TREATMENT OF SUBCLINICAL HYPERTHYROIDISM: EFFECT ON BODY COMPOSITION.

BACKGROUND: subclinical hyperthyroidism (SHT) is associated with harmful effects on cardiovascular system, bone metabolism and progression to clinical hyperthyroidism. Loss of weight is a common fact in patients with clinical hyperthyroidism and of particular relevance in elderly patients. OBJECTIVE: to assess changes in body composition after radioiodine therapy for SHT due to toxic nodular goiter. SUBJECTS AND METHODS: prospective controlled cohort study. Patients with persistent SHT due to toxic nodular goiter were purposed to receive treatment with radioiodine (treatment group) or to delay treatment until the study was over (control group). All treated patients received 555 MBq of ¹³¹I. Body composition (lean mass, fat mass and bone mineral content) was determined by dual-energy X-ray absorptiometry (DEXA) at baseline and 12 months after. RESULTS: twenty-nine patients were studied (age 69.5 ± 11.5; 75.9% women; BMI 27.1 ± 5.7 kg/m²; serum thyrotropin (TSH) 0.20 ± 0.21 µUI/mL; serum free thyroxine (T4) 1.01 ± 0.19 ng/dL), 17 belonging to the treatment group and 12 to the control group. Study groups were comparable, although there was a trend for the treatment group to have more fat mass. No longitudinal changes in body composition were noted in either group, except for a trend to gain fat mass. However, when individuals with age > 65 years were selected, only patients who received radioiodine therapy showed a significant increase in body weight (from 64.1 ± 10.0 to 66.9 ± 9.2 kg), BMI (from 27.3 ± 4.8 to 28.7 ± 4.5 kg/m²), fat mass (from 26.1 ± 8.5 to 27.8 ± 7.9 kg), lean mass (from 36.3 ± 0.4 to 37.4 ± 0.4 kg) and skeletal muscle mass index (SMI) (from 6.0 ± 0.6 to 6.3 ± 0.6 kg/m²). CONCLUSIONS: treatment of SHT has impact on body composition in subjects older than 65 years. Weight gain reflects increases in fat and, more interestingly, in lean mass.

Introducción: el hipertiroidismo subclínico (HS) se asocia a efectos deletéreos sobre el sistema cardiovascular, el metabolismo óseo y puede progresar a hipertiroidismo clínico. La pérdida de peso es habitual en los pacientes con hipertiroidismo clínico y adquiere especial relevancia en los sujetos añosos. Objetivo: evaluar los cambios en la composición corporal después del tratamiento del HS por bocio nodular con radioyodo. Sujetos y métodos: estudio de cohortes prospectivo controlado. A los pacientes con HS persistente debido a bocio nodular tóxico se les ofreció la opción de recibir tratamiento con radioyodo (grupo tratamiento) o retrasar dicho tratamiento hasta que el estudio hubiera acabado (grupo control). Al final, todos los pacientes recibieron 555 MBq de 131I. La composición corporal (masa magra, masa grasa y contenido mineral óseo) se determinó por absorciometría con rayos X de doble energía (DEXA) al inicio y a los 12 meses. Resultados: se estudiaron 29 pacientes (edad 69,5 ± 11,5; 75,9% mujeres; BMI 27,1 ± 5,7 kg/m²; tirotropina sérica (TSH) 0,20 ± 0,21 µUI/mL; tiroxina libre sérica(T4) 1,01 ± 0,19 ng/dL), 17 pertenecientes al grupo tratamiento y 12 al grupo control. Los grupos de estudio fueron comparables, aunque existía una tendencia del grupo tratamiento a presentar más masa grasa. No se detectaron cambios en la composición corporal en ningún grupo, salvo una tendencia general a ganar masa grasa. Sin embargo, cuando se seleccionaron los individuos con edad > 65 años, sólo los pacientes que recibieron tratamiento con radioyodo mostraron un significativo incremento de peso (de 64,1 ± 10,0 a 66,9 ± 9,2 kg), IMC (de 27,3 ± 4,8 a 28,7 ± 4,5 kg/m²), masa grasa (de 26,1 ± 8,5 a 27,8 ± 7,9 kg), masa magra (de 36,3 ± 0,4 a 37,4 ± 0,4 kg) e índice de masa muscular esquelética (de 6,0 ± 0,6 a 6,3 ± 0,6 kg/m²). Conclusiones: el tratamiento del HS tiene impacto sobre la composición corporal en sujetos mayores de 65 años. La ganancia de peso refleja incrementos en la masa grasa y, lo que es más interesante, en la masa magra.

Treatment of subclinical hyperthyroidism: effect on body composition / Tratamiento del hipertiroidismo subclínico: efecto sobre la composición corporal

Background: subclinical hyperthyroidism (SHT) is associated with harmful effects on cardiovascular system, bone metabolism and progression to clinical hyperthyroidism. Loss of weight is a common fact in patients with clinical hyperthyroidism and of particular relevance in elderly patients. Objective: to assess changes in body composition after radioiodine therapy for SHT due to toxic nodular goiter. Subjects and methods: prospective controlled cohort study. Patients with persistent SHT due to toxic nodular goiter were purposed to receive treatment with radioiodine (treatment group) or to delay treatment until the study was over (control group). All treated patients received 555 MBq of 131I. Body composition (lean mass, fat mass and bone mineral content) was determined by dual-energy X-ray absorptiometry (DEXA) at baseline and 12 months after. Results: twenty-nine patients were studied (age 69.5 ± 11.5; 75.9% women; BMI 27.1 ± 5.7 kg/m²; serum thyrotropin (TSH) 0.20 ± 0.21 µUI/mL; serum free thyroxine (T4) 1.01 ± 0.19 ng/dL), 17 belonging to the treatment group and 12 to the control group. Study groups were comparable, although there was a trend for the treatment group to have more fat mass. No longitudinal changes in body composition were noted in either group, except for a trend to gain fat mass. However, when individuals with age > 65 years were selected, only patients who received radioiodine therapy showed a significant increase in body weight (from 64.1 ± 10.0 to 66.9 ± 9.2 kg), BMI (from 27.3 ± 4.8 to 28.7 ± 4.5 kg/m²), fat mass (from 26.1 ± 8.5 to 27.8 ± 7.9 kg), lean mass (from 36.3 ± 0.4 to 37.4 ± 0.4 kg) and skeletal muscle mass index (SMI) (from 6.0 ± 0.6 to 6.3 ± 0.6 kg/m²). Conclusions: treatment of SHT has impact on body composition in subjects older than 65 years. Weight gain reflects increases in fat and, more interestingly, in lean mass (AU)

Introducción: el hipertiroidismo subclínico (HS) se asocia a efectos deletéreos sobre el sistema cardiovascular, el metabolismo óseo y puede progresar a hipertiroidismo clínico. La pérdida de peso es habitual en los pacientes con hipertiroidismo clínico y adquiere especial relevancia en los sujetos añosos. Objetivo: evaluar los cambios en la composición corporal después del tratamiento del HS por bocio nodular con radioyodo. Sujetos y métodos: estudio de cohortes prospectivo controlado. A los pacientes con HS persistente debido a bocio nodular tóxico se les ofreció la opción de recibir tratamiento con radioyodo (grupo tratamiento) o retrasar dicho tratamiento hasta que el estudio hubiera acabado (grupo control). Al final, todos los pacientes recibieron 555 MBq de 131I. La composición corporal (masa magra, masa grasa y contenido mineral óseo) se determinó por absorciometría con rayos X de doble energía (DEXA) al inicio y a los 12 meses. Resultados: se estudiaron 29 pacientes (edad 69,5 ± 11,5; 75,9% mujeres; BMI 27,1 ± 5,7 kg/m²; tirotropina sérica (TSH) 0,20 ± 0,21 µUI/mL; tiroxina libre sérica(T4) 1,01 ± 0,19 ng/dL), 17 pertenecientes al grupo tratamiento y 12 al grupo control. Los grupos de estudio fueron comparables, aunque existía una tendencia del grupo tratamiento a presentar más masa grasa. No se detectaron cambios en la composición corporal en ningún grupo, salvo una tendencia general a ganar masa grasa. Sin embargo, cuando se seleccionaron los individuos con edad > 65 años, sólo los pacientes que recibieron tratamiento con radioyodo mostraron un significativo incremento de peso (de 64,1 ± 10,0 a 66,9 ± 9,2 kg), IMC (de 27,3 ± 4,8 a 28,7 ± 4,5 kg/m²), masa grasa (de 26,1 ± 8,5 a 27,8 ± 7,9 kg), masa magra (de 36,3 ± 0,4 a 37,4 ± 0,4 kg) e índice de masa muscular esquelética (de 6,0 ± 0,6 a 6,3 ± 0,6 kg/m²). Conclusiones: el tratamiento del HS tiene impacto sobre la composición corporal en sujetos mayores de 65 años. La ganancia de peso refleja incrementos en la masa grasa y, lo que es más interesante, en la masa magra (AU)

Obesity and cardiovascular disease.

BACKGROUND: The prevalence of obesity has reached epidemic proportions, and in terms of the extent of its negative impact on the health has been compared to those of tobacco and alcohol. One of the first medical consequences of obesity to be recognised was cardiovascular disease (CVD). Obesity, particularly abdominal obesity, predisposes a person to a number of other cardiovascular risk factors, and is an independent predictor of clinical CVD including coronary death, coronary heart disease, heart failure and stroke. MATERIALS AND METHODS: A Medline search using the following keywords (obesity, cardiovascular disease, body mass index, cardiovascular risk factors, type 2 diabetes, metabolic syndrome) was performed looking for high impact factor English-written references. RESULTS: Ninety-nine (N=99) relevant articles published in the last 15 years were selected and commented. As detailed throughout the text, current therapies available for weight management can improve or prevent many of these obesity-related risk factors for CVD. However, there is some controversy as to whether weight loss is beneficial for health, and large clinical outcome trials such as the Look-AHEAD (Action for Health in Diabetes) trial or the SCOUT (Sibutramine Cardiovascular Outcomes Trial) study are currently ongoing. DISCUSSION: In the present review, we summarise the effects of obesity as well as the efficacy of weight-loss interventions on cardiovascular risk factors and CVD.