OBJECTIVE: Overt hypothyroidism has been associated with abnormalities of lipid metabolism; however conflicting results regarding the degree of lipid changes in subclinical hypothyroidism (SCH) have been reported. The aim of this study was to assess differences in lipid profile parameters between people with and without SCH in Korean population. METHODS: Serum lipid parameters of 37 patients with SCH and 44 euthyroid control subjects were evaluated in a retrospective cross-sectional study. RESULTS: The mean serum triglycerides (TG) level was significantly higher in patients with SCH than in controls (p < 0.05). The mean serum high-density lipoprotein cholesterol (HDL-C) level was significantly lower in patients with SCH than in controls (p < 0.05). When adjusted by age, the odds ratio for the association of HDL-C with SCH was significant at 0.893 (95% confidence interval 0.809–0.986) compared with that of the euthyroid controls. No association with SCH was found with total cholesterol level, low-density lipoprotein cholesterol level or serum thyroid-stimulating hormone level. In addition, the lipid profile did not differ significantly between premenopausal and postmenopausal women. CONCLUSIONS: We found variations of lipid profiles in patients with SCH, characterized by a significantly lower HDL-C level.
Cholesterol ; Cross-Sectional Studies ; Female ; Humans ; Hypothyroidism* ; Lipid Metabolism ; Lipoproteins ; Odds Ratio ; Retrospective Studies ; Thyrotropin ; Triglycerides

Bone is a dynamic tissue undergoing life-long remodeling, a process of bone resorption by osteoclast and bone formation by osteoblast, regulated by diverse hormones including estrogen. Recently, several pituitary hormones have been identified as a modulator of this process. Here, we reviewed the role of thyroid stimulating hormone signaling per se in bone metabolism.
Bone Remodeling ; Bone Resorption ; Estrogens ; Metabolism* ; Osteoblasts ; Osteoclasts ; Osteogenesis ; Pituitary Hormones ; Thyroid Gland* ; Thyrotropin*

Bone is a dynamic tissue undergoing life-long remodeling, a process of bone resorption by osteoclast and bone formation by osteoblast, regulated by diverse hormones including estrogen. Recently, several pituitary hormones have been identified as a modulator of this process. Here, we reviewed the role of thyroid stimulating hormone signaling per se in bone metabolism.
Bone Remodeling ; Bone Resorption ; Estrogens ; Metabolism* ; Osteoblasts ; Osteoclasts ; Osteogenesis ; Pituitary Hormones ; Thyroid Gland* ; Thyrotropin*

OBJECTIVETo investigate the neonatal umbilical cord blood thyroid stimulating hormone (TSH) level in the universal iodized salt areas and put forward the cut-point, then analyze its application.

METHODSSeven provinces were selected where the pregnant women having satisfied urinary iodine levels, then the urinary samples of pregnant women and the neonates cord blood were collected for urine iodine and TSH tests, and the relative factors were also recorded.

RESULTSTotal 1 524 urine and cord blood samples were collected from pregnant women and their new borns respectively. The median urinary iodine of pregnant women was 246.0 micro g/L, and the median TSH was 3.58 mU/L. The TSH level among seven areas and the neonatal delivery type varied significantly.

CONCLUSIONSThe neonatal cord blood TSH was influenced by several factors and could not be controlled, thus not be suitable as a iodine deficiency disorders surveillance indicator.

Delivery, Obstetric ; Female ; Fetal Blood ; drug effects ; metabolism ; Humans ; Iodine ; pharmacology ; urine ; Pregnancy ; Thyrotropin ; blood

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

OBJECTIVETo study the clinical characteristics, diagnosis and surgical effects of thyroid-stimulating hormone pituitary adenomas (TSH-omas).

METHODSThe clinical data of 19 patients (14 female and 5 male) with TSH-omas were analyzed retrospectively in this study from January 2001 to December 2008. The patients ranged from 20 to 70 years old (average 40.5 years old) and had disease histories from 1 to 228 months (average 55 months). Among these patients, 15 of them complained of thyrotoxicosis symptoms, while the other 4 patients' symptoms were associated with headache and/or visual disturbance caused by the tumor mass effect. Initially, 12 of the 15 patients with thyrotoxicosis symptoms were misdiagnosed with Grave's disease. As a result 2 of them received (131) Iodine, and one received subtotal thyroidectomy. All of these patients underwent transsphenoidal microsurgery.

RESULTSAverage follow-up period was 3.6 years (6 months-7 years). Pathological analysis of the surgical specimen showed pituitary adenoma in all patients, immunohistochemistry were positive for TSH in 17 cases, negative for TSH in 2, positive for growth hormone in 2, positive for prolactin in 1, and positive for adrenocorticotrophic hormone in 1. Postoperative MRI revealed that the tumors in 15 patients were removed totally, though 4 patients still had residual tumors. The thyroid hormone level tests suggested that 13 patients could be considered normal 3 months after their tumors were removed, though 2 of patients with normal postoperative MRI and thyroid hormones showed increased levels of TSH. For these 2 patients, tumors did not recur and their thyroid hormone levels returned to normal after pituitary radiotherapy. The cure rate was 11/19 after surgery and 13/19 after surgery plus pituitary radiotherapy.

CONCLUSIONSThe screening test for hyperthyroidism patients with high TSH levels is a key point to improve the accuracy rate in early diagnoses of TSH-omas. The transsphenoidal microsurgery is first choice to treat TSH-omas, while pituitary radiotherapy and somatostatin analogs are beneficially adjunctive therapies.

Adult ; Aged ; Female ; Humans ; Hyperthyroidism ; metabolism ; Male ; Middle Aged ; Pituitary Neoplasms ; diagnosis ; metabolism ; surgery ; Retrospective Studies ; Thyrotropin ; metabolism ; Young Adult

Thyroglobulin is the most important and abundant protein in thyroid follicles and has been widely studied as a tumor marker of thyroid cancer recurrence and persistence. Tg is considered the material basis of thyroid hormone synthesis and does not participate in the regulation of thyroid hormone synthesis and secretion. This review summarizes the recent progress in the research of thyroid hormone synthesis and secretion regulation via a negative feedback regulation mechanism by the thyroid-hypothalamus-pituitary axis. Thyroglobulin can negatively regulate the synthesis of thyroid hormone by thyroid follicular cells and antagonize the positive regulation of thyrotropin TSH. The function of thyroid follicular cells is presumably a result of Tg and TSH interaction, and a follicular cycle model is proposed to explain the causes of follicular heterogeneity in glands. We also discuss the prospects and clinical significance of studies into the negative feedback regulation mechanism of the thyroid-hypothalamus-pituitary axis and compare two theories for this mechanism.
Feedback, Physiological ; Humans ; Hypothalamo-Hypophyseal System ; physiology ; Neoplasm Recurrence, Local ; Thyroglobulin ; metabolism ; Thyroid Gland ; physiology ; Thyroid Hormones ; metabolism ; Thyrotropin ; metabolism

The present study determined the thyroid hormone interference of tetrabromobisphenol A (TBBPA) in Sprague-Dawley (SD) rats, and the derived-reference dose (RfD) of different endpoint effects on mammals based on experimental results and data collection. Based on repeated exposure toxicity tests on mammals and extensive research, the present study used BMDS240 Software to derive a benchmark dose, and analyzed the accuracy and uncertainty, and similarity with other studies. Test results on triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) demonstrated that all the indicators presented a non-monotonous dose-effect relationship clearly, except TSH in male rats exposed to 0-1000 mg/kg BW per day. Therefore, RfDs were derived from different critical effects. In summary, RfD for mammals in the present study was found to be 0.6 mg/kg per day.
Animals ; Dose-Response Relationship, Drug ; Female ; Male ; Polybrominated Biphenyls ; toxicity ; Rats ; Rats, Sprague-Dawley ; Thyroid Hormones ; metabolism ; Thyrotropin ; metabolism ; Thyroxine ; metabolism ; Triiodothyronine ; metabolism

OBJECTIVETo explore the expression of thyroid stimulating hormone (TSH) receptor in differentiated thyroid carcinoma and its clinical significance.

METHODSSeventy-four patients with differentiated thyroid carcinoma treated in our department from January 2009 to January 2011 were selected as the observation group, and 28 patients with nodular goiter were selected as the control group. Expression of TSH receptor in the two groups were detected by immunohistochemistry.

RESULTSThe positive rate of TSH receptor expression in the observation group was 55.4 (41/74), significantly lower than that of the control group (89.3%, 25/28), with a significant difference between the two groups (χ(2) = 10.21, P < 0.05). In the observation group, the positive rate of TSH receptor expression was 75.9% (22/29) in the stage I patients, 47.8% (11/23) in the stage II patients, 38.9%6 (7/18) in the stage III patients, and 25.0% (1/4) in the stage IV patients. Along with the increase of TNM staging, the positive rate of TSH receptor expression was decreased gradually, with a significant difference between them (χ(2) = 8.93, P < 0.05). The positive rate of TSH receptor expression was 53.8% (14/26) in the lymph node metastasis positive group and 56.3% (27/48) in the lymph node metastasis negative groups, with a non-significant difference between them (χ(2) = 0.04, P > 0.05).

CONCLUSIONSExpression of TSH receptors in the patients with differentiated thyroid carcinoma is quite low, and along with the increase of TNM staging, its positive rate is decreasing gradually. Testing the expression of TSH receptor may provide a basis for TSH suppression therapy after thyroid cancer surgery. This TSH suppression therapy should be personalized in order to reduce the side effects and improve their quality of life.

Adenocarcinoma, Follicular ; metabolism ; pathology ; Adult ; Carcinoma, Papillary ; metabolism ; pathology ; Female ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Receptors, Thyrotropin ; metabolism ; Thyroid Neoplasms ; metabolism ; pathology

BACKGROUND: A correct thyroid function reference range is important for the accurate diagnosis of thyroid disease during pregnancy. However, there is no consensus on whether thyroid function reference ranges in Chinese population should follow the America Thyroid Association (ATA) guidelines. This study aimed to establish a thyroid function reference range more suited to the Chinese population by evaluating the current thyroid function reference range in pregnant Chinese women and comparing it to the ATA guidelines. METHODS: A total of 52,027 pregnant women were enrolled from January 2013 to December 2016. Thyroid stimulating hormone (TSH), free thyroxine (FT4), and thyroid peroxidase antibody (TPOAb) levels were tested during the first and third trimesters of pregnancy. Reference ranges of TSH and FT4 were established from the 2.5th and 97.5th percentiles of the TPOAb-negative population of women. The Mann-Whitney U test was used to compare thyroid hormones between the TPOAb-positive and TPOAb-negative groups. RESULTS: We obtained that the TSH reference ranges were 0.03 to 3.52 mU/L and 0.39 to 3.67 mU/L, and the FT4 reference ranges were 11.7 to 19.7 pmol/L and 9.1 to 14.4 pmol/L, in the first and third trimester, respectively. If we used the 2011 ATA criteria about 7.0% and 4.0% pregnant women would be over diagnosed in first and third trimester, respectively, compared with local population thyroid hormone reference. When we compared our local criteria with the new 2017 ATA criteria, about 1.2% and 0.8% pregnant women would have a missed diagnosis in first and third trimester, respectively. CONCLUSIONS: Based on our data, which is in line with the current ATA guidelines, a population-based thyroid function reference range would be the first choice for diagnosis of thyroid disease during pregnancy in China. In case such population-based thyroid function reference ranges are unavailable in the east of China, our reference ranges can be adopted, if the same assay is used. TRIAL REGISTRATION www.chictr.org.cn (No. ChiCTR1800014394).
Adult ; Asian Continental Ancestry Group ; Female ; Humans ; Iodide Peroxidase ; metabolism ; Pregnancy ; Thyroid Gland ; metabolism ; physiopathology ; Thyrotropin ; metabolism ; Thyroxine ; metabolism ; Young Adult