Macro TSH como causa de hipotiroidismo refractario: a propósito de dos casos clínicos / Macro TSH as a cause of refractory hypothyroidism: based on two clinical cases

Se presenta el caso de dos mujeres con hipotiroidismo, con TSH persistentemente elevada, lo que hacía aumentar la dosis de levotiroxina y llegar a un hipertiroidismo clínico con TSH anormalmente alto. Se realizó un seguimiento de los niveles de TSH y T4 libre, durante un período de 20 y 10 meses respectivamente. En ambas situaciones no hubo una respuesta esperable a las dosis de levotiroxina ascendentes. Después de descartar causas posibles que explicaran esta situación, se sospechó y confirmó la presencia de Macro TSH, que es un complejo biológicamente inactivo de TSH e Inmunoglobulina G. Se obtiene como resultado la estabilidad de ambas pacientes siendo su seguimiento prioritariamente clínico y con mediciones de T4L, comprendiendo por qué la TSH persiste elevada. Nos pareció interesante la comunicación de estos casos, que permite recordar causas atípicas de refractariedad al tratamiento con levotiroxina, como es la macro TSH, indispensable pesquisar para el manejo adecuado de estos pacientes.

An inadequate response to levothyroxine treatment in a patient with hypothyroidism suggests lack of intake, lack of absorption, nephrotic syndrome, thyroid hormone resistance among other reasons. We present the case of two women with hypothyroidism and a persistently elevated level of TSH, which required increasing the dose of levothyroxine, resulting in a clinical hyperthyroidism with an abnormally high TSH. A TSH and free T4 follow up was performed during a period of 20 and 10 months respectively, in both situations there was not an adequate response to rising levothyroxine treatment. After ruling out other possible causes that could explain this situation, it was suspected and then confirmed the presence of Macro TSH, which is a biologically inactive complex of TSH and Immunoglobulin G. Therefore, both patients achieved disease stability once controlled by clinical state and free T4 measurements, understanding why THS persited high. We present these interesting cases, because this allows us to remember atypical causes of refractory treatment with levothyroxine, such as the Macro TSH, indispensable to search for the proper management of these patients.

Correlation Between Tsh And Body Mass Index In Male And Female Patients With Subclinical Hypothyroidism

Hypothyroidism is a syndrome resulting from thyroid hormone deficiency or rarely inefficacy. It is a common endocrinological problem affecting especially women and the elderly. Thyroid hormones play an important role in synthesis, metabolism and mobilization of lipids. One of the most important symptoms of hypothyroidism is weight gain or inability to lose weight. The rapid increase in the prevalence of obesity in the past 20 to 30 years emphasizes the important role of lifestyle and environmental factors, because genetic changes could not have occurred so rapidly. Obesity is a complicated process that depends on signals of satiety and hunger, genetics, endocrine abnormalities, and other factors. Our study purposes to investigate the relationship between BMI and thyroid function in patients of subclinical hypothyroidism. Objective of this study is to correlate thyroid stimulating hormones (TSH) and body mass index (BMI) in male and female patients with subclinical hypothyroidism. This cross sectional study included 42 Subclinical hypothyroid patients, both males and females between 20-45 years of age and without a history of alcohol or tobacco consumption, history of any cardiovascular disorders or diabetes mellitus and any drug history like corticosteroids, beta blockers. and TSH test estimated by VITROS 5600 integrated analyzer and correlated with body mass index. The results showed a positive Correlation analysis in subclinical Hypothyroid males between BMI and TSH, (r= 0.47), which was found to be statistically significant (p=0.02*) in case of subclinical Hypothyroid females the results indicated positive correlation between BMI and TSH (r= 0.58) which was found to be statistically significant (p=0.005*). A strong positive correlation between Body Mass Index (BMI) and Thyroid stimulating hormones (TSH).