Exposición a nitratos en agua y su relación con disfunción de la glándula tiroides: revisión sistemática ¿Existen riesgos para la salud de la población? / Exposure to nitrates in drinking water and its association with thyroid gland dysfunction

Background: Nitrate exposure may be associated with thyroid gland dysfunction. Aim: To review the available evidence about the relationship between nitrates in drinking water and thyroid gland dysfunction. Material and Methods: A wide search was performed using Medline, Cochrane, Lilacs, IBECS and Scielo databases using pertinent keywords, finding a total of 66 related studies. After filtering and in depth reviewing, a total of 12 studies were included in this review. Results: The main results reveal the importance of this ion for human health, finding evidence both in animals and human beings that suggest pathological changes in the gland as its relationship with the occurrence of subclinical hypothyroidism, and potentially cancer of the thyroid gland. In Chile, nitrate is not considered a critical contaminant so its regular measuring and control is not enforced. Conclusions: In light of the present review we believe that there is evidence to consider nitrate as a critical contaminant whose measurement, registration and correct implementation of valid policies would have a direct benefit for the population of this country. Without this information, it is not possible to quantify the damage to human health, especially in vulnerable groups residing in areas at greatest risk of exposure.

Should human chorionic gonadotropine treatment increase thyroid volume?

Objective Our aim was to investigate the thyroid function tests and thyroid volume differences among males with isolated hypogonadotropic hypogonadism (IHH) who take androgen replacement treatment (ART). Materials and methods Forty-four male with IHH with a mean age 33.2 (18-54), diagnosed in Endocrinology and Metabolism Department between September 2013 and September 2014 and 40 healthy male control with a mean age 27.77 (18-55) were involved to study. Patient group was divided to testosterone-treated patients (n = 19) and human chorionic gonadotropine (hCG)-treated patients (n = 25). Patient group was compared in terms of total testosterone, thyroid function tests [thyroid stimulating hormone (TSH), free thyroxine (fT4)] and thyroid volume, before and 6 months after treatment. Patient group was compared with control group as well. Results When we compared the patient group with the control group, there was no significant difference for age, Body mass index, TSH, fT4 and thyroid volume between two groups before treatment. There was no difference in terms of TSH, but fT4, testosterone levels and thyroid volume were significantly higher after treatment, when the patient group was compared before and after treatment (p < 0.05). When we compared testosterone-treated patients and hCG-treated patients; thyroid volume was higher among hCG-treated patients (p = 0.001) but there was no difference for thyroid volume before and after testosterone treatment (p > 0.05). There was no statistically significant correlation between testosterone levels with TSH, fT4 and thyroid volume (r = 0.09, p = 0.32; r = 0.14, p = 0.11; r = 0.15, p = 0.09, respectively). Conclusion Our study showed that ART increases the thyroid volume especially in hCG-treated patients. Therefore, we suggest that thyroid volume changes should be followed up in hCG-treated patients.

Synergic actions of polyphenols and cyanogens of peanut seed coat (Arachis hypogaea) on cytological, biochemical and functional changes in thyroid.

In animals, long-term feeding with peanut (Arachis hypogaea) seed coats causes hypertrophy and hyperplasia of the thyroid gland. However, to date there have been no detailed studies. Here, we explored the thyroidal effects of dietary peanut seed coats (PSC) in rats. The PSC has high levels of pro-goitrogenic substances including phenolic and other cyanogenic constituents. The PSC was mixed with a standard diet and fed to rats for 30 and 60 days, respectively. Animals fed with the PSC-supplemented diet showed a significant increase in urinary excretion of thiocyanate and iodine, thyroid enlargement, and hypertrophy and/or hyperplasia of thyroid follicles. In addition, there was inhibition of thyroid peroxidase (TPO) activity, 5’-deiodinase-I (DIO1) activity, and (Na+-K+)-ATPase activity in the experimental groups of rats as compared to controls. Furthermore, the PSC fed animals exhibited decreased serum circulating total T4 and T3 levels, severe in the group treated for longer duration. These data indicate that PSC could be a novel disruptor of thyroid function, due to synergistic actions of phenolic as well as cyanogenic constituents.

Incidence of and risk factors for thyroid dysfunction during peginterferon alpha and ribavirin treatment in patients with chronic hepatitis C

BACKGROUND/AIMS: Thyroid dysfunction (TD) is more likely to occur in patients with chronic hepatitis C (CHC) and is particularly associated with interferon (IFN) treatment. The purpose of this study was to investigate the incidence, outcomes, and risk factors for TD during pegylated interferon (PEG-IFN) and ribavirin (RBV) combined therapy in patients with CHC. METHODS: A total of 242 euthyroid patients with CHC treated with PEG-IFN/RBV were included. Thyroid function and autoantibodies were measured at baseline, and virologic response and thyroid function were assessed every 3 months during therapy. RESULTS: TD developed in 67 patients (27.7%) during the PEG-IFN/RBV treatment. The types of TD were subclinical hypothyroidism (50.7%), hypothyroidism (14.9%), thyroiditis (11.9%), subclinical hyperthyroidism (10.4%), and hyperthyroidism (10.4%). Most of the patients with TD recovered spontaneously; however, seven patients (10.4%) needed thyroid treatment. The sustained virological response rate was higher in patients with TD than those without (65.7% vs. 49.1%, p = 0.02). Baseline thyroid stimulating hormone (TSH) concentrations (odds ratio [OR], 2.09; 95% confidence interval [CI], 1.96 to 8.77; p < 0.001), presence of the thyroid peroxidase antibody (OR, 8.81; 95% CI, 1.74 to 44.6; p = 0.009), and PEG-IFNalpha-2b (OR, 3.01; 95% CI, 1.43 to 6.39; p = 0.004) were independent risk factors for the development of TD. CONCLUSIONS: TD developed in 27.7% of patients with CHC during PEG-IFN/RBV treatment, and 10.4% of these patients needed thyroid treatment. TD is associated with a favorable virologic response to PEG-IFN/RBV. Assessment of TSH and thyroid autoantibodies at baseline and close monitoring of thyroid function during PEG-IFN/RBV therapy are necessary for early detection and management of IFN-induced TD.

Dual ectopic thyroid presenting with an anterior neck mass

No abstract available.

Effects of magnesium on cytomorphology and enzyme activities in thyroid of rats.

Till date knowledge regarding the effects of high dietary magnesium on thyroid gland is incomprehensive though certain epidemiological studies reported development of thyroid gland dysfunctions in people with chronic exposure to hard water (especially with high magnesium) despite sufficient iodine consumption. The present study is to explore the effects of chronic high dietary magnesium exposure on thyroid morphology and functional status. Male adult albino Wistar strain rats were treated with graded doses of magnesium sulphate (MgSO4; 0.5, 1.0 and 1.5 g %) for 60 days and changes in different thyroid parameters were investigated. Significantly stimulated thyroid peroxidase and Na+–K+-ATPase and altered idothyronine 5/- deiodinase type I activities, enhanced serum thyroxine (T4) (both total and free), total triiodothyronine (T3) and thyroid stimulating hormone with decreased free T3 levels and T3/T4 ratio (T3:T4) along with enlargement of thyroid with associated histopathological changes were observed in the treated groups. The results clearly confirm that chronic high dietary magnesium exposure causes potential thyroid disruption as reported in earlier epidemiological studies.

Use of potassium iodide in Dermatology: updates on an old drug / Uso do iodeto de potássio na Dermatologia: considerações atuais de uma droga antiga

Potassium iodide, as a saturated solution, is a valuable drug in the dermatologist's therapeutic arsenal and is useful for the treatment of different diseases due to its immunomodulatory features. However, its prescription has become increasingly less frequent in dermatology practice. Little knowledge about its exact mechanism of action, lack of interest from the pharmaceutical industry, the advent of new drugs, and the toxicity caused by the use of high doses of the drug are some possible explanations for that. Consequently, there are few scientific studies on the pharmacological aspects, dosage and efficacy of this drug. Also, there is no conventional standard on how to manipulate and prescribe the saturated solution of potassium iodide, which leads to unawareness of the exact amount of the salt being delivered in grams to patients. Considering that dosage is directly related to toxicity and the immunomodulatory features of this drug, it is essential to define the amount to be prescribed and to reduce it to a minimum effective dose in order to minimize the risks of intolerance and thus improve treatment adherence. This review is relevant due to the fact that the saturated solution of potassium iodide is often the only therapeutic choice available for the treatment of some infectious, inflammatory and immune-mediated dermatoses, no matter whether the reason is specific indication, failure of a previous therapy or cost-effectiveness.

Iodeto de potássio, sob a forma de solução saturada, é um valioso medicamento no arsenal terapêutico do dermatologista. É usado há mais de um século e útil para doenças de fisiopatologias diversas em virtude de seu caráter imunomodulador. Prescrevê-lo, entretanto, tem se tornado cada vez menos frequente na prática dermatológica. O pouco conhecimento sobre seu exato mecanismo de ação, o desinteresse da indústria farmacêutica com o advento de novos fármacos, além da toxicidade do medicamento pelas altas doses utilizadas são algumas das possíveis justificativas. Dessa forma, os estudos científicos envolvendo seus aspectos farmacológicos, posológicos e de eficácia são relativamente raros. Consequentemente, não se convencionou uma padronização na forma de manipular e prescrever a solução saturada de iodeto de potássio, o que causa um verdadeiro desconhecimento da dose exata em gramas do sal que está sendo fornecida aos pacientes. Ao considerar que a dose está diretamente relacionada toxicidade e o conhecimento da característica imunomoduladora dessa droga, é importante definir a quantidade a ser fornecida, reduzindo-a até a dose mínima eficaz, de forma a diminuir a intolerância e melhorar a adesão ao tratamento. A relevância do tema se deve ao fato da solução saturada de iodeto de potássio ser, muitas vezes, a única escolha na terapêutica disponível para o tratamento de algumas dermatoses de origem infecciosa, inflamatória ou imunomediada, quer por indicação específica, por falha de outro medicamento ou por seu custo acessível.

Endocrine disturbances related to the use of lithium / Distúrbios endocrinológicos relacionados ao uso de lítio

Despite recent advances in pharmacological treatment of psychiatric disorders, lithium salts remain frequently used, as they are effective and inexpensive alternatives, especially in the treatment of bipolar disorders. Their use is commonly associated with various endocrine disorders, mainly in thyroid and parathyroid function, and in mineral metabolism. This article aims at reviewing these potential endocrinopathies related to the use of lithium to make health care professionals aware and familiar with these possible complications when they follow up patients using this drug, and to make them able to monitor, identify and institute early and appropriate treatment.

Apesar dos recentes avanços farmacológicos no tratamento dos transtornos psiquiátricos, os sais de lítio permanecem como uma alternativa eficaz e de menor custo, sendo usados com frequência principalmente no tratamento dos transtornos bipolares. O seu uso é comumente relacionado com diversas alterações endocrinológicas, principalmente nas funções tiroidiana, paratiroidiana e do metabolismo iônico. Este artigo tem por objetivo fazer uma revisão dessas potenciais endocrinopatias relacionadas ao uso do lítio, para que, no seguimento de pacientes em uso dessa medicação, os profissionais de saúde estejam atentos e familiarizados com essas possíveis complicações, conseguindo identificar e instituir tratamento precocemente.

Evaluation of effect of isoflavone on thyroid economy & autoimmunity in oophorectomised women: A randomised, double-blind, placebo-controlled trial.

Background and objectives: The potential of soy isoflavones to interfere with thyroid function has been reported. However, there are limited data regarding their effect on thyroid function and autoimmunity in surgical menopausal women. The present study aimed to evaluate the effect of isoflavones on thyroid function and autoimmunity, menopausal symptoms, serum follicle stimulating hormone (FSH) and estradiol levels in oophorectomised women. Methods: A randomized, double blind, placebo-controlled trial was conducted in 43 oophorectomised women to evaluate the effect of soy isoflavones (75 mg/day for 12 wk) on serum thyroid profile (free T3 , free T4 , TSH, TBG and anti-TPO antibody titres) assessed at baseline, 6 and 12 wk after randomization. Assessment was also done for menopause symptom score (MSS) three weekly, and FSH and estradiol levels at baseline and at study completion. Results: There was a significant alteration in free T 3 levels in the group receiving isoflavones (4.05 ± 0.36, 4.12 ± 0.69 and 3.76 ± 0.55 pmol/l at baseline, 6 and 12 wk, respectively; P=0.02). However, the mean change in various thyroid parameters at 12 wk from baseline was not significantly different between the two groups. MSS was also significantly decreased at 9 and 12 wk from baseline with isoflavones (12.47 ± 8.15, 9.35 ± 5.23 and 9 ± 5.14 at baseline, 9 and 12 wk respectively; P=0.004) with significant improvement in urogenital symptoms compared to placebo. Isoflavones did not significantly affect other parameters during study period. There were no serious adverse events reported and the proportion of patients experiencing adverse events was similar between the two groups. Interpretation and conclusions: Modest reduction in serum free T3 levels in the isoflavone group in the absence of any effect on other thyroid parameters might be considered clinically unimportant.

Amiodarona e tireotoxicose: relatos de casos / Amiodarone and thyrotoxicosis: case reports / Amiodarona y tirotoxicosis: relatos de casos

Relata-se que a disfunção tireoidiana induzida pela amiodarona afeta de 2 a 24 por cento dos usuários. Embora seja fácil tratar o hipotireoidismo induzido pela amiodarona, o desenvolvimento da tireotoxicose leva a uma abordagem difícil na maioria dos casos. O objetivo deste estudo é descrever três casos diferentes de pacientes com tireotoxicose induzida por amiodarona e discutir os aspectos clínicos e laboratoriais, e as diferentes abordagens para esses casos. É essencial avaliar cuidadosamente os pacientes antes e durante o tratamento com amiodarona, tendo em vista que o diagnóstico e o tratamento imediato dessa condição são cruciais em pacientes com alto risco cardiovascular.

Amiodarone-induced thyroid dysfunction has been reported to affect 2-24 percent of users. Despite the easy management of amiodarone-induced hypothyroidism, the development of thyrotoxicosis leads to a difficult approach in most cases. The aim of this study is to describe three different cases of patients with amiodarone-induced thyrotoxicosis and discuss the clinical and laboratorial aspects, and the different approaches to them. It is essential to carefully evaluate patients before and during amiodarone therapy, since the prompt diagnosis and treatment of this condition is essential in patients with high cardiovascular risk.

Se relata que la disfunción tiroidea inducida por la amiodarona afecta de 2 a 24 por ciento de los usuarios. Aunque sea fácil tratar el hipotiroidismo inducido por la amiodarona, el desarrollo de la tirotoxicosis lleva a un abordaje difícil en la mayoría de los casos. El objetivo de este estudio es describir tres casos diferentes de pacientes con tirotoxicosis inducida por amiodarona y discutir los aspectos clínicos y de laboratorio, y los diferentes abordajes para esos casos. Es esencial evaluar cuidadosamente los pacientes antes y durante el tratamiento con amiodarona, teniendo en vista que el diagnóstico y el tratamiento inmediato de esa condición son cruciales en pacientes con alto riesgo cardiovascular.

Effect of hydroalcoholic extract of caraway on thyroid gland structure and hormones in female rat

Caraway is one of the medicinal plants used for digestion problems, however, it has been reported that the long term use of this plant in large doses might cause hyperthyroidism symptoms such as leanness, hair loss, severe sweating and tremulousness. Therefore, the aim of this study was to evaluate the effect of hydroalcoholic extract of caraway on the level of thyroid hormones and morphologic changes of thyroid gland in rats. For this purpose, 60 rats were divided into 5 experimental and control groups. Experimental groups were orally given 100, 400, 800 and 1600 mg/kg of extract for 45 days by gavage. The same volume of saline was given to the control group. Blood samples were taken before and after the experiments for the measurement of hormones. The rats were dissected under deep anesthesia and their thyroid glands were removed, processed and stained with H and E. Results show that T[3] and T[4] were increased and TSH was decreased significantly at high doses compared to those in the control group, but no change was observed in the structure of the gland and the size of follicles. It seems that caraway can temporally increase thyroid hormones and cause hyperthyroidism, but further studies are required to clarify the issue

effect of mercury on thyroid function in sheep

The purpose of this experiment was to determine the effect of long-term low-dose administration of mercury [Hg] on thyroid function in sheep. In this experiment, 10 clinically healthy, adult, male Iranian sheep, aged approximately 1 year, were randomly allocated into the control [n=5] and mercury [Hg-]-treated [n=5] groups. Both groups were kept under identical conditions in terms of food and environment. The treatment group received mercuric chloride [5 mg/kg/day] orally for eight weeks. Blood samples were drawn between the hours of 0800 and 0900 from both groups on days 0, 14, 28, 42, 56 and 70. Thyroid function was evaluated by measuring the levels of the serum thyroid hormones, including triiodothyronine [T3], thyroxine [T4], free T3 [FT3], free T4 [FT4] and thyroid-stimulating hormone [TSH]. Hepatic function was evaluated in both groups by measuring alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyltransferase [GGT] and total bilirubin [TBIL]. Renal function was assessed using serum creatinine [Cr] and blood urea nitrogen [BUN] levels. Serum T3 [from day 28 onwards] and serum T4, FT3, FT4 and TSH [from day 14 onwards] decreased in the Hg-treated group [p<0.05]. Serum ALT, AST and GGT increased from days 42, 56 and 70, respectively, when compared to the control group [p<0.05]. The concentrations of total protein and albumin decreased on day 70 and total bilirubin [TBIL], BUN and Cr levels increased on day 70 when compared to the control group [p<0.05]. It was concluded that chronic administration of Hg may expose sheep to the risk of hypothyroidism

Hyperpustic thyroid gland; steroid hazards

The study was conducted to see the effects of dexamethasone [synthetic corticosteroid] on involution of hyperplastic thyroid gland in albino rats, and to evaluate its uses in thyroid diseases. Comparative histological study done in Postgraduate Medical Institute Lahore in 1998. 54 adult male rats were taken and divided at random into control group having 27 rats and experimental groups containing 27 rats. Control group was given normal diet along with 2 microgram of Potassium iodide for 21 days while experimental groups further subdivided into group A having 3 rats and group B and C containing 12 rats each. All the experimental groups were treated with Thiourea. Group A was sacrificed on day 22 after withdrawal of thiourea. Group B was given Potassium iodide after stoppage of thiourea on day 21 and were sacrificed on days 22, 26, 30 and 50 in 4 sub groups [B1- B4]. Group C was injected Dexamethasone daily from day 22 to day 50 and sacrificed on same days in 4 subgroups [C1-C2] to study involution process. Histologically experimental group A exhibited significant increase in width and length of follicular cells lining the small sized follicles having scanty colloid. The results of experimental subgroups B revealed early and complete involution whereas subgroups C showed significantly persistent hyperplastic changes in the form of tall follicular cells lining small empty follicles. Thus it was concluded that dexamehasone did retain hyperplastic changes during involution process, so steroid should consciously be used in thyroid diseases

El litio y su influencia en la función tiroidea / Lithium and the influence in thyroid function

El Litio, utilizado como tratamiento de primera línea en la enfermedad maníaco depresiva, genera cambios en la fisiología tiroidea. En los últimos trabajos entre los años 1999 y 2007, se ha encontrado una alta prevalencia de hipofunción tiroidea en pacientes bipolares principalmente en el sexo femenino y a mayor edad. Aparentemente su aparición no se correlaciona con la duración del tratamiento ni con la Litemia. Dada la escasa literatura existente acerca de este tema, el objetivo de esta revisión es actualizar los datos últimamente publicados.

Lithium, used as a first line treatment in maniac depression disease, affects the thyroid gland function. In the last papers published between 1999 and 2007, it has been found a high prevalence of hypothyroidism in bipolar patients, especially in females and when starting lithium at a later age. The duration of treatment and Lithemia seams to have no correlation with the begining of hypothyroidism. Because of the poor literature written about this issue, the aim of this review is to update the last papers published.

effects of topical iodine containing antiseptics on thyroidal status of preterm versus term babies

To determine the effect of iodine containing antiseptics on thyroid function for the first 3 weeks in non-very-low-birth weight preterm and term babies, and to evaluate their thyroid function and behavioral status 7 years later. Cohort I [between the years 1997-1998] was studied in 57 preterm [30-35 weeks] and 29 term newborns, 7 years later cohort II [in the year 2005] was created from same 28 preterm and 18 term infants at Behcet Uz Children's Hospital, Izmir, Turkey. Serum thyrotropin, triiodothyronine, total and free thyroxine were measured on the first, seventh, and twenty-first days [cohort I], and at the age of 7 [cohort II]. In respect of used antiseptics, the patients were divided into 2 groups. The evaluation of patients was performed according to the Turgay Diagnostic and Statistical Manual for Psychiatric Disorders, 4th edition based child and adolescent behavior disorders screening and rating scale. On the seventh day of life, iodine-exposed newborns had significantly higher mean thyrotropin levels and lower free thyroxine, total thyroxine, and triiodothyronine levels. On the twenty-first day, thyrotropin levels of iodine-exposed newborns were similar to controls. The cohort II results showed normal thyroid function in all patents with increased hyperactivity among children born prematurely, and particularly experienced exposure to iodine. Iodine excess may cause transient hypothyroxinemia in preterm babies [>30 weeks gestational age, >1.5 kg] and this may be one of the reasons for behavior problems observed later in these children

Hyperplastic thyroid gland; vascular and follicular changes produced by dexamethasone during involution

The study was conducted to see the vascular and follicular changes induced by dexamethasone [synthetic corticosteroid] during involution of hyperplastic thyroid gland in albino rats. A comparative histological study done in Post Graduate Medical Institute Lahore in 1998. 54 adult rats were taken and divided at random into two control groups having 27 rats and experimental groups containing 27 rats. Control group was given normal diet along with 2 microgram of Potassium iodide intraperitonealy for 21 days while experimental groups further subdivided into group A having 3 rats and group B and C containing 12 rats each. All the experimental groups were treated with Thiourea for 21 days. Group A was sacrificed on day 22 after withdrawal of thiourea. Group B was given Potassium iodide intraperitonealy after stoppage of TU on day 21 and were sacrificed on days 22, 26, 30 and 50 in 4 sub groups [B1-B4] to study the involution process. Group C was injected dexamethasone from 22 to 50 days after withdrawal of TU and sacrificed on same days in 4 subgroups [C1-C4] as sub groups B. The results of experimental group. A showed increase in thyroid and relative tissue weight. Histologically this group exhibited significant increase in stromal congestion with tall follicular cells lining the small sized follicles having scanty colloid. The results of experimental groups B and C demonstrated increase in thyroid and relative tissue weight but microscopically subgroups B revealed early and complete involution whereas subgroups C showed significantly persistent hyperplastic changes in the form of stromal congestion, vessels wall remained well defined and tall follicular cells lining small empty follicles. It was concluded that dexamehasone did retain hyperplastic changes during involution evident by stromal congestion and small sized regular follicle lined by tall follicular cells, so it should be carefully used in thyroid diseases