Psychotic symptoms in Chinese adolescent patients with major depressive disorder: prevalence and related endocrine clinical factors.

OBJECTIVE: Major depressive disorder (MDD) is often accompanied by psychotic symptoms. However, few studies have examined the relationship between psychotic symptoms and endocrine factors in adolescent patients with MDD. Therefore, this study aimed to investigate the prevalence and related endocrine clinical factors of psychotic symptoms in Chinese adolescent patients with MDD. METHODS: In total, 601 patients (aged 12-18) with MDD were recruited. The Patient Health Questionnaire - 9 items (PHQ - 9) was utilized for assessing depressive symptoms. Psychotic symptoms were assessed through clinical interviews. Prolactin (PRL), thyroid-stimulating hormone (TSH), triiodothyronine (T3), free triiodothyronine (FT3), thyroxine (T4), and free thyroxine (FT4) were also measured. RESULTS: The incidence of psychotic symptoms in adolescent patients with MDD was 22.6%. The findings demonstrated that age, self-harming behavior, PHQ-9 score, FT4, and normalized PRL were independently associated with psychotic symptoms in patients with MDD (All p < 0.05). CONCLUSIONS: PRL and FT4 levels are more likely to be abnormally elevated in major depressive adolescents with psychotic symptoms. Prolactin and thyroid hormones in patients with MDD should be paid more attention.

The correlation between the thyroid function and urinary iodine/creatinine ratio of pregnant women attending a tertiary hospital in Beijing, China, during different trimesters.

OBJECTIVE: This study investigated the correlation between thyroid function and urinary iodine/creatinine ratio (UI/Cr) in pregnant women during different trimesters and explored potential influencing factors. METHODS: In this cross-sectional study, serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), and UI/Cr were measured in 450 pregnant women. Correlations were analyzed using Pearson's correlation coefficient and multiple linear regression. Subgroup analyses were performed based on age, body mass index (BMI), parity, gestational age, education, occupation, and family history of thyroid disorders. RESULTS: UI/Cr was positively correlated with FT4 levels in the first and second trimesters, particularly in women with older age, higher BMI, multiparity, higher education, and employment. No significant correlations were found between UI/Cr and TSH or FT3 levels. CONCLUSION: UI/Cr is positively correlated with FT4 levels in early pregnancy, especially in women with certain risk factors. Regular monitoring of iodine status and thyroid function is recommended for pregnant women to ensure optimal maternal and fetal health.

A predictive model for L-T4 dose in postoperative DTC after RAI therapy and its clinical validation in two institutions.

Purpose: To develop a predictive model using machine learning for levothyroxine (L-T4) dose selection in patients with differentiated thyroid cancer (DTC) after resection and radioactive iodine (RAI) therapy and to prospectively validate the accuracy of the model in two institutions. Methods: A total of 266 DTC patients who received RAI therapy after thyroidectomy and achieved target thyroid stimulating hormone (TSH) level were included in this retrospective study. Sixteen clinical and biochemical characteristics that could potentially influence the L-T4 dose were collected; Significant features correlated with L-T4 dose were selected using machine learning random forest method, and a total of eight regression models were established to assess their performance in prediction of L-T4 dose after RAI therapy; The optimal model was validated through a two-center prospective study (n=263). Results: Six significant clinical and biochemical features were selected, including body surface area (BSA), weight, hemoglobin (HB), height, body mass index (BMI), and age. Cross-validation showed that the support vector regression (SVR) model was with the highest accuracy (53.4%) for prediction of L-T4 dose among the established eight models. In the two-center prospective validation study, a total of 263 patients were included. The TSH targeting rate based on constructed SVR model were dramatically higher than that based on empirical administration (Rate 1 (first rate): 52.09% (137/263) vs 10.53% (28/266); Rate 2 (cumulative rate): 85.55% (225/263) vs 53.38% (142/266)). Furthermore, the model significantly shortens the time (days) to achieve target TSH level (62.61 ± 58.78 vs 115.50 ± 71.40). Conclusions: The constructed SVR model can effectively predict the L-T4 dose for postoperative DTC after RAI therapy, thus shortening the time to achieve TSH target level and improving the quality of life for DTC patients.

Fetal sexual dimorphism of maternal thyroid function parameters during pregnancy, a single center retrospective real-world study.

Introduction: Thyroid function during pregnancy fluctuates with gestational weeks, seasons and other factors. However, it is currently unknown whether there is a fetal sex-specific thyroid function in pregnant women. The purpose of this study was to investigate the fetal sex differences of maternal thyroid-stimulating hormone (TSH) and free thyroxine (FT4) in pregnant women. Methods: This single-center retrospective real-world study was performed by reviewing the medical records of pregnant women who received regular antenatal health care and delivered liveborn infants in Shanghai First Maternity and Infant Hospital (Pudong branch), from Aug. 18, 2013 to Jul. 18, 2020. Quantile regression was used to evaluate the relationship between various variables and TSH and FT4 concentrations. The quantile regression also evaluated the sex impact of different gestational weeks on the median of TSH and FT4. Results: A total of 69,243 pregnant women with a mean age of 30.36 years were included. 36197 (52.28%) deliveries were boys. In the three different trimesters, the median levels (interquartile range) of TSH were 1.18 (0.66, 1.82) mIU/L and 1.39 (0.85, 2.05) mIU/L, 1.70 (1.19, 2.40) mIU/L; and the median levels (interquartile range) of FT4 were 16.63 (15.16, 18.31) pmol/L, 14.09 (12.30, 16.20) pmol/L and 13.40 (11.52, 14.71) pmol/L, respectively. The maternal TSH upper limit of reference ranges was decreased more in mothers with female fetuses during gestational weeks 7 to 12, while their FT4 upper limit of the reference ranges was increased more than those with male fetuses. After model adjustment, the median TSH level was 0.11 mIU/L lower (P <0.001), and FT4 level was 0.14 pmol/L higher (P <0.001) for mothers with female fetuses than those with male fetuses during gestational weeks 9 to 12. Discussion: We identified sexual dimorphism in maternal thyroid function parameters, especially during 9-12 weeks of pregnancy. Based on previous research, we speculated that it may be related to the higher HCG levels of mothers who were pregnant with girls during this period. However, longitudinal studies are needed to determine if fetal sex differences impact the maternal thyroid function across pregnancy.

Role of Lugol solution before total thyroidectomy for Graves' disease: randomized clinical trial.

BACKGROUND: Lugol solution is often administered to patients with Graves' disease before surgery. The aim is to reduce thyroid vascularization and surgical morbidity, but its real effectiveness remains controversial. The present study was designed to evaluate the effects of preoperative Lugol solution on thyroid vascularization and surgical morbidity in patients with Graves' disease undergoing total thyroidectomy. METHODS: Fifty-six patients undergoing total thyroidectomy for Graves' disease were randomly assigned to receive 7 days of Lugol treatment (Lugol+ group, 29) or no Lugol treatment (LS- group, 27) before surgery in this single-centre and single-blinded trial. Preoperative hormone and colour Doppler ultrasonographic data for assessing thyroid vascularization were collected 8 days before surgery (T0) and on the day of surgery (T1). The primary outcome was intraoperative and postoperative blood loss. Secondary outcomes included duration of surgery, thyroid function, morbidity, vascularization, and microvessel density at final pathology. RESULTS: No differences in demographic, preoperative hormone or ultrasonographic data were found between LS+ and LS- groups at T0. At T1, free tri-iodothyronine (FT3) and free thyroxine (FT4) levels were significantly reduced compared with T0 values in the LS+ group, whereas no such variation was observed in the LS- group. No differences between T0 and T1 were found for ultrasonographic vascularization in either group, nor did the histological findings differ. There were no significant differences between the LS+ and LS- groups concerning intraoperative/postoperative blood loss (median 80.5 versus 94 ml respectively), duration of surgery (75 min in both groups) or postoperative morbidity. CONCLUSION: Lugol solution significantly reduces FT3 and FT4 levels in patients undergoing surgery for Graves' disease, but does not decrease intraoperative/postoperative blood loss, thyroid vascularization, duration of surgery or postoperative morbidity. REGISTRATION NUMBER: NCT05784792 (https://www.clinicaltrials.gov).

Correlation between thyroid hormone sensitivity and diabetic peripheral neuropathy in euthyroid patients with type 2 diabetes mellitus.

Previous studies have revealed that thyroid hormone (TH) levels are associated with the risk of diabetic peripheral neuropathy (DPN) in euthyroid patients with type 2 diabetes mellitus (T2DM). However, the relationship between TH sensitivity, a complementary method for assessing thyroid function, and DPN remains unclear. This study aimed to investigate the correlation between DPN and TH sensitivity in euthyroid patients with T2DM. Exactly 708 euthyroid adults with T2DM were retrospectively enrolled. The FT3/FT4 ratio was used to estimate peripheral TH sensitivity. Central TH sensitivity was assessed using the Thyrotroph T4 Resistance Index (TT4RI), Thyroid-Stimulating Hormone Index (TSHI), Thyroid Feedback Quantile-based Index (TFQI), and Parametric TFQI (PTFQI). DPN was assessed using neurologic symptoms, signs, and nerve conduction velocity tests. The relationship between DPN and TH sensitivity was examined using logistic regression analysis. We observed that an elevated FT3/FT4 ratio was associated with DPN (OR = 1.36, 95%CI: 1.13-1.63, p = 0.0012). For each standard deviation (SD) increase in the TT4RI, TSHI, TFQI, and PTFQI, the OR of DPN was 0.80 (95%CI: 0.68-0.94, p = 0.0078), 0.72 (95%CI: 0.60-0.86, p = 0.0002), 0.69 (95%CI: 0.58-0.83, p < 0.0001), and 0.69 (95%CI: 0.58-0.82, p < 0.0001), respectively. These results suggested that reduced central and peripheral TH sensitivity is associated with a decreased risk of developing DPN.

Correlation of serum thyrotropin and thyroid hormone levels with diabetic kidney disease: a cross-sectional study.

OBJECTIVE: The relationship between thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and diabetic kidney disease (DKD) is still controversial, and this study analyzed the correlation between TSH, FT3, FT4 and DKD in patients with type 2 diabetes mellitus (T2DM). METHODS: T2DM patients (1216) were divided into five groups based on serum TSH, FT3, and FT4 levels, differences in urinary albumin excretion rate (UACR), estimated glomerular filtration rate (eGFR) were compared. Binary logistic regression verified independent correlations among TSH, FT3, FT4 and UACR, eGFR. TSH and FT3 predictive values for DKD were analyzed using receiver operating characteristic (ROC) curves. RESULTS: The prevalence of albuminuria with decreased eGFR was higher in T2DM patients with subclinical hypothyroidism and overt hypothyroidism than that in patients with normal thyroid function. TSH positively correlated with UACR (r = 0.133, p < 0.001) and positively correlated with eGFR (r = -0.218, p < 0.001), FT3 negatively correlated with UACR (r = -0.260, p < 0.001) and positively correlated with eGFR (r = 0.324, p < 0.001). With the change from the lower normal level to the increased level of TSH and the change from the higher normal level to the reduced level of FT3, the prevalence of albuminuria gradually increased, the prevalence of decreased eGFR gradually increased in TSH groups and FT3 groups. After adjusting for age, BMI, duration of diabetes, TPOAb, TGAb, smoking, drinking, hypertension, the use of anti-diabetic medications (metformin, sodium-glucose cotransporter 2 inhibitors), HbA1c, CRP, TC, TG, LDL-C, and HDL-C, both TSH and FT3 correlated with increased UACR (TSH: OR 1.253, p = 0.001; FT3: OR 0.166, p < 0.001) and decreased eGFR (TSH: OR 1.245, p < 0.001, FT3: OR 0.579, p < 0.001), but this correlation of TSH with eGFR < 60 mL/min/1.73 m2 was not found in male. The area under the ROC curve (AUC) for FT3 was greater than that for TSH (FT3: 0.64; TSH: 0.61). CONCLUSIONS: Increased TSH and reduced FT3 levels were associated with DKD in T2DM patients, but in a sex-dependent manner. FT3 had a higher predictive value for DKD.

Analysis of Inflammatory and Thyroid Hormone Levels Based on Hepatitis A and B Virus Immunity Status: Age and Sex Stratification.

This study investigated the potential associations between hepatitis virus antibody status and thyroid and inflammatory function. The C-reactive protein (CRP), thyroid-stimulating hormone (TSH), and free thyroxine (FT4) levels were measured in individuals with and without antibodies to the hepatitis A virus (HAV) and hepatitis B virus (HBV). Participants were stratified by age, sex, and HAV/HBV antibody status. Participants with and without antibodies to HAV and HBV had normal CRP, TSH, and FT4 levels. However, notable discrepancies were observed in FT4 levels among participants with HAV antibodies and in CRP and FT4 levels among those with both HAV and HBV antibodies, suggesting potential associations between viral immunity and thyroid function, especially in younger participants. Significant variations in thyroid hormone levels were noted when the sample was stratified by sex and HAV and HBV antibody status, indicating that the association between antibody status and thyroid hormone levels varied by sex. This study underscores the need for further research on the effect of viral immunity on inflammatory parameters and thyroid hormone levels.

Triiodothyronine levels in athyreotic pediatric patients during levothyroxine therapy.

Objective: Levothyroxine (LT4) monotherapy is the current recommended approach for treating pediatric patients post-total thyroidectomy (TT) based on the assumption that peripheral conversion of thyroxine (T4) to triiodothyronine (T3) normalizes thyroid hormone levels. In adults, approximately 15% of post-TT patients on LT4 monotherapy have altered T4:T3 ratios with ongoing debate in regard to the clinical impact with respect to health-related quality of life (hrQOL). The ability to normalize T3 and T4 levels on LT4 monotherapy for pediatric patients' post-TT is important but not previously described. This study reports data on T3 levels in athyreotic pediatric patients to determine if a similar cohort of patients exists on LT4 monotherapy targeting normalization of TSH (LT4 replacement) or suppression (LT4 suppression). Methods: Thyroid function tests (TFTs) were retrospectively extracted from medical charts for patients <19 years old who underwent TT for definitive treatment of Graves' disease (GD) or differentiated thyroid cancer (DTC) between 2010-2021. LT4 dosing was selected to normalize the TSH in GD patients (LT4 replacement) or suppress TSH in DTC patients (LT4 suppression). Pre- and post-surgical TSH, T3 and T4 levels were compared. Results: Of 108 patients on LT4 replacement (n=53) or LT4 suppression (n=55) therapy, 94% (102/108) of patients demonstrated T3 levels in the normal range post-TT. However, the majority of patients on LT4 replacement (44/53; 83%) and LT4 suppression (31/55; 56%) displayed post-TT T3 levels in the lower half of the normal range despite 50% (22/44) and 48% (15/31) of these patients, respectively, having post-TT fT4 levels above the upper limit of the normal range. Conclusion: A significant number of pediatric patients do not achieve similar T3 and T4:T3 levels pre- and post-TT. Future multi-center, prospective studies evaluating LT4 monotherapy in comparison to combined LT4/LT3 therapy are warranted to determine the potential clinical impact of altered T3 levels in athyreotic pediatric patients.

The Effects of Triiodothyronine on the Free Thyroxine Set Point Position in the Hypothalamus Pituitary Thyroid Axis.

In clinical endocrinology, it is often assumed that the results of thyroid hormone function tests (TFTs) before total thyroidectomy are considered euthyroid when the circulating concentrations of thyrotropin [TSH] and free thyroxine [FT4] are within the normal reference ranges. Postoperative thyroid replacement therapy with levothyroxine. The aim of L-T4 is to reproduce the preoperative euthyroid condition. Currently, intra-individual changes in the euthyroid set point before and after total thyroidectomy are only partly understood. After total thyroidectomy, a greater postoperative [FT4] than preoperative [FT4] for equivalent euthyroid [TSH] was found, with differences ranging from 3 to 8 pmol/L. This unexplained difference can be explained by the use of a mathematical model of the hypothalamus-pituitary-thyroid (HPT) axis set point theory. In this article, the postoperative HPT euthyroid set point was calculated using a dataset of total thyroidectomized patients with at least three distinguishable postoperative TFTs. The postoperative [TSH] set point was used as a homeostatic reference for the comparison of preoperative TFTs. The preoperative [FT4] value was equal to the postoperative [FT4] value in 50% of the patients, divided by a factor of ~ 1.25 (within +/- 10%). The factor of 1.25 stems from the lack of postoperative use of thyroidal triiodothyronine (T3). Furthermore, approximately 25% of the patients presented a greater preoperative [FT4] difference than postoperative [FT4]/1.25 combined with a normal [TSH] difference. Based on these observations, the effect of T3 on the value of the [FT4] set point was analyzed and explained from a control theory perspective.

Normal Values for the fT3/fT4 Ratio: Centile Charts (0-29 Years) and Their Application for the Differential Diagnosis of Children with Developmental Delay.

Primary congenital hypothyroidism is easily diagnosed on the basis of elevated plasma levels of thyroid-stimulating hormone (TSH). In contrast, in the rare disorders of thyroid hormone resistance, TSH and, in mild cases, also thyroid hormone levels are within the normal range. Thyroid hormone resistance is caused by defects in hormone metabolism, transport, or receptor activation and can have the same serious consequences for child development as congenital hypothyroidism. A total of n = 23,522 data points from a large cohort of children and young adults were used to generate normal values and sex-specific percentiles for the ratio of free triiodothyronine (T3) to free thyroxine (T4), the fT3/fT4 ratio. The aim was to determine whether individuals with developmental delay and genetically confirmed thyroid hormone resistance, carrying defects in Monocarboxylate Transporter 8 (MCT8), Thyroid Hormone Receptor alpha (THRα), and Selenocysteine Insertion Sequence-Binding Protein 2 (SECISBP2), had abnormal fT3/fT4 ratios. Indeed, we were able to demonstrate a clear separation of patient values for the fT3/fT4 ratio from normal and pathological controls (e.g., children with severe cerebral palsy). We therefore recommend using the fT3/fT4 ratio as a readily available screening parameter in children with developmental delay for the identification of thyroid hormone resistance syndromes. The fT3/fT4 ratio can be easily plotted on centile charts using our free online tool, which accepts various SI and non-SI units for fT3, fT4, and TSH.

Differences in Vitamin A Levels and Their Association with the Atherogenic Index of Plasma and Subclinical Hypothyroidism in Adults: A Cross-Sectional Analysis in China.

BACKGROUND: This study evaluates the association between vitamin A levels, AIP (the atherogenic index of plasma), and subclinical hypothyroidism. METHODS: A cross-sectional analysis was conducted involving a representative sample of 3530 Chinese adults. Linear and logistic regression models were utilized to evaluate the associations between AIP and subclinical hypothyroidism, stratified by vitamin A levels. These analyses were further differentiated by sex and age groups to identify any demographic-specific associations. RESULTS: In the vitamin A-sufficient group, an increase in AIP was associated with elevated total triiodothyronine (TT3) levels (ß = 0.26, 95%CI: 0.09, 0.41, p = 0.003). Conversely, in the group with severe vitamin A deficiency, higher AIP levels were linked to increased free triiodothyronine (fT3) and TT3 levels and decreased free thyroxine (fT4) levels (ß = 0.12, 0.03, and -0.29, respectively). Additionally, severe vitamin A deficiency increased the risk associated with AIP and subclinical hypothyroidism (OR = 1.66, 95%CI: 1.07, 2.58, p = 0.025). This risk was notably more pronounced in women and older adults, with odds ratios of 2.44 (95%CI: 1.55, 3.86, p < 0.001) and 2.14 (95%CI: 1.36, 3.38, p = 0.001), respectively. CONCLUSIONS: Vitamin A deficiency may increase the risk of the association between AIP and subclinical hypothyroidism, particularly among women and the elderly.

Delta check limits for thyroid function tests adjusted for clinical settings.

BACKGROUND: This study aimed to determine practical delta check limits (DCLs) for thyroid function tests (TFTs) to detect sample misidentifications across various clinical settings. METHODS: Between 2020 and 2022, 610,437 paired TFT results were collected from six university hospitals. The absolute DCL (absDCL) was determined using the 95th percentile for each clinical setting from a random 60 % of the total data. These absDCLs were then tested within and across different settings using the remaining 40 % of the data, alongside mix-up datasets for result and sample comparisons. The sensitivities of absDCL were calculated within and across groups in the mix-up datasets. RESULTS: Health screening absDCLs were notably lower than in other settings (2.58 vs. 5.93-7.08 for thyroid-stimulating hormone; 4.12 vs. 8.24-10.04 for free thyroxine; 0.49 vs. 0.82-0.91 for total triiodothyronine). The proportion of results exceeding absDCL of health screening differed from those of other clinical settings. Furthermore, sensitivity between health screening and other clinical settings was significantly different in both the result mix-up and sample mix-up datasets. CONCLUSIONS: This study determined practical DCLs for TFTs and highlighted differences in absDCLs between health screening and other settings. These findings emphasize the importance of tailored DCLs in improving the accurate reporting of TFTs.

Association Between Subclinical Thyroid Dysfunction and Cognitive Decline: Findings From the ELSA-Brasil Study.

BACKGROUND: Thyroid dysfunction has been associated with cognitive decline and dementia. However, the role of subtle thyroid hormone alterations in cognitive function is still debatable. METHODS: Participants without overt thyroid dysfunction aged 35-74 years at baseline were evaluated in 3 study waves (2008-2010, 2012-2014, and 2017-2019). We assessed baseline thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3). Cognitive performance was evaluated every 4 years in each wave using 10-word immediate and late recall, word recognition, semantic (animals category) and phonemic (letter f) verbal fluency, and the trail-making B-version tests. A global composite z-score was derived from these tests. The associations of TSH, FT4, and FT3 levels with cognitive decline over time were evaluated using linear mixed-effect models adjusted for sociodemographic, clinical, and lifestyle variables. RESULTS: In 9 524 participants (mean age 51.2 ±â€…8.9 years old, 51% women, 52% White), there was no association between baseline TSH, FT4, and FT3 levels and cognitive decline during the follow-up. However, increase in FT4 levels over time was associated with faster memory (ß = -0.004, 95% CI = -0.007; -0.001, p = .014), verbal fluency (ß = -0.003, 95% CI = -0.007; -0.0005, p = .021), executive function (ß = -0.004, 95% CI = -0.011; -0.003, p < .001), and global cognition decline (ß = -0.003, 95% CI = -0.006; -0.001, p = .001). Decrease in FT4 levels over time was associated with faster verbal fluency (ß = -0.003, 95% CI = -0.007; -0.0004, p = .025) and executive function (ß = -0.004, 95% CI = -0.007; -0.0003, p = .031) decline. CONCLUSIONS: An increase or decrease in FT4 levels over time was associated with faster cognitive decline in middle-aged and older adults without overt thyroid dysfunction during 8 years of follow-up.

GENDER DIFFERENCES IN THYROIDECTOMY-INDUCED WEIGHT LOSS AND IMPAIRED GLUCOSE LEVELS: ROLE OF L-THYROXINE.

Thyroxine, a key regulator of metabolic pathways, plays a pivotal role in glucose metabolism and the maintenance of glucose homeostasis. In clinical practice, L-thyroxine replacement therapy is commonly prescribed for patients with hypothyroidism. However, the specific effects of L-thyroxine and thyroidectomy (TX) on glucose levels remain an area of interest and investigation. In this study, 20 rats were divided into two groups (n=10 per group). The TX group (male and female rats) underwent thyroidectomy for 4 weeks. After 4 weeks, male and female thyroidectomized rats received L-thyroxine (10 µg/100 g/day, intraperitoneally) for 4 weeks. The rats' weights were monitored weekly post-surgery. Compared to the initial level, thyroidectomy resulted in weight loss, whereas L-thyroxine replacement therapy normalized the weight loss induced by thyroidectomy. Additionally, thyroidectomy led to impaired glucose levels, which were restored to normal levels with L-thyroxine treatment. These findings underscore the impact of thyroid function on glucose metabolism and highlight the potential therapeutic role of L-thyroxine.

Overall, sex-and race/ethnicity-specific prevalence of thyroid dysfunction in US adolescents aged 12-18 years.

Background: Thyroid dysfunction significantly affects the health and development of adolescents. However, comprehensive studies on its prevalence and characteristics in US adolescents are lacking. Methods: We investigated the prevalence of thyroid dysfunction in US adolescents aged 12-18 years using data from the National Health and Nutrition Examination Survey (NHANES) 2001-2002 and 2007-2012 cycles. Thyroid dysfunction was assessed using serum thyroid-stimulating hormone (TSH) and free thyroxine (fT4) measurements. We analyzed the prevalence across demographic subgroups and identified associated risk factors. Results: The study included 2,182 participants, representing an estimated 12.97 million adolescents. The group had a weighted mean age of 15.1 ± 0.06 years, with males constituting 51.4%. Subclinical hyperthyroidism emerged as the most prevalent thyroid dysfunction, affecting 4.4% of the population. From 2001-2002 to 2011-2012, subclinical hyperthyroidism remained consistent at 4.99% vs. 5.13% in the overall cohort. Subclinical and overt hypothyroidism was found in 0.41 and 1.03% of adolescents respectively, and overt hyperthyroidism was rare (0.04%). The prevalence of thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) positivity in the overall population were 5.8 and 9.8%, respectively. Positivity for TgAb was risk factors for hypothyroidism, while older age, female and Black Americans were risk factors for hyperthyroidism. Female adolescents and adolescents with an older age were more likely to be positive for TPOAb and TgAb, while Black and Mexican Americans had a lower risk of TPOAb and TgAb positivity. Conclusion: Subclinical hyperthyroidism was the most common form of thyroid dysfunction, and its prevalence remained stable from 2001-2002 to 2011-2012. Notable disparities in the prevalence of hyperthyroidism and antibody positivity were observed among different age, sex and racial/ethnic groups.

Evaluation of the value of combined thyroid function-related indexes in the prognosis prediction of patients with differentiated thyroid cancer.

This study aims to evaluate the prognostic significance of thyroid function-related indices in patients with differentiated thyroid cancer (DTC). This retrospective analysis included 90 patients diagnosed with DTC and treated at our hospital from January 2010 to January 2019. Patients were classified into 2 groups based on whole-body imaging results: 67 with a favorable prognosis and 23 with a poor prognosis. The study compared clinical data and thyroid function indices between these groups to assess their efficacy in prognostic prediction. Patients in the poor prognosis group had a higher occurrence of T3-4 stage cancer (P = .006) and ≥2 lymph node metastases (P = .019). Notably, levels of total thyroxine (TT4), thyroid-stimulating hormone (TSH), and thyroglobulin antibody (Tg-Ab) were significantly elevated in this group (P < .001 for each). Receiver operating characteristic analysis revealed substantial predictive accuracy for TT4, TSH, and Tg-Ab (area under curve of 0.747, 0.820, and 0.720, respectively). The columnar graphical model used for prediction demonstrated a high concordance index (C-index = 0.919), superior to single-indicator evaluations. Thyroid function indices, specifically TT4, TSH, and Tg-Ab, play a crucial role in the prognostic assessment of patients with DTC. The column-line diagram model effectively enhances prophetic prediction, aiding in clinical decision-making.

The association between TSH and thyroid hormones in the normal or subclinical dysfunction range with left ventricular diastolic dysfunction.

Thyroid hormones modulate the cardiovascular system. However, the effects of subclinical thyroid dysfunction and euthyroidism on cardiac function remain unclear. We investigated the association between left ventricular (LV) diastolic dysfunction and subclinical thyroid dysfunction or thyroid hormones within the reference range. This cross-sectional study included 26,289 participants (22,197 euthyroid, 3,671 with subclinical hypothyroidism, and 421 with subclinical thyrotoxicosis) who underwent regular health check-ups in the Republic of Korea. Individuals with thyroid stimulating hormone (TSH) levels > 4.2 µIU/mL and normal free thyroxine (FT4, 0.78-1.85 ng/dL) and triiodothyronine (T3, 76-190 ng/dL) levels were defined as having subclinical hypothyroidism. Individuals with serum TSH levels < 0.4 µIU/mL and normal FT4 and T3 levels were defined as having subclinical thyrotoxicosis. The cardiac structure and function were evaluated using echocardiography. LV diastolic dysfunction with normal ejection fraction (EF) was defined as follows: EF of > 50% and (a) E/e' ratio > 15, or (b) E/e' ratio of 8-15 and left atrial volume index ≥ 34 mL/m2. Subclinical hypothyroidism was significantly associated with cardiac indices regarding LV diastolic dysfunction. The odds of having LV diastolic dysfunction was also increased in participants with subclinical hypothyroidism (adjusted odds ratio [AOR] 1.36, 95% confidence interval [CI], 1.01-1.89) compared to euthyroid participants. Subclinical thyrotoxicosis was not associated with LV diastolic dysfunction. Among the thyroid hormones, only serum T3 was significantly and inversely associated with LV diastolic dysfunction even within the normal range. Subclinical hypothyroidism was significantly associated with LV diastolic dysfunction, whereas subclinical thyrotoxicosis was not. Serum T3 is a relatively important contributor to LV diastolic dysfunction compared to TSH or FT4.

Effects of 1, 2-bis (2,4, 6-tribromophenoxy) ethane and bis (2-ethylhexyl) tetrabromophthalate on serum metabolic and lipid profiles in male rats.

This study explored the effects of 1, 2-bis (2,4, 6-tribromophenoxy) ethane (BTBPE) and bis (2-ethylhexyl) tetrabromophthalate (TBPH) on serum metabolites and lipids in male Sprague-Dawley (SD) rats. Rats were orally gavaged 250 mg/kg bw of BTBPE and 500 mg/kg bw of TBPH for 28 consecutive days. Serum samples were collected for metabolomics and lipidomics analysis. Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to explore changes in rat metabolic patterns. Least absolute shrinkage and selection operator (LASSO) regression models were established using serum levels of total thyroxine (TT4), free thyroxine (FT4), and rats' grouping information as variables to screen for robust differential substances. SuperPred was the database to obtain potential targets. The metabolomics and lipidomics results showed that BTBPE and TBPH had an impact on rat metabolic patterns, affecting pathways such as vitamin B6 synthesis. For BTBPE treatment, pyridoxal and ceramide (Cer) 24:0;4O were selected as differential substances related to thyroid hormones. For TBPH treatment, dehydroascorbic acid, acylcarnitine (CAR) 19:0, and diglyceride (DG) 38:4 were selected as differential substances related to thyroid hormones. Serotonin 2c receptor and cyclooxygenase-2 were chosen as potential targets of BTBPE and TBPH, respectively. In conclusion, this study found that BTBPE and TBPH impacted the metabolism of rats, and this effect may be related to changes in thyroid function.

Moderation of thyroid hormones for the relationship between amyloid and tau pathology.

BACKGROUND: Altered thyroid hormone levels have been associated with increased risk of Alzheimer's disease (AD) dementia and related cognitive decline. However, the neuropathological substrates underlying the link between thyroid hormones and AD dementia are not yet fully understood. We first investigated the association between serum thyroid hormone levels and in vivo AD pathologies including both beta-amyloid (Aß) and tau deposition measured by positron emission tomography (PET). Given the well-known relationship between Aß and tau pathology in AD, we additionally examined the moderating effects of thyroid hormone levels on the association between Aß and tau deposition. METHODS: This cross-sectional study was conducted as part of the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer's Disease (KBASE) cohort. This study included a total of 291 cognitively normal adults aged 55 to 90. All participants received comprehensive clinical assessments, measurements for serum total triiodothyronine (T3), free triiodothyronine (fT3), free thyroxine (fT4), and thyroid-stimulating hormone (TSH), and brain imaging evaluations including [11C]-Pittsburgh compound B (PiB)- PET and [18F] AV-1451 PET. RESULTS: No associations were found between either thyroid hormones or TSH and Aß and tau deposition on PET. However, fT4 (p = 0.002) and fT3 (p = 0.001) exhibited significant interactions with Aß on tau deposition: The sensitivity analyses conducted after the removal of an outlier showed that the interaction effect between fT4 and Aß deposition was not significant, whereas the interaction between fT3 and Aß deposition remained significant. However, further subgroup analyses demonstrated a more pronounced positive relationship between Aß and tau in both the higher fT4 and fT3 groups compared to the lower group, irrespective of outlier removal. Meanwhile, neither T3 nor TSH had any interaction with Aß on tau deposition. CONCLUSION: Our findings suggest that serum thyroid hormones may moderate the relationship between cerebral Aß and tau pathology. Higher levels of serum thyroid hormones could potentially accelerate the Aß-dependent tau deposition in the brain. Further replication studies in independent samples are needed to verify the current results.