• Development and Reproduction
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• v.25 no.4
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• pp.293-298
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• 2021

Di(2-ethylhexyl)phthalate (DEHP) could induce metabolic disorders through interfering with thyroid homeostasis. Therefore, we evaluated the effects of short term to environmental relevant doses of DEHP on thyroid hormones. Four week old Sprague-Dawley (SD) rats were treated with vehicle (corn oil), and DEHP 0.75, 7.5, and 150 mg/kg/day. The rats were treated with once daily by oral gavage and were sacrificed with after 1 week. They were measured body weight and relative thyroid weight, serum thyroid hormones and histological changes of thyroid. There was no difference in body weight between the control and DEHP exposed rats. Relative thyroid weight in DEHP 150 mg/kg/day treated group was significantly lower than control. Serum thyroxine levels was decreased in rats exposed to 0.75 and 150 mg/kg/day DEHP. No histological changes were observed in the thyroid of rats administered DEHP compared to control. Exposure to DEHP at environmental relevant levels, even short-term exposure, can cause hypothyroidism in adolescent rats even the exposure period is relative short.

• Korean Journal of Biological Psychiatry
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• v.21 no.4
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• pp.175-181
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• 2014

Objectives It was the aim to examine the association of the thyroid-related hormones with cognitive function, depression, and subjective memory impairment in community-dwelling elders with questionable dementia. Methods The sample consisted of 399 community residents with 'questionable dementia' aged 60 or over in whom serum thyroid-related hormones [thyroid stimulating hormone (TSH) and thyroxine] had been assayed. Cognitive impairment was defined using the Korean version of the Consortium Establish a Registry for Alzheimer's Disease. Depression was diagnosed using the Korean version of Geriatric Depression Scale and subjective memory complaint (SMC) was checked using the subjective memory complaints questionnaire (SMCQ). Age, gender, education, and the presence of apolipoprotein E {\varepsilon}4 were included as covariates. Results There was a significant positive association between verbal fluency test (VFT) score and serum TSH levels (p = 0.01). There was a significant negative association between SMCQ total score and word list memory test (WLMT)(p = 0.002) or word list recall test (WLRT) score (p = 0.013). Conclusions Lower serum TSH levels were associated with semantic memory (VFT), and we found that SMC was associated with episodic memory (WLMT and WLRT) in this sample.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.4
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• pp.131-135
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• 2015

The thyroid hormones act on nearly every cell in the body. Moreover, the thyroid gland continuously interacts with the ovaries, and the thyroid hormones are involved in almost all phases of reproduction. Thyroid dysfunctions are relatively common among women of reproductive age, and can affect fertility in various ways, resulting in anovulatory cycles, high prolactin levels, and sex hormone imbalances. Undiagnosed and untreated thyroid disease can be a cause of subfertility. Subclinical hypothyroidism (SCH), also known as mild thyroid failure, is diagnosed when peripheral thyroid hormone levels are within the normal reference laboratory range, but serum thyroid-stimulating hormone levels are mildly elevated. Thyroid autoimmunity (TAI) is characterized by the presence of anti-thyroid antibodies, which include anti-thyroperoxidase and anti-thyroglobulin antibodies. SCH and TAI may remain latent, asymptomatic, or even undiagnosed for an extended period. It has also been demonstrated that controlled ovarian hyperstimulation has a significant impact on thyroid function, particularly in women with TAI. In the current review, we describe the interactions between thyroid dysfunctions and subfertility, as well as the proper work-up and management of thyroid dysfunctions in subfertile women.

• The Korean Journal of Nuclear Medicine
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• v.14 no.2
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• pp.45-51
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• 1980

In an attempt to evaluate the diagnostic significance of the serum thyroid hormones in various thyroid function states, the author measured serum $T_3$ uptake, serum $T_3$, serum $T_4$, serum free $T_4$ and free $T_3$ index in 27 cases of normal subjects, 11 cases of hypothyroidism, 152 cases of euthyroidism and 81 cases of hyperthyroidism by the radioimmunoassay method. The results were as follows: 1. The ranges of serum thyroid hormones in normal subjects were, serum $T_3$ uptake; $27.4{\sim}42.1%$, serum $T_3;\;93{\sim}245ng/dl$, serum $T_4;\;4.08{\sim}12.9ug/dl$ and serum free $T_4;\;0.57{\sim}1.53ng/dl(M{\pm}2S.D.)$. 2. Free $T_4$ index and serum $T_4$ show relatively high diagnostic value in euthyroidism group, and serum $T_3\;and\;T_4$ in hypothyroidism group, while serum $T_3$, free $T_4\;and\;T_4$ show relatively high diagnostic value in hyperthyroidism group. 3. There were significant correlation between free $T_4$ index and serum $T_4$(r=0.68), and between free $T_4$ index and serum free $T_4$(r=0.67) in hyperthyroidism group.

• Animal Bioscience
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• v.35 no.8
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• pp.1184-1194
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• 2022

Objective: High concentrate diets are widely used to satisfy high-yielding dairy cows; however, long-term feeding of high concentrate diets can cause subacute ruminal acidosis (SARA). The endocrine disturbance is one of the important reasons for metabolic disorders caused by SARA. However, there is no current report about thyroid hormones involved in liver metabolic disorders induced by a high concentrate diet. Methods: In this study, 12 mid-lactating dairy cows were randomly assigned to HC (high concentrate) group (60% concentrate of dry matter, n = 6) and LC (low concentrate) group (40% concentrate of dry matter, n = 6). All cows were slaughtered on the 21st day, and the samples of blood and liver were collected to analyze the blood biochemistry, histological changes, thyroid hormones, and the expression of genes and proteins. Results: Compared with LC group, HC group showed decreased serum triglyceride, free fatty acid, total cholesterol, low-density lipoprotein cholesterol, increased hepatic glycogen, and glucose. For glucose metabolism, the gene and protein expression of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the liver were significantly up-regulated in HC group. For lipid metabolism, the expression of sterol regulatory element-binding protein 1, long-chain acyl-CoA synthetase 1, and fatty acid synthase in the liver was decreased in HC group, whereas carnitine palmitoyltransferase 1α and peroxisome proliferator activated receptor α were increased. Serum triiodothyronine, thyroxin, free triiodothyronine (FT3), and hepatic FT3 increased in HC group, accompanied by increased expression of thyroid hormone receptor (THR) in the liver. Conclusion: Taken together, thyroid hormones may increase hepatic gluconeogenesis, β-oxidation and reduce fatty acid synthesis through the THR pathway to participate in the metabolic disorders caused by a high concentrate diet.

• Journal of Preventive Medicine and Public Health
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• v.41 no.2
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• pp.128-134
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• 2008

Objectives : This study was conducted to determine the reference interval of serum thyroid hormones(TSH, $FT_3$, $FT_4$) in healthy Korean adults. Methods : Health examination data from 1,591 healthy Korean adults who visited an university hospital were analyzed. Patients with specific health conditions capable of altering laboratory results were excluded from the study. Serum thyroid hormones were measured using IMMULITE 2000 (DPC, USA, 2002). Subjects were 18-65 years old; 911 were male, and 690 were female. Results : The arithmetic means of TSH, $FT_3$, and $FT_4$ values for male subjects were $1.28{\pm}1.84\;{\mu}IU/ml$, $3.23{\pm}0.57\;pg/ml$, and $1.42{\pm}0.22\;ng/dl$, respectively. In female subjects, the arithmetic means of TSH, FT3, and FT4 values were $1.49{\pm}2.08\;{\mu}IU/ml$, $3.08{\pm}0.54\;pg/ml$, and $1.29{\pm}0.24\;ng/dl$, respectively. The arithmetic mean $FT_4$ value for males decreased with age (p<0.01). The arithmetic mean $FT_3$ value for females increased with age (p<0.01). The arithmetic mean thyroid hormone values of all study subjects differed significantly based on season. The arithmetic mean of male $FT_4$ decreased with increasing BMI (p<0.01). The arithmetic mean of female $FT_3$ increased with increasing BMI (p<0.01). The reference intervals recommended by the IMMULITE 2000 manufacturer are $0.40-4.00\;{\mu}IU/ml$ for TSH, 1.80-4.20 pg/ml for $FT_3$, and 0.80-1.90 ng/dl for $FT_4$ (same values for both genders). Conclusions : There was a significant difference in the interval of thyroid hormones between males and females, but the reference interval of IMMULITE 2000 was not established by gender. There is a need to reestablish the reference interval for thyroid hormones in Korean healthy adults.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6643-6647
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• 2014

The breast and the thyroid are hormone responsive organs that are closely related with changes of endocrine function and glandular disease. An association between thyroid disorders and breast cancer (BC) risk has been suggested, although the results are inconclusive. The purpose of the present study was to summarize evidence supporting a relationship between BC and the level of thyroid hormones and antibodies. The MEDLINE and EMBASE electronic databases were searched for studies published between 2000 and 2014. The pooled effects were presented as weighted mean differences (WMD) with 95% confidence intervals (CI) using fixed or random effect models. We summarized the results of 8 cross-sectional studies with 4, 189 participants. The overall pooled results showed that the levels of $FT_3$ and $FT_4$ were significantly increased in patients with BC (WMD=1.592 pmol/l; 95% CI: 0.15-3.033 and WMD=0.461 ng/dl; 95% CI: 0.015-0.906; p=0.043). The TPOAb level in patients with BC was higher than that in the control group (WMD=81.4 IU/ml; 95% CI: 78.7-84.0; p=0.000). The overall pooled results of the TgAb with random effects analyses showed that the TgAb level was significantly increased in patients with BC (WMD=101.3 IU/ml; 95% CI: 48.7-153.9; p=0.000). The present results indicated that the serum levels of $FT_3$, TPOAb and TgAb are significantly higher in patients with breast cancer than in healthy controls.

• The Korean Journal of Nuclear Medicine
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• v.17 no.1
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• pp.63-69
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• 1983

Fifteen cases of Korean hemorrhagic fever who were admitted Chungnam National University Hospital from October 1981 to December 1981 were analysed on the evaluation of metabolic.changes of the thyroid hormones, and thyroid function status in each clinical phase. 1. Serum $T_3,\;T_4$ concentratron, $FT_4I\;and\;T_4/TBG$ ratio were significantly lower (p<0.001, p<0.005, p<0.005, p<0.001, respectively) than control group in oliguric and early diuretic phase of Korean hemorrhagic fever. With the recovery of illness, abnormal thyroid hormones and thyroid function indices tend to become normal range. But Serum $FT_4$, TSH and TBG concentration were within normal range in all phase of KHF. Thus in Korean hemorrhagic fever, euthyroidism is probably maintained by normal or elevated serum $FT_4$ 2. $T_4/T_3\;and\;rT_3/T_3$ rato (p<0.005, p<0.005) were increased in oliguric and early diuretic phase of KHF. These results might be explained by decreased peripheral conversion of $T_4\;to\;T_3$ in oliguric and early diuretic phase.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.1
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• pp.60-68
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• 2019

Objectives : The association between thyroid-related hormones and cognitive function has been controversial. The purpose of this study is to compare the levels of thyroid-related hormones in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI). Furthermore, we investigated the relationship between thyroid-related hormones and cognitive function. Methods : From January 2011 to December 2018, we retrospectively reviewed 105 patients who were diagnosed with AD and MCI by visiting a dementia clinic at Ilsan Paik Hospital. Thyroid-related hormones [triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH)] was measured using chemiluminescent immunoassay. An independent sample t-test was performed to analyze the mean value of thyroid-related hormones in patients of AD and MCI. To investigate whether thyroid-related hormones correlate significantly with Global deterioration scale (GDS), Clinical dementia rating (CDR) and scores of each The Korean version of the consortium to establish a registry for Alzheimer's disease items, we conducted a partial correlation analysis with geriatric depression scale-Korean version (GDS-K) scores as covariates. Results : There was no significant difference in the mean serum T3, T4 and TSH levels between patients of the AD and the MCI, but the Construction Praxis Test (CPT) showed a significant positive correlation with the serum TSH concentration (p-value=0.004). Conclusions : In our study, the positive correlation between serum TSH level and the CPT associated with executive function was found to be helpful in understanding the association between thyroid-related hormones and the pathophysiology of dementia. Prospective studies in regard of the pathophysiology of thyroid-related hormones on cognitive function will be necessary in the future.

• Korean Journal of Veterinary Research
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• v.54 no.3
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• pp.165-169
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• 2014

The present study compared leptin, adiponectin, and thyroid hormone concentrations in normal and obese dogs, and evaluated the association between leptin and adiponectin concentrations and thyroid function. The serum leptin, adiponectin, thyroid-stimulating hormone (TSH), total thyroxine (tT4), free thyroxine (fT4), triiodothyronine (T3), and cortisol concentrations were measured in 18 normal dogs (body condition score [BCS]: 4-5/9) and 16 obese dogs (BCS: 8-9/9). Leptin and T3 concentrations were higher in the obese group than the normal weight group (p < 0.01 and p < 0.05, respectively). In both groups, the T3 and leptin concentrations were correlated (r = 0.370, p < 0.05), as were the TSH and fT4 and adiponectin concentrations (r = -0.373, p < 0.05 and r = 0.369, p < 0.05, respectively). In the normal weight group, the TSH and fT4 concentrations were correlated with the adiponectin concentrations (r = -0.528, p < 0.05 and r = 0.482, p < 0.05, respectively). The results of the present study suggest that leptin and T3 concentrations are significantly higher in obese dogs than normal weight dogs, and the serum T3 and leptin concentrations are positively correlated.