Physiology and pharmacology of iodized oil in goiter prophylaxis

Iodine Nutritional Status of Pregnant Women After 14 Years of Lipiodol Supplementation: a Cross-Sectional Study in Historically Iodine-Deficient Areas of China

Southern Xinjiang has a history of serious iodine deficiency. Since 2007, pregnant women in this area have taken iodized salt and oral lipiodol preparations to prevent iodine deficiency disorders. However, the current status of iodine nutrition and thyroid function in this population is unknown. A cross-sectional study was conducted on 555 pregnant women from 5 counties (cities) in southern Xinjiang and 429 pregnant women from 3 counties in northern Xinjiang. The participants were given a questionnaire and serum concentrations of free triiodothyronine (FT3), free thyroxine (FT4), thyrotropic stimulating hormone (TSH), thyroglobulin antibody (Tg-Ab), and thyroid peroxidase antibody (TPO-Ab), and the urine iodine concentration (UIC) was measured. The median UIC and interquartile range [M (IQR)] of the 984 pregnant women in the study was 189.38 (143.15, 288.77) μg/L. Positive Tg-Ab and TPO-Ab titers were detected in 6.74% and 9.55%, 8.30% and 9.84%, and 7.39% and 10.55% in T1, T2, and T3, respectively. The incidence of subclinical hypothyroidism, clinical hypothyroidism, and isolated hypothyroxinemia in pregnant women in areas where lipiodol pills were taken was 4.32%, 0%, and 1.44%, respectively, which was significantly lower than those in areas where lipiodol pills were not taken. The median UIC (IQR) of pregnant women in the two regions was 213.80 (130.44, 331.77) μg/L and 168.30 (155.0, 254.8) μg/L, the UIC of pregnant women who took lipiodol pills was higher than in those who did not take lipiodol pills, and the difference was statistically significant (p < 0.05). According to WHO standards, all pregnant women in southern Xinjiang are in a state of adequate iodine nutrition. Taking lipiodol pills has improved the iodine nutrition level of pregnant women in this area. The results of this study did not find that oral lipiodol pills had adverse effects on pregnant women's thyroid function, but it is necessary to further study the effect of oral lipiodol pills on the offspring.

The Impact of Preconceptional Hysterosalpingography with Oil-based Contrast on Maternal and Neonatal Iodine Status

The objective of this study is to investigate the impact of preconceptional exposure to oil-based iodinated contrast in the hysterosalpingography (HSG) on pregnant women and their offspring's iodine status, thyroid function, and the outcomes of pregnancy. A cross-sectional evaluation of iodine status was performed on pregnant women with the preconceptional experience of ethiodized-oil HSG. For those found to have iodine excess (with serum iodine concentration (SIC) > 92 μg/L), a prospective follow-up was conducted until termination of the pregnancy or 1 week postpartum. Among 70 of 425 pregnant women with preconceptional ethiodized-oil HSG, iodine excess was initially confirmed in 38 (54.3%), with an elevated SIC (294.00 μg/L [142.00, 123.20]) and urinary iodine-to-creatinine ratio (UI/Cr) (830.00 μg/g Cr [437.50, 255.30]), both higher than the normative data (P = 0.000, P = 0.000). Subsequent follow-up in pregnancy showed a downward trend in both SIC and UI/Cr. Thirty-four women delivered healthy neonates at full term, though the other 4 cases of premature birth, abnormal fetal karyotype, spontaneous abortion, and neonatal cardiac defect were reported. After delivery, the iodine concentration in maternal breast milk and neonatal urine was 584.50 μg/L [328.50, 1507.50] and 424.00 μg/L [277.00, 657.50], respectively, both higher than normative data (P = 0.001, P = 0.015). For thyroid evaluation, 25 cases (65.79%) of clinical or subclinical hypothyroidism and 2 cases (5.26%) of thyrotoxicosis were confirmed in women with iodine excess. Neither goiter nor thyroid dysfunction was detected in any offspring. Preconceptional exposure to oil-based contrast in HSG might exert a far-reaching impact on maternal and offspring iodine status, and tend to result in increased risk of maternal thyroid dysfunction.

Iodine nutrition: Disorders, monitoring and policies

Iodine is an essential mineral nutrient and an integral component of thyroid hormones. Iodine deficiency is typically associated with goiter, but can have more serious health implications. Adequate iodine status is important for normal brain development. Iodine deficiency in utero or in early life can cause severe neurological and cognitive impairment. Over the last three decades, global efforts have reduced the prevalence of iodine deficiency disorders (IDD) in many areas of the world with implementation of nutrition policies and programs such as "salt" iodization. However, in a number of areas iodine deficiency is still widespread. Iodine deficiency in remote regions with high poverty will be more difficult to eradicate. Efforts to eliminate IDD in affected areas and sustaining successful iodine programs will be a priority given the substantial public health and economic benefits. A key component will be periodic monitoring of population iodine status to ensure sufficient intakes and the absence of excessive intakes. Median urinary iodine concentration (UIC), a validated biomarker for assessing population iodine status, will facilitate monitoring. Research validating "usual" UIC for use in combination with the Estimated Average Requirement cut-point method will expand its utility and allow accurate determination of the prevalence of inadequate intakes in populations. Further research on the development of biomarkers for assessment of individual iodine status for routine patient care will be important.

Back to the Future: Lipiodol in Lymphography-From Diagnostics to Theranostics

Lipiodol is an iodinated poppy seed oil first synthesized in 1901. Originally developed for therapeutic purposes, it has mainly become a diagnostic contrast medium since the 1920s. At the end of the 20th century, Lipiodol underwent a transition back to a therapeutic agent, as exemplified by its increasing use in lymphangiography and lymphatic interventions. Nowadays, indications for lymphangiography include chylothorax, chylous ascites, chyluria, and peripheral lymphatic fistula or lymphoceles. In these indications, Lipiodol alone has a therapeutic effect with clinical success in 51% to 100% of cases. The 2 main access sites to the lymphatic system for lymphangiography are cannulation of lymphatic vessels in the foot (transpedal) and direct puncture of (mainly inguinal) lymph nodes (transnodal). In case of failure of lymphangiography alone to occlude the leaking lymphatic vessel as well as in indications such as protein-losing enteropathy, postoperative hepatic lymphorrhea, or plastic bronchitis, lymphatic vessels can also be embolized directly by injecting a mixture of Lipiodol and surgical glues (most commonly in thoracic duct embolization). The aim of this article is to review the historical role of Lipiodol and the evolution of its clinical application in lymphangiography over time until the current state-of-the-art lymphatic imaging techniques and interventions.

An Imaging and Histological Study on Intrahepatic Microvascular Passage of Contrast Materials in Rat Liver

Background. Lipiodol has been applied for decades in transarterial chemoembolization to treat liver malignancies, but its intrahepatic pathway through arterioportal shunt (APS) in the liver has not been histologically revealed. This rodent experiment was conducted to provide evidence for the pathway of Lipiodol delivered through the hepatic artery (HA) but found in the portal vein (PV) and to elucidate the observed unidirectional APS. Methods. Thirty rats were divided into 5 groups receiving systemic or local arterial infusion of red-stained iodized oil (RIO) or its hydrosoluble substitute barium sulfate suspension (BSS), or infusion of BSS via the PV, monitored by real-time digital radiography. Histomorphology of serial frozen and paraffin sections was performed and quantified. Results. After HA infusion, RIO and BSS appeared extensively in PV lumens with peribiliary vascular plexus (PVP) identified as the responsible anastomotic channel. After PV infusion, BSS appeared predominantly in the PV and surrounding sinusoids and to a much lesser extent in the PVP and HA (P < 0.001). Fluid mechanics well explains the one-way-valve phenomenon of APS. Conclusions. Intravascularly injected rat livers provide histomorphologic evidences: (1) the PVP exists in between the HA and PV, which is responsible to the APS of Lipiodol; and (2) the intrahepatic vascular inflow appears HA-PVP-PV unidirectional without a physical one-way valve, which can be postulated by the fluid mechanics.

A multifunctional contrast dye for morphological research

OBJECTIVES

We sought to devise and test a multifunctional contrast dye agent for X-ray based digital radiography (DR) or computer tomography (CT), magnetic resonance imaging (MRI), and colored staining in ex vivo validation part of animal experiments.

MATERIALS AND METHODS

The custom-formulated contrast dye namely red iodized oil (RIO) was prepared by solubilizing a lipophilic dye Oil Red O in iodized poppy seed oil (Lipiodol or LPD) followed by physicochemical characterizations. To explore and test the utility of RIO, normal rats (n = 10) and rabbits (n = 10) with myocardial infarction (MI) were euthanized by overdose of pentobarbital for infusion of RIO through catheterization. The bodies and/or excised organs including heart, liver, spleen, kidneys, pancreas, and intestines of the rats and rabbits were imaged at clinical mammography, CT and MRI units. These images were qualitatively studied and quantitatively analyzed using Wilcoxon Rank test with a P value < 0.05 being considered of a statistically significant difference. Imaging findings were verified by histomorphology.

RESULTS

All experimental procedures were carried out successfully with the use of RIO. T1 and T2 relaxation time was 234.2 ± 2.6 ms and 141.9 ± 3.0 ms for RIO, close to that of native LPD. Proton ((1) H) NMR spectroscopy revealed almost identical profiles between RIO and native LPD. The clinical mammography unit, 128-slice CT scanner and 3.0T MRI magnet were well adapted for the animal experiments. Combined use of RIO with DR, MRI, CT and histology enabled microangiography of the organs, 3D visualization of rat pancreas, validation of in vivo cardiac quantification of MI and cause determination of the rabbit death after coronary occlusion. RIO appeared as red droplets and vacuoles in vessels by frozen and paraffin sections. Image analysis showed the superiority of DR images, which provided better overall image quality (4.35 ± 0.49) for all analyzed liver vessel segments. MRI images revealed moderate to good overall image quality ratings (3.45 ± 0.52). Comparing the signal intensities of vessel and liver with different MRI sequences, all P values were <0.01.

CONCLUSIONS

RIO proved to be a multifunctional contrast dye, which could be applied as an imaging biomarker for tissue vascularity or blood perfusion, for visualization of organ anatomy and for ex vivo validation of in vivo animal experiments.

Systematic review of the effects of iodised salt and iodine supplements on prenatal and postnatal growth: study protocol

INTRODUCTION

Iodine is an essential micronutrient and component of the thyroid hormones. Sufficient ingestion of iodine is necessary for normal growth and development. If iodine requirements are not met, growth can be impaired. Salt iodisation and supplementation with iodine can prevent iodine deficiency disorders and stunted growth. No systematic review has yet collated the evidence linking iodine to growth. With an increased emphasis on stunting within the WHO Global Nutrition Targets for 2025, we propose a systematic review to address this question.

METHODS AND ANALYSIS

We will undertake a systematic review, and if appropriate, meta-analyses, evaluating the effects of iodised salt or iodine supplements on prenatal and postnatal somatic growth, until age 18. We will search a number of databases, including MEDLINE, EMBASE, Web of Science, CINAHL, PsychINFO, the Cochrane Library, including the CENTRAL register of Controlled Trials and also the WHO library and ICTRP (International Clinical Trials Registry Platform), which includes the Clinicaltrials.gov repository. We will also search Wanfang Data and the China Knowledge Resource Integrated Database. Included studies must have compared exposure to iodised salt, iodine supplements or iodised oil, to placebo, non-iodised salt or no intervention. Primary outcomes will be continuous and categorical markers of prenatal and postnatal somatic growth. Secondary outcomes will cover further measures of growth, including growth rates and indirect markers of growth such as insulin-like growth factor-1 (IGF-1).

ETHICS AND DISSEMINATION

The systematic review will be published in a peer-reviewed journal, and will be sent directly to the WHO, United Nations Children's Fund, International Council for the Control of Iodine Deficiency Disorders and other stakeholders. The results generated from this systematic review will provide evidence to support future programme recommendations regarding iodine fortification or supplementation and child growth.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42014012940.

Nutrition: Breast milk--a gateway to iodine-dependent brain development

Iodine from the diet is fundamental for brain development. Via milk, infants receive 40-45% of the iodine in their mother's diet during breastfeeding; however, it is unclear to what extent depot iodine supplements (that is, iodized oil) given to iodine-deficient breastfeeding mothers compares with direct supplementation of the infants.

Direct iodine supplementation of infants versus supplementation of their breastfeeding mothers: a double-blind, randomised, placebo-controlled trial

BACKGROUND

Iodine deficiency in infants can damage the developing brain and increase mortality. Present recommendations state that oral iodised oil should be given to breastfeeding mothers to correct iodine deficiency in infancy when iodised salt is not available, and that direct supplementation should be given to infants who are not being breastfed or receiving iodine-fortified complimentary foods. However, there is little evidence for these recommendations. We aimed to assess the safety and efficacy of direct versus indirect supplementation of the infant.

METHODS

We did this double blind, randomised, placebo-controlled trial in Morocco. Healthy breastfeeding mothers and their term newborn babies (aged ≤8 weeks) were block randomised by clinic day to receive either: one dose of 400 mg iodine to the mother and placebo to the infant (indirect infant supplementation), or one dose of about 100 mg iodine to the infant and placebo to the mother (direct infant supplementation). Randomisation was masked to participants and investigators. Coprimary outcomes were: maternal and infant urinary iodine concentrations, breastmilk iodine concentration, maternal and infant thyroid-stimulating hormone (TSH) concentrations, maternal and infant thyroxine (T4) concentrations, and infant growth. These outcomes were measured at baseline, and when infants were aged about 3 months, 6 months, and 9 months, and the two groups were compared using mixed effects models. This study is registered with ClinicalTrials.gov, number NCT01126125.

FINDINGS

We recruited 241 mother-infant pairs between Feb 25, and Aug 10, 2010, and completed data collection by Aug 6, 2011. At baseline, median urinary iodine concentration was 35 μg/L (IQR 29-40) in mothers and 73 μg/L (29-237) in infants, suggesting iodine deficiency. During the study, maternal urinary iodine concentration (p=0.011), breastmilk iodine concentration (p<0.0001), and infant urinary iodine concentration (p=0.042) were higher in the indirect infant supplementation group than in the direct supplementation group. Maternal TSH (p=0.276) and T4 (p=0.074) concentrations did not differ between the groups over the course of the study, nor did infant TSH (p=0.597) and T4 (p=0.184) concentrations, but the number of infants with thyroid hypofunction was lower (p=0.023) in the indirect supplementation group than the direct supplementation group. The infant groups did not differ in anthropomorphic measures, except that length-for-age Z score was slightly greater in the direct infant supplementation group (p=0.032). At 3 months and 6 months of age, median infant urinary iodine concentration in the indirect infant supplementation group was sufficient (>100 μg/L), whereas infant urinary iodine concentration was sufficient only at 6 months in the direct supplementation group. There were no serious adverse events in either group.

INTERPRETATION

In regions of moderate-to-severe iodine deficiency without effective salt iodisation, lactating women who receive one dose of 400 mg iodine as oral iodised oil soon after delivery can provide adequate iodine to their infants through breastmilk for at least 6 months, enabling the infants to achieve euthyroidism. Direct supplementation is less effective in improving infant iodine status.

FUNDING

ETH Zurich, Switzerland; the Medicor Foundation, Vaduz, Lichtenstein.

Use of Lipiodol as a drug-delivery system for transcatheter arterial chemoembolization of hepatocellular carcinoma: a review

Hepatocellular carcinoma (HCC) remains a major public health problem. Transarterial chemoembolization (TACE) is recognized as the standard of care for patients with unresectable, asymptomatic, noninvasive and multinodular HCC. This procedure is based on percutaneous administration of a cytotoxic drug emulsified with Lipiodol followed by embolization of the tumour-feeding arteries. The standard procedure involves Lipiodol, an oily contrast medium which consists of a mixture of long-chain di-iodinated ethyl esters of poppy seed fatty acids. The aim of this review is to discuss the physical properties, tumour uptake behaviour and drug delivery effects of Lipiodol, the parameters influencing tumour uptake and future prospects. Lipiodol has a unique place in TACE as it combines three specific characteristics: drug delivery, transient and plastic embolization and radiopacity properties. Substantial heterogeneity in the physicochemical characteristics of Lipiodol/cytotoxic agent emulsions might reduce the efficacy of this procedure and justifies the current interest in Lipiodol for drug delivery.

Chronic hypothyroidism only marginally affects adult-type Leydig cell regeneration after EDS administration

Chronic prenatally induced dietary hypothyroidism delays adult-type Leydig cell development, but does not block this process. Using a chemical model to induce hypothyroidism, it was suggested that development of a new population of Leydig cells was completely inhibited following the addition of the cytotoxic compound ethane-1,2-dimethyl sulphonate (EDS). In this study, we used a dietary approach to induce hypothyroidism and reinvestigated the regeneration of the Leydig cell population following EDS administration. Eighty-four day old euthyroid and chronically hypothyroid rats received an injection of EDS and were killed directly before or at regular intervals up to 77 days after EDS. In some control and hypothyroid animals, the first progenitor-type Leydig cells were observed at day 12 after EDS. At day 16, Leydig cell progenitors were present in all rats. The percentage of proliferating Leydig cells peaked in the euthyroid animals at day 21 after EDS. In the hypothyroid testis such a peak was not observed, although the percentage of proliferating regenerating Leydig cells was significantly higher from days 35 to 56 compared with the controls. This suggested that the wave of Leydig cell proliferation was delayed in the hypothyroid animals as compared with the euthyroid controls. On the day of EDS injection, the Leydig/Sertoli cell ratio was 37% lower in the hypothyroid rats compared with the controls. The Leydig/Sertoli cell ratio remained lower in the EDS-treated hypothyroid animals compared with the controls at all time points investigated. At day 77 after EDS, the Leydig cell population had returned to its pre-treatment size in both groups. Plasma testosterone production was reduced to below detectable levels immediately after EDS injection, and started to increase again on day 16, reaching pre-treatment values on day 21 in both groups. Taken together, severely reduced thyroid hormone levels did not block the regeneration of the adult-type Leydig cell population following EDS, as has been suggested previously.

Iodine status in a Sherpa community in a village of the Khumbu region of Nepal

OBJECTIVE

To assess the iodine status of Sherpa residents living in Kunde village, Khumbu region, Nepal.

DESIGN

Prevalence of goitre was determined by palpation. Urinary iodine concentrations (UIC) were determined in casual morning samples, and thyroid-stimulating hormone (TSH) in finger-prick blood samples on filter paper. Dietary and demographic data were obtained via questionnaire, and selected foods analysed for iodine.

SETTING

Khumbu region is an area of low soil iodine in Nepal, where the prevalence of goitre was greater than 90% in the 1960s prior to iodine intervention.

SUBJECTS

Two hundred and fifteen of 219 permanent residents of Kunde were studied.

RESULTS

Overall prevalence of goitre was 31% (Grade 1 goitre, 27.0%; Grade 2, 4.2%). When adjusted to a world population, goitre prevalence was 27% (95% CI 23, 32%); Grade 2 goitre prevalence was 2.8% (95% CI 1.0, 4.6%). Median UIC was 97 microg/l, but only 75 microg/l in women of childbearing age. Thirty per cent had UIC < 50 microg/l and 52% had UIC < 100 microg/l, while 31% of children aged <14 years had UIC > 300 microg/l. Ten per cent of participants had TSH concentrations >5 microU/ml.

CONCLUSIONS

The prevalence of severe iodine deficiency has decreased since the 1960s, but mild iodine deficiency persists, particularly in women of childbearing age. The consumption of high-iodine uncooked instant noodles and flavour sachets by school-aged children contributed to their low prevalence of goitre and excessive UIC values. This finding may obscure a more severe iodine deficiency in the population, while increasing the risk of iodine-induced hyperthyroidism in children. Ongoing monitoring is essential.

Effect of excessive iodine exposure on the placental deiodinase activities and Hoxc8 expression during mouse embryogenesis

Excessive iodine induces thyroid dysfunction. However, the effect of excessive iodine exposure on maternal-fetal thyroid hormone metabolism and on the expression of genes involved in differentiation, growth and development is poorly understood. Since a thyroid hormone receptor response element was found in the Hoxc8 promoter region, Hoxc8 expression possibly regulated by excessive iodine exposure was firstly investigated. In the present study, Balb/C mice were given different doses of iodine in the form of potassium iodate (KIO3) at the levels of 0 (sterile water), 1.5, 3.0, 6.0, 12.0 and 24.0 microg/ml in drinking water for 4 months, then were mated. On 12.5 d postcoitum, placental type 2 and type 3 deiodinase activities and fetal Hoxc8 expression were determined. The results showed that excessive iodine exposure above 1.5 microg/ml resulted in an increase of total thyroxine and a decrease of total triiodothyronine in the serum of maternal mice, which was mainly associated with the inhibition of type 1 deiodinase activity in liver and kidney. Placental type 2 deiodinase activity decreased, showing an inverse relationship with maternal thyroxine level. Hoxc8 mRNA and protein expression at 12.5 d postcoitum embryos were down regulated. Because Hoxc8 plays an important role in normal skeletal development, this finding provides a possible explanation for the skeletal malformation induced by excessive iodine exposure and also provides a new clue to study the relationship between iodine or thyroid hormones and Hox gene expression pattern.

Developmental toxic effects of chronic exposure to high doses of iodine in the mouse

Chronic exposure to high doses of iodine induces thyroid dysfunction, but effects of chronic exposure to high amounts of iodine on pregnancy and fetal outcome are uncertain. In the present study, Balb/C mice were given different doses of iodine at the levels of 0 (sterile water), 1,500, 3,000, 6,000, 12,000 and 24,000 micro g/L in drinking water for 4 months, then were mated and the developmental toxicity and teratogenicity were evaluated. An obvious colloid goiter was observed, and serum total thyroxine (TT4) levels increased and serum total triiodothyronine (TT3) levels decreased significantly in dams when iodine dose reached 3,000 micro g/L. Maternal effect was evident by the reduction of average daily food consumption in higher doses of iodine groups. Embryotoxicity and teratogenicity were mainly indicated by the reduced body weight in female fetuses, the decreased number of live fetuses, and the increased incidence of resorptions, and especially skeletal variations. These results suggest that exposure to maternally toxic doses of iodine may have a potential developmental toxic effect.

Iodine nutrition and breast feeding

A survey of the databanks Medline and Web of science identified studies dealing with maternal and infant iodine nutrition during breast feeding. The iodine concentration of human milk varies widely due to maternal iodine intake. Mean breast milk iodine concentrations are reported as ranging from 5.4 to 2170 microg/L (median 62 microg/L) in worldwide studies. In the few studies that compared length of lactation, gestation length, and parity number, these factors did not significantly affect milk-iodine concentrations. In studies of maternal iodine deficiency, untreated goiter had no impact on breast milk iodine when compared with controls. Iodine in human milk responds quickly to dietary iodine intake, either supplemented or consumed in natural foods. Easily absorbable iodine from foods, supplemental sources, iodine-based medication or iodine-based antiseptic solutions used during parturition, is taken up by the maternal thyroid and mammary glands through the Na(+)/I(-) symporter system. This transmembrane carrier protein transports iodine against a high concentration gradient. Hormonal iodine in breast milk occurs mainly as T-4, but depending on maternal iodine intake, high concentrations of the inorganic form (iodide) are found. In less developed countries, where natural-food-iodine intake is low, adequate maternal iodine nutritional status depends exclusively on enforcement of food iodination. In industrialized countries, maternal iodine intake has increased as a function of increasing consumption of dairy products. The human infant is sensitive to maternal iodine nutrition during fetal development and later during breast feeding. Environmental factors, not directly related to maternal iodine intake, such as intake of selenium and organochlorine pollutants, can affect thyroid hormone homeostasis in breast-fed infants. In spite of low iodine concentrations found in milk of mothers consuming low-iodine natural foods, long lasting or even life-lasting benefits to the breast-fed infant are demonstrable.