RESUMEN
OBJECTIVE: Brown adipose tissue (BAT) controls metabolic rate through thermogenesis. As its regulatory factors during the transition from hyperthyroidism to euthyroidism are not well established, our study investigated the relationships between supraclavicular brown adipose tissue (sBAT) activity and physiological/metabolic changes with changes in thyroid status. DESIGN: Participants with newly diagnosed Graves' disease were recruited. A thionamide antithyroid drug (ATD) such as carbimazole (CMZ) or thiamazole (TMZ) was prescribed in every case. All underwent energy expenditure (EE) measurement and supraclavicular infrared thermography (IRT) within a chamber calorimeter, as well as 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/magnetic resonance (PET/MR) imaging scanning, with clinical and biochemical parameters measured during hyperthyroidism and repeated in early euthyroidism. PET sBAT mean/maximum standardized uptake value (SUV mean/max), MR supraclavicular fat fraction (sFF) and mean temperature (Tscv) quantified sBAT activity. RESULTS: Twenty-one (16 female/5 male) participants aged 39.5 ± 2.5 years completed the study. The average duration to attain euthyroidism was 28.6 ± 2.3 weeks. Eight participants were BAT-positive while 13 were BAT-negative. sFF increased with euthyroidism (72.3 ± 1.4% to 76.8 ± 1.4%; P < 0.01), but no changes were observed in PET SUV mean and Tscv. Significant changes in serum-free triiodothyronine (FT3) levels were related to BAT status (interaction P value = 0.04). FT3 concentration at hyperthyroid state was positively associated with sBAT PET SUV mean (r = 0.58, P = 0.01) and resting metabolic rate (RMR) (P < 0.01). CONCLUSION: Hyperthyroidism does not consistently lead to a detectable increase in BAT activity. FT3 reduction during the transition to euthyroidism correlated with BAT activity.
Asunto(s)
Tejido Adiposo Pardo/metabolismo , Hipertiroidismo/metabolismo , Hipertiroidismo/rehabilitación , Tejido Adiposo Pardo/diagnóstico por imagen , Tejido Adiposo Pardo/efectos de los fármacos , Adulto , Anciano , Antitiroideos/farmacología , Antitiroideos/uso terapéutico , Composición Corporal/efectos de los fármacos , Composición Corporal/fisiología , Carbimazol/uso terapéutico , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/fisiología , Femenino , Fluorodesoxiglucosa F18 , Enfermedad de Graves/tratamiento farmacológico , Enfermedad de Graves/metabolismo , Enfermedad de Graves/rehabilitación , Humanos , Hipertiroidismo/diagnóstico , Hipertiroidismo/tratamiento farmacológico , Imagen por Resonancia Magnética , Masculino , Metimazol/uso terapéutico , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Inducción de Remisión , Singapur , Termogénesis/efectos de los fármacos , Termogénesis/fisiología , Glándula Tiroides/diagnóstico por imagen , Glándula Tiroides/efectos de los fármacos , Glándula Tiroides/metabolismo , Glándula Tiroides/fisiología , Adulto JovenRESUMEN
A randomized clinical trial was conducted to asses the effects of dexamethasone on brain oedema following acute ischemic stroke in the departments of Medicine of different hospitals from July, 2003 to December, 2006. A total of 60 patients were included in the study. They were divided into two groups keeping the similarity regarding the age, sex and severity of the stroke between two groups. There were 30 patients in experimental group and 30 in control group. The level of consciousness was compared by Glasgow Coma Scale (GCS) on 3rd, 7th and 10th day of intervention and improvement was found in both the groups, but the improvement of level of consciousness was statistically significant in Dexamethasone treated group. The volume of hypodense area did not differ significantly in two groups in CT scans before and after treatment (p=0.74). The study results demonstrate that Dexamethasone improves the level of consciousness in acute ischemic stroke associated with brain oedema but did not reduce volume of hypodense area.