Numerical simulation of the thyroxin producing process of a human body is presented to analyze the dynamic and static variation laws of the process. The relationship between the static value of thyroxin and the reaction coefficients of various physiologic chemical reactions upon the producing thyroxin is clarified. The simulation results provided in this paper can be utilized as some reference data for clinical pathogeny analysis of some thyroxin diseases.
Computer Simulation ; Humans ; Mathematics ; Models, Theoretical ; Numerical Analysis, Computer-Assisted ; Thyroid Gland ; secretion ; Thyroxine ; biosynthesis

BACKGROUND: Thyroid dysfunction is associated with cardiovascular diseases. However, the role of thyroid function in lipid metabolism remains partly unknown. The present study aimed to investigate the causal association between thyroid function and serum lipid metabolism via a genetic analysis termed Mendelian randomization (MR). METHODS: The MR approach uses a genetic variant as the instrumental variable in epidemiological studies to mimic a randomized controlled trial. A two-sample MR was performed to assess the causal association, using summary statistics from the Atrial Fibrillation Genetics Consortium (n = 537,409) and the Global Lipids Genetics Consortium (n = 188,577). The clinical measures of thyroid function include thyrotropin (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) levels, FT3:FT4 ratio and concentration of thyroid peroxidase antibodies (TPOAb). The serum lipid metabolism traits include total cholesterol (TC) and triglycerides, high-density lipoprotein, and low-density lipoprotein (LDL) levels. The MR estimate and MR inverse variance-weighted method were used to assess the association between thyroid function and serum lipid metabolism. RESULTS: The results demonstrated that increased TSH levels were significantly associated with higher TC (β = 0.052, P = 0.002) and LDL (β = 0.041, P = 0.018) levels. In addition, the FT3:FT4 ratio was significantly associated with TC (β = 0.240, P = 0.033) and LDL (β = 0.025, P = 0.027) levels. However, no significant differences were observed between genetically predicted FT4 and TPOAb and serum lipids. CONCLUSION Taken together, the results of the present study suggest an association between thyroid function and serum lipid metabolism, highlighting the importance of the pituitary-thyroid-cardiac axis in dyslipidemia susceptibility.
Lipid Metabolism/genetics* ; Mendelian Randomization Analysis ; Thyroid Function Tests ; Thyroid Gland ; Thyrotropin ; Thyroxine ; Triiodothyronine

Familial dysalbuminemic hyperthyroxinemia (FDH) is an inherited disease characterized by increased circulating total thyroxine (T4) levels and normal physiological thyroid function. Heterozygous albumin gene (ALB) variants have been reported to be the underlying cause of FDH. To our knowledge, there have been no confirmed FDH cases in Korea. We recently observed a female patient with mild T4 elevation (1.2 to 1.4-fold) and variable levels of free T4 according to different assay methods. Upon Sanger sequencing of her ALB, a heterozygous c.725G>A (p.Arg242His) variant was identified. The patient's father and eldest son had similar thyroid function test results and were confirmed to have the same variant. Although the prevalence of FDH might be very low in the Korean population, clinical suspicion is important to avoid unnecessary evaluation and treatment.
Adult ; Albumins/*genetics ; Base Sequence ; Female ; Heterozygote ; Humans ; Hyperthyroxinemia, Familial Dysalbuminemic/*genetics ; Pedigree ; Radioimmunoassay ; Sequence Analysis, DNA ; Thyroxine/analysis

OBJECTIVETo evaluate the key indicators in the pituitary-target gland axes in the animal model of Shen-yang deficiency syndrome (SYDS).

METHODSThe 8 biological indicators [thyroid stimulating hormone (TSH), 3, 3', 5-triiodothyronine (T3), thyroxine (T4), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), adrenocorticotropic hormone (ACTH), and cortisol (CORT)] in the pituitary-target gland axes were grouped using factor analysis. Then the sensitivity of every indicator was calculated according to the sensitivity function defined in this paper, so as to find all the most sensitive indicators in every group as key indicators of SYDS.

RESULTSThe key indicators in the early period of SYDS were T, LH, T4, and CORT. The key indicators in the middle period were LH,T, CORT, and ACTH. The key indicators in the late period were LH, T, CORT, and FSH.

CONCLUSIONST, LH, and CORT were the common key indicators of the three periods, and other different key indicator of SYDS in the early, middle and late period were T4, ACTH, and FSH respectively, which changed from the thyroid axis to the adrenal axis and then to the gonadal axis as the period changed. The key indicators in the late period were mainly in the gonadal axis, showing gonadal dysfunction in the late period.

Animals ; Disease Models, Animal ; Estradiol ; analysis ; Factor Analysis, Statistical ; Follicle Stimulating Hormone ; analysis ; Hydrocortisone ; analysis ; Luteinizing Hormone ; analysis ; Male ; Pituitary-Adrenal System ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Testosterone ; analysis ; Thyrotropin ; analysis ; Thyroxine ; analysis ; Yang Deficiency ; physiopathology

OBJECTIVETo explore the relationship of occupational stressors with the serum levels of triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH).

METHODSUsing convenience sampling and cluster sampling methods, 225 policemen from a local police station in China were enrolled as subjects. Questionnaires were used to investigate demographic features and occupational stressors in those subjects. The serum levels of T3, T4, and TSH were measured by radioimmunoassay. The SPSS 13.0 software was used to perform t test or analysis of variance, partial correlation analysis, and multivariate non-conditional logistic regression analysis.

RESULTSReward was positively correlated with the level of T3(P<0.05). Daily tension was positively correlated with the level of T4(P<0.05). Psychological demand, effort, and daily tension were negatively correlated with the level of TSH (all P<0.05). The quality of sleep was positively correlated with the level of TSH (P<0.05). The logistic regression analysis revealed that the risk of increase in T3 level in the group with a high score for daily tension was 3.19-fold higher than that in the group with a low score, while the risk of increase in T3 level in the group with a high score for negative emotion was 1.32-fold higher than that in the group with a low score. The risk of increase in TSH level in the group with a high score for negative emotion was 0.43-fold that in the group with a low score.

CONCLUSIONThe occupational stressors are correlated with the serum levels of thyroid hormones. Occupational stress can result in an increase in T3 level and a decrease in TSH level. However, occupational stress has no effect on T4 level.

China ; Humans ; Logistic Models ; Multivariate Analysis ; Police ; Stress, Psychological ; Surveys and Questionnaires ; Thyrotropin ; blood ; Thyroxine ; blood ; Triiodothyronine ; blood

BACKGROUND/AIMS: Although a low triiodothyronine (T3) state is closely associated with heart failure (HF), it is uncertain whether total T3 levels on admission is correlated with the clinical outcomes of acute myocardial infarction (AMI). The aim of this study is to investigate the prognostic value of total T3 levels for major adverse cardiovascular and cerebrovascular events (MACCEs) in patients with AMI undergone percutaneous coronary intervention (PCI). METHODS: A total of 765 PCI-treated AMI patients (65.4 ± 12.6 years old, 215 women) between January 2012 and July 2014 were included and 1-year MACCEs were analyzed. We assessed the correlation of total T3 and free thyroxine (fT4) with prevalence of 1-year MACCEs and the predictive values of total T3, fT4, and the ratio of total T3 to fT4 (T3/fT4), especially for HF requiring re-hospitalization. RESULTS: Thirty patients (3.9%) were re-hospitalized within 12 months to control HF symptoms. Total T3 levels were lower in the HF group than in the non-HF group (84.32 ± 21.04 ng/dL vs. 101.20 ± 20.30 ng/dL, p < 0.001). Receiver operating characteristic curve analysis showed the cut-offs of total T3 levels (≤ 85 ng/dL) and T3/fT4 (≤ 60) for HF (area under curve [AUC] = 0.734, p < 0.001; AUC = 0.774, p < 0.001, respectively). In multivariate analysis, lower T3/fT4 was an independent predictor for 1-year HF in PCI-treated AMI patients (odds ratio, 1.035; 95% confidential interval, 1.007 to 1.064; p = 0.015). CONCLUSIONS: Lower levels of total T3 were well correlated with 1-year HF in PCI-treated AMI patients. The T3/fT4 levels can be an additional marker to predict HF.
Area Under Curve ; Heart Failure* ; Heart* ; Humans ; Multivariate Analysis ; Myocardial Infarction* ; Percutaneous Coronary Intervention ; Prevalence ; Prognosis ; ROC Curve ; Thyroxine* ; Triiodothyronine*

OBJECTIVETo report a family of familial dysalbuminaemic hyperthyroxinaemia(FDH).

METHODSFour members, including the female proband, mother, daughter and brother, went through the measurement of thyroid hormone and thyroid-stimulating hormone (TSH). Electrophoretic analysis of the patient's serum proteins was carried out after the patient's serum being incubated with fluorescein isothiocyanate (FITC) labeled thyroxine(T4), The point mutation of Alb gene was determined in all members.

RESULTSThe measurements of thyroid hormane and TSH showed that in three members (the proband, her mother and her daughter), the total thyroxine(TT4) serum level was high, the total triiodothyronine(TT3), FT4, FT3 and TSH serum levels were normal. And the enhanced albumin binding of fluorescenced T4 by electrophoresis showed a mutation transition 653 G-->A on DNA coding region of albumin. But in the proband's brother, the thyroid function and the results of electrophoresis of thyroxine-binding protein and determination of albumin gene were normal.

CONCLUSIONA family with FDH in China is firstly reported here, a mutation at albumin gene DNA coding region 653G-->A causing enhanced albumin binding of T4 results in high T4 level.

Adult ; Base Sequence ; DNA Mutational Analysis ; Family Health ; Female ; Humans ; Hyperthyroxinemia, Familial Dysalbuminemic ; blood ; genetics ; Male ; Pedigree ; Point Mutation ; Polymerase Chain Reaction ; Thyrotropin ; blood ; Thyroxine ; blood ; Thyroxine-Binding Proteins ; genetics ; Triiodothyronine ; blood

OBJECTIVETo observe the influence of (99m)Tc-pertechnetate on radioactive iodine uptake (RAIU) in patients with Graves' disease (GD) hyperthyroidism after thyroid scintigraphy.

METHODSTotally 40 patients in whom thyrotoxicosis was diagnosed at Peking Union Medical College Hospital from 2013 March to May were recruited, and RAIU were performed in all patients. Gamma-count rates at 1 h,25 h,49 h,73 h and 169 h were examined respectively after intravenous injection of 185 MBq (5mCi)of (99m)Tc-pertechnetate. The counts of (99m)Tc and (131)I as well as effective half-life of (99m)Tc (Teff (99m)Tc) were calculated respectively according to the half-life formula. The ratio of (99m)Tc to background counts (1200) was calculated as a reference value to evaluate biokinetics of (99m)Tc.The relationship between the effective half-life of (99m)Tc(Teff (99m)Tc) and the level of free triiodothyronine (FT3), free thyroxine (FT4), and effective half-life of (131)I (Teff (131)I)were also evaluated.

RESULTSAfter intravenous injection of (99m)Tc-pertechnetate, (99m)Tc counts at 1h, 25h, 49h, 73h and 169h was (440.16±247.35)×10(4), (11.37±10.67)×10(4), (0.13±0.36)×10(4), (-0.1±0.19)×10(4), respectively, and the ratio of (99m)Tc to background at 1h, 25 h, and 49 h was 3668, 94.75, and 1.08, respectively. The Teff (99m)Tc was (4.41±0.49)h. Inverse correlations were noted between the effective half-life of Teff (131)I and level of FT3 (r=-0.503, P=0.003) and FT4 (r=-0.516, P=0.002), while no significant correlation was found between the Teff (99m)Tc and FT3, FT4 as well as the Teff (131)I.

CONCLUSIONSTeff (99m)Tc is 4.41h, (99m)Tc-pertechnetate thyroid imaging does not influence RAIU three days after injection of (99m)Tc-pertechnetate. Teff (99m)Tc shows no correlation with the thyroid hormone level and RAIU of Graves's hyperthyroidism.

Adult ; Female ; Graves Disease ; diagnostic imaging ; Humans ; Iodine Radioisotopes ; metabolism ; Male ; Middle Aged ; Radionuclide Imaging ; Sodium Pertechnetate Tc 99m ; Thyroid Gland ; diagnostic imaging ; Thyroxine ; analysis ; Triiodothyronine ; analysis

BACKGROUND: It was not established whether a normal range of thyroid stimulating hormone (TSH) influences the presence and outcome of coronary atherosclerosis. We evaluated that the effect of TSH level on prognosis of elderly angina patients who have normal thyroid function. METHODS: We studied 166 angina patients (70.8+/-4.02 years, male 43.4%) who underwent elective coronary angiography. TSH, free thyroxine, serum lipid levels and high-sensitivity C-reactive protein levels were measured before coronary angiography. According to TSH level, the patients divided into two groups; patients with high level of TSH (> or =2.5 microIU/mL) and low level of TSH (<2.5 microIU/mL). Laboratory findings and 1 year major adverse cardiac events (MACE) were compared between the two groups. RESULTS: Serum creatinine levels were significantly higher in patients with high TSH level (p=0.048). A significant correlation was observed between the levels of TSH and triglyceride level and creatinine level (r=0.704 and 0.512, respectively, p<0.05). MACE occurred in 5.1% of patients with higher TSH and 16.7% of patients with lower TSH (p=0.034). The multivariate analysis revealed that creatinine (OR 5.33, p=0.012) and TSH (OR 1.46, p=0.042) were independent predictors for MACE. CONCLUSIONS: The high level of serum TSH is associated with poor outcome in elderly angina patients with normal range of thyroid function.
Aged* ; C-Reactive Protein ; Coronary Angiography ; Coronary Artery Disease ; Creatinine ; Humans ; Male ; Multivariate Analysis ; Prognosis* ; Reference Values ; Thyroid Gland* ; Thyrotropin* ; Thyroxine ; Triglycerides

PURPOSE: Delayed treatment of congenital hypothyroidism (CH) is a common cause of mental retardation. The aim of the present study was to evaluate intellectual outcomes in preschool children with treated CH. METHODS: We retrospectively reviewed the clinical records of 43 children (age range: 13 to 60 days of life; 22 girls and 21 boys) diagnosed with CH. Children aged 5 to 7 years were examined using the Korean Wechsler Intelligence Scale for Children or the Korean Wechsler Preschool and Primary Scale of Intelligence. RESULTS: The patients started treatment between 13 and 60 days of age. The mean intelligence quotient (IQ) of patients tested at age 5 to 7 years was 103.14±11.68 (IQ range: 76–126). None had intellectual disability (defined as an IQ <70). Twenty-one subjects were treated with a low dose (6.0–9.9 µg/kg/day) and 22 with a high dose of levothyroxine (10.0–16.0 µg/kg/day). There was no significant difference in the mean full-scale IQ (FSIQ), verbal IQ (VIQ), and performance IQ (PIQ) scores between the 2 groups. FSIQ, PIQ, and VIQ scores were not significantly correlated with initial dose of L-T4, initial fT4, age at treatment in multivariate analysis. CONCLUSION: IQ scores of subjects with early treated CH diagnosed through a neonatal screening test were within normal range, regardless of etiology, thyroid function, initial dose of levothyroxine, and age at start of treatment.
Child ; Child, Preschool* ; Congenital Hypothyroidism* ; Female ; Humans ; Hypothyroidism ; Infant, Newborn ; Intellectual Disability ; Intelligence ; Multivariate Analysis ; Neonatal Screening ; Reference Values ; Retrospective Studies ; Thyroid Gland ; Thyroxine