ABSTRACT
OBJECTIVE: The aim of this study was to assess the impact of a program of supervised physical exercises (WEB protocol) versus home-based exercises on body composition (lean mass and fat mass) in postmenopausal women. METHODS: The initial sample comprised 60 women who were randomized into two groups. After exclusion, the final randomized sample included a supervised group (n = 16; mean age, 66.4 ± 6.5 y) and a home group (n = 18; mean age, 68.2 ± 6.0 y). Both groups underwent a 12-month intervention with physical exercises, including muscle impact exercises and strength and stretching consisting of two weekly sessions of 60 minutes. Body composition was determined by densitometry. RESULTS: The supervised group exhibited increased lean mass in the upper limbs (P = 0.003) and lower limbs (P = 0.011), total lean tissue (P = 0.015), and appendicular lean mass index (P = 0.001) compared with baseline. The home group exhibited no differences in the lean mass assessments. CONCLUSIONS: Our results suggest that regular supervised physical exercises with free weights and elastic bands can promote greater improvements in lean body mass than unsupervised exercises in postmenopausal women.
Subject(s)
Body Composition , Exercise , Postmenopause , Resistance Training/methods , Absorptiometry, Photon , Aged , Female , Humans , Middle Aged , Prospective StudiesABSTRACT
Objective Consuming a low-iodine diet (LID) is a widely accepted practice before administering radioiodine (131I) to evaluate and to treat thyroid disease. Although this procedure is well established for the management of patients with differentiated thyroid cancer, its use in patients with benign disease is unclear. So, we aimed to evaluate the influence of a LID on the outcome in patients with Graves’ disease (GD) treated with131I. Subjects and methods We evaluated 67 patients with GD who were divided into 2 groups: one group (n = 31) consumed a LID for 1-2 weeks, and the second group (n = 36) was instructed to maintain a regular diet (RD). Results The LID group experienced a 23% decrease in urinary iodine after 1 week on the diet and a significant 42% decrease after 2 weeks on the diet. The majority (53%) of the patients in the LID group had urinary iodine levels that were consistent with deficient iodine intake. However, there was no difference in the rate of hyperthyroidism’s cure between the LID and the RD groups 6 months after 131I therapy. Furthermore, the therapeutic efficacy did not differ in patients with varying degrees of sufficient iodine intake (corresponding urinary iodine levels: < 10 μg/dL is deficient; 10-29.9 μg/dL is sufficient; and > 30 μg/dL is excessive). Conclusion In the present study, we demonstrated that although a LID decreased urinary iodine levels, those levels corresponding with sufficient or a mild excess in iodine intake did not compromise the therapeutic efficacy of131I for the treatment of GD.
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Graves Disease/diet therapy , Graves Disease/drug therapy , Iodine Radioisotopes/therapeutic use , Iodine/administration & dosage , Trace Elements/pharmacology , Combined Modality Therapy , Follow-Up Studies , Food, Formulated , Iodine/urine , Nutritional Status , Treatment OutcomeABSTRACT
OBJECTIVE: Consuming a low-iodine diet (LID) is a widely accepted practice before administering radioiodine (131I) to evaluate and to treat thyroid disease. Although this procedure is well established for the management of patients with differentiated thyroid cancer, its use in patients with benign disease is unclear. So, we aimed to evaluate the influence of a LID on the outcome in patients with Graves' disease (GD) treated with 131I. SUBJECTS AND METHODS: We evaluated 67 patients with GD who were divided into 2 groups: one group (n = 31) consumed a LID for 1-2 weeks, and the second group (n = 36) was instructed to maintain a regular diet (RD). RESULTS: The LID group experienced a 23% decrease in urinary iodine after 1 week on the diet and a significant 42% decrease after 2 weeks on the diet. The majority (53%) of the patients in the LID group had urinary iodine levels that were consistent with deficient iodine intake. However, there was no difference in the rate of hyperthyroidism's cure between the LID and the RD groups 6 months after 131I therapy. Furthermore, the therapeutic efficacy did not differ in patients with varying degrees of sufficient iodine intake (corresponding urinary iodine levels: < 10 µg/dL is deficient; 10-29.9 µg/dL is sufficient; and > 30 µg/dL is excessive). CONCLUSION: In the present study, we demonstrated that although a LID decreased urinary iodine levels, those levels corresponding with sufficient or a mild excess in iodine intake did not compromise the therapeutic efficacy of 131I for the treatment of GD.
Subject(s)
Graves Disease/diet therapy , Graves Disease/drug therapy , Iodine Radioisotopes/therapeutic use , Iodine/administration & dosage , Trace Elements/pharmacology , Adolescent , Adult , Aged , Combined Modality Therapy , Female , Follow-Up Studies , Food, Formulated , Humans , Iodine/urine , Male , Middle Aged , Nutritional Status , Treatment Outcome , Young AdultABSTRACT
INTRODUCTION: A restricted iodine diet (RID) may be recommended for depletion of the whole-body iodine pool in patients with differentiated thyroid cancer referred for radioiodine treatment or a whole-body scan. Evaluation of the iodine pool is possible through urinary iodide (UI) measurements, which can be collected in 24-hour (24U) or spot urinary (sU) samples. However, the minimum period required for an RID to lower the iodine pool, the measurement of iodine in sU samples as a iodine pool marker, and the influence of the iodine pool on Na(+)/I(-) symporter (NIS) expression are debatable in the literature. OBJECTIVES: To compare the effects of 15- and 30-day RID on UI measurements in 24U and sU samples and the impact of RID on NIS expression. METHODS: Thyroidectomized patients went on a 15- or 30-day RID and collected 24U and sU samples before and after the RID. Twenty healthy individuals were evaluated for mRNA NIS expression before and after the RID. RESULTS: Of 306 patients, only 125 properly complied with both the RID and 24U collection. We observed a correlation between sU and 24U UI before the RID (n = 306, ρ = 0.47, p < 0.001), after a 15-day RID (n = 79, ρ = 0.49, p < 0.001), and after a 30-day RID (n = 46, ρ = 0.73, p < 0.001). There was a significant decrease in UI after the RID. The median UI measurement was 275 µg/l at baseline and 99 and 80 µg/l after a 15- and 30-day RID, respectively. There was a significant increase in NIS expression after a 15-day RID. CONCLUSIONS: A 15-day RID is sufficient to deplete the iodine pool. sU can replace 24U UI as a marker for assessing the iodine pool. NIS expression was increased after a 15-day RID.
ABSTRACT
BACKGROUND: Since several countries have established mandatory food iodine fortification, there has been a decrease in rates of iodine deficiency disorders in parallel with an increase in prevalence of autoimmune thyroid diseases. This study compared the nutritional iodine status and the prevalence of autoimmune thyroiditis and thyroid hypoechogenicity on ultrasound in schoolchildren in São Paulo (Brazil) in two distinct periods of time in which fortified salt had different concentrations of iodine. METHODS: We conducted a cross-sectional study evaluating 206 children aged 7-14 years and without a history of thyroid disease. Assessments included measurements of thyrotropin (TSH), free thyroxine, antithyroperoxidase (anti-TPO), and antithyroglobulin (anti-TG) antibodies, urinary iodine concentration, and thyroid ultrasound. RESULTS: Mean urinary iodine concentration was 165.1 µg/L. Eleven children (5.3%) were diagnosed with autoimmune thyroiditis based on at least two of four criteria adopted in our study: positive anti-TPO or anti-TG antibody, hypoechogenicity of the thyroid parenchyma on ultrasound, and a TSH >4.0 µU/mL. Comparing our results with those from a similar study conducted during a period in which concentrations of iodine in the salt were higher (median urinary iodine concentration >300 µg/L), we observed a trend toward a lower prevalence of autoimmune thyroiditis, although no definitive conclusion could be established. CONCLUSION: The current nutritional iodine status in our cohort was within optimal levels and lower than levels found in 2003. The prevalence of autoimmune thyroiditis seems to be decreasing in parallel with a decrease in iodine intake, although we could not reach a definitive conclusion.
Subject(s)
Food, Fortified , Iodine , Thyroid Gland/diagnostic imaging , Thyroiditis, Autoimmune/epidemiology , Adolescent , Autoantibodies/blood , Brazil/epidemiology , Child , Cross-Sectional Studies , Female , Humans , Male , Nutritional Status , Prevalence , Thyroglobulin/immunology , Thyroiditis, Autoimmune/blood , Thyroiditis, Autoimmune/diagnostic imaging , Thyrotropin/blood , Thyroxine/blood , UltrasonographyABSTRACT
BACKGROUND: There is a concern regarding the use of iodinated contrast agents (ICA) for chest and neck computed tomography (CT) to localize metastatases in patients with differentiated thyroid cancer (DTC). This is because the iodine in ICA can compete with (131)I and interfere with subsequent whole scans or radioactive iodine treatment. The required period for patients to eliminate the excess iodine is not clear. Therefore, knowing the period for iodine levels to return to baseline after the injection of ICA would permit a more reliable indication of CT for DTC patients. The most widely used marker to assess the plasmatic iodine pool is the urinary iodine (UI) concentration, which can be collected over a period of 24 hours (24U) or as a single-spot urinary sample (sU). As 24U collections are more difficult to perform, sU samples are preferable. It has not been established, however, if the measurement of iodine in sU is accurate for situations of excess iodine. METHODS: We evaluated 25 patients with DTC who received ICA to perform chest or neck CT. They collected 24U and sU urinary samples before the CT scan and 1 week and 1, 2, and 3 months after the test. UI was quantified by a semiautomated colorimetric method. RESULTS: Baseline median UI levels were 21.8 µg/dL for 24U and 26 µg/dL for sU. One week after ICA, UI median levels were very high for all patients, 800 µg/dL. One month after ICA, however, UI median levels returned to baseline in all patients, 19.0 µg/dL for 24U and 20 µg/dL for sU. Although the values of median UI obtained from sU and 24U samples were signicantly different, we observed a significant correlation between samples collected in 24U and sU in all evaluated periods. CONCLUSION: One month is required for UI to return to its baseline value after the use of ICA and for patients (after total thyroidectomy and radioiodine therapy) to eliminate the excess of iodine. In addition, sU samples, although not statistically similar to 24U values, can be used as a good marker to evaluate patients suspected of contamination with iodine.
Subject(s)
Contrast Media , Iodine Radioisotopes/therapeutic use , Iodine/urine , Radiopharmaceuticals , Thyroid Neoplasms/radiotherapy , Adolescent , Adult , Carcinoma/radiotherapy , Carcinoma/surgery , Carcinoma, Papillary , Contrast Media/pharmacokinetics , Female , Humans , Iodine/pharmacokinetics , Iodine Compounds/urine , Male , Middle Aged , Postoperative Period , Radiopharmaceuticals/pharmacokinetics , Thyroid Cancer, Papillary , Thyroid Neoplasms/surgery , Thyroidectomy , Tomography, X-Ray Computed , Young AdultABSTRACT
Radioactive patients may expose others after radiopharmaceutical administrations, and evaluation of the absorbed dose or exposure rates close to patients is important in keeping radiation doses as low as reasonably achievable. Two theoretical exposure models, point source and line source models, are frequently used to calculate exposure or dose rates without the support of actual measurements. If measurements of exposure rates were performed near patients, an experimental exposure model could be implemented. When measurements of exposure rates are performed, these measurements are made inside therapy rooms or other confined places, in which case scattered radiation may significantly influence the measurements. In this study we measured exposure rates from radioactive patients without the influence of scattered radiation and determined correction factors for the theoretical exposure models. The exposure rates from a total of 110 radioactive patients were measured at 1.0 h after oral administration of Na131I for thyroid therapy; the results +/-1 SD at distances of 0.5, 1.0, 1.5, 2.0, 3.0, and 4.0 m in front of the patients were (29 +/- 6), (9.9 +/- 1.7), (4.6 +/- 0.9), (2.7 +/- 0.5), (1.31 +/- 0.25) and (0.74 +/- 0.12) x 10(-10) C kg(-1) MBq(-1) h(-1) [1.0 x 10(-10) C kg(-1) MBq(-1) h(-1) = 14.34 x 10(-6) R mCi(-1) h(-1)], respectively. To obtain more accurate estimates of the actual exposure rates from patients using the theoretical exposure models, we found that correction factors should be applied; the functions CFEM = 1.19 + 32.80e(5.92D) and CFLS = 0.022LnD + 0.639 describe these correction factors for distances less than or equal to 1.0 m from the patients for experimental and line source exposure models, respectively. The function that describes the correction factors to the point source model is CFPS = 0.224LnD + 0.638 at the same distances; applying these correction factors leads to a reduction from 56% to 1% in the difference between measured exposure rates and theoretical exposure rates calculated by the point source exposure model at a distance of 1.0 m from patients. The results given here provide more accuracy in evaluation of exposure rates and consequently absorbed doses near radioactive patients and allow for more effective radiological protection procedures during patient management.
Subject(s)
Iodine Radioisotopes/therapeutic use , Radiation Monitoring , Radiation Protection , Radiopharmaceuticals/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Hyperthyroidism/radiotherapy , Iodine Radioisotopes/adverse effects , Male , Middle Aged , Radiopharmaceuticals/adverse effects , Thyroid Neoplasms/radiotherapyABSTRACT
OBJECTIVE: To correlate body fat distribution evaluated by waist circumference, dual-energy X-ray absorptiometry and ultrasonography to insulin resistance and lipid profile in obese and non-obese postmenopausal women. METHODS: We studied 40 obese and 47 non-obese postmenopausal women, assessing obesity by measuring waist circumference and fat tissue using dual-energy X-ray absorptiometry and ultrasonography, and examining their correlation with metabolic parameters: insulin resistance as determined by the homeostasis model assessment technique (HOMA-IR) and lipid profile including triglycerides (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), very-low-density lipoprotein, lipoprotein(a) (Lp(a)) and apoplipoprotein A-I (Apo A-I). RESULTS: There was no difference in lipid profile between the two groups. Insulin resistance was the metabolic disturbance of highest prevalence in the obese group, evaluated by HOMA-IR (obese: 3.38 +/- 2.2; non-obese: 1.20 +/- 0.7; p < 0.001). Obesity was not a confounding factor in linear regression analyses among HOMA-IR, HDL-C, TG, Lp(a), Apo A-I and the methods used to measure body fat distribution. Waist circumference was the method that best explained HOMA-IR (R(2) = 34.9%, p < 0.001) and TG concentration (R(2) = 10.9%, p = 0.002). HDL-C presented a positive association with subcutaneous fat evaluated by ultrasonography (R(2) = 12.5%, p < 0.001). Obesity was a confounding factor in multiple regression analyses between TC and LDL-C, when related to abdominal fat evaluated by ultrasonography, and resulted in a positive association among the obese and a negative association among the non-obese women. The sensibility of this method was related to the quantity of fat in the visceral region. CONCLUSIONS: Waist circumference showed the highest association with insulin resistance. Fat distribution evaluated by dual-energy X-ray absorptiometry and ultrasound was also associated with insulin resistance, but with lower intensity. The relationship of visceral fat distribution evaluated by ultrasound to TC cholesterol and LDL-C showed opposed results between obese and non-obese menopausal women.
Subject(s)
Body Fat Distribution , Insulin Resistance , Lipids/blood , Obesity/physiopathology , Postmenopause , Absorptiometry, Photon , Apolipoprotein A-I/blood , Body Weights and Measures , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Female , Homeostasis , Humans , Linear Models , Lipoprotein(a)/blood , Lipoproteins, VLDL/blood , Middle Aged , Obesity/diagnosis , Triglycerides/blood , UltrasonographyABSTRACT
OBJETIVO: Analisar medidas tomadas para aumentar a dose de radiação absorvida (DOSE) durante o tratamento do carcinoma diferenciado da tireóide (CDT) com iodo-131. MÉTODOS: As abordagens para aumentar a DOSE na radioiodoterapia são: redução da competição com iodo não-radioativo, estímulo da captação/retenção celular e aumento da atividade administrada. Revisaram-se os fundamentos e resultados de cada um destes métodos. RESULTADOS: Apesar de ser difícil confirmar aumento de sobrevida, existe relação direta entre a DOSE e a resposta no CDT. Diferentes abordagens permitem o aumento da DOSE nos tecidos, inferindo-se uma possível melhora na resposta dos tumores ao tratamento com iodo-131. Apesar do prognóstico relativamente benigno da doença, a melhoria da resposta é importante nos casos de alto risco, em que as alternativas de tratamento são limitadas. CONCLUSÕES: As intervenções descritas permitem aumentar a DOSE durante o tratamento do CDT, podendo ser empregadas para casos de alto risco.
Subject(s)
Humans , Iodine Radioisotopes/administration & dosage , Thyroid Neoplasms/radiotherapy , Dose-Response Relationship, Radiation , Iodine Radioisotopes/pharmacokinetics , Radiotherapy DosageABSTRACT
OBJECTIVES: Our aim was to analyze measures taken to increase the radiation absorbed dose (DOSE) during treatment of well-differentiated thyroid cancer (DTC) with iodine-131. METHODS: An increase in DOSE is achieved by: avoiding competition with non-radioactive iodine, stimulating cellular uptake/retention, increasing the administered activity. Basis and results of each one of these methods were reviewed. RESULTS: Although it is difficult to demonstrate an increase in survival, there is a direct relation between DOSE and tumoral response in DTC. Different approaches can be used aiming an increase in DOSE, with a possible improvement in tumoral response for treatment with iodine-131. Although DTC is a relatively benign disease, a better response to treatment is highly desirable in high-risk patients, who have few other options of therapy. CONCLUSIONS: An increase in DOSE during treatment of DTC can be achieved using the described interventions, which should be used in high-risk cases of DTC.
Subject(s)
Iodine Radioisotopes/administration & dosage , Thyroid Neoplasms/radiotherapy , Dose-Response Relationship, Radiation , Humans , Iodine Radioisotopes/pharmacokinetics , Radiotherapy Dosage , Thyroid Neoplasms/metabolismABSTRACT
FUNDAMENTOS: A progressão linfática do melanoma maligno habitualmente se inicia pelo linfonodo sentinela (LNS), cuja análise histopatológica permite predizer o acometimento de toda a cadeia. OBJETIVO: O trabalho tem por objetivo descrever a utilização do 99mTc-Fitato na detecção do LNS em pacientes com melanoma maligno, revisando as indicações e informações fornecidas por sua biópsia. MÉTODO: A pesquisa de LNS foi realizada por meio da linfocintilografia com 99mTc-Fitato em 92 pacientes com melanoma (54,0±14,3 anos). Após 18-24 horas, 88 pacientes foram submetidos à localização intra-operatória com detector portátil, seguida da ressecção e análise histopatológica do LNS. RESULTADOS: A linfocintilografia permitiu a identificação do LNS em todos os estudos, havendo detecção intra-operatória em 98,8% dos casos. O LNS estava acometido em 23 pacientes (26%). O valor preditivo negativo foi de 100% e não se observaram reações adversas pelo uso do 99mTc-Fitato. CONCLUSÃO: A detecção do LNS pode ser realizada com diferentes radiofármacos, incluindo o 99mTc-Fitato, que apresenta vantagens de custo e disponibilidade no Brasil. A pesquisa de LNS resulta em maior acurácia e menor morbidade no estadiamento de pacientes com melanoma maligno.
ABSTRACT
A medicina nuclear permite a caracterização funcional de tecidos, acrescentando dados à avaliação anatômica realizada por outros métodos de imagem, como a tomografia computadorizada, ressonância magnética ou ultra-som. Além do diagnóstico e estadiamento, as informações funcionais fornecidas pela medicina nuclear são particularmente úteis no seguimento e avaliação de resposta terapêutica dos pacientes com linfoma. A presença de massa residual após quimioterapia ou a infiltração de linfonodos de pequenas dimensões são exemplos de situações nas quais a avaliação isolada de características anatômicas é insuficiente. Os principais métodos utilizados são a cintilografia com gálio-67, traçador com alta afinidade por transferrina e receptores de ferro, e os estudos com flúor-deoxiglicose, emissor de pósitron que permite a caracterização do metabolismo de glicose nos tecidos. Outros traçadores, como o tálio-201, sestamibi-Tc99m e octreotide-In111, também são utilizados em menor escala na avaliação dos pacientes com linfoma. Os mecanismos de captação, principais indicações dos estudos, limitações e resultados de literatura serão revistos
Nucelar medicine procedures allow funcional characerization of organs and tissues, that can be compared to the anatomical evaluation provided by computed tomography, magnetic resonance imaging and ultrasonography. Functional information are usefull not only in diagnostis and staging, but mainly in the follow-up and evaluation of the therapeutic response of lymphoma patients. Prersistent or residual mediastinal mass and infiltration of small nodes are some examples of situations in which purrely anatomical evaluation is insufficient. The main methods in use are scintigraphy with galium-67, a transferrin avid tracer, and PET with fluoro-desoxyglucose, indicated for the metabolic evaluation of tissues. Other tracers are also described, as thalluim-201, 99m Tc-sestamibi, and 111 in-octreotide,. Mechanisms of uptake, indication, limitations and results of the literature are and discussed in this review.
Subject(s)
Humans , Lymphoma , Lymphoma , Nuclear MedicineSubject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Graves Disease/radiotherapy , Iodine Radioisotopes/therapeutic use , Thyrotoxicosis/radiotherapy , Graves Disease/complications , Iodine Radioisotopes/adverse effects , Retrospective Studies , Statistics, Nonparametric , Thyrotoxicosis/etiology , Treatment OutcomeABSTRACT
Analisosu-se o valor de quatro parâmetros laboratoriais - relaçäo T3/T4, níveis plasmáticos de TSH, volume da glândula tiróide e níveis plasmáticos de TSAb - na previsäo de remissäo da doença de Basedow-Graves. Cinquenta pacientes portadores dessa forma de tiroxicose foram estudados prospectivamente durante (8-20 meses) e após (24-36 meses) tratamento com propiltiouracil. Trinta pacientes foram eliminados do estudo por abandono (50%) ou reaçäo adversa a medicaçäo (10%). Nos 20 pacientes restantes, as taxas de remissäo-recidiva dos pacientes com relaçäo T3/T4 > 20(21% vs. 79%) näo diferiram daquelas dos pacientes com relaçäo T3/T4 < 20 (16% vs. 84%); verificou-se discreto aumento da taxa de remissäo nos pacientes con níveis plasmáticos de TSH > 0,1uU/ml imediatamente após o período de tratamento (30% vs. 10%); os pacientes que, por ocasiäo do início do tratamento, apresentavam volume glandular > 60 cm3 apresentaram taxa de remissäo de 8%, enquanto que naqueles com volume glandular < ou = 60cm3 a taxa de remissäo foi de 50%; a taxa de remissäo dos pacientes apresentando níveis normais de TSAb (< 15%) após 6 meses de tratamento clínico foi de 100%, enquanto que naqueles pacientes nos quais os níveis de TSAb se mantiveram acima do normal a taxa de recidiva foi de 100%. Conclui-se que a medida dos níveis plasmáticos de TSAb é uma parâmetro eficaz na previsäo de remissöes e recidivas da doença de Basedow-Graves
Subject(s)
Child , Adolescent , Adult , Middle Aged , Humans , Male , Female , Propylthiouracil , Graves Disease , Thyroxine/blood , Triiodothyronine/blood , Thyrotropin/blood , Prospective Studies , Follow-Up Studies , PrognosisABSTRACT
A osteoporose é freqüentemente diagnosticada somente após o aparecimento de fraturas, quando a terapia é menos efetiva. A densitometria por dois fótons tem sido o método proposto para o diangóstico precoce dessa doença. No presente estudo, relatamos nossa experiência na medida de massa óssea das vértebras lombares e fémur proximal utilizando um densitômetro DP-3 Lunar em 82-voluntárias jovens normais e 103 mulheres com osteoporose diagnosticada clínica e radiologicamente. Os valores encontrados nas pacientes com osteoporose foram significativamente inferiores aos normais, tanto em coluna lombar (L2-L4) como em fêmur proximal. O coeficiente de variaçäo do método foi < 0,5%, quando determiando com auxílio de um phanton sintético, e < 1,5%, repetindo-se o exame em dez voluntárias normais. Esses resultados confirmam que a densitometria por dois fótons é um método simples, näo invasivo e sensível para diagnóstico precoce e acompanhamento terapêutico de pacientes portadores de osteoporose
Subject(s)
Adult , Humans , Female , Femur , Lumbar Vertebrae , Osteoporosis , DensitometryABSTRACT
A concentraçäo sérica de TSH de 225 indivíduos normais e 348 pacientes portadores de diversas patologias tiroideanas foi analisada através de um Kit comercial imunorradiométrico (IRMA) ultra-sensível para dosagem deste hormônio (Med Lab/DPC). A sensibilidade do método foi de 0,10 micronU/ml. O valor médio detectado nos indivíduos normais foi 1,06 ñ 0,56, sendo que nessa populaçäo näo se detectou nenhum valor abaixo de 0,30 micronU/ml e nem acima de 3,5 micronU/ml. Quarenta e nove pacientes portadores de doença de Graves com tirotoxicose apresentaram valores abaixo de 0,10 micronU/ml. O mesmo aconteceu com oito pacientes portadores de nódulo autônomo de tiróide. Oitenta e três pacientes com doença de Graves, compensados clinicamente pelo uso de propiltioouracil (PTU), apresentaram valores de < 0,10-3,9 micronU/ml. Cento e vinte pacientes com hipotiroidismo primário, sem medicaçäo, apresentaram valores de 4,0-700 micronU/ml, enquanto que 49 pacientes recebendo l-tiroxina (T4) mostraram valores de < 0,10-10 micronU/ml. Quatorze pacientes portadores de bócio simples tratados com T4 apresentaram valores de < 0,10-0,50 micronU/ml, enquanto que 22 com carcinoma de tiróide, recebendo T4, mostraram valores de < 0,10-0,26 micronU/ml. A análise dos valores de TSH após estímulo com TRH mostrou nítida correlaçäo entre os valores basais e pós-estímulo. Pacientes com TSH basal superior a 4,0 micronU/ml apresentaram hiper-resposta ao TRH (>30 micronU/ml mostraram resposta máxima após TRH sempre inferior a 2,0 micronU/ml. Oito pacientes apresentando TSH basal indetectável responderam parcialmente ao TRH (<2,0 micronU/ml enquanto 15 näo apresentaram resposta detectável. Estes resultados, somados a larga experiência internacional com este método, indicam que a medida ultrasensivel do TSH pode ser considerada e, potencialmente pode se transformar no teste inicial de avaliaçäo em todas as situaçöes de suspeita de disfunçäo desta glândula