Irisin in thyroid diseases.

Irisin, a hormone-like adipo-myokine, has garnered considerable attention in recent years for its potential impact in metabolic diseases. Its physiological effects are similar to those of thyroid hormones, prompting numerous investigations into potential correlations and interactions between irisin and thyroid function through various in vitro and animal experiments. However, existing studies suggest that the relationship between irisin and thyroid diseases is highly complex and multifaceted. In this paper, we have summarized the research results on serum irisin and thyroid function, providing an overview of advancements and constraints in current research on irisin and thyroid hormones. The aim is to offer insights and directions for future clinical trials in this field.

Zinc and Ferritin Levels and Their Associations with Functional Disorders and/or Thyroid Autoimmunity: A Population-Based Case-Control Study.

Population zinc and iron status appear to be associated with an increased risk of thyroid function abnormalities and thyroid autoimmunity (AITD). In the present study, we aimed to determine whether zinc and/or iron levels (assessed by ferritin levels) were associated with the presence of AITD and with alterations in thyroid function. A population-based case-control study (n = 1048) was conducted (cases: n = 524; controls: n = 524). Participants were measured for blood concentrations of zinc and ferritin, TSH, FT4, FT3, and thyroid autoantibodies. No significant differences were found in relation to ferritin levels between cases and controls. Among cases, the prevalence of low zinc levels in those with hypothyroidism (both subclinical and overt) was 49.1% [odds ratio (OR) of low zinc levels: 5.926; 95% CI: 3.756-9.351]. The prevalence of low zinc levels in participants with hyperthyroidism (both subclinical and overt) was 37.5% [OR of low zinc levels: 3.683; 95% CI: 1.628-8.33]. The zinc value that best discriminated the highest frequency of AITD was 70.4 µg/dL [sensitivity: 0.947, 1-specificity: 0.655, specificity: 0.345]. The highest frequency of AITD was calculated based on a zinc value <70 µg/dL (relative to a normal value), with this frequency being significantly higher in cases than in controls [OR: 9.3; 95% CI: 6.1-14.3 (p = 0.001)]. In conclusion, the results of our study suggest that zinc deficiency is associated with an increased frequency of functional thyroid disorders and thyroid autoimmunity.

Thyroid functions and insulin resistance in pregnant Sudanese women.

BACKGROUND: The thyroid function test (free triiodothyronine [FT3], free thyroxine [FT4], and thyroid-stimulating hormone [TSH]) is one of the key determinant of glucose homeostasis by regulating the balance of insulin. Thyroid dysfunction alters glucose metabolism, leading to insulin resistance (IR). This study aimed to assess the association between thyroid function and IR in pregnant Sudanese women. METHOD: A cross-sectional study was conducted in Saad Abuelela Hospital, Khartoum-Sudan, from January to April 2021. Obstetric/sociodemographic characteristics were gathered through questionnaires. Serum TSH, FT3, FT4, fasting plasma glucose (FPG), and fasting insulin levels were measured and evaluated, and IR was estimated using the homeostatic model assessment for insulin resistance (HOMA-IR) equation. RESULTS: In total, the study included 127 pregnant women with a median age of 27.0 years (interquartile range [IQR] 23.0‒31.2) and a median gestational (IQR) age of 25.0 (IQR 25.0‒27.0) weeks. The medians (IQRs) of the TSH, FT3, and FT4 were 1.600 (1.162‒2.092) IU/ml, 2.020(1.772‒2.240) nmol/l, and 10.70 (9.60‒11.90) pmol/l, respectively. The median (IQR) of the FPG and fasting blood insulin level was [69.0 (62.00‒78.00) mg/dl] and [5.68(2.99‒11.66) IU/ml], respectively. The median (IQR) of the HOMA-IR level was 0.9407 (0.4356‒2.1410). There was a positive correlation between HOMA -IR and FT3 levels (r = 0.375; P < 0.001) and a negative correlation with FT4 levels (r= -0.312; P < 0.001). Also, a significant positive correlation was found between fasting insulin levels and FT3 levels (r = 0.438; P < 0.001) and a negative correlation with FT4 levels (r= -0.305; P < 0.001). CONCLUSIONS: This study indicated that FT3 has positive correlation with HOMA-IR, while FT4 has negative correlation among healthy pregnant women without a history of thyroid dysfunction. This may indicate screening of euthyroid pregnant women for thyroid dysfunction and IR. Further studies are needed.

Recent advances in liquid chromatography-tandem mass spectrometry for the detection of thyroid hormones and thyroglobulin in clinical samples: A review.

Thyroid hormones (THs), including triiodothyronine (T3), thyroxine (T4), and their metabolites, are essential for regulating development, growth, and energy metabolism. Thyroglobulin (Tg) produced by thyroid follicular cells acts as an essential substrate for TH synthesis. The combination of THs with Tg is a widely used serological laboratory test for thyroid function assessment. Early detection and timely intervention are significant for preventing and managing thyroid disease. In recent years, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has emerged as a powerful tool for the precise detection of small molecular analytes and steroid hormones in clinical practice as a result of its high sensitivity and specificity. While LC-MS/MS has been increasingly used for detecting THs and Tg recently, its application in clinical practice is still in its early stages. Recent advances in the assessment of thyroid metabolism using LC-MS/MS in clinical samples published during 2004-2023 were reviewed, with a special focus on the use of this technique for quantifying molecules involved in thyroid diseases.

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.

Establishment of reference intervals of thyroid-related hormones for adults with normal liver function in Zhejiang Province by indirect method.

Objective: Thyroid disorders are prevalently diagnosed yet face significant challenges in their accurate identification in China. Predominantly, the reference intervals (RIs) currently in use across Chinese medical facilities derive from company-provided data, lacking stringent scientific validation. This practice underscores the urgent necessity for establishing tailored RIs for thyroid-related hormones, specifically tailored to the coastal area populations. Such refined RIs are imperative for empowering clinicians with the precise tools needed for the accurate diagnosis of both overt and subclinical thyroid conditions. Methods: This investigation analyzed the medical histories of 6021 euthyroid individuals mainly from East coastal area of China between June 2019 and December 2020. The cohort comprised residents of coastal areas, focusing on extracting insights into the regional specificity of thyroid hormone levels. A thorough examination protocol was implemented, encompassing inquiries into thyroid health history, ultrasound screenings, palpations during thyroid surgery, detections of thyroid antibodies, and reviews of medication histories. Adherence to the CLSI C28-A3 guidelines facilitated the derivation of RIs for thyroid-related hormones, subsequently juxtaposed against those provided by commercial entities. Results: The study delineated the following gender- and age-specific RIs for Thyroid-Stimulating Hormone (TSH): for males under 50 years, 0.57-3.37; males over 50 years, 0.51-4.03; females under 50 years, 0.53-3.91; and females over 50 years, 0.63-4.31. Further analysis revealed the RIs for Free Thyroxine (FT4), Free Triiodothyronine (FT3), Total Thyroxine (TT4), and Total Triiodothyronine (TT3) amongst males and females, with notable distinctions observed between the two genders and across age brackets. These findings are in stark contrast to the standardized intervals provided by manufacturers, particularly highlighting differences in TT3 and FT3 levels between genders and a tendency for TSH levels to increase with age. Conclusion: This research successfully establishes refined RIs for thyroid-related hormones within the Chinese coastal area populations, taking into account critical demographic factors such as gender and age. These tailored RIs are anticipated to significantly enhance the diagnostic accuracy for thyroid diseases, addressing the previously noted discrepancies with manufacturer-provided data and underscoring the importance of regionally and demographically adjusted reference intervals in clinical practice.

Associations between thyroid function, thyroid diseases, and primary aldosteronism.

OBJECTIVE: Previous studies focusing on primary aldosteronism (PA) and thyroid diseases were controversial. Hence, this study aimed to examine associations between thyroid function, thyroid diseases, and PA and its subtypes. DESIGN AND METHODS: This was a cross-sectional study, which enrolled 1023 patients with PA and 6138 patients with essential hypertension (EH) admitted to Hypertension Center of People's Hospital of Xinjiang Uygur Autonomous Region from August 2011 to June 2022. All patients with PA were accurately classified into aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) by adrenal vein sampling (AVS). Multivariate logistic regression analysis was used to assess the relationship of thyroid function, thyroid nodules, and PA and its subtypes. RESULTS: A total of 7161 patients (327 APA and 696 IHA, and 6138 EH) were included with a mean age of 48.20 ± 8.83 years. PA patients and PA subtypes showed lower FT4, FT3, TT4, TT3, and prevalence of positive TPOAb, meanwhile higher prevalence of thyroid nodules than EH patients (PA: 56.10%, IHA: 56.90%, APA: 54.80%, and EH: 48.90%, respectively). PA (adjusted OR: 1.290, 95% CI: 1.035-1.607, P = .02) and its subtype (IHA) (adjusted OR: 1.316, 95% CI: 1.005-1.724, P = .04) were significantly associated with thyroid nodules. Compared to patients with lower plasma aldosterone concentration (PAC) levels (<12 ng/dL), patients with PAC levels ≥ 12 ng/dL presented a higher prevalence of thyroid nodules. CONCLUSIONS: PA patients had lower thyroid function and higher prevalence of thyroid nodules compared to EH patients. Therefore, the screening of thyroid function and thyroid nodules may be indispensable for PA patients.

Cogent integration of inflammatory biomarkers and perioperative complications of thyroid surgery in thyroidology.

OBJECTIVE: Back to the sources, postoperative nausea and vomiting, hypo- and hypertension, heart rate alterations, and hypoxemia due to laryngospasm might be considered perioperative complications. METHODS: This cross-sectional study was conducted at an Education and Research Hospital between January 2018 and June 2023. The study included a total of 437 cases of thyroid surgery. The demographic data such as age, sex, co-morbidities of the instances, hypotension, hypertension, bradycardia, hypoxemia, and postoperative nausea and vomiting, as well as laboratory data were obtained and analyzed. RESULTS: Of 437 cases, 334 (76%) were females and 103 (24%) were males, with a mean age of 51.83±11.91 years and 55.32±11.87 years, respectively. No statistical significance was realized between the complications, co-morbid diseases, and age. Notably, no liaison between the complications after awakening from the anesthesia and preoperative laboratory parameters was discerned. However, a high but no significant relationship was revealed between the platelet-to-lymphocyte ratio (P/L) in cases with hypoxemia and hypotension. Finally, no significance between laboratory values, bradycardia, hypertension, and postoperative nausea and vomiting was distinguished. CONCLUSION: We postulate that the so-called inflammatory biomarkers measured at the time of preoperative examination in the blood count concept selectively do not enrich for anticipating complications that arise in the perioperative echelon.

Association Between Long-Term Exposure to Environmental Fine Particulate Matter and the Prevalence of Thyroid Disorders: A National Cross-Sectional Study in China.

Background: Exposure to particles with an aerodynamic diameter of ≤2.5 µm (PM2.5) is associated with the occurrence of thyroid dysfunction among pregnant women and neonates, but it is not known if this association occurs in the general population. We aimed to determine the association of prolonged exposure to PM2.5 with the prevalence of thyroid disorders among adults in China. Methods: A nationally representative cross-sectional study of thyroid disorders, iodine status, and diabetes status was carried out in all 31 provinces across China from 2015 to 2017. In total, 73,900 adults aged 18 years and older were included. Serum concentrations of thyroid hormones, thyrotropin, and thyroid antibodies and the urine iodine concentration were measured. The environmental concentration of PM2.5 for each participant's residential address at a spatial resolution of 1 × 1 km was estimated. Results: The average long-term exposure to PM2.5 at residential addresses was 66.41 µg/m3, ranging from 17.58 µg/m3 to 120.40 µg/m3. Compared with that of individuals with lower exposure levels, the prevalence of thyroid diseases such as autoimmune thyroiditis and subclinical hypothyroidism was greater in those with PM2.5 concentrations within the third quartile range (60.18 to 73.78 µg/m3). Compared with those in the first quartile (17.58 to 46.38 µg/m3), participants in the highest PM2.5 quartile (73.78 to 120.40 µg/m3) presented an increased risk of overt hypothyroidism (OR 1.23 [CI 0.94-1.61]), subclinical hypothyroidism (1.10 [1.01-1.21]), autoimmune thyroiditis (1.09 [1.00-1.18]), and thyroglobulin antibody positivity (1.17 [1.07-1.29]). However, there was no association between PM2.5 exposure and overt hyperthyroidism, subclinical hyperthyroidism, Graves' disease, or thyroid peroxidase antibody positivity (p > 0.05). Each 10 µg/m³ increase in the PM2.5 concentration was associated with an increased risk of overt hypothyroidism (OR 1.05 [1.00-1.11]), subclinical hypothyroidism (1.02 [1.00-1.03]), and thyroglobulin antibody positivity (1.02 [1.00-1.04]). Furthermore, a nearly linear exposure-response relationship was observed between long-term PM2.5 exposure and thyroglobulin antibody positivity. Conclusions: PM2.5 exposure was associated with thyroid disorders among Chinese adults. A dose-response relationship between PM2.5 exposure and autoimmune thyroiditis, as well as thyroglobulin antibody positivity, was also observed.

Testing for a causal role of thyroid hormone measurements within the normal range on human metabolism and diseases: a systematic Mendelian randomization.

BACKGROUND: Variation in thyroid function parameters within the normal range has been observationally associated with adverse health outcomes. Whether those associations reflect causal effects is largely unknown. METHODS: We systematically tested associations between genetic differences in thyrotropin (TSH) and free thyroxine (FT4) within the normal range and more than 1100 diseases and more than 6000 molecular traits (metabolites and proteins) in three large population-based cohorts. This was performed by combining individual and summary level genetic data and using polygenic scores and Mendelian randomization (MR) methods. We performed a phenome-wide MR study in the OpenGWAS database covering thousands of complex phenotypes and diseases. FINDINGS: Genetically predicted TSH or FT4 levels within the normal range were predominately associated with thyroid-related outcomes, like goitre. The few extra-thyroidal outcomes that were found to be associated with genetic liability towards high but normal TSH levels included atrial fibrillation (odds ratio = 0.92, p-value = 2.13 × 10-3), thyroid cancer (odds ratio = 0.57, p-value = 2.97 × 10-4), and specific biomarkers, such as sex hormone binding globulin (ß = -0.046, p-value = 1.33 × 10-6) and total cholesterol (ß = 0.027, p-value = 5.80 × 10-3). INTERPRETATION: In contrast to previous studies that have described the association with thyroid hormone levels and disease outcomes, our genetic approach finds little evidence of an association between genetic differences in thyroid function within the normal range and non-thyroidal phenotypes. The association described in previous studies may be explained by reverse causation and confounding. FUNDING: This research was funded by the Swiss National Science Foundation (P1BEP3_200041). The Fenland study (DOI 10.22025/2017.10.101.00001) is funded by the Medical Research Council (MC_UU_12015/1, MC_PC_13046 and MC_UU_00006/1). The EPIC-Norfolk study (DOI 10.22025/2019.10.105.00004) has received funding from the Medical Research Council (MR/N003284/1, MC-UU_12015/1, MC_PC_13048 and MC_UU_00006/1).

Clinical value of complete blood count ratio in benign and malignant thyroid diseases.

OBJECTIVE: To investigate the clinical value of blood routine derivative biomarkers and thyroid function biomarkers in differentiating different thyroid diseases. METHODS: The differences of blood routine derived indexes neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), platelet-large cell rate (P-LCR) and thyroid function indexes between benign and malignant thyroid diseases were compared, and the differences of each index between different benign thyroid diseases were further compared. Univariate regression analysis model was used to analyze the clinical value of various indexes. Receiver operating characteristic curve (ROC) was used to calculate the area under the curve (AUC). RESULTS: There were statistically significant differences in PLR, NLR and P-LCR between patients with benign and malignant thyroid diseases (P < 0.05 for each). The results of univariate logistic regression analysis showed that P < 0.05 for all indicators except LMR, when PLR and NLR value increased by 1, the risk of thyroid malignancy decreased by 1 % and 21 %, when P-LCR value increased by 1, the risk of thyroid malignancy increased by 4 %. CONCLUSIONS: PLR, NLR and P-LCR are helpful to distinguish different benign thyroid diseases and to diagnose benign and malignant thyroid diseases.

Development and Validation of a Prediction Model for Thyroid Dysfunction in Patients During Immunotherapy.

OBJECTIVE: This study was designed to develop and validate a predictive model for assessing the risk of thyroid toxicity following treatment with immune checkpoint inhibitors. METHODS: A retrospective analysis was conducted on a cohort of 586 patients diagnosed with malignant tumors who received programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors. The patients were randomly divided into training and validation cohorts in a 7:3 ratio. Logistic regression analyses were performed on the training set to identify risk factors of thyroid dysfunction, and a nomogram was developed based on these findings. Internal validation was performed using K-fold cross-validation on the validation set. The performance of the nomogram was assessed in terms of discrimination and calibration. Additionally, decision curve analysis was utilized to demonstrate the decision efficiency of the model. RESULTS: Our clinical prediction model consisted of 4 independent predictors of thyroid immune-related adverse events, namely baseline thyrotropin (TSH, OR = 1.427, 95%CI:1.163-1.876), baseline thyroglobulin antibody (TgAb, OR = 1.105, 95%CI:1.035-1.180), baseline thyroid peroxidase antibody (TPOAb, OR = 1.172, 95%CI:1.110-1.237), and baseline platelet count (platelet, OR = 1.004, 95%CI:1.000-1.007). The developed nomogram achieved excellent discrimination with an area under the curve of 0.863 (95%CI: 0.817-0.909) and 0.885 (95%CI: 0.827-0.944) in the training and internal validation cohorts respectively. Calibration curves exhibited a good fit, and the decision curve indicated favorable clinical benefits. CONCLUSION: The proposed nomogram serves as an effective and intuitive tool for predicting the risk of thyroid immune-related adverse events, facilitating clinicians making individualized decisions based on patient-specific information.

Defining Gestational Thyroid Dysfunction Through Modified Nonpregnancy Reference Intervals: An Individual Participant Meta-analysis.

BACKGROUND: Establishing local trimester-specific reference intervals for gestational TSH and free T4 (FT4) is often not feasible, necessitating alternative strategies. We aimed to systematically quantify the diagnostic performance of standardized modifications of center-specific nonpregnancy reference intervals as compared to trimester-specific reference intervals. METHODS: We included prospective cohorts participating in the Consortium on Thyroid and Pregnancy. After relevant exclusions, reference intervals were calculated per cohort in thyroperoxidase antibody-negative women. Modifications to the nonpregnancy reference intervals included an absolute modification (per .1 mU/L TSH or 1 pmol/L free T4), relative modification (in steps of 5%) and fixed limits (upper TSH limit between 3.0 and 4.5 mU/L and lower FT4 limit 5-15 pmol/L). We compared (sub)clinical hypothyroidism prevalence, sensitivity, and positive predictive value (PPV) of these methodologies with population-based trimester-specific reference intervals. RESULTS: The final study population comprised 52 496 participants in 18 cohorts. Optimal modifications of standard reference intervals to diagnose gestational overt hypothyroidism were -5% for the upper limit of TSH and +5% for the lower limit of FT4 (sensitivity, .70, CI, 0.47-0.86; PPV, 0.64, CI, 0.54-0.74). For subclinical hypothyroidism, these were -20% for the upper limit of TSH and -15% for the lower limit of FT4 (sensitivity, 0.91; CI, 0.67-0.98; PPV, 0.71, CI, 0.58-0.80). Absolute and fixed modifications yielded similar results. CIs were wide, limiting generalizability. CONCLUSION: We could not identify modifications of nonpregnancy TSH and FT4 reference intervals that would enable centers to adequately approximate trimester-specific reference intervals. Future efforts should be turned toward studying the meaningfulness of trimester-specific reference intervals and risk-based decision limits.

Mass spectrometry in measurement of thyroid biomarkers.

In 2022, the number of patients with thyroid disease in China exceeded 200 million (10 million with hyperthyroidism, 90 million with hypothyroidism, and 100 million with other thyroid disease such as goiter, thyroid nodules, and thyroid cancer). Well-established markers include FT3, FT4, TT3, TT4, and TSH tested by a number of immunoassay methods. This approach is based on the primary binding of antigen with antibody and a subsequent secondary chemical reaction that provides an indirect measure. The use of traceable standards for quantitation remains an important factor to ensure inter-assay reliability and precision. Recently, mass spectrometry (MS) has received considerable attention as an analytic tool due to high resolution and quantitative accuracy. In addition, MS allows for sensitive determination of low-abundance markers making it ideal for development of traceable standards. Furthermore, this technology will allow for the development of highly accurate thyroid biomarker assays to facilitate diagnosis, enable early treatment and improve outcomes. Herein, we provide a systematic review and summary of MS in enhancing the analysis of thyroid biomarkers.

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.

Towards Personalized TSH Reference Ranges: A Genetic and Population-Based Approach in Three Independent Cohorts.

Background: Serum thyroid-stimulating hormone (TSH) measurement is the diagnostic cornerstone for primary thyroid dysfunction. There is high inter-individual but limited intra-individual variation in TSH concentrations, largely due to genetic factors. The currently used wide population-based reference intervals may lead to inappropriate management decisions. Methods: A polygenic score (PGS) including 59 genetic variants was used to calculate genetically determined TSH reference ranges in a thyroid disease-free cohort (n = 6,834). Its effect on reclassification of diagnoses was investigated when compared to using population-based reference ranges. Next, results were validated in a second independent population-based thyroid disease-free cohort (n = 3,800). Potential clinical implications were assessed in a third independent population-based cohort including individuals without thyroid disease (n = 26,321) as well as individuals on levothyroxine (LT4) treatment (n = 1,132). Results: PGS was a much stronger predictor of individual TSH concentrations than FT4 (total variance in TSH concentrations explained 9.2-11.1% vs. 2.4-2.7%, respectively) or any other nongenetic factor (total variance in TSH concentrations explained 0.2-1.8%). Genetically determined TSH reference ranges differed significantly between PGS quartiles in all cohorts, while the differences in FT4 concentrations were absent or only minor. Up to 24.7-30.1% of individuals, previously classified as having subclinical hypo- and hyperthyroidism when using population-based TSH reference ranges, were reclassified as euthyroid when genetically determined TSH reference ranges were applied. Individuals in the higher PGS quartiles had a higher probability of being prescribed LT4 treatment compared to individuals from the lower PGS quartiles (3.3% in Q1 vs. 5.2% in Q4, Pfor trend =1.7 × 10-8). Conclusions: Individual genetic profiles have the potential to personalize TSH reference ranges, with large effects on reclassification of diagnosis and LT4 prescriptions. As the currently used PGS can only predict approximately 10% of inter-individual variation in TSH concentrations, it should be further improved when more genetic variants determining TSH concentrations are identified in future studies.

Association of circulating vitamin levels with thyroid diseases: a Mendelian randomization study.

Background: Previous observational studies have shown conflicting results of vitamins supplementation for thyroid diseases. The causal relationships between vitamins and thyroid diseases are unclear. Therefore, we conducted a two-sample bidirectional Mendelian randomization (MR) study to explore association of circulating vitamin levels with thyroid diseases. Methods: We performed a bidirectional MR analysis using genome-wide association study (GWAS) data. Genetic tool variables for circulating vitamin levels include vitamins A, B9, B12, C, D, and E, Genetic tool variables of thyroid diseases include autoimmune hyperthyroidism, autoimmune hypothyroidism, thyroid nodules (TNs), and Thyroid cancer (TC). Inverse-variance weighted multiplicative random effects (IVW-RE) was mainly used for MR Analysis, weighted median (WM) and MR Egger were used as supplementary methods to evaluate the relationships between circulating vitamin levels and thyroid diseases. Sensitivity and pluripotency were evaluated by Cochran's Q test, MR-PRESSO, Radial MR, MR-Egger regression and leave-one-out analysis. Results: Positive MR evidence suggested that circulating vitamin C level is a protective factor in autoimmune hypothyroidism (ORIVW-RE=0.69, 95%CI: 0.58-0.83, p = 1.05E-04). Reverse MR Evidence showed that genetic susceptibility to autoimmune hyperthyroidism is associated with reduced level of circulating vitamin A(ORIVW-RE = 0.97, 95% CI: 0.95-1.00, p = 4.38E-02), genetic susceptibility of TNs was associated with an increased level of circulating vitamin D (ORIVW-RE = 1.02, 95% CI: 1.00-1.03, p = 6.86E-03). No causal and reverse causal relationship was detected between other circulating vitamin levels and thyroid diseases. Conclusion: Our findings provide genetic evidence supporting a bi-directional causal relationship between circulating vitamin levels and thyroid diseases. These findings provide information for the clinical application of vitamins prevention and treatment of thyroid diseases.

Routine screening serum tests to detect underlying thyroid and autoimmune diseases in patients with moyamoya disease.

BACKGROUND: Recent studies have revealed that thyroid and autoimmune diseases may be associated with sporadic moyamoya disease. However, whether routine screening serum tests to detect these underlying diseases are useful or not remains unclear. METHODS: We retrospectively evaluated 459 patients with moyamoya disease but without previous history of thyroid or autoimmune diseases who underwent the screening serum tests targeting thyroid and autoimmune diseases from 2016 to 2023 in our institute. The number of patients who were diagnosed as thyroid or autoimmune diseases after these tests were investigated. RESULTS: Among the patients who were screened, 237 (42.6 %) patients had abnormal results for some factors, such as thyroid hormones or autoantibodies. After consultation with endocrinologists or rheumatologists, 27 (5.9 %) patients were newly diagnosed with thyroid diseases, including six (1.3 %) patients with Graves' disease, 19 (4.1 %) patients with Hashimoto thyroiditis and two (0.4 %) patients with other thyroid diseases; however, none of the patients were diagnosed with nonthyroidal autoimmune diseases, such as Sjogren's syndrome, antiphospholipid syndrome, or rheumatoid arthritis, listed as moyamoya-related diseases and targeted by our screening serum tests. Patients with newly diagnosed underlying diseases were more likely to be female compared to patients without new diagnosis (96.3 % vs. 72.2 %, p = 0.03). CONCLUSION: Routine thyroid-related serum screening may be clinically meaningful in patients with moyamoya disease to detect occult thyroid diseases, especially in female patients. However, routine serum screening tests targeting other autoimmune diseases are not recommended unless the patients have equivalent symptoms.

A class-imbalanced hybrid learning strategy based on Raman spectroscopy of serum samples for the diagnosis of hepatitis B, hepatitis A, and thyroid dysfunction.

Computer-aided vibrational spectroscopy detection technology has achieved promising results in the field of early disease diagnosis. Yet limited by factors such as the number of actual samples and the cost of spectral acquisition in clinical medicine, the data available for model training are insufficient, and the amount of data varies greatly between different diseases, which constrain the performance optimization and enhancement of the diagnostic model. In this study, vibrational spectroscopy data of three common diseases are selected as research objects, and experimental research is conducted around the class imbalance situation that exists in medical data. When dealing with the challenge of class imbalance in medical vibrational spectroscopy research, it no longer relies on some kind of independent and single method, but considers the combined effect of multiple strategies. SVM, K-Nearest Neighbor (KNN), and Decision Tree (DT) are used as baseline comparison models on Raman spectroscopy medical datasets with different imbalance rates. The performance of the three strategies, Ensemble Learning, Feature Extraction, and Resampling, is verified on the class imbalance dataset by G-mean and AUC metrics, respectively. The results show that all the above three methods mitigate the negative impact caused by unbalanced learning. Based on this, we propose a hybrid ensemble classifier (HEC) that integrates resampling, feature extraction, and ensemble learning to verify the effectiveness of the hybrid learning strategy in solving the class imbalance problem. The G-mean and AUC values of the HEC method are 82.7 % and 83.12 % for the HBV dataset, is 2.02 % and 1.98 % higher than the optimal strategy; 83.62 % and 83.76 % for the HCV dataset, is 9.79 % and 8.47 % higher than the optimal strategy; while for the thyroid dysfunction dataset are 77.56 % and 77.85 %, is 6.92 % and 6.36 % higher than that of the optimal strategy, respectively. The experimental results show that the G-mean and AUC metrics of the HEC method are higher than those of the baseline classifier as well as the optimal combination using separate strategies. It can be seen that the HEC method can effectively counteract the unfavorable effects of imbalance learning and is expected to be applied to a wider range of imbalance scenarios.

Thyroid function spectrum in Cushing's syndrome.

PURPOSE: Thyroid disorders have been reported in hypercortisolism patients. Endogenous Cushing's syndrome (CS) potentially complicates its metabolic sequelae. We investigated thyroid function in CS patients to determine this relationship. METHODS: In this cross-sectional study, we screened CS patients from 2016 to 2019 at our hospital. Patient demographic, medical history, and laboratory data were collected. Additionally, we performed a meta-analysis to demonstrate the prevalence of thyroid dysfunction in patients with CS. RESULTS: Among 129 CS patients, 48.6% had triiodothyronine (TT3), 27.9% had thyroxine (TT4), 24.6% had free T3 (FT3), 27.7% had free T4 (FT4), and 6.2% had thyroid-stimulating hormone (TSH) levels below the reference values. Those with clinical CS showed more pronounced thyroid suppression than did those with subclinical CS. Cortisol levels were markedly greater in patients with pituitary hypothyroidism (P < 0.001). Serum cortisol levels throughout the day and post low-dose dexamethasone-suppression test (LDDST) results correlated with thyroid hormone levels, particularly in ACTH-independent CS. Correlations varied by thyroid status; FT3 and TSH were linked to cortisol in euthyroid individuals but not in those with low T3 or central hypothyroidism. TSH levels notably halved from the lowest to highest cortisol tertile post-LDDST. Finally, meta-analysis showed 22.7% (95% CI 12.6%-32.9%) central hypothyroidism in 528 CS patients of nine studies. CONCLUSION: Thyroid hormone levels are significantly correlated with cortisol levels and are impaired in patients with CS. However, the physiological adaptation and pathological conditions need further study.