Objective: This study aims to determine the effect of iodine excess in pregnant mothers on thyroid function, growth and neurodevelopment in the neonates when assessed at 12 weeks of age. Methodology: This prospective study enrolled term neonates with birth weight >2500 gm of mothers having urine iodine concentration (UIC) ≥500 µg/L documented in the third trimester of the peripartum period. Neonatal TSH was collected by heel prick on dried blood spots within 24-72 hours of age and measured by time-resolved fluroimmunoassay. Neonates with TSH ≥11 mIU/L at birth were followed up at 2 and 12 weeks to monitor thyroid dysfunction, growth and development. Results: A total of 2354 (n = 1575 in the delivery room) maternal urine samples were collected of which 598 (25.4%) had elevated UIC. Forty-nine (12.2%) neonates had TSH ≥11mIU/L on newborn screening of whom 18 and 3 neonates had residual elevated TSH at 2 and 12 weeks of life, respectively. Maternal iodine levels correlated weakly with TSH at 2 weeks (rho = 0.299; p = 0.037). No child required treatment for congenital hypothyroidism. Eight babies additionally had TSH >5 mIU/L at 12 weeks of life. The growth and development of babies with or without TSH elevation was comparable at three months (p > 0.05). Conclusion Maternal iodine excess in pregnancy and peripartum period causes transient hyperthyrotropinemia in neonates that did not affect the growth and development at 3 months of age.
Thyroid ; Thyroid Gland ; Hypothyroidism ; Thyroid Function Tests

Female ; Humans ; Hypothyroidism ; Infant ; Mothers ; Thyroid Diseases/diagnosis* ; Thyroid Function Tests

BACKGROUND: Changes in thyroid hormone levels are commonly recognized characters among the elderly, which were reported to potentially influence incident frailty. Therefore, we examined the cross-sectional associations of thyroid hormones (THs) with frailty as well as the five components characterizing frailty (fatigue, resistance, ambulation, number of illnesses, and loss of weight) among the oldest-old. METHODS: Four hundred and eighty-seven community-dwelling oldest-old from a local community in Haidian District, Beijing, participated in our recruitment campaign between April 2019 and May 2020. The primary outcomes were a definitive diagnosis of frailty according to the FRAIL scale (Fatigue, Resistance, Ambulation, Illnesses, Loss of weight) and a positive score for each frailty subdomain. Demographic information (age, sex, marital status, and educational status), comorbidities, and details on the participants' lifestyles were recorded. Serum THs including free triiodothyronin (fT3), triiodothyronine (T3), free thyroxine (fT4), and thyroxine (T4) and thyroid stimulating hormone (TSH) levels were also measured at the beginning of our study. Logistic regressions were conducted to screen for potential risk factors for frailty and its subdomains. RESULTS: Among the total 487 subjects at enrollment, 60 (12.23%) of them were diagnosed with subclinical hypothyroidism and 110 (22.59%) of the total population scored positive for frailty. Logistic regression analyses adjusted for all potential confounders, showed that frailty was significantly associated with the serum TSH concentration (odds ratio [OR]: 1.06), fT3 concentration (OR: 0.54), and subclinical hypothyroidism score (OR: 2.18). The association between fT4 and frailty was absent in our observational study. The fT3/fT4 ratio characterizing peripheral hormone conversion was also tested to be correlated with frailty. CONCLUSION Subclinical hypothyroidism, higher TSH level, lower fT3 level, and decreased fT3/fT4 ratio were all associated with frailty assessed by the FRAIL scale among the community-dwelling oldest-old, suggesting a relevant role of thyroid function in aging. Future longitudinal studies are warranted to determine the casual relationship between thyroid dysfunction and frailty in the oldest-old.
Humans ; Aged, 80 and over ; Aged ; Thyroxine ; Cross-Sectional Studies ; Thyrotropin ; Frailty ; Independent Living ; Triiodothyronine ; Thyroid Function Tests ; Thyroid Hormones ; Hypothyroidism ; Fatigue

OBJECTIVES: A variety of causes can lead to cholestasis, however, cholestasis caused by Graves' disease is usually overlooked clinically. Here we analyze the clinical characteristics of Graves' disease associated cholestasis so as to have a better understanding for the disease. METHODS: We retrospectively collected 13 inpatients' data who suffered from the Graves' disease associated cholestasis in the Department of Infectious Disease of Xiangya Hospital from January 2000 to December 2018. The characteristics of the patients' age, gender, liver function, thyroid function, coagulation function, the special cardiac examination, treatment, and follow-up data were analyzed. RESULTS: Thirteen patients, including 10 males and 3 females with the age range from 33 to 55 (median 43) years old presented cholestasis, pruritus, and hypermetabolic symptoms. The levels of total bilirubin (TBIL), direct bilirubin (DBIL), glutamic-pyruvic transferase, glutamic-oxaloacetic transferase, alkaline phosphosphatase, and gamma glutamyl transpeptidase were 170.4-976.7 (median 388.8) µmol/L, 93.2-418.1 (median 199.2) µmol/L, 25.1-182.1 (median 106.4) U/L, 38.2-265.7 (median 59.7) U/L, 105.3-332.0 (median 184.5) U/L, and 20.7-345.1 (median 47.6) U/L, respectively. The levels of free triiodothyronine (FT CONCLUSIONS Graves' disease can cause cholestasis, with the low incidence. The symptoms of cholestasis can be improved or even eradicated with the cure of the Graves' disease. The cholestasis may be idiopathic. For patients with cholestasis and hyperthyroidism, Graves' disease should be considered for differential diagnosis.
Adult ; Cholestasis/etiology* ; Female ; Graves Disease/complications* ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Thyroid Function Tests ; Thyroxine ; Triiodothyronine

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

OBJECTIVES: Thyroid hormone deficiency during the neurodevelopmental period can impair brain development and induce psychiatric symptoms. This study examined the association between thyroid dysfunction and the severity of symptoms in schizophrenia patients, and the treatment response of patients with schizophrenia. METHODS: Three hundred thirty-eight schizophrenia patients, with no prior history of thyroid disease or taking medication associated with it, were studied. We assessed the blood thyroid hormone level, the Brief Psychiatric Rating Scale (BPRS) scores on the day of admission and discharge, admission period, dose of administered antipsychotics, and the number of antipsychotic combinations. The collected data were subsequently analyzed using the Kruskal-Wallis test and Pearson's chi-square test. RESULTS: The percentage of schizophrenia patients who presented with abnormal thyroid hormone level was 24.6%. High total triiodothyronine (TT3) (p = 0.003), low TT3 (p = 0.001), and high free thyroxine (fT4) (p < 0.001) groups showed a higher BPRS score on admission than did the normal thyroid hormone group, while thyroid stimulating hormone (TSH) levels were not significantly correlated with the severity of symptoms. Furthermore, thyroid hormone was not associated with the treatment response assessed by the rate of BPRS score reduction, admission days, use of clozapine, and dose of antipsychotics. CONCLUSIONS: The TT3 and fT4 hormone levels were significantly associated with the severity of symptoms in schizophrenia patients. These relations suggested that thyroid dysfunction may be associated with the severity of schizophrenia. And hence, further analysis of the results of the thyroid function test, which is commonly used in cases of psychiatric admission, is required.
Antipsychotic Agents ; Brain ; Brief Psychiatric Rating Scale ; Clozapine ; Humans ; Inpatients ; Schizophrenia ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland ; Thyroid Hormones ; Thyrotropin ; Thyroxine ; Triiodothyronine

PURPOSE: This study aimed to investigate the prevalence of delayed thyroid dysfunction based on iodine disinfectant use and to analyze associated risk factors.METHODS: A retrospective study was conducted on late preterm infants admitted to the neonatal intensive care unit between January 2010 and June 2018, who underwent neonatal thyroid screening (NTS) and ≥2 thyroid function tests (TFTs). NTS was performed 3 days after birth, with at least two TFTs 1 week and 2 to 4 weeks after birth. To distinguish between normal and dysfunctional thyroid levels, we reviewed TFT results at 2 to 4 weeks and examined possible risk factors for the development of thyroid dysfunction.RESULTS: Of 295 late preterm infants, 262 were enrolled with a mean gestational age and birth weight of 34.8±0.7 weeks and 2,170±454 g, respectively. A total of 7.6% developed hyperthyrotropinemia at the age of 24.3±14.6 days (range, 12 to 69). The incidence of hyperthyrotropinemia during iodine use was approximately 12.6%, while that during discontinuation was 2.4% (P=0.002). Multivariate analysis revealed that small for gestational age (SGA), iodine disinfectant use, and abnormal NTS results were significant risk factors for delayed hyperthyrotropinemia (adjusted odds ratio [AOR]: 4.27, P=0.008; AOR: 8.24, P=0.003; and AOR: 7.80, P=0.002, respectively).CONCLUSION: Delayed hyperthyrotropinemia was prevalent in late preterm infants exposed to topical iodine and those identified as being SGA. Secondary TFTs should be considered 2 to 4 weeks after birth for this population at risk.
Birth Weight ; Congenital Hypothyroidism ; Gestational Age ; Humans ; Incidence ; Infant, Newborn ; Infant, Premature ; Intensive Care, Neonatal ; Iodine ; Mass Screening ; Multivariate Analysis ; Odds Ratio ; Parturition ; Population Characteristics ; Prevalence ; Retrospective Studies ; Risk Factors ; Thyroid Function Tests ; Thyroid Gland ; Thyrotropin

BACKGROUND: The detection of thyroid nodules through ultrasonography (US) has improved with the development of imaging technologies and thyroid cancer screening in Korea. We evaluated the relationship between the presence of thyroid nodules on US and thyroid function test (TFT) results in healthy individuals.METHODS: We performed a retrospective review of data from 449 adults (313 men and 136 women) who underwent tests to evaluate serum thyrotropin (TSH) and free thyroxine levels, thyroid US, and if needed, fine needle aspiration cytology (FNAC).RESULTS: Of the 449 subjects, 144 subjects (32.1%) had thyroid nodules. Among the 144 with thyroid nodules, 24 (16.7%) were advised to undergo FNAC, and all of them showed normal serum TSH levels. Logistic regression analysis showed that the presence of thyroid nodules was not related to abnormalities noted on TFTs after adjusting for age, sex, smoking status, and presence of risky drinking behavior and hypertension (P=0.647).CONCLUSION: The presence of thyroid nodules on US in healthy adults was not associated with abnormal TFT results. Serum TSH check-ups during the evaluation of thyroid nodules discovered through US in asymptomatic individuals living in areas with a low prevalence of autonomous functioning thyroid nodules might not be necessary from the perspective of cost-effectiveness and subject convenience.
Adult ; Biopsy, Fine-Needle ; Drinking Behavior ; Humans ; Hypertension ; Korea ; Logistic Models ; Male ; Mass Screening ; Prevalence ; Retrospective Studies ; Smoke ; Smoking ; Thyroid Function Tests ; Thyroid Gland ; Thyroid Neoplasms ; Thyroid Nodule ; Thyrotropin ; Thyroxine ; Ultrasonography

Thyroid disorders are common, affecting more than 10% of people in the US, and laboratory tests are integral in the management of these conditions. The repertoire of thyroid tests includes blood tests for thyroid-stimulating hormone (TSH), free thyroxine, free triiodothyronine, thyroglobulin (Tg), thyroglobulin antibodies (Tg-Ab), thyroid peroxidase antibodies (TPO-Ab), TSH receptor antibodies (TRAb), and calcitonin. TSH and free thyroid hormone tests are frequently used to assess the functional status of the thyroid. TPO-Ab and TRAb tests are used to diagnose Hashimoto's thyroiditis and Graves' disease, respectively. Tg and calcitonin are important tumor markers used in the management of differentiated thyroid carcinoma and medullary thyroid carcinoma (MTC), respectively. Procalcitonin may replace calcitonin as a biomarker for MTC. Apart from understanding normal thyroid physiology, it is important to be familiar with the possible pitfalls and caveats in the use of these tests so that they can be interpreted properly and accurately. When results are discordant, clinicians and laboratorians should be mindful of possible assay interferences and/or the effects of concurrent medications. In addition, thyroid function may appear abnormal in the absence of actual thyroid dysfunction during pregnancy and in critical illness. Hence, it is important to consider the clinical context when interpreting results. This review aims to describe the above-mentioned blood tests used in the diagnosis and management of thyroid disorders, as well as the pitfalls in their interpretation. With due knowledge and care, clinicians and laboratorians will be able to fully appreciate the clinical utility of these important laboratory tests.
Antibodies ; Biomarkers, Tumor ; Calcitonin ; Critical Illness ; Diagnosis ; Graves Disease ; Hematologic Tests ; Iodide Peroxidase ; Physiology ; Pregnancy ; Receptors, Thyrotropin ; Thyroglobulin ; Thyroid Function Tests ; Thyroid Gland* ; Thyroid Neoplasms ; Thyroiditis ; Thyrotropin ; Thyroxine ; Triiodothyronine

Resistance to thyroid hormone (RTH) is a condition caused by a mutation in the thyroid hormone receptor gene. It is rarely reported in individuals with no family history of RTH or in premature infants, and its clinical presentation varies. In our case, a premature infant with no family history of thyroid diseases had a thyroid stimulating hormone level of 85.0 µIU/mL and free thyroxine level of 1.64 ng/dL on a thyroid function test. The patient also presented with clinical signs of hypothyroidism, including difficulties in feeding and weight gain. The patient was treated with levothyroxine; however, only free thyroxine and triiodothyronine levels increased without a decrease in thyroid-stimulating hormone levels. Taken together with thyroid gland hypertrophy observed on a previous ultrasound examination, RTH was suspected and the diagnosis was eventually made based on a genetic test. A de novo mutation in the thyroid hormone receptor β gene in the infant was found that has not been previously reported. Other symptoms included tachycardia and pulmonary hypertension, but gradual improvement in the symptoms was observed after liothyronine administration. This report describes a case involving a premature infant with RTH and a de novo mutation, with no family history of thyroid disease.
Diagnosis ; Goiter ; Humans ; Hypertension, Pulmonary ; Hypertrophy ; Hypothyroidism ; Infant ; Infant, Newborn ; Infant, Premature ; Receptors, Thyroid Hormone ; Tachycardia ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland ; Thyroid Hormone Receptors beta ; Thyroid Hormone Resistance Syndrome ; Thyrotropin ; Thyroxine ; Triiodothyronine ; Ultrasonography ; Weight Gain