Association of energy metabolism with serum thyroid hormone levels in patients with liver failure and their impact on prognosis / 临床肝胆病杂志

Objective To explore the predictive value of the model for end-stage liver disease (MELD) score, energy metabolism and serum thyroid hormone levels on the severity and prognosis of patients with liver failure and their correlation. Methods This study collected clinicopathological data from 60 liver failure patients, e.g., end-stage liver disease (MELD) score, energy metabolism, and serum thyroid hormone levels. The χ 2 test was performed to analyze the categorical variables, while the Mann-Whitney U test and independent sample t test were performed to assess the continuous variables between the two groups. Spearman correlation coefficient test was used to evaluate correlation of each index. The receiver operating characteristic (ROC) curve was used to analyze the optimal cut-off points of serum total triiodothyronine (TT3) and free triiodothyronine (FT3) levels in predicting prognosis of the patients. Results The rates of low TT3 and FT3 levels in liver failure patients were 78.2% and 69.1%, respectively, whereas the low TT3 rates were 95.2% and 67.6% and the low FT3 rates were 90.5% and 55.9% in survival and non-survival groups of patients, respectively (both P < 0.05). Moreover, the MELD score was significantly higher in the non-survival patients than in survival patients [26.0(21.0-29.0) vs 21.0 (19.0-24.0), Z =-3.396, P =0.001], while TT3 and FT3 levels were significantly lower in the non-survival patients than in the survival patients [0.69(0.62-0.73) vs 0.83(0.69-0.94) and 2.17(1.99-2.31) vs 2.54(2.12-2.86), respectively; Z =-2.884、-2.876, all P < 0.01]. The MELD score was negatively associated with serum TT3, FT3, and thyroid stimulating hormone (TSH) levels and the respiratory quotient (RQ) ( r =-0.487、-0.329、-0.422、-0.350, all P < 0.01), whereas the RQ was associated with serum TT3 and FT3 levels ( r =0.271、0.265, all P < 0.05). The optimal cutoff values in predicting the severity and survival of patients was 0.75 nmol/L and 2.37pmol/L with the sensitivity values of 67.6% and 64.7% and the specificity of 90.5% and 81.0%, respectively. Conclusion Abnormal thyroid hormone levels and low respiratory quotient could be used to predict the severity and prognosis of patients with liver failure.

Predictive factors for the diagnosis of permanent congenital hypothyroidism and its temporal changes in Sergipe, Brazil - A real-life retrospective study

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 the aim of grouping them into homogeneous clusters. The mean incidence of PCH and TCH was calculated from 2004 to 2010 and 2011 to 2015. Results: Sixty-six children were diagnosed with PCH, and 99 were diagnosed with TCH. Eighty-one percent of PCH children and all TCH children with thyroid imaging had glands in situ. Eighty children (61.5%) were in Cluster 1, 8 children (6.2%) were in Cluster 2 and 42 children (32.3%) were in Cluster 3. No children had PCH in Cluster 1, while 87.5% of children in Cluster 2 and all children in Cluster 3 had PCH. The most important predictor for PCH was the initial serum TSH, which was marginally higher in importance than the blood spot TSH, followed by the initial serum free T4. The mean incidence of PCH (odds ratio: 1.95, 95% CI 1.36 to 2.95, p < 0.0001) and TCH (odds ratio 1.33, 95%, CI 1.02 to 1.77, p = 0,038) increased over time. Conclusions: The most important PCH predictors are the initial serum TSH and the blood spot TSH. The mean incidence of both PCH and TCH in our series increased.

Association between psoriasis and thyroid function: results from the Brazilian Longitudinal Study of Adults Health (ELSA-Brasil)

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 variable. Logistic regression models were built as crude and adjusted by main confounders (age, sex, education level, race/ethnicity, and smoking). Results: From 9,649 participants (52.3% women; 59.2 ± 8.7 years old), the prevalence of psoriasis was 2.8% (n = 270). TSH, FT4, TPOAb positivity, and subclinical hypothyroidism were not associated with psoriasis in the main analyses. In the stratified analysis, our findings showed positive associations of the lowest (OR = 2.01; 95% CI 1.05-3.84; p = 0.036) and the highest (OR = 2.13; 95% CI 1.12-4.05; p = 0.022) quintiles of FT4 and a protective association of TPOAb positivity (OR = 0.43; 95% CI 0.19-0.98; p = 0.046) with prevalent psoriasis in women. In the logistic regression for FT3, participants in the 1st quintile showed a statistically significant association with psoriasis for the whole sample (OR = 1.66; 95% CI 1.11-2.46; p = 0.013) and for men (OR = 2.25; 95% CI 1.25-4.04; p = 0.007) in the sex-stratified analysis. Conclusions: The present study showed that the association of FT4 levels with psoriasis are different according to sex, with a possible U-shaped curve in women but not in men. Although there were some associations of FT3 with psoriasis, they may be a consequence of non-thyroidal illness syndrome. Further prospective data may clarify the association of thyroid function and psoriasis.

Reference ranges and influencing factors of thyroid function in preterm infants at 14 d after birth / 中华围产医学杂志

Objective:To investigate the reference ranges for thyroid function and its influencing factors in preterm infants at 14 d after birth.Methods:This retrospective study involved 514 preterm infants who met the inclusion criteria in Affiliated Hospital of Inner Mongolia Medical University from January 1, 2019 to December 31, 2021. They were divided into three group according to their gestational age [early premature group (26-31 +6 weeks, n=153), middle premature group (32-33 +6 weeks, n=129) and late premature group (34-36 +6 weeks, n=232)] or birth weight (BW) [<1 500 g group ( n=129), 1 500-2 000 g group ( n=120) and ≥2 000 g group ( n=265)]. Venous blood samples were collected from the infants at 14 d after birth and their thyroid function was determined by chemiluminescence immunoassay. The reference values of free triiodothyronine (FT 3), free thyroxine (FT 4) and thyroid stimulating hormone (TSH) were calculated based on the values of 95% confidence intervals ( CI) and expressed as percentiles in the range from P2.5 to P97.5. Mann-Whitney U test or Kruskal-Wallis H test was used to compare those thyroid hormone levels between groups. Spearman correlation analysis was used to study the correlation of gestational age or birth weight with FT 3, FT 4 and TSH levels. The factors influencing the levels of thyroid hormones were analyzed by multiple linear regression. Results:The reference ranges for FT 3, FT 4 and TSH were 1.53-3.72 pg/ml, 0.81-1.91 ng/dl and 1.32-7.80 μIU/ml in the early premature infants, 1.74-4.16 pg/ml, 0.90-2.82 ng/dl and 0.63-7.64 μIU/ml in middle prematures and 2.07-4.88 pg/ml, 1.09-2.27 ng/dl and 1.14-7.06 μIU/ml in late prematures. The reference ranges for the above three indexes were 1.53-4.06 pg/ml, 0.81-1.83 ng/dl and 1.14-7.84 μIU/ml in premature infants with BW<1 500 g, 1.67-3.98 pg/ml, 0.88-2.97 ng/dl and 0.94-7.64 μIU/ml in those whose BW between 1 500 g and 2 000 g and 1.91-4.75 pg/ml, 1.09-2.31 ng/dl and 1.14-6.32 μIU/ml in those whose BW≥2 000 g. Multiple linear regression showed that the level of FT 3 was positively correlated with gestational age ( β=0.119, P<0.05) and birth weight ( β=1.950×10 －4, P<0.05); that of FT 4 was positively correlated with gestational age only ( β=0.031, P<0.05); and TSH level was negatively correlated with birth weight ( β=－4.250×10 －4, P<0.05). Conclusions:Gestational age and birth weight are the factors influencing thyroid function in preterm infants at 14 d after birth. Evaluation of thyroid function with FT 4 and TSH should based on the references ranges of different gestational age and birth weight .

Association of serum biomarkers with frailty in elderly hospitalized patients / 中华老年医学杂志

Objective:To evaluate the association of different biomarkers with frailty in elderly hospitalized patients.Methods:In this cross-sectional study, a total of 319 elderly patients aged 65 years or older hospitalized in Beijing Hospital between September 2018 and February 2019 were enrolled.Patients had a mean age of(75.0±6.6)years and 151(47.3%)were women.Based on the Fried phenotype, patients were divided into a non-frail group(244 cases, 76.5%)and a frail group(75 cases, 23.5%). The clinical characteristics and biomarker levels of the two groups were compared.The association of different biomarkers with frailty was evaluated by using the receiver operating characteristic(ROC)curve.The Youden index was used for the optimal cutoff values and the area under the curve(AUC)were calculated.AUCs of different biomarkers were compared to assess their correlations with frailty.Results:Hemoglobin, lipid levels(triglycerides, total cholesterol and low-density lipoprotein cholesterol), and prealbumin were significantly lower in the frail group than in the non-frail group( P<0.05), while N-terminal pro-B type natriuretic peptide(NT-proBNP)and high-sensitivity C reactive protein(hsCRP)levels were significantly higher than in the non-frail group( P<0.05). Thyrotropin(TSH)and free triiodothyronine(FT3)levels were significantly lower( P<0.05)and trans-triiodothyronine(rT3)was significantly higher( P<0.05)in the frail group.The combination of six biomarkers[hemoglobin, prealbumin, hsCRP, 25-dihydroxy vitamin D3[25(OH)D3], rT3 and NT-pro BNP]had the most powerful correlation with frailty(AUC=0.705, 95% CI: 0.652-0.755), but the correlation was not significantly different from that of the combination of 3 markers(hemoglobin, rT3 and hsCRP)(ROC=0.010, 95% CI: -0.0106-0.0306, P>0.05). Either of the two combinations was significantly better than the combination of 2 markers(hemoglobin and rT3)(ROC=0.143, 95% CI: 0.0406-0.245; ROC=0.153, 95% CI: 0.0498-0.256; all P<0.01). Conclusions:Hemoglobin, lipids, prealbumin, TSH and FT3 levels decrease while NT-proBNP and hsCRP levels increase in elderly hospitalized frail patients.The 6-biomarker combination[hemoglobin, prealbumin, hsCRP, 25(OH)D3, rT3 and NT-pro BNP]and 3-biomarker combination(hemoglobin, rT3 and hsCRP)have better correlation with frailty than the 2-biomarker combination(hemoglobin and rT3).

Thyroxine promotes the progression of integrin α vβ 3-positive differentiated thyroid cancer through the ERK1/2 pathway / 中华核医学与分子影像杂志

Objective:To explore whether thyroxine (T 4) could promote differentiated thyroid cancer (DTC) progression by binding to integrin α vβ 3in vitro and its downstream mechanism. Methods:Papillary thyroid cancer cell lines TPC-1, K1 and follicular thyroid cancer (FTC) cell line FTC133 were cultured in vitro, and the expressions of integrin α vβ 3 in those 3 DTC cell lines were determined with immunofluorescence and flow cytometry analysis. After the treatment of T 4, tetraiodo thyroacetic acid (Tetrac) and Arg-Gly-Asp (RGD) peptide alone or in combination, the proliferation and metastatic potential of DTC cell lines were detected by cell counting kit-8 (CCK-8), Transwell migration and invasion assays. The small interfering RNA (siRNA) transfection was used to verify whether integrin α v or β 3 subunit knockdown could reverse the effect of T 4 on DTC cells. The expression levels of downstream signaling proteins phosphorylated extracellular signal-regulated kinase (p-ERK)1/2 and total extracellular signal-regulated kinase (ERK)1/2 were detected by Western blot. The effects of mitogen-activated protein kinase kinase (MEK)1/2 inhibitor (GSK1120212) on the proliferation, migration and invasion of T 4-treated cells were detected. One-way analysis of variance and Tukey test were used for data analysis. Results:The integrin α vβ 3 expressions in TPC-1, K1 and FTC133 cells were all positive, with the relative mean fluorescence intensity (MFI) of 61.93±18.61, 16.89±2.43 and 32.36±0.83, and the percentages of positive cells of (94.38±1.30)%, (74.11±3.87)% and (50.67±1.78)%, respectively ( F values: 13.36 and 217.30, P=0.006 and P<0.001). Compared with control group, the proliferation, migration and invasion in the three DTC cell lines treated with T 4 were significantly enhanced (96 h, F values: 62.67-297.50, q values: 13.15-20.73, all P<0.001). T 4-induced cell proliferation, migration and invasion were markedly reversed by Tetrac or RGD (96 h, q values: 8.61-17.54, all P<0.001). T 4-induced cell proliferation, migration and invasion were also significantly inhibited by the knockdown of integrin α v or β 3 subunit (72 h, F values: 7.75-70.98, q values: 4.77-15.21, all P<0.05). Western blot results showed that the phosphorylation levels of ERK1/2 in DTC cells were significantly increased by T 4 treatment, and the T 4-induced activation of ERK1/2 signaling pathway could be blocked by Tetrac, RGD, integrin α v or β 3 subunit knockdown. T 4-induced cell proliferation, migration and invasion were significantly reversed by GSK1120212 (96 h, F values: 47.53-151.40, q values: 10.32-16.65, all P<0.001). Conclusion:T 4 can promote cell proliferation and metastasis of DTC cells by binding to integrin α vβ 3 and activating the ERK1/2 pathway.

Relationship between thyroid hormone level and obesity related indices in patients with type 2 diabetes mellitus / 中国基层医药

Objective:To investigate the relationship between serum thyroid hormone levels in the normal range and body weight, blood glucose, blood lipids, and other obesity-related indexes in patients with type 2 diabetes mellitus.Methods:Seventy obese patients with type 2 diabetes mellitus and ninety-two patients with type 2 diabetes mellitus with normal weight who were treated in the Nangang Branch of Heilongjiang Provincial Hospital from May 2020 to May 2021 were included in this study. Thyroid-stimulating hormone level was in the normal range (0.35-4.94 mU/L) in all participants. Serum levels of free triiodothyronine, free thyroxine, thyroid-stimulating hormone, thyroid peroxidase antibody, thyroglobulin antibody, triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting blood glucose, glycosylated hemoglobin, fasting C peptide, fasting insulin, systolic blood pressure, diastolic blood pressure, and serum uric acid were measured in all participants.Results:Free triiodothyronine level was positively correlated with fasting blood glucose and glycosylated hemoglobin levels ( r = 0.19, P = 0.021; r = 0.21, P = 0.017). Free thyroxine level was positively correlated with serum glycosylated hemoglobin level ( r = 0.25, P = 0.009) and negatively correlated with total cholesterol ( r = -0.17, P = 0.029). Thyroid-stimulating hormone level was positively correlated with body mass index as well as total cholesterol and low-density lipoprotein cholesterol levels ( r = 0.33, P < 0.001; r = 0.33, P < 0.001; r = 0.32, P < 0.001). Conclusion:Thyroid hormones in the normal range play an important role in the regulation of body weight, blood glucose, and blood lipids in patients with type 2 diabetes mellitus. Blood glucose level increases markedly in patients with relatively high free triiodothyronine and free thyroxine levels. The risks of obesity and dyslipidemia increase in patients with relatively high serum thyroid-stimulating hormone levels

Medical treatment in pregnant women with subclinical hypothyroidism: systematic review and meta-analysis / Tratamiento médico en gestantes con hipotiroidismo subclínico: revisión sistemática y meta-análisis

Abstract Objectives: to determine the effectiveness of medical therapy in reducing complications associated with subclinical hypothyroidism during pregnancy. Methods: in 2021, a systematic review of available cohort studies was carried out in three databases, with no publication date limit. Study selection and data extraction were performed in duplicate. Random-effects meta-analysis was performed, and odds ratios were calculated, with the corresponding 95% confidence intervals. Cohort risk of bias was assessed using the Newcastle-Ottawa Scale (NOS). The certainty of the evidence was assessed using the GRADE methodology. Results: five studies were included for qualitative and quantitative synthesis. A statistically significant relationship was found between medical treatment in pregnant women with subclinical hypothyroidism with respect to spontaneous abortion (p=0.03; OR=0.77; CI95%=0.61-0.97), and no statistically significant relationship was found for delivery preterm (p=0.46; OR=1.11; CI95%=0.85-1.44), nor for abrupt placentae (p=0.56; OR=1.60; CI95%=0.33-7.66). Three studies were at moderate risk of bias, and two were at low risk of bias. In all the results the certainty was very low. Conclusions: medical treatment of subclinical hypothyroidism during pregnancy can have a beneficial effect in reducing cases of spontaneous abortion.

Resumo Objetivos: determinar la efectividad de la terapia médica para disminuir las complicaciones asociadas al hipotiroidismo subclínico durante la gestación. Métodos: en el 2021 se realizó una revisión sistemática de estudios de cohortes disponibles en tres bases de datos, sin límite de fecha de publicación. La selección de estudios y extracción de datos se realizaron por duplicado. Se realizó metaanálisis de efectos aleatorios y se calcularon los Odds ratio, con los correspondientes intervalos de confanza al 95%. El riesgo de sesgo de las cohortes se evaluó mediante la escala de Newcastle-Ottawa (NOS). La certeza de la evidencia se evaluó con la metodología GRADE. Resultados: cinco estudios fueron incluidos para síntesis cualitativa y cuantitativa. Se encontró una relación estadísticamente significativa del tratamiento médico en gestantes con hipotiroidismo subclínico con respecto al aborto espontáneo (p=0,03; OR=0,77; IC95%=0,61-0.97), no se encontró relación estadísticamente significativa para parto pre término (p=0.46; OR=1,11; IC95%=0.85-1.44), ni para abrupto placentae (p=0.56; OR=1,60; IC95%=0.33-7.66). Tres estudios tenían riesgo moderado de sesgo, y dos tenían riesgo de sesgo bajo. En todos los resultados la certeza fue muy baja. Conclusiones: el tratamiento médico del hipotiroidismo subclínico durante la gestación puede tener un efecto beneficioso para reducir los casos de aborto espontaneo.

A case of subclinical hypothyroidism with cerebellar ataxia

Hypothyroidism is a common condition, the symptoms and signs of which vary with the duration and magnitude of thyroid hormone deficiency. Hypothyroidism can have rare neurologic problems such as reversible cerebellar ataxia. Subclinical hypothyroidism refers to biochemical evidence of thyroid hormone deficiency in patients who have few or no apparent clinical features of hypothyroidism. Here, we present a case of a 70-year-old woman with complaints of giddiness and unsteadiness of 6 months’ duration. Subsequent evaluation revealed titubation, broad-based reeling gait, and dysarthria. A MRI of the brain showed diffuse moderate cerebral atrophy with periventricular ischemic white matter changes and normal cerebellum. Further investigations revealed evidence of subclinical hypothyroidism. The patient was started on oral thyroxine supplements with a relief of symptoms following 3 weeks after the initiation of treatment and a complete recovery from symptoms after about 3 months of the initiation of treatment. The association of cerebellar involvement at the stage of subclinical hypothyroidism is a rare finding, making the case academically interesting.

¿El tratamiento del hipotiroidismo subclínico tiene efecto sobre la morbimortalidad cardiovascular? / Does treatment of subclinical hypothyroidism have an effect on cardiovascular morbidity and mortality?

Un estudio mostró que el aumento de valores de la hormona estimulante de la tiroides se asoció a un aumento de mortalidad por todas las causas, estimando que las enfermedades cardiovasculares mediaban dicha asociación en aproximada-mente el 14 % de los casos. Asimismo se observó que el reemplazo con levotiroxina disminuiría los niveles de colesterol, lo cual podría tener un efecto en la reducción de enfermedades cardiovasculares. Partiendo de una viñeta clínica la autora intenta, a través de una búsqueda bibliográfica y análisis de la evidencia, determinar si el tratamiento del hipotiroidismo subclínico en adultos mayores reduciría la morbimortalidad por eventos cardiovasculares. (AU)

A study showed that increased thyroid-stimulating hormone levels were associated with increased all-cause mortality, with cardiovascular disease estimated to mediate this association in approximately 14 % of cases. Additionally, levothyroxine replacement was found to lower cholesterol levels, which could have an effect in reducing cardiovascular diseases. Basedon a clinical vignette, the author attempts, through a literature search and an analysis of the evidence, to determine whether treatment of subclinical hypothyroidism in older adults would reduce morbidity and mortality from cardiovascular events. (AU)

Doença de Graves e sua recidiva: relato de caso / Grave's disease and its relapse: case repor

A doença de Graves (DG) é uma patologia autoimune que acomete a glândula tireoide e é a causa mais comum de hipertireoidismo. O principal grupo acometido por DG são as mulheres. Sendo assim, relatamos caso de paciente com 52 anos, do sexo feminino, com diagnóstico de Doença de Graves, que caracteriza quadro de hipertireoidismo. A paciente iniciou tratamento com tapazol (tiamazol) durante um ano e realizou pausa, recomendada pelo médico. No entanto, a paciente não retratou melhora e iniciou sintomatologia semelhante a dengue, como mal estar geral e fadiga muscular. Assim, realizou procura médica, e, inicialmente, foi diagnosticada com quadro de dengue, mas não houve melhora dos sintomas e procurou, portanto, endocrinologista. Realizou novos exames e foi confirmado quadro recidivo de Doença de Graves. Dessa maneira, iniciou novo tratamento. O estudo tem como objetivo relatar e discutir quadro de Doença de Graves associada a hipertireoidismo

Grave's disease (DG) is an autoimmune pathology that affects the thyroid gland and it's the most commom cause of hipertireoidism. The main group affected by DG are woman. That way we related a case of patient with 52 years, female with the diagnose of Grave's disease, that shows a patient conditioning of hipertireoidism. The patient began the treatment with tapazol during a year and made a pause recommended by the doctor. Therefore the patient didn't indicate progress and started a symptomatology similar to dengue fever, as general malaise and muscle fatigue. There by the patient searched for a doctor and initially was diagnosed with a patient conditioning of dengue fever, but she didn't manifested a improving of symptoms, and then searched for an endocrinologist. Realized then new exams and a recurrence case of grave´s disease was confirmed. This way the patient started a new treatment. Thus, the present study aims to report and discuss Graves' disease associated with hyperthyroidism.

Hiperplasia de hipófise secundária a hipotireoidismo primário - relato de caso / Pituitary hyperplasia secondary to primary hypothyroidism - case report

A hiperplasia hipofisária é definida como um aumento não neoplásico no número de um dos tipos de células presentes na hipófise. Ela pode ocorrer por um processo fisiológico ou patológico. O hipotireoidismo primário prolongado é uma das causas patológicas desta condição, e ocorre devido a perda do feedback negativo. O objetivo desse relato foi demonstrar a presença de hiperplasia hipofisária em um paciente masculino com características corporais sugestivas de acromegalia. A investigação laboratorial confirmou a presença de hipotireoidismo primário e descartou a acromegalia. Foi instituído tratamento com levotiroxina, levando a regressão da hiperplasia hipofisária. Esse caso ilustra a importância de uma investigação apropriada em pacientes com hiperplasia hipofisária, bem como discute a fisiopatologia e o tratamento dessa doença.

Pituitary hyperplasia is defined as a non-neoplastic increase in the number of one of the cell types present in the pituitary gland. It can occur by a physiological or pathological process. Prolonged primary hypothyroidism is one of the pathological causes of this condition and occurs due to the lack of negative feedback. The objective of this report was to demonstrate the presence of pituitary hyperplasia in a male patient with body characteristics suggestive of acromegaly. Laboratory investigation confirmed the presence of primary hypothyroidism and ruled out acromegaly. Treatment with levothyroxine was instituted, leading to regression of pituitary hyperplasia. This case illustrates the importance of an appropriate investigation in patients with pituitary hyperplasia, as well as discussing the pathophysiology and treatment of this disease.

A suggested screening method for hypothyroidism in very preterm and/or very low birth weight neonates / Método de triagem para hipotireoidismo sugerido em recém-nascidos muito prematuros ou de muito baixo peso

ABSTRACT Objective: To assess thyroid function in very preterm or very low birth weight (VLBW) neonates by measuring combination levels of thyroid-stimulating hormone TSH and free T4 (FT4) Methods: Inclusion criteria were defined as all very preterm (gestational age <32 weeks) or VLBW (birth weight ≤1500g) neonates with initial Thyroid Function Test (TFT) who were admitted to the Neonatal Intense Care Unit (NICU) of Taleghani Hospital, Tabriz, Iran, from March 2015 to March 2016. Exclusion criteria were the absence of initial TFT with any major congenital anomaly. The primary value of TSH was evaluated at 3-5 days, and mean levels of TSH with FT4 were measured at 2, 4, and 8-weeks. Results: Ninety-five neonates with a mean gestational age of 29.5 weeks were included, and the mean levels of thyrotropin and FT4 at postnatal week two were 4.4mIU/L and 1.4ng/dL, respectively. Two of the patients had serum TSH concentration >25mIU/L that was considered as permanent primary hypothyroidism. Among nine hypothyroxinemia cases, two had elevated TSH levels (10.8±0.4mIU/L at the end of 8 weeks) and normal FT4 concentration, and were considered transient hypothyroidism. Seven cases had normal TSH levels (1.6±1.0mIU/L at 2 weeks, 3.5±2.8mIU/L at 8 weeks) and low FT4 concentrations. Conclusions: Combined venous TSH and FT4 concentration at the end of the first postnatal month can be an efficient approach for detecting neonatal hypothyroidism.

RESUMO Objetivo: Avaliar a função da tireoide em recém-nascidos muito prematuros ou de muito baixo peso por meio dos níveis de combinação de TSH e T4 livre (FT4). Métodos: Os critérios de inclusão foram: todos os recém-nascidos muito prematuros (idade gestacional <32 semanas) ou de muito baixo peso (peso ao nascer ≤500g) com teste de função tireoidiana inicial e que foram admitidos na Unidade de Terapia Intensiva Neonatal do Hospital de Taleghani, Tabriz, Irã, de março de 2015 a março de 2016. Os critérios de exclusão foram: ausência de TFT inicial com qualquer anomalia congênita importante. Resultados: 95 neonatos com idade gestacional média de 29.5 semanas foram incluídos, e os níveis médios de tireotropina e FT4 na 2ª semana pós-natal foram 4.4mIU/L e 1.4ng/dL, respectivamente. Dois dos pacientes apresentavam concentração sérica de TSH >25mIU/L, considerada hipotireoidismo primário permanente. Entre nove casos de hipotiroxinemia, dois tinham níveis elevados de TSH (10.8±0.4mIU/L ao final de 8 semanas) e concentração normal de FT4 e foram considerados hipotireoidismo transitório. Sete casos tinham níveis normais de TSH (1,6±1,0mIU/L em 2 semanas, 3,5±2,8mIU/L em 8 semanas) e baixas concentrações de FT4. Conclusões: A concentração combinada de TSH e FT4 venoso no final do primeiro mês pós-natal pode ser uma abordagem eficiente para detectar hipotireoidismo neonatal.

Clinical study on thyroid function in children with congenital hypothyroidism / 中国基层医药

Objective:To investigate thyroid function, physical growth, and psychological and behavioral development in children with congenital hypothyroidism.Methods:Thirty-two children with congenital hypothyroidism who were born in Yuyao People's Hospital from January 2014 to December 2018 were included in the observation group. Thirty healthy neonates who were born in the same period were included in the control group. Thyroid function index changes at the age of 1 year relative to at birth, physical, intellectual, and neuropsychological development and bone age at the age of 1 year were compared between the observation and control groups.Results:Thyroid-stimulating hormone level at birth was significantly higher in the observation group than in the control group [(18.23 ± 2.71) mU/L vs. (2.85 ± 0.34) mU/L, t = 30.84, P < 0.001]. Free thyroxine level at birth was significantly lower in the observation group than in the control group [(6.76 ± 1.54) pmol/L vs. (17.91 ± 2.04) pmol/L, t = 24.39, P < 0.001]. In the observation group, thyroid-stimulating hormone and free thyroxine levels at the age of 1 year were (2.68 ± 0.78) mU/L and (17.26 ± 2.11) pmol/L, respectively, which were not significantly different from those in the control group [(2.77 ± 0.63) mU/L and (17.54 ± 2.20) pmol/L, t = 0.50, 0.51, both P > 0.05]. Body weight, body length, head circumference, and bone age at the age of 1 year were (9.21 ± 1.20) kg, (79.84 ± 3.05) cm, (43.73 ± 1.42) cm, (1.01 ± 0.15) years old, respectively in the observation group, which were significantly lower than those in the control group [(10.12 ± 1.32) kg, (84.54 ± 3.41) cm, (45.85 ± 2.04) cm, (1.14 ± 0.28) years old, t = 2.84, 5.73, 4.77, 2.30, P < 0.05]. The proportion of children patients with bone age lag was significantly higher in the observation group than in the control group [21.88% (7/32) vs. 3.33% (1/30), χ2 = 4.74, P < 0.05]. There was a significant difference in intellectual development at the age of 1 year between the two groups ( χ2 = 7.05, P < 0.05). Gross movement, fine movement, adaptability, language ability, and social ability in the observation group were scored (90.43 ± 6.96) points, (92.03 ± 6.03) points, (88.45 ± 4.85) points, (84.04 ± 5.71) points, and (85.05 ± 6.17) points, respectively, which were significantly lower than those in the control group [(99.47 ± 5.40) points, (104.12 ± 5.71) points, (98.47 ± 5.22) points, (94.16 ± 4.98) points, and (104.34 ± 5.70) points ( t = 5.69, 8.09, 7.84, 7.42, 12.76, all P < 0.001]. Conclusion:Neonate patients with congenital hypothyroidism have obvious physical growth and psychological and behavioral development disorders. Early screening and treatment of neonatal congenital hypothyroidism should be strengthened to improve the prognosis.

Association between thyroid function in the first trimester in twin pregnancies and gestational diabetes mellitus / 中华围产医学杂志

Objective:To explore the associations between thyroid function in the first trimester in twin pregnancies and gestational diabetes mellitus (GDM) and the risk factors of twin pregnancies complicated by GDM.Methods:Retrospective analysis was performed on 745 twin pregnancies delivered after 28 weeks at the Third Affiliated Hospital of Sun Yat-sen University from January 2015 to December 2021, and they were divided into GDM group ( n=186) and the control (non-GDM) group ( n=559). Thyroid dysfunction was diagnosed based on the reference range of singleton and twin pregnancies recommended by the Guideline on diagnosis and management of thyroid diseases (2nd edition) in China and the literature, respectively. Independent sample t-test, Chi-square test, or Fisher exact test, and Mann-Whitney U test were used to compare the general clinical characteristics and thyroid function between the two groups. Spearman rank correlation analysis was performed to analyze the correlation between free thyroxine (FT 4), thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), and fasting plasma glucose (FPG) in the first trimester as well as glucose levels in 75 g oral glucose tolerance test (OGTT). The associations between FT 4, TSH at different levels, and the detection rate of GDM, and the risk factors of GDM in twin pregnancies were analyzed using logistic regression. Results:(1) The prevalence of GDM in twin pregnancies was 25.0% (186/745). The positive rate of TPOAb was 13.6% (101/745). FPG in the first trimester was higher in the GDM group than that in the control [(4.7±0.5) vs (4.5±0.4) mmol/L, t=－5.08, P<0.001]. (2) No correlation between FT 4, TSH levels, the positive rate of TPOAb in the first trimester and FPG in the first trimester as well as OGTT results was found (all P>0.05). (3) There was no significant difference when using the thyroid function reference range for twin or singleton pregnancy in detecting hypothyroidism [0.5% (4/745) vs 0.4% (3/745)] and subclinical hypothyroidism [1.2% (9/745) vs 1.3% (10/745)] among the included subjects (both P>0.05), however, there were significant differences in the detection rates of hypothyroxinemia alone [25.0% (186/745) vs 12.9% (96/745)], hyperthyroidism [2.4% (18/745) vs 12.9% (96/745)] and subclinical hyperthyroidism [5.8% (43/745) vs 12.1% (90/745)]( χ2 were 35.43, 33.43 and 18.24, all P<0.001). There was no significant difference in the detection rate of thyroid disease between the GDM and control groups (all P>0.05). (4) FT 4 and TSH levels were grouped into quartiles ( Q1, Q2, Q3, and Q4), which showed that the detection rate of GDM was the highest [27.8% (52/187)] in women with FT 4 in Q1 and was the lowest [23.0% (43/187)] in those with FT 4 in Q2. However, the detection rate was the lowest in women with TSH in Q1 [24.1% (45/187)] and was the highest [27.4%(51/186)] in those with TSH in Q4. Taking Q1 of FT 4 and TSH as a reference, the logistic regression model showed that there were no statistically significant differences between FT 4, TSH at different levels, and GDM, even after adjusting for age, preconception-body mass index (pre-BMI), family history of diabetes, mode of conception, and chorionicity (all P>0.05). (5) Multivariate logistic regression analysis showed that maternal age ( OR=1.10, 95% CI: 1.05-1.15), pre-BMI ( OR=1.13, 95% CI: 1.07-1.21), family history of diabetes ( OR=2.73, 95% CI: 1.53-4.85), and FPG in the first trimester ( OR=2.14, 95% CI: 1.38-3.32) were independent risk factors for twin pregnancies complicated by GDM. Conclusions:Twin pregnant women with higher maternal age, pre-BMI, FPG in the first trimester and family history of diabetes were at higher risk of GDM. No significant correlation is found between maternal thyroid function in the first trimester and GDM in twin pregnancies.

Thyroid Function of Pregnant Women and Perinatal Outcomes in North Macedonia / Função tireoidiana de mulheres grávidas e resultados perinatais na Macedônia do Norte

Abstract Objective Thyroid diseases are the second most common endocrine disorders in the reproductive period of women. They can be associated with intrauterine growth restriction (IUGR), preterm delivery, low Apgar score, low birthweight (LBW) or fetal death. The aim of the present study is to explore thyroid dysfunction and its relationship with some poor perinatal outcomes (Apgar Score, low birthweight, and preterm delivery). Methods Dried blood spot samples from 358 healthy pregnant women were analyzed for thyroid stimulating hormone (TSH), total thyroxine (TT4), and thyroglobulin (Tg). Neonatal data were collected upon delivery. Four groups were formed based on thyroid function tests (TFTs). Results Of the 358 tested women, 218 (60.72%) were euthyroid. Isolated hypo thyroxinemia was present in 132 women (36.76%), subclinical hyperthyroidism in 7 women (1.94%), and overt hypothyroidism in 1 (0.28%). The perinatal outcomes IUGR (p = 0.028) and Apgar score 1 minute (p = 0.015) were significantly different between thyroid function test [TFT]-distinct groups. In the multiple regression analysis, TT4 showed a statistically significant inverse predictive impact on LBW (p < 0.0001), but a positive impact of Tg on LBW (p = 0.0351). Conclusion Thyroid hormones alone do not have a direct impact on neonatal outcomes, but the percentage of their participation in the total process cannot be neglected. Based on the regression analysis, we can conclude that TT4 and Tg can be used as predictors of neonatal outcome, expressed through birthweight and Apgar score. The present study aims to contribute to determine whether a test for thyroid status should become routine screening during pregnancy.

Resumo Objetivo As doenças da tireoide são as segundas doenças endócrinas mais comuns no período reprodutivo das mulheres. Elas podem estar associadas à restrição de crescimento intrauterino (RCIU), parto prematuro, baixo índice de Apgar, baixo peso ao nascer (BPN) ou morte fetal. O objetivo do presente estudo é explorar a disfunção tireoidiana e sua relação com alguns resultados perinatais insatisfatórios (índice de Apgar, baixo peso ao nascer e parto prematuro). Métodos Amostras secas de sangue em 358 gestantes saudáveis foram analisadas para hormônio estimulador da tireoide (TSH), tiroxina total (TT4) e tireoglobulina (Tg). Os dados neonatais foram coletados no momento do parto. Quatro grupos foram formados com base em testes de função tireoidiana (TFT). Resultados Das 358 mulheres testadas, 218 (60,72%) eram eutireoidianas. Hipotiroxinemia isolada estava presente em 132 mulheres (36,76%), hipertireoidismo subclínico em 7 mulheres (1,94%) e hipotireoidismo evidente em 1 (0,28%). Os resultados perinatais RCIU (p = 0,028) e índice de Apgar de 1 minuto (p = 0,015) foram significativamente diferentes entre os grupos distintos de TFT. Na análise de regressão múltipla, TT4 mostrou impacto preditivo inverso estatisticamente significativo no BPN (p < 0,0001), mas impacto positivo da Tg no BPN (p = 0,0351). Conclusão Isoladamente, os hormônios tireoidianos não têm impacto direto no desfecho neonatal, mas o percentual de sua participação no processo total não pode ser desprezado. Com base na análise de regressão, podemos concluir que TT4 e Tg podem ser usados como preditores do resultado neonatal, expressos por meio do peso ao nascer e do índice de Apgar. O presente estudo tem como objetivo contribuir para que um teste para verificar o estado da tireoide deva se tornar um rastreamento de rotina durante a gravidez.

Serum concentration of thyroxine and triiodothyronine in newborn calves from cows supplemented with barium selenate / Concentración sérica de tiroxina y triiodotironina en terneros recién nacidos de madres suplementadas con selenato de bario / Concentração de tiroxina e triiodotironina sérica em bezerros recém-nascidos de mães suplementadas com selenato de bário

Abstract Background: Barium selenate is an inorganic source of selenium (Se) used in prolonged-release preparations to treat selenium deficiency in bovines. Objective: To evaluate serum concentrations of triiodothyronine (T3) and thyroxine (T4) hormones in newborn calves from mothers supplemented with barium selenate during prepartum. Methods: Six black Frisian pregnant cows were supplemented with barium selenate subcutaneously during the last two months of gestation, until calving. Six cows were used as controls. All cows were subjected to a low Se diet, consisting of hay from natural pasture and commercial concentrate lacking Se. The Se balance was measured through the activity of erythrocyte glutathione peroxidase (GPx). Serum concentration of T3 and T4 in calves was determined by electrochemiluminescence. Results: Se supplementation during prepartum increased GPx activity in cows from day 45 post-supplementation (p<0.05). Calves from supplemented mothers showed higher average serum Se concentration than calves from non-supplemented mothers. The average concentration of T3 in the calves from supplemented mothers was lower in the first hour of life (p<0.05) compared with calves from mothers of the non-supplemented group. A decrease (p<0.05) in T4 serum concentrations was observed in both groups at seven days of age. Conclusions: Administration of barium selenate to cows during prepartum generates a reduction in serum concentration of T3 in the first hour of life of calves.

Resumen Antecedentes: El selenato de bario es una fuente inorgánica de selenio (Se) utilizada en preparaciones de liberación prolongada para corregir el estado de carencia de Se en bovinos. Objetivo: Evaluar las concentraciones séricas de triyodotironina (T3) y tiroxina (T4) en terneros recién nacidos de madres suplementadas durante el preparto con selenato de bario. Métodos: Seis vacas frisón negro con 7 meses de gestación fueron suplementadas vía subcutánea con selenato de bario dos meses previos a la fecha de parto. Otras seis vacas permanecieron como controles. Todas las vacas se mantuvieron con una dieta cuyo aporte de Se fue inferior a los requerimientos y consistió en heno de pradera natural y concentrado comercial sin Se. El balance de Se se midió usando la actividad eritrocitaria de glutatión peroxidasa (GPx) y las concentraciones de T3 y T4 en terneros mediante electroquimioluminiscencia. Resultados: La suplementación con Se aumentó la actividad de GPx en vacas desde el día 45 post suplementación (p<0,05). Los terneros de madres suplementadas mostraron una concentración sérica promedio de Se mayor que los terneros de madres no suplementadas. La concentración promedio de T3 de terneros de madres suplementadas fue menor en la primera hora de vida (p<0,05) que en terneros de madres no suplementadas. A los 7 días de edad hubo una disminución (p<0,05) en las concentraciones séricas de T4 en ambos grupos. Conclusión: La administración de selenato de bario en vacas preparto genera una disminución en la concentración sérica de T3 en la primera hora de vida del ternero.

Resumo Antecedentes: O selenato de bário é uma fonte inorgânica de selênio (Se) usada em preparações de liberação prolongada para corrigir o status de deficiência de Se em bovinos. Objetivo: Avaliar as concentrações séricas de triiodotironina (T3) e tiroxina (T4) em bezerros recém-nascidos de mães suplementadas durante o pré-parto com selenato de bário. Métodos: Seis vacas friesianas negras aos 7 meses de gestação foram suplementadas com selenato de bário por via subcutânea dois meses antes do parto. Seis outras vacas permaneceram como controle. Todas as vacas foram mantidas em uma dieta cuja contribuição de Se foi inferior aos requeridos e consistiram em feno natural da pradaria e concentrado comercial sem Se. O balanço de Se foi medido usando a atividade eritrocitária das concentrações de glutationa peroxidase (GPx) e T3 e T4 em bezerros por eletroquimiluminescência. Resultados: A suplementação com atividade de GPx aumentou em vacas a partir do dia 45 após a suplementação (p<0,05). Os bezerros de mães suplementadas apresentaram uma concentração sérica média de Se maior que os bezerros de mães não suplementadas. A concentração média de T3 dos bezerros das mães suplementadas foi menor na primeira hora de vida (p<0,05) do que nos bezerros das mães não suplementadas. Aos 7 dias de idade houve uma diminuição (p<0,05) nas concentrações séricas de T4 nos dois grupos. Conclusão: A administração de selenato de bário em vacas de parto gera uma diminuição na concentração sérica de T3 na primeira hora de vida do bezerro.

Alendronato de sódio, levotiroxina e inibidores da bomba de prótons: há interação entre eles? / Sodium alendronate, levothyroxine and proton pump inhibitors: is there an interaction between them? / Alendronato de sodio, levotiroxina e inhibidores de la bomba de protones: ¿hay alguna interacción entre ellos?

Introdução: As interações medicamentosas podem alterar a segurança e/ou efetividade no tratamento das doenças. Alguns medicamentos precisam ser utilizados em jejum e a literatura apresenta informações divergentes sobre o real impacto clínico do uso destes no mesmo horário. Objetivos: Analisar as evidências sobre a relevância clínica de potenciais interações entre inibidores da bomba de prótons (IBPs), levotiroxina e alendronato de sódio. Métodos: Realizou-se uma revisão narrativa de artigos disponíveis na base de dados PubMed, além de consulta de potenciais interações medicamentosas em fontes de informações sobre medicamentos disponíveis na World Wide Web. Resultados: Em apenas três das 17 fontes de informações consultadas foi relatado uma possível redução dos níveis plasmáticos e/ou da efetividade da levotiroxina, quando administrada de forma concomitante com omeprazol ou outro da classe. Somente uma fonte relata leve redução dos níveis plasmáticos de alendronato de sódio por interação com a levotiroxina, e apenas duas fontes evidenciam possível redução do efeito terapêutico do alendronato de sódio por interação com IBPs. Apenas dois estudos relatam resultados significativos relacionados à existência de interação entre levotiroxina ou alendronato no uso concomitante de IBPs. Em todas as fontes consultadas, as interações são descritas como menores, leves, moderadas ou de significado desconhecido. Todas as fontes de informações sugerem a continuidade da terapia para manejo da interação. Conclusão: Até o momento não há evidências robustas que demonstrem impedimento de uso de inibidores da bomba de prótons, levotiroxina e alendronato de sódio no mesmo horário, sendo essencial o acompanhamento dos parâmetros clínicos e laboratoriais.

Introduction: Drug interactions can alter safety and/or effectiveness in the treatment of diseases. Some medications need to be used on an empty stomach and the literature presents divergent information about the real clinical impact of using them at the same time. Objectives: To analyze the evidence on the clinical relevance of potential interactions between proton pump inhibitors, levothyroxine and sodium alendronate. Methods: A narrative review of articles available in the PubMed database was carried out, in addition to consulting potential drug interactions in sources of information on drugs available on the World Wide Web. Results: In only three of the 17 information sources consulted, a report was reported possible reduction in plasma levels and the effectiveness of levothyroxine, when administered concomitantly with omeprazole or another in the class. Only one source reports a slight reduction in plasma sodium alendronate levels due to interaction with levothyroxine, and only two sources show a possible reduction in the therapeutic effect of sodium alendronate through interaction with PPIs. Only two studies report significant results related to the existence of an interaction between levothyroxine or alendronate in concomitant use of PPIs. In all sources consulted, interactions are described as minor, mild, moderate or of unknown significance. All sources of information suggest the continuity of therapy to manage the interaction. Conclusion: To date, there is no robust evidence demonstrating that it is impossible to use proton pump inhibitors, levothyroxine and sodium alendronate at the same time, and it is essential to monitor clinical and laboratory parameters.

Introducción: Las interacciones farmacológicas pueden alterar la seguridad y / o efectividad en el tratamiento de enfermedades. Algunos medicamentos deben usarse con el estómago vacío y la literatura presenta información divergente sobre el impacto clínico real de usarlos al mismo tiempo. Objetivo: Analizar la evidencia sobre la relevancia clínica de las posibles interacciones entre los inhibidores de la bomba de protones, la levotiroxina y el alendronato de sodio. Métodos: Se realizó una revisión narrativa de los artículos disponibles en la base de datos Pubmed, además de la consulta de posibles interacciones farmacológicas en las fuentes de información sobre medicamentos disponibles en la World Wide Web. Resultados: En solo tres de las 17 fuentes de información consultadas, se informó posible reducción en los niveles plasmáticos y la efectividad de la levotiroxina, cuando se administra concomitantemente con omeprazol u otro en la clase. Solo una fuente informa una ligera reducción en los niveles plasmáticos de alendronato de sodio debido a la interacción con levotiroxina, y solo dos fuentes muestran una posible reducción en el efecto terapéutico del alendronato de sodio a través de la interacción con los IBP. Solo dos estudios informan resultados significativos relacionados con la existencia de una interacción entre levotiroxina o alendronato en el uso concomitante de IBP. En todas las fuentes consultadas, las interacciones se describen como leves, moderadas o de significancia desconocida. Todas las fuentes de información sugieren la continuidad de la terapia para gestionar la interacción. Conclusión: Hasta la fecha, no existe evidencia sólida que demuestre que es imposible usar inhibidores de la bomba de protones, levotiroxina y alendronato de sodio al mismo tiempo, y es esencial monitorear los parámetros clínicos y de laboratorio.

Preliminary study of levo-thyroxine gel in the treatment of hypothyroidism in rat model / 中华核医学与分子影像杂志

Objective:To investigate the therapeutic effect of levo-thyroxine ( L-T 4) gel on hypothyroidism in rat model. Methods:A total of 30 Wistar rats (15 males, 15 females, 2-month age) were completely randomized into 6 groups ( n=5 per group) with one group as the normal control and the other 5 groups were established as the hypothyroidism models by intraperitoneal injection of 18.5 MBq 131I. Of the 5 hypothyroidism groups, 3 groups were given 0.2 g (high-dose group), 0.1 g (medium-dose group) and 0.05 g (low-dose group) L-T 4 gel per 100 g body mass on alternate days, respectively, one group was given 0.1 g blank gel per 100 g body mass daily and the other group was given 5 μg levo-thyroxine sodium tablets (Euthyrox) per 100 g body mass daily. The levels of total thyroxine (TT 4), free triiodothyronine (FT 3), free thyroxine (FT 4) and thyroid stimulating hormone (TSH) in serum were determined by radioimmunoassay and chemiluminescence immunoassay at 2, 4 and 8 weeks after administration, respectively. One-way analysis of variance and Bonferroni test were used for data analysis. Results:At 2 weeks after administration, compared with the normal control group, TT 4, FT 4 decreased and TSH increased in the oral Euthyrox group (TT 4: (65.04±8.20) vs (40.34±1.41) nmol/L, FT 4: (29.63±4.03) vs (18.03±2.76) pmol/L, TSH: (6.04±0.80) vs (10.07±1.01) mU/L; F values: 60.081-108.128, t values: from -4.44 to 4.86, all P<0.05). However, TT 4 ((67.88±14.27) nmol/L), FT 3 ((4.04±0.84) vs (4.45±0.34) pmol/L), FT 4 ((33.76±7.71) pmol/L) and TSH ((8.20±0.40) mU/L) in the L-T 4 gel low-dose group showed no significant differences with the normal control group ( t values: 0.44-2.61, all P>0.05). At 4 weeks after administration, there were no significant differences of TT 4, FT 3, FT 4 and TSH between the L-T 4 gel low-dose group/the oral Euthyrox group and the normal control group ( F values: 34.527-90.976, t values: from -0.95 to 0.35, all P>0.05). The differences of TT 4, FT 3, FT 4 and TSH were not significant between the L-T 4 gel low-dose group and the oral Euthyrox group ( t values: from -0.71 to 1.03, all P>0.05), which was still not significantly different at 8 weeks ( F values: 47.239-160.679, t values: from -0.58 to 1.02, all P>0.05). Conclusions:L-T 4 gel has obvious therapeutic effect on hypothyroidism in rats. Its effect is fast and stable, and its therapeutic effect is better than L-T 4 sodium tablets (Euthyrox).