1
|
Campos RDO, Barreto IDS, Maia LRDJ, Rebouças SCL, Cerqueira TLDO, Oliveira CA, Santos CADST, Mendes CMC, Teixeira LSG, Ramos HE. Iodine nutritional status in Brazil: a meta-analysis of all studies performed in the country pinpoints to an insufficient evaluation and heterogeneity. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2015; 59:13-22. [DOI: 10.1590/2359-3997000000004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 10/12/2014] [Indexed: 11/21/2022]
|
2
|
Ferreira SMS, Navarro AM, Magalhães PKR, Maciel LMZ. Iodine insufficiency in pregnant women from the State of São Paulo. ACTA ACUST UNITED AC 2014; 58:282-7. [DOI: 10.1590/0004-2730000002979] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 11/15/2013] [Indexed: 12/21/2022]
Abstract
Objective : The intake of adequate amounts of iodine during pregnancy is essential for the neurological development of the fetus. The aim of this study was to assess iodine nutrition status in pregnant women from the state of São Paulo, Brazil.Material and methods : We analyzed urinary iodine concentration (UIC) in 191 pregnant and 58 non-pregnant women matched by age. We used the World Health Organization criteria to define sufficient iodine supply (median UIC: 150-249 µg/L among pregnant women, and 100-199 µg/L for non-pregnant women).Results : Median UIC of the pregnant women studied was lower than the recommended value (median = 137.7 µg/L, 95% CI = 132.9 – 155.9), while non-pregnant women had UIC levels within the appropriate range (median = 190 μg/L; 95% IC = 159.3-200.1). UIC was below 150 µg/L in 57% of the pregnant women.Conclusions : Although a larger sample is needed to consolidate these findings, these results raise concerns about the adequacy of the iodine supply of pregnant women in Brazil, especially considering the new determinations of the Brazilian government, which have recently reduced the concentrations of iodine in table salt to 15-45 mg/kg of salt. Arq Bras Endocrinol Metab. 2014;58(3):282-7
Collapse
|
3
|
Boasquevisque PCR, Jarske RD, Dias CC, Quintaes IPP, Santos MCLFS, Musso C. [Correlation between iodine urinary levels and pathological changes in thyroid glands]. ACTA ACUST UNITED AC 2014; 57:727-32. [PMID: 24402019 DOI: 10.1590/s0004-27302013000900009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 06/28/2013] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To determine iodine nutrition in the population and to correlate levels of iodine found in random samples of urine with pathological changes observed in thyroids collected in this population. MATERIALS AND METHODS Urinary iodine was determined in 30 random samples of urine and the pathological study was carried out in 55 thyroid glands from corpses received by the Department of Forensic Medicine of Vitória, Espírito Santo, Brazil from May to August 2011. RESULTS In 29 urine samples (96.7%) urinary iodine was above the maximum limit recommended by the World Health Organization (WHO), of 300 mg/L. Fourteen thyroids (25.5%) showed the presence of histological changes compatible with thyroiditis. Higher levels of iodine in urine were observed in females and in of thyroid that showed inflammation (thyroiditis). CONCLUSIONS We conclude that, in this population, there is excess iodine intake, and greater incidence of inflammatory thyroid disease.
Collapse
|
4
|
de Lima LF, Barbosa F, Navarro AM. Excess iodinuria in infants and its relation to the iodine in maternal milk. J Trace Elem Med Biol 2013; 27:221-5. [PMID: 23499317 DOI: 10.1016/j.jtemb.2013.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 12/13/2012] [Accepted: 01/23/2013] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Iodine is an essential micro nutrient, and a deficiency or excessive intake of this mineral is related to changes in thyroid function. In Brazil, both deficiency and excessive intake of iodine are common; however, excessive intakes have recently been observed. Thus, the objective of the present study was to assess the iodine concentration in maternal milk, taking into account the salt iodine concentration of the participating households and in the infants' urine. METHOD Urine samples from 33 infants (less than 6 months of age), maternal milk samples and samples of the kitchen salt used by the mothers were collected. The iodine levels in the urine and maternal milk were assessed by ICP-MS; the iodine levels in the salt were assessed by titration. RESULT The median iodinuria value in the infants was 293 μg/L; the mean iodine concentration was 206 μg/L in the maternal milk and 39.9 mg I/kg in the salt. There was a positive correlation between the iodine concentration in the maternal milk and the infant iodinuria value. CONCLUSION The median infant iodinuria was elevated due to the high iodine concentration present in the maternal milk. High iodine values were caused by high salt iodine levels, which should be reduced.
Collapse
Affiliation(s)
- Livia Fernandes de Lima
- Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, Avenida Bandeirantes 3900, Monte Alegre, 14049-900 Ribeirão Preto, SP, Brazil.
| | | | | |
Collapse
|
5
|
Abstract
PURPOSE Inadequate iodine intake may result in iodine deficiency disorders (IDD). Thus, for more than 50 years, policies for the regulation of salt fortification with iodine have existed in Brazil. In 2003, a study on 6-14-year-old schoolchildren from regions of the state of São Paulo showed a median urinary iodine concentration of 360 μg/L. The objective of the present study was to assess the iodine nutrition status among schoolchildren. METHODS The study was conducted on 828 schoolchildren aged 4-13 years from eight schools in the interior of the state of São Paulo. A casual urine sample was collected from each volunteer for iodine determination by the adapted method of Sandell-Kalthoff. RESULTS Only 1.9% (n = 16) of the children evaluated had low values of urinary iodine (<100 μg/L), while 24.6% had urinary iodine excretion values between 200 and 300 μg/L, and 67.1% had values above >300 μg/L. CONCLUSIONS The results show that the iodine nutritional status of the schoolchildren studied is characterized by a high urinary iodine excretion, which might reveal an increase in iodine consumption by this population.
Collapse
|
6
|
Medeiros-Neto G. Iodine nutrition in Brazil: where do we stand? ACTA ACUST UNITED AC 2010; 53:470-4. [PMID: 19649387 DOI: 10.1590/s0004-27302009000400014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 03/02/2009] [Indexed: 11/22/2022]
Abstract
Brazilian legislation, since 1955, failed to achieve its objectives because the issue was not properly addressed: iodized salt was only available in endemic areas, at a low amount of 10 mg Iodine/kg salt. Lack of surveillance and cooperation were common errors. From 1982 to 1992, the INAN distributed potassium iodate to the industry free of charge, but it was abolished in 1991. Only four years later (1995) was a new law enacted effective in determining that all salt for human use should be iodized at levels established by the Health Authorities. During the period comprising 1998 to 2004, excessive iodination of salt (40 to 100 mg/kg) could lead to an increased prevalence of chronic autoimmune thyroiditis and iodine-induced hyperthyroidism. In 2003, the content of iodine/kg of salt was lowered to 20 to 60 mg I/kg salt. A national survey of schoolchildren is currently underway and will indicate the changes required for adequate iodine in salt for human use.
Collapse
Affiliation(s)
- Geraldo Medeiros-Neto
- Laboratório Molecular de Tireoide, Universidade de São Paulo, São Paulo, SP, Brazil.
| |
Collapse
|
7
|
Romão R, Rubio IGS, Tomimori EK, Camargo RY, Knobel M, Medeiros-Neto G. High prevalence of side effects after recombinant human thyrotropin-stimulated radioiodine treatment with 30 mCi in patients with multinodular goiter and subclinical/clinical hyperthyroidism. Thyroid 2009; 19:945-51. [PMID: 19678745 DOI: 10.1089/thy.2008.0394] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Treatment of multinodular goiters (MNGs) is highly controversial. Radioiodine (RAI) therapy is a nonsurgical alternative for the elderly who decline surgery. Recently, recombinant human thyrotropin (rhTSH) has been used to augment RAI uptake and distribution. In this study, we determined the outcome of 30 mCi RAI preceded by rhTSH (0.1 mg) in euthyroid (EU) and hyperthyroid (subclinical/clinical) patients with large MNGs. METHODS This was a prospective cohort study. Forty-two patients (age, 43-80 years) with MNGs were treated with 30 mCi RAI after stimulation with 0.1 mg of rhTSH. Patients were divided into three groups, according to thyroid function: EU (n = 18), subclinically hyperthyroid (SC-H, n = 18), and clinically hyperthyroid (C-H, n = 6). All patients underwent a 90-day low-iodine diet before treatment, and those with clinical hyperthyroidism received methimazole 10 mg daily for 30 days. Serum TSH, free thyroxine (FT4), total triiodothyronine (TT3), and thyroglobulin were measured at baseline and at 24, 48, 72, 168 hours, and 1, 3, 6, 9, 12, 18, 24, and 36 months after therapy. Thyroid volume was assessed by computed tomography at baseline and every 6 months. RESULTS Patients had high iodine urinary excretion (308 +/- 108 microg I/L) at baseline. TSH levels at baseline were within the normal range (1.5 +/- 0.7 microU/mL) in the EU group and suppressed (<0.3 microU/mL) in the SC-H and C-H groups. After rhTSH, serum TSH peaked at 24 hours reaching 12.4 +/- 5.85 microU/mL. After RAI administration, patients in both hyperthyroid groups had a higher increase in FT4 and TT3 compared with those in the EU group (p < 0.001). Thyroglobulin levels increased equally in all three groups until day 7. Thyroid volume decreased significantly in all patients. Side effects were more common in the SC-H and C-H groups (31.4% and 60.4%, respectively) compared with EU patients (17.8%). Permanent hypothyroidism was more prevalent in the EU group (50%) compared with the SC-H (11%) and C-H (16.6%) groups. CONCLUSIONS Patients with MNG may have subclinical and clinical nonautoimmune iodine-induced hyperthyroidism. Despite a low-iodine diet and therapy with methimazole, hyperthyroid patients have a significantly higher increase in FT4 and TT3 levels after RAI ablation. This can lead to important side effects related mostly to the cardiac system. We strongly advise that patients with SC-H and C-H be adequately treated with methimazole and low-iodine diet aiming to normalize their hyperthyroid condition before rhTSH-stimulated treatment with RAI.
Collapse
Affiliation(s)
- Rossana Romão
- Thyroid Unit (LIM-25), Division of Endocrinology, University of São Paulo Medical School , Hospital das Clínicas, São Paulo, Brazil
| | | | | | | | | | | |
Collapse
|
8
|
Abstract
OBJECTIVE To examine the importance of iodine nutrition during pregnancy. DESIGN Review of existing literature of iodine in pregnancy. SETTING Population surveys and metabolic studies. SUBJECTS Pregnant women. RESULTS The main changes in thyroid function associated with pregnancy are due to an increase in hormone requirements that begin in the first trimester of gestation. This increase can only be met by a proportional increase in hormone production, something that depends directly upon the availability of iodine. When dietary iodine is lacking, an adequate physiological adaptation is difficult to achieve and is progressively replaced by pathological alterations that occur in parallel with the degree and duration of iodine deprivation. CONCLUSIONS Iodine prophylaxis should be given systematically to women during pregnancy. In most public health programmes dealing with the correction of iodine deficiency disorders, iodised salt has been used as the preferred means to deliver iodine to households. Iodised salt, however, is not the ideal means of delivering iodine in the specific instances of pregnancy, breast-feeding and complementary feeding because of the need to limit salt intake during these periods. In European countries, presently it is proposed that iodine is given to pregnant women and breast-feeding mothers by systematically administering multivitamin tablets containing iodine in order to reach the recommended dietary allowance of 250 microg iodine day-1.
Collapse
|
9
|
Esteves RZ, Kasamatsu TS, Kunii IS, Furuzawa GK, Vieira JGH, Maciel RM. Desenvolvimento de um método para a determinação da iodúria e sua aplicação na excreção urinária de iodo em escolares brasileiros. ACTA ACUST UNITED AC 2007; 51:1477-84. [DOI: 10.1590/s0004-27302007000900010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2007] [Accepted: 07/30/2007] [Indexed: 11/21/2022]
Abstract
Desenvolvemos método semi-automatizado em placa para a determinação de iodo urinário; utilizamos, primeiramente, a digestão das amostras de urina com persulfato de amônio e, a seguir, estimamos a quantidade de iodo pela redução do sulfato cérico amoniacal. O método foi validado no inquérito nacional de monitoração da deficiência de iodo, realizado em 1994, que empregou um sistema de amostragem mista da população brasileira e analisou a iodúria em 16.803 amostras de urina de escolares obtidas por coleta casual. Em 401 municípios estudados encontramos 4 com deficiência de iodo de grau moderado (Almas, Arraias e Paraná, em Tocantins, e Cocos, na Bahia) e 116 de grau leve. Desta forma, este estudo mostrou a presença de regiões com deficiência de iodo em 1994, a despeito do programa de iodação do sal. Dados recentes de outros autores, com número menor de municípios, indicam excesso de ingestão de iodo. Assim, num país de dimensões continentais e heterogêneo como o Brasil, é necessária a realização de avaliações periódicas de amplitude nacional para a verificação da ingestão de iodo da população. O método apresentado neste estudo apresenta as características de simplicidade e eficiência necessários para este tipo de estudo populacional.
Collapse
|
10
|
Sebastianes FM, Cerci JJ, Zanoni PH, Soares J, Chibana LK, Tomimori EK, de Camargo RYA, Izaki M, Giorgi MCP, Eluf-Neto J, Meneghetti JC, Pereira MAA. Role of 18F-fluorodeoxyglucose positron emission tomography in preoperative assessment of cytologically indeterminate thyroid nodules. J Clin Endocrinol Metab 2007; 92:4485-8. [PMID: 17684046 DOI: 10.1210/jc.2007-1043] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
OBJECTIVE The objective of the study was to determine the diagnostic accuracy of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) in the preoperative diagnosis of thyroid nodules with indeterminate fine-needle aspiration biopsy results. METHODS Forty-two consecutive patients with thyroid nodules with indeterminate cytological results participated in this study. Abnormal (18)F-FDG PET uptake was assessed visually and by measuring the maximum standardized uptake value (SUVmax) in thyroid topography. All these results were compared with the final pathological results. RESULTS The presence of focal uptake correlated with a greater risk of malignancy (P = 0.018). All 11 malignant nodules had focal uptake (sensitivity of 100%). Of the 31 patients with benign nodules, there were 19 with positive uptake (specificity of 38.7%). The pre-PET probability of cancer was 26.2% (11 of 42), and this probability increased to 36.7% after PET for those patients whose exam showed focal uptake (11 of 30). The preoperative use of (18)F-FDG PET would result in a significant reduction (39%, 12 of 31) in the number of thyroidectomies performed in patients with benign lesions. SUVmax could not improve this degree of accuracy. There was no correlation between thyroid nodule size and SUVmax value (P = 0.96). Patients with carcinomas were younger than patients with benign lesions (P = 0.048). There was no other clinical, laboratory, or ultrasonographic variable related to malignancy. CONCLUSIONS (18)F-FDG PET provides high sensitivity to malignant lesions and may be a potentially useful tool in the evaluation of thyroid nodules with indeterminate cytological findings. For these nodules the number of unnecessary thyroidectomies in a hypothetical algorithm using (18)F-FDG PET would be reduced by 39%.
Collapse
Affiliation(s)
- Fernando M Sebastianes
- Division of Endocrinology, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, CEP 05403-000 São Paulo, Brazil
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Duarte GC, Tomimori EK, Boriolli RA, Ferreira JE, Catarino RM, Camargo RYA, Medeiros-Neto G. Avaliação ultra-sonográfica da tireóide e determinação da iodúria em escolares de diferentes regiões do Estado de São Paulo. ACTA ACUST UNITED AC 2004; 48:842-8. [PMID: 15761558 DOI: 10.1590/s0004-27302004000600010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A iodação do sal é eficiente no combate às doenças decorrentes da deficiência de iodo, sendo empregada em todo território nacional desde 1995. O Estado de São Paulo é considerado uma área ioda-suficiente. Para avaliar a ingesta de iodo, foram selecionados aleatoriamente 844 escolares entre 6 e 14 anos, de seis regiões do Estado. Foram avaliados, sob o ponto de vista ecográfico da tireóide, 423 meninos e 421 meninas. Os volumes da glândula tireóide elevaram-se progressivamente com a idade, guardando correlação positiva e significativa com a superfície corporal. Cerca de 1,6% dos escolares apresentava bócio. Nódulos, cistos, hemiagenesia foram detectados em 1,4% dos examinados. Notamos excessiva excreção urinária de iodo nesta população, cerca de 53% eliminou acima de 300<FONT FACE=Symbol>µ</FONT>g Iodo/L e valores acima de 600<FONT FACE=Symbol>µ</FONT>gI/L foram encontrados em 21% dos escolares. As amostras de sal doméstico apresentavam valores entre 28,1 e 63,3mg Iodo/kg de sal. Concluímos que a população escolar do Estado de São Paulo apresenta excessiva ingestão diária de iodo, a qual, extrapolada para a população em geral, pode induzir várias alterações da função tireóidea, como hipertiroidismo subclínico (em idosos) e tireoidite crônica autoimune na população adulta, em geral.
Collapse
Affiliation(s)
- Glaucia C Duarte
- Unidade de Tireóide, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP
| | | | | | | | | | | | | |
Collapse
|
12
|
Glinoer D. The regulation of thyroid function during normal pregnancy: importance of the iodine nutrition status. Best Pract Res Clin Endocrinol Metab 2004; 18:133-52. [PMID: 15157832 DOI: 10.1016/j.beem.2004.03.001] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The main change in thyroid function associated with the pregnant state is the requirement of an increased production of thyroid hormone that depends directly upon the adequate availability of dietary iodine and integrity of the glandular machinery. Physiologic adaptation takes place when the iodine intake is adequate, while this is replaced by pathologic alterations when there is a deficient iodine intake. Pregnancy acts typically, therefore, as a revelator of underlying iodine restriction. Iodine deficiency (ID) has important repercussions for both the mother and the fetus, leading to sustained glandular stimulation, hypothyroxinemia and goitrogenesis. Furthermore, because severe ID may be associated with an impairment in the psycho-neuro-intellectual outcome in the progeny-because both mother and offspring are exposed to ID during gestation (and the postnatal period), and because ID is still prevalent today in several European countries-it has been proposed already in the early 1990s that iodine supplements be given systematically to pregnant and breast-feeding women. Particular attention is required to ensure that pregnant women receive an adequate iodine supply, by administering multivitamin tablets containing iodine supplements, in order to achieve the ideal recommended dietary allowance of 200-250 microg iodine/day.
Collapse
Affiliation(s)
- Daniel Glinoer
- Department of Internal Medicine and Endocrinology, University Hospital Saint Pierre, Thyroid Investigation Clinic, 322, Rue Haute, B-1000 Brussels, Belgium.
| |
Collapse
|
13
|
Silva MNC, Rubió IGS, Romão R, Gebrin EMMS, Buchpiguel C, Tomimori E, Camargo R, Cardia MS, Medeiros-Neto G. Administration of a single dose of recombinant human thyrotrophin enhances the efficacy of radioiodine treatment of large compressive multinodular goitres. Clin Endocrinol (Oxf) 2004; 60:300-8. [PMID: 15008994 DOI: 10.1046/j.1365-2265.2003.01918.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Patients with very large multinodular goitres, frequently found among elderly people, often suffering from cardiovascular or other disabling disorders, may be considered as unsuitable for surgery. We have evaluated the feasibility of relatively high-dose 131I therapy in such patients. As subclinical or clinical hyperthyroidism is commonly found in these patients, associated with a low radioiodine (RAI) uptake at 24 h, we pretreated a group of patients with a single intramuscular injection of recombinant human TSH (rhTSH 0.45 mg) in order to increase the uptake of the therapeutic dose of RAI. DESIGN AND PATIENTS Forty-one patients with large, long-standing multinodular goitres, were recruited for this study. After a careful and detailed clinical and laboratory evaluation, 34 patients (28 women, six men) were included and randomly assigned to group 1 (control, n = 17, 15 women, two men, age 63.1 +/- 11.2 years) receiving only RAI. Patients in group 2 (n = 17, 13 women, four men, age 63.6 +/- 12.3 years) received the therapeutic dose of RAI, having been pretreated (24 h) with 0.45 mg of rhTSH. Both groups of patients were submitted to a low iodine diet, 4-6 months before RAI treatment, while seven thyrotoxic patients also received methimazole (40 mg/day) until they reached euthyroidism. Ultrasonographic studies were performed for all patients and fine-needle aspiration biopsy (FNAB) were performed on one or two nodules before RAI treatment. RAI was given as a single oral dose to the hospitalized isolated patients. Blood samples for thyroid function tests and serum thyroglobulin (Tg) were collected daily during the first week following RAI treatment, and at 1, 3, 6, 9 and 12 months thereafter. MEASUREMENTS Goitre volume was estimated by computed tomography scan. Thyroid function tests (total T3, free T4, TSH and serum Tg) were assayed with commercial kits. Urinary excretion of iodine was assayed by the Sandell-Kolthoff method. RESULTS After the RAI therapeutic dose, serum thyroid function tests were carried out daily for the first week and then on a monthly basis (1, 3, 6, 9 and 12 months). Serum TSH levels rose to a peak level of 45.9 +/- 19.1 mU/l (24 h) in group 2 returning to normal at 72 h. Free T4 serum concentrations rose significantly to 59.35 +/- 21.61 pmol/l at 48 h (in group 2) returning to normal at 7 days. Similarly, serum TT3 also peaked above normal levels only in group 2 (6.12 +/- 1.89 nmol/l) at 24 h. Serum Tg increased in both groups (significantly higher in group 2) and remained elevated during the following 12 months. Both groups had a significant reduction in goitre volume at 12 months (group 2: 57.8%vs. group 1: 39.7%, P < 0.05). Hypothyroidism was detected after RAI treatment, respectively, in 21.4% (group 1) and 64.7% (group 2), of the patients at 12 months. CONCLUSIONS Our results indicate that the use of hTSH increased the efficacy of the RAI therapeutic dose. This was basically due to an increased uptake of the radionuclide (as a consequence of the higher serum TSH levels) and a more extensive distribution of 131I within the nodules of the multinodular goitre. A more intense radiation effect was reflected in there being a higher output of serum Tg and thyroid hormones (group 2). As a consequence this group had a significantly higher reduction of the goitre volume. Also incidence of hypothyroidism post-RAI was significantly higher in group 2. We concluded that pretreatment with rhTSH in elderly patients with large multinodular goitres increases the uptake of the RAI therapeutic dose, thereby significantly reducing the multinodular goitre volume and relieving the compressive symptoms with relatively few side-effects.
Collapse
Affiliation(s)
- Marcia N C Silva
- Thyroid Study Unit (LIM-25), Division of Endocrinology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Fundamentalmente, a glândula tiróide, face à carência de iodo, se adapta por incremento da captação deste halogênio, aumenta a sua massa glandular (bócio), induz secreção preferencial de T3 e eleva a síntese e liberação de TSH. Os exames laboratoriais e de imagem permitem a comprovação dos mecanismos adaptativos. A iodúria permite avaliação quantitativa do grau de carência iódica. Em algumas populações, coexiste a influência de bocígenos naturais presentes nos alimentos consumidos localmente. O cretinismo endêmico é síndrome neurológica e endócrina que conduz o indivíduo a quadro severo de rebaixamento mental e surdo-mudez. No Brasil, as moléstias associadas à carência de iodo foram sempre avaliadas por inquéritos nacionais em escolares. A correção da deficiência de iodo se faz pela adição de iodato de potássio ao sal de consumo humano. Várias leis e decretos foram elaborados tentando aperfeiçoar o sistema universal de iodação do sal, que, mais recentemente, foi aprimorado e tornou-se mais eficiente em propiciar iodo a toda população brasileira.
Collapse
Affiliation(s)
- Meyer Knobel
- Unidade de Tiróide, Departamento de Clínica Médica, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP
| | | |
Collapse
|