and long-term therapy and who received a large number of loading doses, since these children are at risk to develop AIT, which is more delicate to manage than AIH.

Urinary Iodine and Genetic Predisposition to Hashimoto's Thyroiditis in a Chinese Han Population: A Case-Control Study

Background: We aimed to examine the association of urinary iodine concentration with Hashimoto's thyroiditis (HT) risk, and particularly, to investigate whether the HT-related genetic variations might modify the effects of urinary iodine on HT in the Chinese Han population. Methods: We conducted a case-control study with 1723 Chinese (731 cases, 992 controls). The associations between urinary iodine concentration and HT risk were analyzed using logistic regression models. The effects of interactions between the genetic risk scores (GRSs) and urinary iodine on HT risk were assessed by including the respective interaction terms in the models. We also applied restricted cubic spline regression to estimate the possible nonlinear relationship. The multinomial logistic regression models were performed to determine the associations of urinary iodine with euthyroid-HT and hypothyroidism-HT. Results: After controlling for potential confounders, the odds of HT increased with increasing quartiles of urinary iodine concentration: adjusted odds ratios (ORs) and 95% confidence intervals [CIs] were 1.45 [1.06-1.99], 1.66 [1.17-2.34], and 2.07 [1.38-3.10] for the quartiles 2, 3, and 4, respectively, compared with the first quartile (p for trend <0.001). Multivariable restricted cubic spline regression analysis further demonstrated that there was a near-linear association between urinary iodine concentration and HT risk (p-overall <0.001; p-nonlinear = 0.074). However, we did not find significant interactions between urinary iodine and GRSs on the risk of HT (all p for interaction >0.05). Interestingly, we found that each increment of urinary iodine was associated with a more than twofold increase in the odds of hypothyroidism-HT (adjusted OR = 2.64 [CI = 1.73-4.05]), but not with euthyroid-HT (p > 0.05). Conclusions: Higher urinary iodine concentration was associated with increased risk of HT, and this association was near linear, indicating that increased urinary iodine has a continuous and graded impact on HT risk. Moreover, the iodine-HT association was not modified by genetic predisposition to HT. Interestingly, urinary iodine concentration was significantly associated with increased risk of hypothyroidism.

Iodine Status and Thyroid Function in a Group of Seaweed Consumers in Norway

Seaweeds, or macroalgae, may be a good dietary iodine source but also a source of excessive iodine intake. The main aim in this study was to describe the iodine status and thyroid function in a group of macroalgae consumers. Two urine samples were collected from each participant (n = 44) to measure urinary iodine concentration (UIC) after habitual consumption of seaweed. Serum thyroid stimulating hormone (TSH), free thyroxine (fT₄), free triiodothyronine (fT₃), and peroxidase autoantibody (TPOAb), were measured in a subgroup (n = 19). A food frequency questionnaire and an iodine-specific 24 h recall were used to assess iodine intake and macroalgae consumption. The median (p25–p75) UIC was 1200 (370–2850) μg/L. Median (p25–p75) estimated dietary iodine intake, excluding macroalgae, was 110 (78–680) μg/day, indicating that seaweed was the major contributor to the iodine intake. TSH levels were within the reference values, but higher than in other comparable population groups. One third of the participants used seaweeds daily, and sugar kelp, winged kelp, dulse and laver were the most common species. Labelling of iodine content was lacking for a large share of the products consumed. This study found excessive iodine status in macroalgae consumers after intake of dietary seaweeds. Including macroalgae in the diet may give excessive iodine exposure, and consumers should be made aware of the risk associated with inclusion of macroalgae in their diet.

Causes and predictors of mortality among Ghanaians hospitalised with endocrine disorders

Background

Endocrine disorders have been noted to be on the increase in the developing world, but little is known about their outcomes on the African continent.

Methods

We conducted a retrospective longitudinal study to evaluate the demographic characteristics and determinants of endocrine-related mortality among adult patients over 9 y in a leading tertiary hospital in Ghana. We determined the predictors of inpatient mortality using Kaplan–Meier survival curves and Cox proportional hazard regression analysis.

Results

Overall, 6265 patients (9.7% of all medical admissions) were admitted with various endocrine disorders during the period. The most common endocrine cause of hospitalisation was diabetes mellitus (86.0%), followed in order of decreasing frequency by thyroid disorders (7.7%) and miscellaneous disorders (1.4%). The overall crude mortality rate of endocrine admissions was 16.7%. Death was predicted by increasing age with an adjusted hazard ratio of 1.25 (95% confidence interval 1.15 to 1.65) for every 10-y increase in age.

Conclusions

Almost one in six adults admitted with an endocrine disorder to a tertiary care centre in Ghana died in hospital, and many of the deaths were due to non-communicable disease complications. Enhanced public health disease prevention strategies and endocrine inpatient care processes are warranted.

Safety of Noncontrast Imaging-Guided Deep Brain Stimulation Electrode Placement in Parkinson Disease

BACKGROUND

Deep brain stimulation (DBS) is considered standard of care for the treatment of medically refractory Parkinson disease (PD). The placement of brain electrodes is performed using contrast imaging to enhance blood vessel identification during stereotactic planning. We present our experience with a series of patients implanted using noncontrast imaging.

METHODS

All cases of DBS surgery for PD performed between 2012 and 2018 with noncontrast imaging were retrospectively reviewed. Clinical features, postoperative imaging, and complications were analyzed.

RESULTS

A total of 287 deep-seated electrodes were implanted in 152 patients. Leads were placed at the subthalamic nucleus and globus pallidus internus in 258 and 29 hemispheres, respectively. We identified 2 cases of intracranial hemorrhage (0.7%).

CONCLUSIONS

DBS lead placement can be performed without the use of intravenous contrast with a postoperative intracranial hemorrhage rate comparable with other reported series.

Voiding cystography: an unusual route of induced hypothyroidism by iodine overdose in two newborns with chronic kidney disease

BACKGROUND

Iatrogenic induced hypothyroidism had been described in newborns and more particularly in preterm infants after cutaneous or intravenous exposure to iodine. CASE-DIAGNOSIS : We reported a new risk of iodine intoxication with the cases of two newborns who developed hypothyroidism after intra vesical iodine injection during a cystography, which was performed to confirm antenatal diagnosis of posterior urethral valves (PUV). The newborns both developed transient hypothyroidism due to an iodine overdose.

CONCLUSIONS

These two observations suggest that voiding cystourethrography (VCUG) should be carefully considered in newborns with severe uropathy, particularly in the case of renal insufficiency. If indicated, thyroid function should be monitored in the following weeks, and in case of hypothyroidism treatment should be started.

Determining the Thyroid Gland Volume Causing Tracheal Compression: A Semiautomated 3D CT Volumetry Study

Background and objectives: Increased thyroid gland volume (TV) may bring about tracheal compression, which is one of the causes of respiratory distress. The aim of this study was to investigate the relationship between TV and the severity of tracheal compression independent of patients’ symptoms using semiautomated three-dimensional (3D) volumetry (S3DV) reconstructed from computed tomography (CT) scans. Cut-off TVs leading to different levels of tracheal narrowing were evaluated. Materials and Methods: One hundred sixty-three contrast-enhanced head and neck CT examinations were retrospectively assessed. TVs were measured by S3DV. The degree of tracheal compression was measured at the point where the greatest percent reduction in the cross-sectional area of the trachea adjacent to the thyroid gland was observed. To determine the severity of compression, the tracheal compression ratio (TCR) was defined (TCR = A1 (the narrowest cross-sectional area of trachea)/A2 (the largest cross-sectional area of trachea)). Results: The mean tracheal narrowing was 15% (TCR = 0.85 ± 0.15) in the study population. Patients with more than 15% tracheal compression had significantly higher TV values than those with less than 15% tracheal compression (p < 0.001). In addition, a significant correlation was found between TV and tracheal compression (p < 0.001). Moreover, the receiver operating characteristic (ROC) curve analysis revealed that the cut-off levels for TV that predict a tracheal narrowing of 10%, 20%, 30%, and 40% were 19.75 mL, 21.56 mL, 24.54 mL, and 30.29 mL, respectively (p < 0.05). Conclusions: This study objectively demonstrated that larger thyroid glands cause more severe compression on the trachea. The results may be helpful during the decision-making process for thyroidectomies to be performed due to compression symptoms.

Particulate organohalogens in edible brown seaweeds

Brown algae, rich in antioxidants and other bioactive compounds, are important dietary seaweeds in many cultures. Like other marine macroalgae, brown seaweeds are known to accumulate the halogens iodine and bromine. Comparatively little is known about the chemistry of chlorine in seaweeds. We used synchrotron-based X-ray absorption spectroscopy to measure total non-volatile organochlorine and -bromine in five edible brown seaweeds: Laminaria digitata, Fucus vesiculosus, Pelvetia canaliculata, Saccharina latissima, and Undaria pinnatifida. Organochlorine concentrations range from 120 to 630 mg·kg-1 dry weight and organobromine from 150 to 360 mg·kg-1, comprising mainly aromatic organohalogens in both cases. Aliphatic organochlorine exceeds aliphatic organobromine but is positively correlated with it among the seaweeds. Higher organochlorine levels appear in samples with more lipid moieties, suggesting lipid chlorination as a possible formation pathway. Particulate organohalogens are not correlated with antioxidant activity or polyphenolic content in seaweed extracts. Such compounds likely contribute to organohalogen body burden in humans and other organisms.

Early Identification of Primary Hypothyroidism in Neonates Exposed to Intralymphatic Iodinated Contrast: A Case Series

CONTEXT

In neonates, iatrogenic hypothyroidism can result from topical or IV iodine exposure. Data on intralymphatic iodine exposure, risk factors for disease severity, and timing of hypothyroidism are limited.

CASE DESCRIPTIONS

We report 4 cases of premature neonates with previously normal thyroid function tests (TFTs) who developed hypothyroidism after intralymphatic iodinated contrast. Patients 1 and 2, premature infants with complex medical histories, had chylous effusions and high-volume chest tube output requiring imaging with lymphangiograms on day of life (DOL) 97 and DOL 43, respectively. They developed severe, primary hypothyroidism with TSH of 335.7 mIU/mL (reference range, 1.7 to 9.1) on DOL 111 and TSH of 470.2 mIU/mL (reference range, 1.7 to 9.1) on DOL 68. Patient 3 had prenatally diagnosed fetal hydrops manifesting with chylous effusions and high-volume chest tube output. The infant underwent lymphangiography on DOL 90 and was noted to have an elevated TSH of 13.35 mIU/mL (reference range, 1.7 to 9.1) 4 days later with spot urine iodine of 1742 µg/L (normal, <200). Patient 4 had a lymphatic malformation and underwent sclerotherapy with doxycycline with intralymphatic iodine exposure on DOL 4 and was found to have a TSH of 16.7 µU/mL (reference range, 1.7 to 9.1) 3 days later with spot urine iodine of 228,712 µg/L (normal, <200). The TFT results for all patients improved after levothyroxine administration.

CONCLUSION

Intralymphatic iodine should be considered a major risk factor in the development of iatrogenic primary hypothyroidism, especially in premature neonates soon after exposure. Close monitoring of TFTs is imperative to avoid potential long-term adverse outcomes in this population.