We compared the effects of high and low dosages of antithyroid drugs in 113 patients with Graves' hyperthyroidism. The patients were randomly divided into 2 groups. In group A, 65 patients received either methimazole (MMI): 60 +/- 14.5 mg/day (mean +/- SD); range 40-100 mg/day, or propylthiouracil (PTU): 693 +/- 173 mg/day; range 500-1200 mg/day. These high doses were maintained throughout treatment with later addition of 50-75 micrograms T3 daily. Forty eight patients (group B) were treated with lower doses of MMI or PTU without thyroid hormone addition. The maintenance dose of MMI was 13.6 +/- 7 mg/day (range 5-25 mg/day) and that of PTU was 180 +/- 58 mg/day (range 100-300 mg/day). The treatment period was 15.1 +/- 4.2 (range 10-30) months for group A and 13.5 +/- 2.2 (range 12-20) months for group B. Remission occurred in 75.4% patients from group A and in 41.6% patients from group B (P less than 0.001). The mean follow-up was 42 +/- 14 months (17-81 months). The free T4 index (FT4I) in group A remained below the normal range during treatment. The mean FT4I, obtained during the course of treatment, of patients who went into remission from group A was significantly (P less than 0.001) lower than in relapsed patients (4.8 vs. 6.5). Moreover, there was an inverse correlation between mean FT4I and maintenance daily dose of either MMI (r = -0.567; P less than 0.001), or PTU (r = -0.379; P less than 0.01). A fall in microsomal antibody (MCHA) titer occurred mainly in remission patients, and was more significant (P less than 0.05) in group A patients. In contrast, 11 (7 from group B) of the 16 patients with an increase of microsomal antibody levels relapsed. The frequency of negative tests of thyroid-stimulating antibody was higher in group A patients (71%) than in group B (29%) at the end of therapy (P less than 0.01). No correlation was found between thyroid T3 suppressibility and either mean FT4I or thyroid-stimulatory antibody activity during treatment. Our findings show that patients treated with high doses of PTU or MMI throughout treatment have a higher remission rate when compared to those treated with a more conventional regimen. These results support the hypothesis that large antithyroid drug doses may have greater immunosuppressive effects than low dosage regimens. Furthermore, a high dosage regimen could permit the restoration of the immune surveillance mechanisms and, thus, lasting remission of Graves' disease.

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Subclinical hypothyroidism (SHT) and subclinical hyperthyroidism (SCH) are defined as normal serum free T4 and T3 levels associated with elevated (SHT) or subnormal (SCH) serum TSH levels, respectively. Symptoms and signs of thyroid dysfunction are scarce. The prevalence is low. In SHT, total cholesterol and LDL-C are modestly elevated and levothyroxine may influence the lipids levels. There is decreased cardiac contractility and increased peripheral vascular resistance that improve with treatment. SCH is associated with atrial fibrillation, increased cardiac contractility and left ventricular mass, diastolic and systolic dysfunction that can be reversed with beta-adrenergic antagonists. Bone density is reduced in SCH. Depression, panic disorders and alterations in cognitive testing are frequent in SHT. Treatment of SHT is recommended for serum TSH levels greater than 8 mU/L and presence of thyroid antibodies. Endogenous SCH should be treated for serum TSH levels less than 0.1 mU/L, in the presence of symptoms and in elderly patents.

Objective: To compare ultrasonography (US) to magnetic resonance imaging (MRI) and the clinical activity score (CAS) in Graves' ophthalmopathy. Subjects and methods: Nineteen patients underwent extraocular muscle thickness measurements by US and MRI, reflectivity by US and signal-intensity ratio by MRI. There were also twelve US control subjects. Results: US median thicknesses were greater than in controls. Correlation was found between US and MRI in the median thickness of the left eye rectus medial muscle as well as between signal-intensity ratio (SIR) and thickness by US. An inverse correlation was found between reflectivity and SIR in the inferior and lateral rectus. On associating the tests for detecting activity the best results were obtained with CAS plus MRI (sensitivity 75%), and US and MRI (positive predictive value 77% and specificity 80%). Conclusion: CAS and US results showed poor correlation with MRI results suggesting that they cannot replace each other but when combined these methods can improve the evaluation of thyroid-associated ophthalmopathy. Arq Bras Endocrinol Metab. 2011;55(3):184-8 Keywords Graves' disease; thyroid-associated ophthalmopathy; orbital ultrasonography; magnetic resonance imaging RESUMO Objetivo: Comparar a ultrassonografia (US) à ressonância magnética nuclear (RMN) e o índice de atividade clínica (IAC) na oftalmopatia de Graves. Sujeitos e métodos: Dezenove pacientes submetidos à medida da espessura dos músculos extraoculares por US e RMN, refletividade ao US e razão da intensidade de sinal (RIS) à RMN. Grupo controle para US de 12 indivíduos. Resultados: Espessura mediana ao US foi maior que dos controles. Houve correlação entre US e RMN na espessura mediana dos músculos retos mediais dos olhos esquerdos e entre a RIS e a espessura ao US e correlação inversa entre refletividade e SIR nos retos inferior e lateral. Detectando atividade, os melhores resultados foram associando IAC e RMN (sensitividade de 75%) e US e RMN (valor preditivo positivo de 77% e especificidade de 80%). Conclusão: Resultados do IAC e US mostraram pouca correlação com a RMN, sugerindo que não podem ser substituídos, mas, quando combinados, esses métodos podem melhorar a avaliação da oftalmopatia associada à tiroide. Arq Bras Endocrinol Metab. 2011;55(3):184-8 Descritores Doença de Graves; oftalmopatia associada à tiroide; ultrassonografia orbitária; ressonância magnética nuclear

The value of the criteria used to anticipate the outcome of treatment of Graves' hyperthyroid patients with methimazole (MMI) remains controversial. We have reported that high MMI doses combined with T3 administration was correlated with higher remission rates. In this study, we used the lowest MMI dose able to control the hyperthyroidism, keeping the free T4 index (FT4I) values below the normal range throughout treatment, and compared the results with patients treated with a high MMI regimen. Both groups received T3. We also evaluated the usefulness of goiter size, serum thyroid-stimulating antibody (TSAb: adenylate cyclase stimulation in human thyroid membrane), thyroglobulin (Tg) levels, and the T3 suppressibility of 24 h RAIU as prognostic markers for the outcome of Graves' disease therapy. Twenty-four Graves' hyperthyroid patients were treated with high MMI dose (mean +/- SD 60 +/- 19, range 40-120 mg daily), and 25 patients received low MMI dose (17 +/- 4.3, 5-20 mg daily). T3, 75 micrograms daily, was given to both groups of patients for 15 +/- 4 (13-22) months of treatment. After cessation of drug therapy, 31 patients (63%) remained euthyroid for 18 +/- 3 (13-49) months of follow-up, 15 (62.5%) and 16 (64%) patients in the high and low dose groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)