ABSTRACT Objective: To determine the relationship between psoriasis, thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triodothyronine (FT3), thyroid peroxidase antibodies (TPOAb), and subclinical thyroid dysfunctions in middle-aged and older adults. Materials and methods: Cross-sectional analyses included a self-reported medical diagnosis of psoriasis and thyroid function from the 3rd visit (2017-2019) of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). TSH, FT4, and FT3 levels were analyzed as continuous variables and quintiles, and TPOAb positivity and subclinical hypothyroidism as a yes/no […]

ABSTRACT Objectives: Congenital hypothyroidism (CH) can be permanent (PCH) or transient (TCH). While the importance of thyroxine in myelination of the brain is undisputed, the benefits to neurodevelopmental outcomes of TCH treatment are controversial. Our objectives were to determine predictive factors for PCH and verify its prevalence changes over time. Subjects and methods: A total of 165 children were evaluated at 3 years of age to verify the diagnosis of PCH. 130 were submitted to a two-step cluster analysis, with […]

ABSTRACT Objective Methylenetetrahydrofolate reductase (MTHFR) is involved in DNA methylation that is associated with autoimmune pathology. We investigated the association between MTHFR genetic polymorphisms at g.677C>T and g.1298A>C and their haplotypes, and the risk of thyroid dysfunction among Jordanian females. Subjects and methods A case-control study involving 98 hypothyroidism cases, 66 hyperthyroidism cases and 100 controls was conducted. Polymerase chain reaction/restriction fragment length polymorphism technique was performed to determine genotypes. Statistical analysis using SPSS software was performed. Results Genetic analysis […]

Objective Glycated hemoglobin (HbA1c) may not accurately reflect the level of glycemia in conditions of altered erythrocyte turnover. Hypothyroidism is one condition associated with sluggish erythropoesis. To assess changes in HbA1c, independent of changes in plasma glucose after initiation of thyroxine replacement in patients with overt hypothyroidism. Materials and methods In this prospective longitudinal study carried out in a tertiary care centre, adult non-diabetic patients with overt hypothyroidism recruited between March 2012 to August 2013 were rendered euthyroid on thyroxine. […]

Objective It is believed that gastric pH interferes in levothyroxine absorption. Omeprazole, which acts by blocking the secretion of gastric acid, might interfere in hypothyroidism control in patients using levothyroxine and this effect could be dose dependent. The present study aimed to investigate this possibility. Subjects and methods Twenty-one patients with primary hypothyroidism who had been using a stabilized levothyroxine dosage for at least one year were selected and randomly assigned to take omeprazole at the dosage of 40 mg […]

Laboratory tests are essential for accurate diagnosis and cost-effective management of thyroid disorders. When the clinical suspicion is strong, hormonal levels just confirms the diagnosis. However, in most patients, symptoms are subtle and unspecific, so that only biochemical tests can detect the disorder. The objective of this article is to do a critical analysis of the appropriate use of the most important thyroid function tests, including serum concentrations of thyrotropin (TSH), thyroid hormones and antithyroid antibodies. Through a survey in […]

OBJECTIVE: To evaluate the effects of levothyroxine (L-T4) replacement in echocardiographic parameters of middle-aged women with subclinical hypothyroidism (SH). SUBJECTS AND METHODS: This was a randomized, double-blind, placebo-controlled study. Echocardiographic evaluation was carried out at baseline and one year after restoration of euthyroidism. Thirty-three women with SH were assigned to one of two groups (L-T4 or placebo). RESULTS: The two groups had similar basal characteristics. There was a significant deterioration of left ventricular Tei index after one year of placebo […]

The purpose of this study was to evaluate mammary gland histomorphometry and proliferation rate and apoptosis of thyroxine-treated rats by CDC-47 and caspase-3 immunoexpression. The development of thyroxine-treated rats offspring was also evaluated. Thirty-six female rats were used, distributed in two groups, treated and non-treated with thyroxine. After 60 days of treatment, with thyroxine, rats were mated. Six animals/group were sacrificed on the 2nd and 21st days of lactation and on the 5th day after weaning. A significant difference was […]

The hypothalamus-pituitary-thyroid axis was studied in rats with the “low T3 syndrome” caused by the implantation of the Walker-256 mammary carcinoma. Male adult rats were injected s.c. with 1 x 106 viable tumoral cells and killed 10 days later. The tumor development was associated with decreased thyroid activity characterized by a ~15% reduction in the nuclear area of the thyrocytes and 131I-thyroid uptake (down by ~50%), as well as about 70% lower serum levels of T4 and rTg. The functional […]

An evaluation was made of the timing delays in the various phases of the Screening Program for Congenital Hypothyroidism (HC) and Phenylketonuria (PKU), the coverage and incidence in the State of Sergipe from 1998 to 2003. The results were compared to the data from 1995. The age of the children in the sampling was 12 ± 11 days (mean ± standard deviation) lower than the 30 ± 19 days in the second semester of 1995. In the second half of […]

Thyroxine (T4) is the main product of thyroid secretion, a pro-hormone that must be activated by deiodination to T3 in order to initiate thyroid hormone action. This deiodination reaction occurs in the phenolic-ring (outer-ring deiodination, ORD) of the T4 molecule and is catalyzed by two selenocysteine-containing deiodinases, i.e. D1 and D2. As a counter point to the activation pathway, both T4 and T3 can be irreversibly inactivated by deiodination of the thyrosyl-ring (inner-ring deiodination, IRD), a reaction catalyzed by D3, […]