RESUMO
BACKGROUND: Although overt thyrotoxicosis is associated with reduced insulin sensitivity (IS), the effects of subclinical thyrotoxicosis (SCTox) (i.e., suppressed serum thyroid-stimulating hormone with free thyroxine and tri-iodothyronine within the reference range) on glucose metabolism are not clear. SCTox may be of endogenous origin or due to ingestion of supraphysiological amounts of thyroid hormone. Our hypotheses were that reduced IS is present in SCTox and that the degree of reduction differs between SCTox of endogenous and exogenous origin. METHODS: The study population consisted of 125 premenopausal, normal-weight women, divided into four groups: exogenous SCTox due to L-T4 treatment for benign goiter or hypothyroidism (SCTox-ExogG) (n = 53), endogenous SCTox (SCTox-Endog) (n = 12), exogenous SCTox due to L-T4 treatment for differentiated thyroid cancer (SCTox-ExogDTC) (n = 20), and finally euthyroid women (C) (n = 40) as a control group. After a mixed meal challenge, glucose and insulin were determined at baseline and 120 minutes later. IS was assessed by homeostasis model assessment of insulin resistance (HOMA-IR) index, quantitative IS check index (QUICKI), and 2 hours IS Avignon's index amended by Aloulou for mixed food. Secretion by pancreatic B-cells was calculated by HOMA-B index. Comparison among groups was done by analysis of variance followed by Tukey test. Linear regression analysis of T3 versus HOMA-IR was calculated. RESULTS: IS was reduced in all types of SCTox when compared with C. All SCTox groups had significantly higher levels of insulin (baseline and postmeal) and HOMA-IR and lower values of QUICKI and Aloulou when compared with controls. SCTox-Endog, however, had higher baseline insulin levels and HOMA-IR and a lower QUICKI index than the rest of the SCTox groups. Although within the normal range, total T4, free T4, and T3 levels were also significantly higher in the SCTox groups than in euthyroids. In SCTox-Endog, T3/T4 ratio was increased above the rest of SCTox groups. A moderate linear relationship between T3 and HOMA-IR was found in the whole population. CONCLUSIONS: IR is associated with SCTox of either endogenous or exogenous origin. However, based on our findings of lower IS compared with the rest of the SCTox groups, the endogenous subclinical form might have an even larger metabolic impact.
Assuntos
Glicemia/metabolismo , Resistência à Insulina , Insulina/sangue , Tireotoxicose/fisiopatologia , Adolescente , Adulto , Análise de Variância , Argentina , Doenças Assintomáticas , Biomarcadores , Feminino , Bócio/tratamento farmacológico , Humanos , Hipotireoidismo/tratamento farmacológico , Células Secretoras de Insulina/metabolismo , Modelos Lineares , Pessoa de Meia-Idade , Modelos Biológicos , Período Pós-Prandial , Pré-Menopausa/sangue , Neoplasias da Glândula Tireoide/tratamento farmacológico , Tireotoxicose/sangue , Tireotoxicose/etiologia , Tireotropina/sangue , Tiroxina/efeitos adversos , Tiroxina/sangue , Fatores de Tempo , Tri-Iodotironina/sangue , Adulto JovemRESUMO
OBJECTIVE: It has been shown that patients with insulin resistance (IR) have a higher prevalence of thyroid nodules and bigger thyroid glands. We evaluated the ability of metformin (M) alone or combined with levothyroxine (L-T4) to reduce the nodular size in benign thyroid hyperplastic nodules (<2 cm in diameter). METHODS: A total of 66 women with IR and nodular hyperplasia, diagnosed by fine needle aspiration biopsy (FNAB), who completed this prospective 6-month duration protocol, were assigned to one of four groups: Group I (GI) (n = 14), patients treated with M; GII (n = 18), patients treated with M plus L-T4; GIII (n = 19), patients treated with L-T4; and GIV (n = 15), patients without any treatment. RESULTS: All groups of included patients had no statistically significant different mean baseline characteristics. Patients from GII and GIII showed drops in thyroid-stimulating hormone (TSH) levels and GI and GII normalized the homeostasis model assessment (HOMA) index after treatment, as expected. The median baseline size of all included nodules was 298 mm³ ≈0.84 cm in diameter (range, 32-3,616 mm³). After treatment, patients of Group I and II showed significant reductions in their nodule size [median reduction, 108.50 mm³ (30%) and 184.5 mm³ (55%), P < 0.008 and P < 0.0001, respectively]. Patients in GIII and GIV did not have a significant reduction of their nodules [P = not significant (N.S.)]. CONCLUSIONS: We conclude that M produced a significant decrease in the nodular size in patients with IR and small thyroid nodules, whereas the combination of M with L-T4 was the best treatment in these women.
Assuntos
Resistência à Insulina , Metformina/uso terapêutico , Nódulo da Glândula Tireoide/tratamento farmacológico , Adulto , Idoso , Relação Dose-Resposta a Droga , Esquema de Medicação , Quimioterapia Combinada/métodos , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Resistência à Insulina/fisiologia , Metformina/administração & dosagem , Pessoa de Meia-Idade , Nódulo da Glândula Tireoide/complicações , Nódulo da Glândula Tireoide/patologia , Tiroxina/administração & dosagem , Carga Tumoral/efeitos dos fármacos , Adulto JovemRESUMO
Due to the observation of a great number of patients having achrocordons, when they underwent fine needle biopsies for thyroid nodules, we decided to perform a prospective study to investigate the relationship between this finding and the presence of insulin resistance (IR), since achrocordons are commonly seen in hyperinsulinemic subjects. A total of 120 consecutive women, aged 18-35 yrs were studied. All subjects were also evaluated by thyroid ultrasound (US) for measuring thyroid volume and the presence of non-palpable nodules. Basal and post-prandial serum insulin was measured in all of them, as well as the Homeostasis Model Assessment (HOMA). Subjects were divided in two groups: Group A, with achrocordons (n = 44) and Group B, without achrocordons (n = 76). Group A showed 24 patients (54.5%) with thyroid nodules, whereas Group B only 13 subjects (17.1%); p = 0.0087. When we considered, as having high normal thyroid volume, the glands weighting more than 16 grams by US, without nodules, it was found that 8/44 cases from Group A (18.6%) and 3/76 from Group B (3.9%) fitted in such category, p = 0.0076. In patients with nodules and/or bigger thyroids, IR was observed in 36/44 (81.8%) of Group A and 14/76 (18.4%) of Group B, p = 0.0069, while the overall prevalence of IR was 0.47 in Group A and 0.05 in Group B, p = 0.00094. It is concluded that patients with achrocordons have a higher prevalence of US-detected thyroid nodules and larger thyroid glands. Then, it may be beneficial to search for thyroid abnormalities in those subjects with skin tags.
Assuntos
Resistência à Insulina , Papiloma/etiologia , Neoplasias Cutâneas/etiologia , Nódulo da Glândula Tireoide/complicações , Adolescente , Adulto , Estudos de Casos e Controles , Feminino , Homeostase , Humanos , Papiloma/patologia , Prevalência , Estudos Prospectivos , Neoplasias Cutâneas/patologia , Nódulo da Glândula Tireoide/diagnóstico por imagem , Ultrassonografia , Adulto JovemRESUMO
Due to the observation of a great number of patients having achrocordons, when they underwent fine needle biopsies for thyroid nodules, we decided to perform a prospective study to investigate the relationship between this finding and the presence of insulin resistance (IR), since achrocordons are commonly seen in hyperinsulinemic subjects. A total of 120 consecutive women, aged 18-35 yrs were studied. All subjects were also evaluated by thyroid ultrasound (US) for measuring thyroid volume and the presence of nonpalpable nodules. Basal and post-prandial serum insulin was measured in all of them, as well as the Homeostasis Model Assessment (HOMA). Subjects were divided in two groups: Group A, with achrocordons (n = 44) and Group B, without achrocordons (n = 76). Group A showed 24 patients (54.5%) with thyroid nodules, whereas Group B only 13 subjects (17.1%); p = 0.0087. When we considered, as having high normal thyroid volume, the glands weighting more than 16 grams by US, without nodules, it was found that 8/44 cases from Group A (18.6%) and 3/76 from Group B (3.9%) fitted in such category, p = 0.0076. In patients with nodules and/or bigger thyroids, IR was observed in 36/44 (81.8%) of Group A and 14/76 (18.4%) of Group B, p = 0.0069, while the overall prevalence of IR was 0.47 in Group A and 0.05 in Group B, p = 0.00094. It is concluded that patients with achrocordons have a higher prevalence of US-detected thyroid nodules and larger thyroid glands. Then, it may be beneficial to search for thyroid abnormalities in those subjects with skin tags.
Debido a la alta frecuencia de acrocordones en pacientes que concurrían a nuestro servicio para realizar punciones aspirativas de nódulos tiroideos, realizamos un estudio prospectivo para investigar la relación entre este hallazgo y la presencia de insulino resistencia (IR), dado que los acrocordones son frecuentemente observados en pacientes hiperinsulinémicos. Se incluyeron 120 pacientes consecutivas, con edades entre 18 y 35 años. Todas fueron evaluadas con una ecografía tiroidea para determinar su volumen y la presencia de nódulos no palpables. Se midió insulinemia basal y post prandial, así como el índice Homeostasis Model Assessment (HOMA). Las pacientes se dividieron en 2 grupos: Grupo A, con acrocordones (n = 44) y Grupo B, sin acrocordones (n = 76). En el Grupo A se encontraron 24 (54.5%) con nódulos tiroideos, mientras que el Grupo B, sólo 13 (17.1%); p = 0.0087. Cuando consideramos la presencia de una glándula tiroides de tamaño elevado pero dentro de los límites normales, medida por ecografía (peso mayor a 16 gramos sin nódulos), encontramos que 8/44 casos del Grupo A (18.6%) y 3/76 del Grupo B (3.9%) entraron en esta categoría, p = 0.0076. En aquellas pacientes con nódulos tiroideos o glándula tiroides de mayor tamaño, observamos IR en 36/44 (81.8%) del Grupo A y en 14/76 (18.4%) del Grupo B, p = 0.0069, mientras que la prevalencia total de IR fue del 0.47 en el Grupo A y del 0.05 en el Grupo B, p = 0.00094. En conclusión, las pacientes con acrocordones tuvieron mayor prevalencia de nódulos tiroideos detectados por ecografía, glándula tiroides de mayor tamaño y mayor proporción de insulino resistencia.
Assuntos
Adolescente , Adulto , Feminino , Humanos , Adulto Jovem , Resistência à Insulina , Papiloma/etiologia , Neoplasias Cutâneas/etiologia , Nódulo da Glândula Tireoide/complicações , Estudos de Casos e Controles , Homeostase , Prevalência , Estudos Prospectivos , Papiloma/patologia , Neoplasias Cutâneas/patologia , Nódulo da Glândula TireoideRESUMO
BACKGROUND: Patients with insulin resistance (IR) have a higher prevalence of thyroid nodules. In the present study, we present original data showing that patients with differentiated thyroid carcinoma (DTC) also have a higher frequency of IR. METHODS: Twenty women with DTC (group 1, G1) and 20 euthyroid individuals (control group, CG) were investigated for IR. G1 and CG subjects were matched in pairs by age, gender, and body mass index (BMI). The diagnosis of IR was made when the homeostasis model assesment of insulin resistance (HOMA-IR) index was higher than 2.5. According to the BMI, 20 women (10 with DTC and 10 of the CG) had a BMI < 25, whereas the other 20 had higher BMI values (overweight and obese patients). RESULTS: IR was present in the 50% of G1, but only in the 10% of the CG (P < 0.001). In the groups with lower BMI (<25), we found IR in 30% of G1 and no cases in the CG, whereas in those with BMI > 25 the IR was present in 70% of G1 and 20% of CG. There were no differences between the two subgroups regarding the time in which the IR tests were performed. IR was present in 56.3% of patient with papillary anol 25% of follicular thyroid carcinomas, respectively. CONCLUSIONS: We conclude that such a high prevalence of IR would be an important risk factor for developing DTC, as it is well known with some other nonthyroid carcinomas.
Assuntos
Carcinoma/diagnóstico , Carcinoma/epidemiologia , Resistência à Insulina , Obesidade/complicações , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/epidemiologia , Antropometria/métodos , Pressão Sanguínea , Índice de Massa Corporal , Carcinoma/complicações , Feminino , Homeostase , Humanos , Insulina/metabolismo , Masculino , Sobrepeso , Prevalência , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Neoplasias da Glândula Tireoide/complicaçõesRESUMO
BACKGROUND: Insulin is a thyroid growth factor that stimulates proliferation of thyroid cells in culture. In order to evaluate the effects of insulin resistance (IR) on the thyroid gland, we developed a prospective study in euthyroid women. METHODS: One hundred eleven women (mean age 32.2 +/- 7 years) were evaluated by a thyroid ultrasound (US) and basal and postprandial serum insulin. Subjects were divided into four groups as follows: G1 (n = 42), subjects with IR and obesity; G2 (n = 21), subjects with obesity without IR; G3 (n = 17), subjects with IR and normal weight; and G4 (n = 31) control group (without IR and obesity). RESULTS: The thyroid volume (TV), measured by US, showed the following values: G1, 17 +/- 3 mL; G2, 13.8 +/- 2.8 mL; G3, 16.2 +/- 2.1 mL; and G4,12.1 +/- 2.4 mL. There was no significant difference in TV between G1 and G3, but differences between G1 and G2, and between G3 and G4 were significant at p < 0.05. The percentage of nodular thyroid glands observed by US in each group was as follows: G1, 50%; G2, 23.8%; G3, 61%; G4, 16.1%. Again, the differences between G1 and G2 and between G3 and G4 were statistically significant (p < 0.005 and p < 0.001, respectively, for each comparison). CONCLUSIONS: It is concluded that the higher circulating levels of insulin cause increased thyroid proliferation. The clinical manifestations are the larger thyroid volume and the formation of nodules. Thus, the thyroid gland appears to be another victim of the insulin resistance syndrome.
Assuntos
Resistência à Insulina , Insulina/sangue , Glândula Tireoide/diagnóstico por imagem , Adulto , Antropometria , Proliferação de Células , Feminino , Humanos , Hiperinsulinismo/complicações , Modelos Estatísticos , Estudos Prospectivos , Fatores de Risco , Síndrome , Glândula Tireoide/anormalidades , Glândula Tireoide/anatomia & histologia , UltrassonografiaRESUMO
With the aim of establishing optimal dosage schedules, 171 women with either orvet (OH, n=80) or subclinical (SCH, n=91) hypothyroidism were assessed before and 6 months after starting L-thyroxine (LT4) replacement therapy. Each group was further classified into four subgroups according to post-therapy serum TSH level, as follows; A) complete suppression; B) partial suppression; C) normal range and D) above normal range (insufficient response). In all subgroups, LT4 doses were higher for OH than for SCH, whether expressed as total daily dose (mug) or as a function of either actual or ideal body weight (mug/kg BW). In OH, LT4 dose was higher for subgroups A or B as compared with either C or D. In SCH, subgroup A received a larger dose than the other subgroups. Post-treatment serum thyroxine levels showed the same pattern for both OH and SCH. Mean LT4 dose was similar in patients with high and normal antithyroid antibodies and in patients with goiter and in those without it. In goitrous patients thyroid volume decreased in subgroup B, particularly in those patients that had elevated antithyroid antibodies, but not in subgroup C. In OH patients a significant negative correlation was found between daily LT4 dose per Kg actual BW and actual BW, especially in subgroup C for patients with a body mass index > 27 kg/cm2 (r = -0.90, p<0.001). In subgroup C of the SCH group, a negative correlation between LT4 dose and age was noticed. Both in OH and in SCH, LT4 dose per kg actual BW required to obtain a serum TSH within the normal range was lower in women with a body mass index (BM) > 27 kg/m2 than in those with a BMI = 27 kg/m2. LT4 doses for subgroup C did not differ from those needed in hypothyroid patients with previous Graves' disease, in either OH or SCH patients.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Adulto , Adolescente , Hipotireoidismo/tratamento farmacológico , Tireotropina/sangue , Tiroxina/sangue , Fatores Etários , Índice de Massa Corporal , Peso Corporal , Seguimentos , Doença de Graves/sangue , Doença de Graves/tratamento farmacológico , Hipertireoidismo/sangue , Tiroxina/administração & dosagem , Tiroxina/uso terapêuticoRESUMO
With the aim of establishing optimal dosage schedules, 171 women with either orvet (OH, n=80) or subclinical (SCH, n=91) hypothyroidism were assessed before and 6 months after starting L-thyroxine (LT4) replacement therapy. Each group was further classified into four subgroups according to post-therapy serum TSH level, as follows; A) complete suppression; B) partial suppression; C) normal range and D) above normal range (insufficient response). In all subgroups, LT4 doses were higher for OH than for SCH, whether expressed as total daily dose (mug) or as a function of either actual or ideal body weight (mug/kg BW). In OH, LT4 dose was higher for subgroups A or B as compared with either C or D. In SCH, subgroup A received a larger dose than the other subgroups. Post-treatment serum thyroxine levels showed the same pattern for both OH and SCH. Mean LT4 dose was similar in patients with high and normal antithyroid antibodies and in patients with goiter and in those without it. In goitrous patients thyroid volume decreased in subgroup B, particularly in those patients that had elevated antithyroid antibodies, but not in subgroup C. In OH patients a significant negative correlation was found between daily LT4 dose per Kg actual BW and actual BW, especially in subgroup C for patients with a body mass index > 27 kg/cm2 (r = -0.90, p<0.001). In subgroup C of the SCH group, a negative correlation between LT4 dose and age was noticed. Both in OH and in SCH, LT4 dose per kg actual BW required to obtain a serum TSH within the normal range was lower in women with a body mass index (BM) > 27 kg/m2 than in those with a BMI = 27 kg/m2. LT4 doses for subgroup C did not differ from those needed in hypothyroid patients with previous Graves disease, in either OH or SCH patients. (AU)
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Adulto , Idoso , Adolescente , Estudo Comparativo , Tiroxina/sangue , Tireotropina/sangue , Hipotireoidismo/tratamento farmacológico , Peso Corporal , Índice de Massa Corporal , Hipertireoidismo/sangue , Tiroxina/uso terapêutico , Tiroxina/administração & dosagem , Seguimentos , Fatores Etários , Doença de Graves/sangue , Doença de Graves/tratamento farmacológicoRESUMO
Para valorar la ingesta diaria de iodo se midió la ioduria en 134 escolares de ambos sexos, de 5 - 14 años, de Luján de Cuyo (Mendoza). Los mismos fueron categorizados: a) según la existencia o no de bocio por palpación de 2 observadores; b) según el nivel socioeconómico y c) según la marca comercial de sal consumida. Las muestras provenían de un grupo examinado de 700 escolares. No hubo diferencias significativas en sexo, edad, peso o estatura entre los grupos mencionados. Se recolectaron m-uestras de escolares bociosos en mayor proporción que de normales. La ioduria media de los escolares sin bocio fue significativamente mayor que la de los bociosos, (p < 0,005). La prevalencia de bocio disminuyó en los escolares con ioduria de > 150 mug/24 h (p < 0,05). Los niveles de ioduria de escolares de distinto nivel socioeconómico fueron semejantes (p = 0,56). No se encontraron diferencias significativas entre consumidores de las dos marcas comerciales de sal más comunes (p = 0,07). Aunque los valores medios de ioduria en la población evaluada son aceptables, la amplia variabilidad observada sugiere la implementación de mejores medidas de control y de información a la población y, tal vez, la suplementación de iodo discriminada para optimizar la iodoprofilaxis.
Assuntos
Pré-Escolar , Feminino , Humanos , Adolescente , Criança , Bócio Endêmico/urina , Iodo/urina , Cloreto de Sódio na Dieta/efeitos adversos , Distribuição de Qui-Quadrado , Incidência , Classe Social , Fatores Socioeconômicos , Cloreto de Sódio na Dieta/classificação , Glândula Tireoide/químicaRESUMO
Para valorar la ingesta diaria de iodo se midió la ioduria en 134 escolares de ambos sexos, de 5 - 14 años, de Luján de Cuyo (Mendoza). Los mismos fueron categorizados: a) según la existencia o no de bocio por palpación de 2 observadores; b) según el nivel socioeconómico y c) según la marca comercial de sal consumida. Las muestras provenían de un grupo examinado de 700 escolares. No hubo diferencias significativas en sexo, edad, peso o estatura entre los grupos mencionados. Se recolectaron m-uestras de escolares bociosos en mayor proporción que de normales. La ioduria media de los escolares sin bocio fue significativamente mayor que la de los bociosos, (p < 0,005). La prevalencia de bocio disminuyó en los escolares con ioduria de > 150 mug/24 h (p < 0,05). Los niveles de ioduria de escolares de distinto nivel socioeconómico fueron semejantes (p = 0,56). No se encontraron diferencias significativas entre consumidores de las dos marcas comerciales de sal más comunes (p = 0,07). Aunque los valores medios de ioduria en la población evaluada son aceptables, la amplia variabilidad observada sugiere la implementación de mejores medidas de control y de información a la población y, tal vez, la suplementación de iodo discriminada para optimizar la iodoprofilaxis. (AU)