GWAS of thyroid stimulating hormone highlights pleiotropic effects and inverse association with thyroid cancer

New therapeutic targets and mechanisms of papillary thyroid carcinoma identified by multi-omics analysis

INTRODUCTION

The treatment of papillary thyroid carcinoma (PTC) presents ongoing challenges, underscoring the need for novel therapeutic targets.

METHODS

This study employed proteomic MR analysis, utilizing publicly available data from genome-wide association studies (GWAS) and protein quantitative trait loci (pQTL) studies. We analyzed proteomic data from deCODE and the UK Biobank Protein Project (UKB-PP), along with GWAS data on papillary thyroid carcinoma (PTC) from the Finnish Consortium. This analysis was further supported by eQTL validation and bioinformatics differential analysis to identify potential therapeutic targets for PTC. Additionally, we explored possible downstream mechanisms of the target proteins through mediation analysis.

RESULTS

Our analysis identified two potential therapeutic targets associated with PTC, specifically, LY75 and S100A12. Mediation analysis further investigated their potential mechanistic role in the pathogenesis of PTC.

CONCLUSION

Through multi-omics analysis, we identified new potential therapeutic targets for papillary thyroid carcinoma and investigated their possible underlying mechanisms affecting PTC.

Multiomic Landscape of Primary Hypothyroidism Induced by Subchronic Exposure to Low-Dose Novel PFOS Substitute OBS in Human and Murine Models

Sodium p-perfluorous nonenoxybenzenesulfonate (OBS) as a novel surrogate for perfluorooctanesulfonate (PFOS) has been extensively utilized in industrial manufacturing and daily life. However, studies on OBS-induced environmental health risks of obstructive biosynthesis (OBS) are currently limited, particularly the risk for thyroid diseases. Following the construction of in vivo (mouse) and in vitro (normal human primary thyrocytes) models of subchronic low-dose OBS exposure, we explored the thyroid-disrupting effects of OBS through multiomics approaches and experimental validations. Our results showed that subchronic exposure to low doses of OBS led to primary hypothyroidism in mice, presenting with reduced number and functional abnormalities of thyrocytes. Further in vitro assays confirmed that low-dose OBS-induced disulfidptosis, a newly discovered form of programmed cell death, in human primary thyrocytes. Meanwhile, exposure to low-dose OBS remarkably suppressed thyroid hormone synthesis pathways in mouse and human thyrocytes. The charted multiomic landscape of OBS-induced primary hypothyroidism in mammals revealed the thyroid toxicity and endocrine-disrupting properties of OBS, suggesting that it is not a safe alternative to PFOS.

Causal associations between thyroid function and sarcopenia-related traits: a Mendelian randomization study

BACKGROUND AND OBJECTIVE

As the global population ages, the incidence of sarcopenia increases, resulting in increasing numbers of patients with impairments in physical function. Thyroid function disorders may contribute to the pathogenesis of sarcopenia. This study aimed to establish a causal relationship between thyroid hormones (TH) and sarcopenia using a two-sample Mendelian randomization (MR) analysis method.

STUDY DESIGN

A two-sample MR study was conducted using summary-level data from genome-wide association studies (GWAS) which included publicly available pooled statistics for thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and the FT3 to FT4 ratio from the Thyroidomics Consortium, as well as summary statistics for sarcopenia-related traits, such as appendicular lean mass (ALM), whole-body lean mass (WBLM), grip strength (left and right), and walking pace from the UK Biobank. The MR analysis used genetic exposure tools for assessment of thyroid function (TSH, FT4, FT3, and the FT3 to FT4 ratio) and outcome measures for sarcopenia (ALM, WBLM, grip strength, and walking pace). The inverse variance weighted method was employed to estimate the genetic predictions of the causal effect of thyroid function on sarcopenia risk. Sensitivity analyses were also conducted to validate the reliability of the MR results.

RESULTS

Correlations were observed between ALM and several indicators, as follows: TSH (OR: 1.03; 95% CI: 1.01-1.04), FT4 (OR: 0.95; 95% CI: 0.93-0.98), FT3 (OR: 1.09; 95% CI: 1.03-1.15), and the FT3 to FT4 ratio (OR: 1.25; 95% CI: 1.11-1.42). Furthermore, causal relationships were identified between WBLM and TSH (OR: 1.02; 95% CI: 1.01-1.03), as well as low TSH (OR: 0.99; 95% CI: 0.99-1.00) and high TSH (OR: 0.97; 95% CI: 0.96-1.00). Walking pace was associated with low TSH (OR: 0.99; 95% CI: 0.99-1.00), whereas grip strength was related to TSH (OR: 1.01; 95% CI: 1.00-1.02) and low TSH (OR: 0.99; 95% CI: 0.99-1.00). High TSH (OR: 1.04; 95% CI: 1.01-1.08) and FT3 (OR: 0.96; 95% CI: 0.92-1.00) levels were associated with right grip strength.

CONCLUSION

These results indicate a causal relationship between thyroid function and sarcopenia, highlighting FT3 and the FT3 to FT4 ratio as key indicators. However, total triiodothyronine (TT3) emerges as a potential indicator that requires further investigation in future studies.

Thyroid function and multiple sclerosis: a two-sample mendelian randomization study and mediation analysis

Multiple sclerosis (MS) is a prevalent neurological disorder with a complex etiology, often associated with thyroid function. However, the causal relationship between these two conditions remains poorly understood. This study aimed to elucidate the causal relationship between thyroid function and MS using a bidirectional Mendelian randomization (MR) approach and to investigate the potential mediating role of immune cells. We conducted a two-sample MR analysis using summary statistics from large-scale genome-wide association studies (GWAS). We included results from sensitivity tests such as MR-Egger, weighted median, and leave-one-out analyses to support the robustness and reliability of the findings. The inverse variance-weighted (IVW) method was the primary approach, with sensitivity analyses conducted using seven additional MR methods. Furthermore, multivariable MR and mediation analysis were conducted to uncover potential mediating immune cells underlying the observed associations. The MR analysis showed that Hypothyroidism and elevated Thyroid-Stimulating Hormone (TSH) levels(normal) reduced the risk of MS (P = 0.012, OR (95%CI) :0.914(0.851, 0.98); P = 0.020, OR (95%CI) :0.88(0.789, 0.98)). Free thyroxine (FT4) increased the risk of MS (P = 0.020, OR (95%CI) :1.268(1.051, 1.53)). Mediation analysis showed evidence of indirect effect of FT4 on MS through "HLA DR on CD33br HLA DR + CD14" and "IgD- CD27- %B cell" with a mediated proportion of 39.16% (positive effect), 78.53% (reverse effect) of the total effect. This study provided genetic evidence that FT4 may increase the risk of developing MS. "HLA DR on CD33br HLA DR + CD14" and "IgD- CD27- %B cell", mediated the causal relationship between thyroid function and MS, highlighting the importance of further investigating their roles in these conditions.

Strength of Genetic Associations with Thyrotropin Values Differs Between Populations with Similarity to African and European Reference Populations

Background: Epidemiological data suggest the population distribution of thyrotropin (TSH) values is shifted toward lower values in self-identified Black non-Hispanic individuals compared with self-identified White non-Hispanic individuals. It is unknown whether genetic differences between individuals with genetic similarities to African reference populations (GSA) and those with similarities to European reference populations (GSE) contribute to these observed differences. We aimed to compare genome-wide associations with TSH and putative causal TSH-associated variants between GSA and GSE groups. Methods: We performed genome-wide association studies (GWAS) in 9827 GSA individuals and 9827 GSE individuals with TSH values between 0.45 and 4.5 mU/L. We compared effect sizes and allele frequencies of previously reported putative causal TSH-associated variants and our power to detect associations with these variants between the two groups. We additionally focused on variants in PDE8B and PDE10A, loci that have been most strongly associated with TSH in previous GWAS in GSE populations. Results: Four loci attained genome-wide significance in the GSA group compared with seven in the GSE group. PDE8B was not significantly associated with TSH in the GSA group, despite its strong association in the GSE group. Eight putative causal variants had significantly different effect sizes between groups. There was ≥80% power in the GSA group to detect significant associations with variants in PDE8B, PDE10A, NFIA, and LOC105377480, with higher expected power than in the GSE group for variants in PDE8B, NFIA, and LOC105377480 and similar power for other variants in PDE8B and PDE10A. No additional putative causal variants in PDE8B and PDE10A had effect sizes that differed significantly between the groups; power to identify associations with additional putative causal variants in PDE8B and PDE10A was similar between the groups. Conclusions: Patterns of genetic associations with TSH differed between identically sized GSA and GSE groups. Failure to replicate the strongest associations previously reported in GSE individuals in our GSA population was not fully explained by differences in allele frequencies or power, assuming similar effect sizes. Larger GSA population GWAS are necessary to confirm our findings and further investigate the contribution of genetic factors to population differences in the distribution of TSH values.

Illness anxiety, infertility stress, resilience and thyroid-stimulating hormone among infertile people undergoing ART treatment in China

OBJECTIVE

Infertile people undergoing assisted reproductive technology (ART) treatment in China may experience severe infertility-related stress and illness anxiety (IA). However, little relevant research has been conducted until now.

DESIGN

This study investigated the IA of 340 infertile people undergoing ART treatment, including 43 males, 292 females and 5 who preferred not to answer, in 2 tertiary general public hospitals in Wen Zhou, China.

MAIN OUTCOME MEASURES

Blood samples for thyroid-stimulating hormone (TSH) levels were obtained from 107 women to explore the relationship between IA and TSH. The questionnaire contained the Mandarin version of the Fertility Problem Inventory, the Resilient Trait Scale for Chinese Adults and the Whiteley Index, measuring infertility stress, resilience and IA, respectively.

RESULTS

An incidence rate of 44.1% of IA among infertile people undergoing ART treatment in China was determined, and 30.2% of men and 46.6% of women had severe IA (χ2 = 4.05, p < 0.05). The risk of severe IA in women was around twice that in men (OR = 2.01, 95% CI: 1.01-4.01). Women's IA level was significantly associated with their TSH level (β = 0.27, p < 0.01). Resilience played a moderating role in the relationship between parenthood importance and illness anxiety.

CONCLUSION

This study highlighted the importance and urgency of providing holistic care for illness anxiety of infertile people undergoing ART treatment in China, especially women. The findings of this study indicated that mind-body therapies and resilience empowerment workshops could be conducive to infertile people's holistic health.

THSR Mediated MiR374b Targeting C/EBP β/FOXO1 to Accelerate Thyroid Stimulating Hormone-Induced Hepatic Steatosis

Purpose

Thyroid-stimulating hormone (TSH) has been identified as an independent risk factor for non-alcoholic fatty liver disease (NAFLD), TSH binds to the TSH receptor (TSHR) to exert its function. However, the underlying mechanisms by which TSHR influences NAFLD development remain unclear. This study investigates the role of miR374b in NAFLD progression.

Methods

Firstly, a rat model of non-alcoholic fatty liver was constructed and divided into a normal group and a model group. The liver tissue pathology and fat accumulation were detected by Oil Red O staining and hematoxylin-eosin staining. Western blot and Real time PCR were used to detect for the impact of TSHR/miR-374b/C/EBP β/ FoxO1 pathway in the NAFLD model, and the expression of relevant inflammatory factors in each group was detected by ELISA assay. A NAFLD cell model was constructed using HepG2 cells, TSHR overexpression and interference, combined with miR-374b inhibitor and mimics, were transfected simultaneously to demonstrate TSHR/miR-374b/C/EBP β/ The mechanism of FoxO1 adipogenesis in vitro.

Results

TSHR stimulates miR374b secretion in human liver cancer cells (HepG2) and promotes lipid accumulation in the liver. Deficiency of miR374b in HepG2 cells attenuated NAFLD progression. Mechanistically, TSH increases miR374b expression, which then suppresses the transcription of its target genes, CCAAT/enhancer binding protein-b (C/EBP β) and Forkhead Box Protein O1 (FOXO1). This suppression influences the expression of downstream lipid metabolism proteins, including PPARγ, SREBP2, and SREBP1c. Additionally, miR374b directly targets the 3'UTR of C/EBP β and FOXO1, establishing a negative feedback loop in lipid metabolism.

Conclusion

These findings suggest that TSHR-induced upregulation of miR374b accelerates NAFLD progression by modulating lipid metabolism pathways through C/EBP β and FOXO1.

Mapping biological influences on the human plasma proteome beyond the genome

Broad-capture proteomic platforms now enable simultaneous assessment of thousands of plasma proteins, but most of these are not actively secreted and their origins are largely unknown. Here we integrate genomic with deep phenomic information to identify modifiable and non-modifiable factors associated with 4,775 plasma proteins in ~8,000 mostly healthy individuals. We create a data-driven map of biological influences on the human plasma proteome and demonstrate segregation of proteins into clusters based on major explanatory factors. For over a third (N = 1,575) of protein targets, joint genetic and non-genetic factors explain 10-77% of the variation in plasma (median 19.88%, interquartile range 14.01-31.09%), independent of technical factors (median 2.48%, interquartile range 0.78-6.41%). Together with genetically anchored causal inference methods, our map highlights potential causal associations between modifiable risk factors and plasma proteins for hundreds of protein-disease associations, for example, COL6A3, which possibly mediates the association between reduced kidney function and cardiovascular disease. We provide a map of biological and technical influences on the human plasma proteome to help contextualize findings from proteomic studies.

Application Value of Iodine-131 Combined with Levothyroxine Sodium in Patients with Differentiated Thyroid Cancer after Surgery

INTRODUCTION

This study aimed to evaluate the clinical value of iodine-131 combined with levothyroxine sodium in the treatment of patients with differentiated thyroid cancer (DTC) after surgery.

METHODS

Prospective randomized controlled studies were conducted. A total of 374 DTC patients who underwent total or near-total thyroidectomy in the Department of Thyroid Surgery, Tianjin Union Medical Center and Tianjin Medical University General Hospital, from January 2019 to February 2022 were selected and divided into control group (187 cases) and observation group (187 cases) according to random number table method. The control group was treated with levothyroxine sodium after surgery, and the observation group was treated with iodine-131 on the basis of the control group. Gender, age, course of disease, tumor diameter, pathological type, TNM classification, treatment effect, thyroglobulin (Tg) levels before and after treatment, SF-36 health status questionnaires (SF-36), occurrence of adverse reactions after treatment, and recurrence rate of 1-year follow-up were compared and analyzed between the two groups.

RESULTS

There was no significant difference in baseline data between the two groups. After treatment, the effective rate of the observation group increased by 11.23% compared to the control group, with a statistically significant difference (91.98% vs. 80.75%, p < 0.05). There was no significant difference in Tg level and scores of SF-36 evaluation including physical functioning, physical problems, vitality, pain, mental health, emotional problems, social functioning, and general health perception between the two groups before surgery (p > 0.05), Tg levels and scores of SF-36 evaluation in all dimensions were significantly improved in both groups after treatment (p < 0.05), and the levels of Tg and scores of SF-36 in all dimensions in observation group were significantly better than those in control group after treatment (p < 0.001). There was no significant difference in the incidence of adverse reactions between the two groups (p > 0.05). The recurrence rate in the observation group was 5.89% lower than that in the control group 1 year after treatment, with a statistically significant difference (2.67% vs. 8.56%, p < 0.05).

CONCLUSIONS

The combination of iodine-131 and levothyroxine sodium in the postoperative treatment of DTC can improve the therapeutic effect and reduce the postoperative recurrence rate without increasing adverse reactions, which is worthy of clinical reference and promotion.

Genome-wide association studies of thyroid-related hormones, dysfunction, and autoimmunity among 85,421 Chinese pregnancies

Maintaining normal thyroid function is crucial in pregnancy, yet thyroid dysfunction and the presence of thyroid peroxidase antibodies (TPOAb) affect 0.5% to 18% of pregnant women. Here, we conducted a genome-wide association study (GWAS) of eight thyroid traits, including two thyroid-related hormones, four thyroid dysfunctions, and two thyroid autoimmunity measurements among 85,421 Chinese pregnant women to investigate the genetic basis of thyroid function during pregnancy. Our study identified 176 genetic loci, including 125 previously unknown genome-wide associations. Joint epidemiological and Mendelian randomization analyses revealed significant associations between the gestational thyroid phenotypes and gestational complications, birth outcomes, and later-age health outcomes. Specifically, genetically elevated thyroid-stimulating hormone (TSH) levels during pregnancy correlated with lower glycemic levels, reduced blood pressure, and longer gestational duration. Additionally, TPOAb and thyroid functions during pregnancy share genetic correlations with later-age thyroid and cardiac disorders. These findings provide insights into the genetic determinants of thyroid traits during pregnancy, which may lead to new therapeutics, early pre-diagnosis and preventive strategies starting from early adulthood.

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 (β = -0.046, p-value = 1.33 × 10-6) and total cholesterol (β = 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).

Genetics of posttraumatic stress disorder and cardiovascular conditions using Life's Essential 8, Electronic Health Records, and Heart Imaging

BACKGROUND

Patients with post-traumatic stress disorder (PTSD) experience higher risk of adverse cardiovascular (CV) outcomes. This study explores shared loci, and genes between PTSD and CV conditions from three major domains: CV diagnoses from electronic health records (CV-EHR), cardiac and aortic imaging, and CV health behaviors defined in Life's Essential 8 (LE8).

METHODS

We used genome-wide association study (GWAS) of PTSD (N=1,222,882), 246 CV diagnoses based on EHR data from Million Veteran Program (MVP; N=458,061), UK Biobank (UKBB; N=420,531), 82 cardiac and aortic imaging traits (N=26,893), and GWAS of traits defined in the LE8 (N = 282,271 ~ 1,320,016). Shared loci between PTSD and CV conditions were identified using local genetic correlations (rg), and colocalization (shared causal variants). Overlapping genes between PTSD and CV conditions were identified from genetically regulated proteome expression in brain and blood tissues, and subsequently tested to identify functional pathways and gene-drug targets. Epidemiological replication of EHR-CV diagnoses was performed in AllofUS cohort (AoU; N=249,906).

RESULTS

Among the 76 PTSD-susceptibility risk loci, 33 loci exhibited local rg with 45 CV-EHR traits (|rg|≥0.4), four loci with eight heart imaging traits(|rg|≥0.5), and 44 loci with LE8 factors (|rg|≥0.36) in MVP. Among significantly correlated loci, we found shared causal variants (colocalization probability > 80%) between PTSD and 17 CV-EHR (in MVP) at 11 loci in MVP, that also replicated in UKBB and/or other cohorts. Of the 17 traits, the observational analysis in the AoU showed PTSD was associated with 13 CV-EHR traits after accounting for socioeconomic factors and depression diagnosis. PTSD colocalized with eight heart imaging traits on 2 loci and with LE8 factors on 31 loci. Leveraging blood and brain proteome expression, we found 33 and 122 genes, respectively, shared between PTSD and CVD. Blood proteome genes were related to neuronal and immune processes, while the brain proteome genes converged on metabolic and calcium-modulating pathways (FDR p <0.05). Drug repurposing analysis highlighted DRD2, NOS1, GFAP, and POR as common targets of psychiatric and CV drugs.

CONCLUSION

PTSD-CV comorbidities exhibit shared risk loci, and genes involved in tissue-specific regulatory mechanisms.

Uncovering the shared genetic components of thyroid disorders and reproductive health

OBJECTIVE

The aim of the study is to map the shared genetic component and relationships between thyroid and reproductive health traits to improve the understanding of the interplay between those domains.

DESIGN

A large-scale genetic analysis of thyroid traits (hyper- and hypothyroidism, and thyroid-stimulating hormone levels) was conducted in up to 743 088 individuals of European ancestry from various cohorts.

METHODS

We evaluated genetic associations using genome-wide association study (GWAS) meta-analysis, GWAS Catalog lookup, gene prioritization, mouse phenotype lookup, and genetic correlation analysis.

RESULTS

GWAS meta-analysis results for thyroid phenotypes showed that 50 lead variants out of 253 (including 5/52 of the novel hits) were linked to reproductive health in previous literature. Genetic correlation analyses revealed significant correlations between hypothyroidism and reproductive phenotypes. The results showed that 31.9% of thyroid-associated genes also had an impact on reproductive phenotypes, with the most affected functions being related to genitourinary tract issues.

CONCLUSIONS

The study discovers novel genetic loci linked to thyroid phenotypes and highlights the shared genetic determinants between thyroid function and reproductive health, providing evidence for the genetic pleiotropy and shared biological mechanisms between these traits in both sexes.

Investigating the Bidirectional Association of Rheumatoid Arthritis and Thyroid Function: A Methodologic Assessment of Mendelian Randomization

OBJECTIVE

Rheumatoid arthritis (RA) and thyroid dysfunction are frequently observed in the same patient. However, whether they co-occur or exhibit a causal relationship remains uncertain. We aimed to systematically investigate the causal relationship between RA and thyroid function using a large sample and advanced methods.

METHODS

Bidirectional two-sample Mendelian randomization (MR) analysis was performed based on RA and six thyroid function trait data sets from the European population. The robustness of the results was demonstrated using multiple MR methods and a series of sensitivity analyses. Multivariable MR using Bayesian model averaging (MR-BMA) was performed to adjust for possible competing risk factors. A sensitivity data set, which included data from patients with seropositive RA and controls, was used to repeat the analyses. Furthermore, enrichment analysis was employed to discover the underlying mechanism between RA and thyroid functions.

RESULTS

A significantly positive causal effect was identified for RA on autoimmune thyroid disease (AITD) as well as for AITD on RA (P < 0.001). Further sensitivity analyses showed consistent causal estimates from a variety of MR methods. After removing the outliers, MR-BMA results showed that RA and AITD were independent risk factors in their bidirectional causality, even in the presence of other competing risk factors (adjusted P < 0.05). Enrichment analysis showed immune cell activation and immune response play crucial roles in them.

CONCLUSION

Our results illustrate the significant bidirectional causal effect of RA and AITD, which holds even in multiple competing risk factors. Clinical screening for thyroid dysfunction in patients with RA deserves further attention, and vice versa.

No causal associations of genetically predicted birth weight and life course BMI with thyroid function and diseases

OBJECTIVE

Observational studies have suggested associations of birth weight, childhood BMI, and adulthood BMI with thyroid function or diseases. However, the causal relationships remain unclear due to residual confounding inherent in conventional epidemiological studies.

METHODS

We performed a two-sample Mendelian randomization (MR) study to investigate causal relationships of genetically predicted birth weight, childhood BMI, and adulthood BMI with a range of clinically relevant thyroid outcomes. Additionally, we conducted a reverse MR analysis on adulthood BMI. Data on exposures and outcomes were obtained from large-scale genome-wide association study meta-analyses predominantly composed of individuals of European ancestry.

RESULTS

The MR analysis revealed no evidence of causal associations of birth weight or BMI at different life stages with thyrotropin (TSH) levels, hypothyroidism, hyperthyroidism, autoimmune thyroid disorders, or thyroid cancer. Contrarily, thyroid cancer demonstrated a significant causal relationship with increased adulthood BMI (β = 0.010, 95% CI: 0.006-0.015; p = 5.21 × 10-6).

CONCLUSIONS

Our comprehensive MR did not find causal links of birth weight, childhood BMI, or adulthood BMI with thyroid diseases but provided evidence that thyroid cancer may play a role in weight gain. Our research findings offer valuable insights into the intricate relationship between body weight and thyroid health throughout an individual's life.

Periodontitis and thyroid function: A bidirectional Mendelian randomization study

BACKGROUND AND OBJECTIVE

Previous studies suggest interaction between periodontitis and thyroid function, while the causality has not yet been established. We applied the Mendelian randomization (MR) method to assess bidirectional causal association between periodontitis and thyroid-related traits, including free thyroxine (FT4), thyroid stimulating hormone (TSH), hypothyroidism, hyperthyroidism and autoimmune thyroid disease (AITD).

METHODS

Genetic instruments were extracted from large-scale genome-wide association studies on normal-range FT4 (N = 49 269) and TSH (N = 54 288) levels, TSH in full range (N = 119 715); hypothyroidism (discovery/replication cohorts: N = 53 423/334 316), hyperthyroidism (discovery/replication cohorts: N = 51 823/257 552), AITD (N = 755 406) and periodontitis (N = 45 563). Here, the inverse variance weighted (IVW) method was applied as the primary analysis, and robustness of results were assessed by several pleiotropic-robust methods. Results were adjusted for Bonferroni correction thresholds with significant p < .004 (0.05/13) and suggestive p between .004 and .05.

RESULTS

The IVW analysis revealed a suggestively causal linkage between genetic predisposition to periodontitis and the increased risk of hypothyroidism (discovery cohort: odds ratio [OR] = 1.24, 95% confidence interval [CI] = 1.05-1.46, p = .012; replication cohort: OR = 1.06, 95% CI = 1.01-1.11, p = .011). No evidence was found for supporting the impact of periodontitis on hyperthyroidism and AITD risks (associated p ≥ .209), as well as thyroid-related traits on periodontitis risk (associated p ≥ .105). These findings were robust and consistent through sensitivity analysis with other MR models.

CONCLUSION

This bidirectional MR reveals periodontitis should not be attributed to variations in thyroid function but it has potential causal effect on hypothyroidism risk, which provides a better understanding of the relationship between periodontitis and thyroid function, and potential evidence for the clinical intervention of hypothyroidism. Further investigations are warranted to elucidate the nature and underlying mechanisms of this finding.

A polygenic risk score for alcohol-associated cirrhosis among heavy drinkers with European ancestry

BACKGROUND

Polygenic Risk Scores (PRS) based on results from genome-wide association studies offer the prospect of risk stratification for many common and complex diseases. We developed a PRS for alcohol-associated cirrhosis by comparing single-nucleotide polymorphisms among patients with alcohol-associated cirrhosis (ALC) versus drinkers who did not have evidence of liver fibrosis/cirrhosis.

METHODS

Using a data-driven approach, a PRS for ALC was generated using a meta-genome-wide association study of ALC (N=4305) and an independent cohort of heavy drinkers with ALC and without significant liver disease (N=3037). It was validated in 2 additional independent cohorts from the UK Biobank with diagnosed ALC (N=467) and high-risk drinking controls (N=8981) and participants in the Indiana Biobank Liver cohort with alcohol-associated liver disease (N=121) and controls without liver disease (N=3239).

RESULTS

A 20-single-nucleotide polymorphisms PRS for ALC (PRSALC) was generated that stratified risk for ALC comparing the top and bottom deciles of PRS in the 2 validation cohorts (ORs: 2.83 [95% CI: 1.82 -4.39] in UK Biobank; 4.40 [1.56 -12.44] in Indiana Biobank Liver cohort). Furthermore, PRSALC improved the prediction of ALC risk when added to the models of clinically known predictors of ALC risk. It also stratified the risk for metabolic dysfunction -associated steatotic liver disease -cirrhosis (3.94 [2.23 -6.95]) in the Indiana Biobank Liver cohort -based exploratory analysis.

CONCLUSIONS

PRSALC incorporates 20 single-nucleotide polymorphisms, predicts increased risk for ALC, and improves risk stratification for ALC compared with the models that only include clinical risk factors. This new score has the potential for early detection of heavy drinking patients who are at high risk for ALC.

Functional variants in a TTTG microsatellite on 15q26.1 cause familial nonautoimmune thyroid abnormalities

Insufficient thyroid hormone production in newborns is referred to as congenital hypothyroidism. Multinodular goiter (MNG), characterized by an enlarged thyroid gland with multiple nodules, is usually seen in adults and is recognized as a separate disorder from congenital hypothyroidism. Here we performed a linkage analysis of a family with both nongoitrous congenital hypothyroidism and MNG and identified a signal at 15q26.1. Follow-up analyses with whole-genome sequencing and genetic screening in congenital hypothyroidism and MNG cohorts showed that changes in a noncoding TTTG microsatellite on 15q26.1 were frequently observed in congenital hypothyroidism (137 in 989) and MNG (3 in 33) compared with controls (3 in 38,722). Characterization of the noncoding variants with epigenomic data and in vitro experiments suggested that the microsatellite is located in a thyroid-specific transcriptional repressor, and its activity is disrupted by the variants. Collectively, we presented genetic evidence linking nongoitrous congenital hypothyroidism and MNG, providing unique insights into thyroid abnormalities.

Multidimensional data analysis revealed thyroiditis-associated TCF19 SNP rs2073724 as a highly ranked protective variant in thyroid cancer

BACKGROUND

Thyroid cancer represents the most prevalent malignant endocrine tumour, with rising incidence worldwide and high mortality rates among patients exhibiting dedifferentiation and metastasis. Effective biomarkers and therapeutic interventions are warranted in aggressive thyroid malignancies. The transcription factor 19 (TCF19) gene has been implicated in conferring a malignant phenotype in cancers. However, its contribution to thyroid neoplasms remains unclear.

RESULTS

In this study, we performed genome-wide and phenome-wide association studies to identify a potential causal relationship between TCF19 and thyroid cancer. Our analyses revealed significant associations between TCF19 and various autoimmune diseases and human cancers, including cervical cancer and autoimmune thyroiditis, with a particularly robust signal for the deleterious missense variation rs2073724 that is associated with thyroid function, hypothyroidism, and autoimmunity. Furthermore, functional assays and transcriptional profiling in thyroid cancer cells demonstrated that TCF19 regulates important biological processes, especially inflammatory and immune responses. We demonstrated that TCF19 could promote the progression of thyroid cancer in vitro and in vivo and the C>T variant of rs2073724 disrupted TCF19 protein binding to target gene promoters and their expression, thus reversing the effect of TCF19 protein.

CONCLUSIONS

Taken together, these findings implicate TCF19 as a promising therapeutic target in aggressive thyroid malignancies and designate rs2073724 as a causal biomarker warranting further investigation in thyroid cancer.

Impaired thyroid hormone sensitivity increases the risk of papillary thyroid cancer and cervical lymph node metastasis

BACKGROUND

The association of thyroid hormone sensitivity with papillary thyroid carcinoma (PTC) is unclear. This study investigated the relationship between the thyroid hormone sensitivity indices and the risk of PTC and the influence of thyroid hormone sensitivity on the aggressive clinicopathologic features of PTC.

METHODS

This retrospective study recruited 1225 PTC patients and 369 patients with benign nodules undergoing surgery in Zhongshan Hospital in 2020. The thyroid hormone sensitivity indices were thyroid feedback quantile-based index (TFQI), TSH index (TSHI) and thyrotropin thyroxine resistance index (TT4RI). We employed logistic regression models to explore the correlation between the thyroid hormone sensitivity indices and the risk of PTC and its cervical lymph node metastasis (LNM).

RESULTS

PTC patients had significantly higher levels of TSH, TFQI, TSHI and TT4RI compared to the patients with benign nodules, but thyroid hormone levels did not differ significantly between the two groups. Logistic regression analysis revealed that the higher levels of TFQI, TSHI, and TT4RI were associated with an increased risk of PTC after adjustment for multiple risk factors (TFQI: OR = 1.92, 95% CI: 1.39-2.65, P < 0.001; TSHI: OR = 2.33, 95% CI:1.67-3.26, P < 0.001; TT4RI: OR = 2.41, 95% CI:1.73-3.36, P < 0.001). In addition, patients with decreased thyroid hormone sensitivity had a higher risk of cervical LNM in multiple logistic regression analysis (TFQI: OR = 1.38, 95% CI:1.03-1.86, P = 0.03; TSHI: OR = 1.37, 95% CI:1.02-1.84, P = 0.04; TT4RI: OR = 1.41, 95% CI:1.05-1.89, P = 0.02).

CONCLUSION

Impaired sensitivity to thyroid hormone was associated with an increased risk of PTC, and it is also associated with a higher risk of cervical LNM in PTC patients.

Causal relationships between gut microbiota and hypothyroidism: a Mendelian randomization study

BACKGROUND

Previous studies have shown that the gut microbiota plays an important role in the maintenance of thyroid homeostasis. We aimed to evaluate the causal relationships between gut microbiota and hypothyroidism.

METHODS

Summary statistics for 211 gut microbiota taxa were obtained from the largest available genome-wide association study (GWAS) meta-analysis conducted by the MiBioGen consortium. Summary statistics for hypothyroidism were obtained from two distinct sources: the FinnGen consortium R9 release data (40,926 cases and 274,069 controls) and the UK Biobank data (22,687 cases and 440,246 controls), respectively. A two-sample Mendelian randomization (MR) design was employed, and thorough sensitivity analyses were carried out to ensure the reliability of the results.

RESULTS

Based on the FinnGen consortium, we found increased levels of Intestinimonas (OR = 1.09; 95%CI = 1.02-1.16; P = 0.01) and Ruminiclostridium5 (OR = 1.11; 95%CI = 1.02-1.22; P = 0.02) may be associated with a higher risk of hypothyroidism, while increased levels of Butyrivibrio (OR = 0.95; 95%CI = 0.92-0.99; P = 0.02), Eggerthella (OR = 0.93; 95%CI = 0.88-0.98; P = 0.01), Lachnospiraceae UCG008 (OR = 0.92; 95%CI = 0.85-0.99; P = 0.02), Ruminococcaceae UCG011 (OR = 0.95; 95%CI = 0.90-0.99; P = 0.02), and Actinobacteria (OR = 0.88; 95%CI = 0.80-0.97; P = 0.01) may be associated with a lower risk. According to the UK Biobank data, Eggerthella and Ruminiclostridium5 remain causally associated with hypothyroidism. The sensitivity analysis demonstrates consistent results without evidence of heterogeneity or pleiotropy.

CONCLUSION

This study highlights the impact of specific gut microbiota on hypothyroidism. Strategies to change composition of gut microbiota may hold promise as potential interventions.

Causal relationship between hypothyroidism and temporomandibular disorders: evidence from complementary genetic methods

BACKGROUND

The role of thyroid health in temporomandibular disorders (TMDs) has been emphasized in observational studies. However, whether the causation exists is unclear, and controversy remains about which specific disorder, such as hypothyroidism or hyperthyroidism, is destructive in TMDs. This study aims to investigate the overall and specific causal effects of various thyroid conditions on TMDs.

METHODS

Mendelian randomization (MR) studies were performed using genetic instruments for thyrotropin (TSH, N = 119,715), free thyroxine (fT4, N = 49,269), hypothyroidism (N = 410,141), hyperthyroidism (N = 460,499), and TMDs (N = 211,023). We assessed the overall effect of each thyroid factor via inverse-variance weighted (IVW), weighted median, and MR-Egger methods, and performed extensive sensitivity analyses. Additionally, multivariable MR was conducted to evaluate the direct or indirect effects of hypothyroidism on TMDs whilst accounting for TSH, fT4 and hyperthyroidism, and vice versa.

RESULTS

Univariable MR analyses revealed a causal effect of hypothyroidism on an increased risk of TMDs (IVW OR: 1.12, 95% CI: 1.05-1.20, p = 0.001). No significant association between genetically predicted hyperthyroidism, TSH, or fT4 and TMDs. In the multivariable MR analyses, the effects of hypothyroidism on TMDs occurrence remained significant even after adjSusting for TSH, fT4 and hyperthyroidism (multivariable IVW OR: 1.10, 95% CI: 1.03-1.17, p = 0.006). No pleiotropy and heterogeneity were detected in the analyses (p > 0.05).

CONCLUSIONS

Hypothyroidism might causally increase the risk of TMDs through a direct pathway, highlighting the critical role of managing thyroid health in the prevention of TMDs. Clinicians should give heightened attention to patients with hypothyroidism when seeking medical advice for temporomandibular discomfort. However, caution is warranted due to the potential confounders, pleiotropy, and selection bias in the MR study.

The role of thyroid function in borderline personality disorder and schizophrenia: a Mendelian Randomisation study

BACKGROUND

Genome-wide association studies have reported a genetic overlap between borderline personality disorder (BPD) and schizophrenia (SCZ). Epidemiologically, the direction and causality of the association between thyroid function and risk of BPD and SCZ are unclear. We aim to test whether genetically predicted variations in TSH and FT4 levels or hypothyroidism are associated with the risk of BPD and SCZ.

METHODS

We employed Mendelian Randomisation (MR) analyses using genetic instruments associated with TSH and FT4 levels as well as hypothyroidism to examine the effects of genetically predicted thyroid function on BPD and SCZ risk. Bidirectional MR analyses were employed to investigate a potential reverse causal association.

RESULTS

Genetically predicted higher FT4 was not associated with the risk of BPD (OR: 1.18; P = 0.60, IVW) or the risk of SCZ (OR: 0.93; P = 0.19, IVW). Genetically predicted higher TSH was not associated with the risk of BPD (OR: 1.11; P = 0.51, IVW) or SCZ (OR: 0.98, P = 0.55, IVW). Genetically predicted hypothyroidism was not associated with BPD or SCZ. We found no evidence for a reverse causal effect between BPD or SCZ on thyroid function.

CONCLUSIONS

We report evidence for a null association between genetically predicted FT4, TSH or hypothyroidism with BPD or SCZ risk. There was no evidence for reverse causality.

The Rotterdam Study. Design update and major findings between 2020 and 2024

The Rotterdam Study is a population-based cohort study, started in 1990 in the district of Ommoord in the city of Rotterdam, the Netherlands, with the aim to describe the prevalence and incidence, unravel the etiology, and identify targets for prediction, prevention or intervention of multifactorial diseases in mid-life and elderly. The study currently includes 17,931 participants (overall response rate 65%), aged 40 years and over, who are examined in-person every 3 to 5 years in a dedicated research facility, and who are followed-up continuously through automated linkage with health care providers, both regionally and nationally. Research within the Rotterdam Study is carried out along two axes. First, research lines are oriented around diseases and clinical conditions, which are reflective of medical specializations. Second, cross-cutting research lines transverse these clinical demarcations allowing for inter- and multidisciplinary research. These research lines generally reflect subdomains within epidemiology. This paper describes recent methodological updates and main findings from each of these research lines. Also, future perspective for coming years highlighted.

Quantitative Detection of Thyroid-Stimulating Hormone in Patient Samples with a Nanomechanical Single-Antibody Spectro-Immunoassay

Functional disorders of the thyroid remain a global challenge and have profound impacts on human health. Serving as the barometer for thyroid function, thyroid-stimulating hormone (TSH) is considered the single most useful test of thyroid function. However, the prevailing TSH immunoassays rely on two types of antibodies in a sandwich format. The requirement of repeated incubation and washing further complicates the issue, making it unable to meet the requirements of the shifting public health landscape that demands rapid, sensitive, and low-cost TSH tests. Herein, a systematic study is performed to investigate the clinical translational potential of a single antibody-based biosensing platform for the TSH test. The biosensing platform leverages Raman spectral variations induced by the interaction between a TSH antigen and a Raman molecule-conjugated TSH antibody. In conjunction with machine learning, it allows TSH concentrations in various patient samples to be predicted with high accuracy and precision, which is robust against substrate-to-substrate, intra-substrate, and day-to-day variations. It is envisioned that the simplicity and generalizability of this single-antibody immunoassay coupled with the demonstrated performance in patient samples pave the way for it to be widely applied in clinical settings for low-cost detection of hormones, other molecular biomarkers, DNA, RNA, and pathogens.

Multi-trait analysis characterizes the genetics of thyroid function and identifies causal associations with clinical implications

To date only a fraction of the genetic footprint of thyroid function has been clarified. We report a genome-wide association study meta-analysis of thyroid function in up to 271,040 individuals of European ancestry, including reference range thyrotropin (TSH), free thyroxine (FT4), free and total triiodothyronine (T3), proxies for metabolism (T3/FT4 ratio) as well as dichotomized high and low TSH levels. We revealed 259 independent significant associations for TSH (61% novel), 85 for FT4 (67% novel), and 62 novel signals for the T3 related traits. The loci explained 14.1%, 6.0%, 9.5% and 1.1% of the total variation in TSH, FT4, total T3 and free T3 concentrations, respectively. Genetic correlations indicate that TSH associated loci reflect the thyroid function determined by free T3, whereas the FT4 associations represent the thyroid hormone metabolism. Polygenic risk score and Mendelian randomization analyses showed the effects of genetically determined variation in thyroid function on various clinical outcomes, including cardiovascular risk factors and diseases, autoimmune diseases, and cancer. In conclusion, our results improve the understanding of thyroid hormone physiology and highlight the pleiotropic effects of thyroid function on various diseases.

The Influence of Autoimmune Thyroid Diseases on Viral Pneumonia Development, Including COVID-19: A Two-Sample Mendelian Randomization Study

The association between thyroid function and viral pneumonia has undergone extensive examination, yet the presence of a causal link remains uncertain. The objective of this paper was to employ Two-Sample Mendelian Randomization (MR) analysis to investigate the connections between three thyroid diseases and thyroid hormone indicators with viral pneumonia and COVID-19. We obtained summary statistics datasets from seven genome-wide association studies (GWASs). The primary method used for estimating relationships was inverse-variance weighting (IVW). In addition, we employed weighted median, weighted mode, MR-Egger, and MR-PRESSO as supplementary analytical tools. Sensitivity analyses encompassed Cochran's Q test, MR-Egger intercept test, and MR-PRESSO. Our study revealed significant causal relationships between having a genetic predisposition to autoimmune thyroid disease (AITD) and an increased susceptibility to viral pneumonia (odds ratio [OR]: 1.096; 95% confidence interval [CI]: 1.022-1.176). Moreover, it demonstrated a heightened susceptibility and severity of COVID-19 (OR for COVID-19 susceptibility, COVID-19 hospitalization, and COVID-19 critical illness, with 95% CIs of 1.016, 1.001-1.032; 1.058, 1.003-1.116; 1.045, 1.010-1.081). However, no statistically significant associations were found between TSH, FT4, subclinical hypo- or hyperthyroidism, and the risk of viral pneumonia incidence, or the susceptibility and severity of COVID-19 (all p > 0.05). This study establishes a cause-and-effect relationship between AITD and the development of viral pneumonia, as well as the susceptibility and severity of COVID-19.

Mechanisms of thyrotropin receptor-mediated phenotype variability deciphered by gene mutations and M453T-knockin model

The clinical spectrum of thyrotropin receptor-mediated (TSHR-mediated) diseases varies from loss-of-function mutations causing congenital hypothyroidism to constitutively active mutations (CAMs) leading to nonautoimmune hyperthyroidism (NAH). Variation at the TSHR locus has also been associated with altered lipid and bone metabolism and autoimmune thyroid diseases. However, the extrathyroidal roles of TSHR and the mechanisms underlying phenotypic variability among TSHR-mediated diseases remain unclear. Here we identified and characterized TSHR variants and factors involved in phenotypic variability in different patient cohorts, the FinnGen database, and a mouse model. TSHR CAMs were found in all 16 patients with NAH, with 1 CAM in an unexpected location in the extracellular leucine-rich repeat domain (p.S237N) and another in the transmembrane domain (p.I640V) in 2 families with distinct hyperthyroid phenotypes. In addition, screening of the FinnGen database revealed rare functional variants as well as distinct common noncoding TSHR SNPs significantly associated with thyroid phenotypes, but there was no other significant association between TSHR variants and more than 2,000 nonthyroid disease endpoints. Finally, our TSHR M453T-knockin model revealed that the phenotype was dependent on the mutation's signaling properties and was ameliorated by increased iodine intake. In summary, our data show that TSHR-mediated disease risk can be modified by variants at the TSHR locus both inside and outside the coding region as well as by altered TSHR-signaling and dietary iodine, supporting the need for personalized treatment strategies.

A Detailed Histologic and Molecular Assessment of the Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma

Diffuse sclerosing variant papillary thyroid carcinoma (DS-PTC) is characterized clinically by a predilection for children and young adults, bulky neck nodes, and pulmonary metastases. Previous studies have suggested infrequent BRAFV600E mutation but common RET gene rearrangements. Using strict criteria, we studied 43 DS-PTCs (1.9% of unselected PTCs in our unit). Seventy-nine percent harbored pathogenic gene rearrangements involving RET, NTRK3, NTRK1, ALK, or BRAF; with the remainder driven by BRAFV600E mutations. All 10 pediatric cases were all gene rearranged (P = .02). Compared with BRAFV600E-mutated tumors, gene rearrangement was characterized by psammoma bodies involving the entire lobe (P = .038), follicular predominant or mixed follicular architecture (P = .003), pulmonary metastases (24% vs none, P = .04), and absent classical, so-called "BRAF-like" atypia (P = .014). There was no correlation between the presence of gene rearrangement and recurrence-free survival. Features associated with persistent/recurrent disease included pediatric population (P = .030), gene-rearranged tumors (P = .020), microscopic extrathyroidal extension (P = .009), metastases at presentation (P = .007), and stage II disease (P = .015). We conclude that DS-PTC represents 1.9% of papillary thyroid carcinomas and that actionable gene rearrangements are extremely common in DS-PTC. DS-PTC can be divided into 2 distinct molecular subtypes and all BRAFV600E-negative tumors (1.5% of papillary thyroid carcinomas) are driven by potentially actionable oncogenic fusions.

Thyroid Function and Metabolic Syndrome: A Two-Sample Bidirectional Mendelian Randomization Study

CONTEXT

Thyroid function has been associated with metabolic syndrome (MetS) in a number of observational studies but the direction of effects and the exact causal mechanism of this relationship is still unknown.

OBJECTIVE

To examine genetically predicted effects of thyroid function on MetS risk and its components, and vice versa, using large-scale summary genetic association data.

METHODS

We performed a two-sample bidirectional Mendelian randomization (MR) study using summary statistics from the most comprehensive genome-wide association studies (GWAS) of thyroid-stimulating hormone (TSH, n = 119 715), free thyroxine (fT4, n = 49 269), MetS (n = 291 107), and components of MetS: waist circumference (n = 462 166), fasting blood glucose (n = 281 416), hypertension (n = 463 010), triglycerides (TG, n = 441 016) and high-density lipoprotein cholesterol (HDL-C, n = 403 943). We chose the multiplicative random effects inverse variance weighted (IVW) method as the main analysis. Sensitivity analysis included weighted median and mode analysis, as well as MR-Egger and Causal Analysis Using Summary Effect estimates (CAUSE).

RESULTS

Our results suggest that higher fT4 levels lower the risk of developing MetS (OR = 0.96, P = .037). Genetically predicted fT4 was also positively associated with HDL-C (β = 0.02, P = .008), while genetically predicted TSH was positively associated with TG (β = 0.01, P = .044). These effects were consistent across different MR analyses and confirmed with the CAUSE analysis. In the reverse direction MR analysis, genetically predicted HDL-C was negatively associated with TSH (β = -0.03, P = .046) in the main IVW analysis.

CONCLUSION

Our study suggests that variations in normal-range thyroid function are causally associated with the diagnosis of MetS and with lipid profile, while in the reverse direction, HDL-C has a plausible causal effect on reference-range TSH levels.

Association Between Educational Attainment and Thyroid Function: Results From Mendelian Randomization and the NHANES Study

CONTEXT

Many observational studies have reported on the association between educational attainment (EA) and thyroid function, but the causal relationship remains unclear.

OBJECTIVE

We aimed to obtain causal effects of EA on thyroid function and to quantify the mediating effects of modifiable risk factors.

METHODS

Two-sample mendelian randomization (MR) was performed by using summary statistics from large genome-wide association studies (GWAS) to assess the effect of EA on thyroid function, including hypothyroidism, hyperthyroidism, thyrotropin (TSH), and free thyroxine (FT4). A multivariable analysis was conducted to assess the mediating role of smoking and help to explain the association between EA and thyroid function. Similar analysis was further performed using data from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2002.

RESULTS

In MR analysis, EA was causally associated with TSH (β = .046; 95% CI, 0.015-0.077; P = 4.00 × 10-3), rather than hypothyroidism, hyperthyroidism, and FT4. Importantly, smoking could serve as a mediator in the association between EA and TSH, in which the mediating proportion was estimated to be 10.38%. After adjusting for smoking in the multivariable MR analysis, the β value of EA on TSH was attenuated to 0.030 (95% CI, 0.016-0.045; P = 9.32 × 10-3). Multivariable logistic regression model in NHANES suggested a dose-response relationship between TSH (quartile [Q]4 vs Q1: odds ratio = 1.33; 95% CI, 1.05-1.68; P for trend = .023) and EA. Smoking, systolic blood pressure, and body mass index partially mediated the association between EA and TSH, with the proportion of the mediation effects being 43.82%, 12.28%, and 6.81%, respectively.

CONCLUSION

There is a potentially causal association between EA and TSH, which could be mediated by several risk factors, such as smoking.

Role of ST6GAL1 in Thyroid Cancers: Insights from Tissue Analysis and Genomic Datasets

Thyroid cancer is the predominant endocrine-related malignancy. ST6 β-galactoside α2,6-sialyltransferase 1 (ST6GAL1) has been studied in various types of cancers; however, the expression and function of ST6GAL1 in thyroid cancer has not been investigated so far. Previously, we conducted two genome-wide association studies and have identified the association of the ST6GAL1 gene with plasma thyroglobulin (Tg) levels. Since Tg levels are altered in thyroid pathologies, in the current study, we wanted to evaluate the expression of ST6GAL1 in thyroid cancer tissues. We performed an immunohistochemical analysis using human thyroid tissue from 89 patients and analyzed ST6GAL1 protein expression in papillary thyroid cancer (including follicular variant and microcarcinoma) and follicular thyroid cancer in comparison to normal thyroid tissue. Additionally, ST6GAL1 mRNA levels from The Cancer Genome Atlas (TCGA, n = 572) and the Genotype-Tissue Expression (GTEx) project (n = 279) were examined. The immunohistochemical analysis revealed higher ST6GAL1 protein expression in all thyroid tumors compared to normal thyroid tissue. TCGA data revealed increased ST6GAL1 mRNA levels in both primary and metastatic tumors versus controls. Notably, the follicular variant of papillary thyroid cancer exhibited significantly higher ST6GAL1 mRNA levels than classic papillary thyroid cancer. High ST6GAL1 mRNA levels significantly correlated with lymph node metastasis status, clinical stage, and reduced survival rate. ST6GAL1 emerges as a potential cancer-associated glycosyltransferase in thyroid malignancies, offering valuable insights into its diagnostic and prognostic significance.

Genetically predicted thyroid function and risk of colorectal cancer: a bidirectional Mendelian randomization study

BACKGROUND

Observational studies have reported an association between thyroid function and colorectal cancer (CRC), with conflicting results. Elucidating the causal relationship between thyroid function and CRC facilitates the development of new preventive strategies to reduce CRC incidence.

METHOD

We applied a two-sample Mendelian randomization (MR) method to evaluate the causal relationship between five thyroid-related indexes, including hyperthyroidism, hypothyroidism, thyroid stimulating hormone (TSH), free thyroxine (FT4) and basal metabolic rate (BMR), and CRC. Genome-wide association study statistics for thyroid-related phenotypes were obtained from the ThyroidOmics consortium, and summary statistics for genetic associations with CRC were obtained from the FinnGen consortium. We set a series of criteria to screen single nucleotide polymorphisms (SNPs) as instrumental variables and then performed bidirectional MR analysis, stratified analysis and extensive sensitivity analysis. Multiplicative random-effects inverse variance weighted was the primary analysis method, supplemented by weighted median and MR-Egger.

RESULT

We identified 12 SNPs for hyperthyroidism, 10 SNPs for hypothyroidism, 41 SNPs for TSH, 18 SNPs for FT4, and 556 SNPs for BMR. Genetically predicted hyperthyroidism, hypothyroidism, TSH, and FT4 were not associated with CRC risk (all P > 0.05). Sensitivity analysis revealed no heterogeneity or pleiotropy. Genetically predicted BMR was significantly associated with increased CRC risk after removing outlier (OR = 1.30, P = 0.0029). Stratified analysis showed that BMR was significantly associated with colon cancer (OR = 1.33, P = 0.0074) but not rectal cancer. In the reverse analysis, there was no evidence of an effect of CRC on thyroid function (all P > 0.05).

CONCLUSION

Our bidirectional MR analysis provides new insights into the relationship between thyroid function and CRC. CRC prevention may benefit from enhanced screening of high BMR populations.

Association Between Serum Thyroid Measurements and Hyperhomocysteinemia in Euthyroid Subjects: A Retrospective Cross-Sectional Study

Objective

The objective of this study was to investigate the association between serum thyroid measurements and homocysteine (HCy) in euthyroid participants.

Methods

This retrospective study was based on Hospital Information Systems. After excluding participants with thyroid dysfunction and those who had recently taken medications that affected serum HCy, 775 participants were enrolled. We compared the serum thyroid function measurements of patients with or without hyperhomocysteinemia (HHCy) and analyzed the effect of thyroid indicators on HHCy prevalence and HCy levels. Multivariate regression analysis was utilized to analyze the association of thyroid-stimulating hormone (TSH) and thyroid peroxidase (TPOAb) with HCy.

Results

The serum TSH level (2.10 ± 1.06 mIU/L) of HHCy patients (n = 98) was significantly higher than controls (n = 677) (1.65 ± 0.90 mIU/L) (p < 0.05), as was the positive rate of TPOAb (19.4% vs 10.0%, p < 0.05). The serum HCy levels in subjects with TSH within the highest quartile were significantly higher than those in the lowest quartile (13.49 ± 7.78 vs 9.81 ± 3.59 μmol/L, p < 0.05). HCy was also significantly higher in TPOAb-positive patients than in negative subjects (14.06 ± 8.89 vs 11.48 ± 5.47 μmol/L, p < 0.05). Among the TSH quartiles, the prevalence of HHCy showed a similar significant upward trend to that described above. The prevalence of HHCy was also significantly higher in TPOAb-positive patients. The results of multivariate regression analysis suggested that both TSH elevation and TPOAb positivity were independent risk factors for HCy elevation and HHCy prevalence. However, we found no definitive association between linear increases in TPOAb titers and HCy concentrations or HHCy prevalence.

Conclusion

Patients with HHCy had significantly higher TSH levels and positive rates of TPOAb. Elevated TSH and positive TPOAb levels were independent risk factors for elevated HCy concentrations and HHCy risk.

Genome-wide association study of thyroid-stimulating hormone highlights new genes, pathways and associations with thyroid disease

Thyroid hormones play a critical role in regulation of multiple physiological functions and thyroid dysfunction is associated with substantial morbidity. Here, we use electronic health records to undertake a genome-wide association study of thyroid-stimulating hormone (TSH) levels, with a total sample size of 247,107. We identify 158 novel genetic associations, more than doubling the number of known associations with TSH, and implicate 112 putative causal genes, of which 76 are not previously implicated. A polygenic score for TSH is associated with TSH levels in African, South Asian, East Asian, Middle Eastern and admixed American ancestries, and associated with hypothyroidism and other thyroid disease in South Asians. In Europeans, the TSH polygenic score is associated with thyroid disease, including thyroid cancer and age-of-onset of hypothyroidism and hyperthyroidism. We develop pathway-specific genetic risk scores for TSH levels and use these in phenome-wide association studies to identify potential consequences of pathway perturbation. Together, these findings demonstrate the potential utility of genetic associations to inform future therapeutics and risk prediction for thyroid diseases.

Causal link between thyroid function and schizophrenia: a two-sample Mendelian randomization study

Schizophrenia is a chronic psychiatric disorder with inconsistent behavioral and cognitive abnormalities with profound effects on the individual and the society. Individuals with schizophrenia have altered thyroid function, but results from observational studies are conflicting. To date, it remains unclear whether and in which direction there is a causal relationship between thyroid function and schizophrenia. To investigate causal paths, a bidirectional two-sample Mendelian randomization (MR) study was conducted using summary statistics from genome-wide association studies including up to 330,132 Europeans. Thyroid function was described by the normal-range thyroid-stimulating hormone (TSH) and free thyroxine levels as well as an increased and decreased TSH status. The iterative radial inverse-variance weighted approach with modified second order weights was used as the main method. Based on a discovery and replication sample for schizophrenia, pooled effect estimates were derived using a fixed-effect meta-analysis. Robustness of results was assessed using both a range of pleiotropy robust methods and a network analysis that clustered genetic instruments potentially responsible for horizontal pleiotropy. Genetic liability for hypothyroidism was inversely associated with schizophrenia ([Formula: see text]; 95% CI: (-0.10; -0.02); [Formula: see text]). No notable associations were observed between other thyroid parameters and schizophrenia. Furthermore, no associations could be detected in the reverse direction. Our results suggest that an elevated level of TSH reduce the risk for schizophrenia. The role of thyroid function and the hypothalamic-pituitary-thyroid axis in the development of schizophrenia should be subject of further research.

Whole Exome-Wide Association Identifies Rare Variants in GALNT9 Associated with Middle Eastern Papillary Thyroid Carcinoma Risk

Papillary thyroid carcinoma (PTC) is the commonest thyroid cancer. The majority of inherited causes of PTC remain elusive. However, understanding the genetic underpinnings and origins remains a challenging endeavor. An exome-wide association study was performed to identify rare germline variants in coding regions associated with PTC risk in the Middle Eastern population. By analyzing exome-sequencing data from 249 PTC patients (cases) and 1395 individuals without any known cancer (controls), GALNT9 emerged as being strongly associated with rare inactivating variants (RIVs) (4/249 cases vs. 1/1395 controls, OR = 22.75, p = 5.09 × 10-5). Furthermore, three genes, TRIM40, ARHGAP23, and SOX4, were enriched for rare damaging variants (RDVs) at the exome-wide threshold (p < 2.5 × 10-6). An additional seven genes (VARS1, ZBED9, PRRC2A, VWA7, TRIM31, TRIM40, and COL8A2) were associated with a Middle Eastern PTC risk based on the sequence kernel association test (SKAT). This study underscores the potential of GALNT9 and other implicated genes in PTC predisposition, illuminating the need for large collaborations and innovative approaches to understand the genetic heterogeneity of PTC predisposition.

Genetic determinants of thyroid function in children

OBJECTIVE

Genome-wide association studies in adults have identified 42 loci associated with thyroid stimulating hormone (TSH) and 21 loci associated with free thyroxine (FT4) concentrations. While biologically plausible, age-dependent effects have not been assessed. We aimed to study the association of previously identified genetic determinants of TSH and FT4 with TSH and FT4 concentrations in newborns and (pre)school children.

METHODS

We selected participants from three population-based prospective cohorts with data on genetic variants and thyroid function: Generation R (N = 2169 children, mean age 6 years; N = 2388 neonates, the Netherlands), the Avon Longitudinal Study of Parents and Children (ALSPAC; N = 3382, age 7.5 years, United Kingdom), and the Brisbane Longitudinal Twin Study (BLTS; N = 1680, age 12.1 years, Australia). The association of single nucleotide polymorphisms (SNPs) with TSH and FT4 concentrations was studied with multivariable linear regression models. Weighted polygenic risk scores (PRSs) were defined to combine SNP effects.

RESULTS

In childhood, 30/60 SNPs were associated with TSH and 11/31 SNPs with FT4 after multiple testing correction. The effect sizes for AADAT, GLIS3, TM4SF4, and VEGFA were notably larger than in adults. The TSH PRS explained 5.3%-8.4% of the variability in TSH concentrations; the FT4 PRS explained 1.5%-4.2% of the variability in FT4 concentrations. Five TSH SNPs and no FT4 SNPs were associated with thyroid function in neonates.

CONCLUSIONS

The effects of many known thyroid function SNPs are already apparent in childhood and some might be notably larger in children as compared to adults. These findings provide new knowledge about genetic regulation of thyroid function in early life.

Mendelian randomization study of thyroid function and anti-Müllerian hormone levels

Objective

Although previous studies have reported an association between thyroid function and anti-Müllerian hormone (AMH) levels, which is considered a reliable marker of ovarian reserve, the causal relationship between them remains uncertain. This study aims to investigate whether thyrotropin (TSH), free thyroxine (fT4), hypo- and hyperthyroidism are causally linked to AMH levels.

Methods

We obtained summary statistics from three sources: the ThyroidOmics Consortium (N = 54,288), HUNT + MGI + ThyroidOmics meta-analysis (N = 119,715), and the most recent AMH genome-wide association meta-analysis (N = 7,049). Two-sample MR analyses were conducted using instrumental variables representing TSH and fT4 levels within the normal range. Additionally, we conducted secondary analyses to explore the effects of hypo- and hyperthyroidism. Subgroup analyses for TSH were also performed.

Results

MR analyses did not show any causality relationship between thyroid function and AMH levels, using normal range TSH, normal range fT4, subclinical hypothyroidism, subclinical hyperthyroidism and overt hypothyroidism as exposure, respectively. In addition, neither full range TSH nor TSH with individuals <50 years old was causally associated with AMH levels. MR sensitivity analyses guaranteed the robustness of all MR results, except for the association between fT4 and AMH in the no-DIO1+DIO2 group.

Conclusion

Our findings suggest that there was no causal association between genetically predicted thyroid function and AMH levels in the European population.

Genome-wide association studies: utility and limitations for research in physiology

Physiological systems are subject to interindividual variation encoded by genetics. Genome-wide association studies (GWAS) operate by surveying thousands of genetic variants from a substantial number of individuals and assessing their association to a trait of interest, be it a physiological variable, a molecular phenotype (e.g. gene expression), or even a disease or condition. Through a myriad of methods, GWAS downstream analyses then explore the functional consequences of each variant and attempt to ascertain a causal relationship to the phenotype of interest, as well as to delve into its links to other traits. This type of investigation allows mechanistic insights into physiological functions, pathological disturbances and shared biological processes between traits (i.e. pleiotropy). An exciting example is the discovery of a new thyroid hormone transporter (SLC17A4) and hormone metabolising enzyme (AADAT) from a GWAS on free thyroxine levels. Therefore, GWAS have substantially contributed with insights into physiology and have been shown to be useful in unveiling the genetic control underlying complex traits and pathological conditions; they will continue to do so with global collaborations and advances in genotyping technology. Finally, the increasing number of trans-ancestry GWAS and initiatives to include ancestry diversity in genomics will boost the power for discoveries, making them also applicable to non-European populations.

Advances in Antioxidant Applications for Combating 131I Side Effects in Thyroid Cancer Treatment

Thyroid cancer is the most common endocrine cancer, and its prevalence has been increasing for decades. Approx. 95% of differentiated thyroid carcinomas are treated using ¹³¹iodine (¹³¹I), a radionuclide with a half-life of 8 days, to achieve optimal thyroid residual ablation following thyroidectomy. However, while ¹³¹I is highly enriched in eliminating thyroid tissue, it can also retain and damage other body parts (salivary glands, liver, etc.) without selectivity, and even trigger salivary gland dysfunction, secondary cancer, and other side effects. A significant amount of data suggests that the primary mechanism for these side effects is the excessive production of reactive oxygen species, causing a severe imbalance of oxidant/antioxidant in the cellular components, resulting in secondary DNA damage and abnormal vascular permeability. Antioxidants are substances that are capable of binding free radicals and reducing or preventing the oxidation of the substrate in a significant way. These compounds can help prevent damage caused by free radicals, which can attack lipids, protein amino acids, polyunsaturated fatty acids, and double bonds of DNA bases. Based on this, the rational utilization of the free radical scavenging function of antioxidants to maximize a reduction in ¹³¹I side effects is a promising medical strategy. This review provides an overview of the side effects of ¹³¹I, the mechanisms by which ¹³¹I causes oxidative stress-mediated damage, and the potential of natural and synthetic antioxidants in ameliorating the side effects of ¹³¹I. Finally, the disadvantages of the clinical application of antioxidants and their improving strategies are prospected. Clinicians and nursing staff can use this information to alleviate ¹³¹I side effects in the future, both effectively and reasonably.

Association Between Systemic Lupus Erythematosus and Primary Hypothyroidism: Evidence from Complementary Genetic Methods

INTRODUCTION

Systemic lupus erythematosus (SLE) and hypothyroidism often coexist in observational studies; however, the causal relationship between them remains controversial.

METHODS

Complementary genetic approaches, including genetic correlation, Mendelian randomization (MR), and colocalization analysis, were conducted to assess the potential causal association between SLE and primary hypothyroidism using summary statistics from large-scale genome-wide association studies. The association between SLE and thyroid-stimulating hormone (TSH) was further analyzed to help interpret the findings. In addition, findings were verified using a validation data set, as well as through different MR methods with different model assumptions.

RESULTS

The linkage disequilibrium score regression revealed a shared genetic structure between SLE and primary hypothyroidism, with the significant genetic correlation estimated to be 0.2488 (P = 6.00 × 10-4). MR analysis with the inverse variance weighted method demonstrated a bidirectional causal relationship between SLE and primary hypothyroidism. The odds ratio (OR) of SLE on primary hypothyroidism was 1.037 (95% CI, 1.013-1.061; P = 2.00 × 10-3) and that of primary hypothyroidism on SLE was 1.359 (95% CI, 1.217-1.520; P < 0.001). The OR of SLE on TSH was 1.007 (95% CI, 1.001-1.013; P = 0.032). However, TSH was not causally associated with SLE (P = 0.152). Similar results were found using different MR methods. In addition, colocalization analysis suggested that shared causal variants existed between SLE and primary hypothyroidism. The results of the validation analysis indicated a bidirectional causal relationship between SLE and primary hypothyroidism, as well as shared loci.

CONCLUSION

In summary, a bidirectional causal relationship between SLE and primary hypothyroidism was observed with complementary genetic approaches.

Migraine and thyroid dysfunction: Co-occurrence, shared genes and biological mechanisms

BACKGROUND AND PURPOSE

Migraine and thyroid dysfunction, particularly hypothyroidism, are common medical conditions and are known to have high heritability. Thyroid function measures, thyroid stimulating hormone (TSH) and free thyroxine (fT4), are also known to be genetically influenced. Although observational epidemiological studies report an increased co-occurrence of migraine and thyroid dysfunction, a clear and combined interpretation of the findings is currently lacking. A narrative review is provided of the epidemiological and genetic association evidence linking migraine, hypothyroidism, hyperthyroidism and thyroid hormones TSH and fT4.

METHODS

An extensive literature search was conducted in the PubMed database for epidemiological, candidate gene and genome-wide association studies using the terms migraine, headache, thyroid hormones, TSH, fT4, thyroid function, hypothyroidism and hyperthyroidism.

RESULTS

Epidemiological studies suggest a bidirectional relationship between migraine and thyroid dysfunction. However, the nature of the relationship remains unclear, with some studies suggesting migraine increases the risk for thyroid dysfunction whilst other studies suggest the reverse. Early candidate gene studies have provided nominal evidence for MTHFR and APOE, whilst more recently genome-wide association studies have provided robust evidence for THADA and ITPK1 being associated with both migraine and thyroid dysfunction.

CONCLUSIONS

These genetic associations improve our understanding of the genetic relationship between migraine and thyroid dysfunction, provide an opportunity to develop biomarkers to identify migraine patients most likely to benefit from thyroid hormone therapy, and indicate that further cross-trait genetic studies have excellent potential to provide biological insight into their relationship and inform clinical interventions.

Variants in TPO rs2048722, PTCSC2 rs925489 and SEMA4G rs4919510 affect thyroid carcinoma susceptibility risk

BACKGROUND

Thyroid carcinoma (THCA) is a malignant endocrine tumor all around the world, which is influenced by genetic and environmental factors.

OBJECTIVE

To explore the association between TPO rs2048722, PTCSC2 rs925489, SEMA4G rs4919510 polymorphisms and THCA susceptibility in Chinese population.

METHODS

We recruited 365 THCA patients and 498 normal controls for the study. Logistic regression analysis was used to evaluate the association between TPO rs2048722, PTCSC2 rs925489, SEMA4G rs4919510 polymorphisms and THCA susceptibility. MDR was used to assess the genetic interactions among the three SNPs.

RESULTS

Overall analysis demonstrated that rs925489 of PTCSC2 was evidently associated with increased risk of THCA in multiple genetic models (OR = 1.59, 95%CI = 1.12-2.24, p = 0.009). The results of stratified analysis illustrated that rs2048722 of TPO can significantly increase the THCA susceptibility of participants less than or equal to 44 years old and smokers. Similarly, rs925489 of PTCSC2 obviously improved the risk of THCA among participants older than 44 years, males, smokers and drinkers. However, rs4919510 of SEMA4G has a protective effect on the development of THCA among participants with less than or equal to 44 years old and non-drinkers. Interestingly, there was a strong genetic interaction among the three SNPs in the occurrence of THCA risk.

CONCLUSION

TPO rs2048722, PTCSC2 rs925489 and SEMA4G rs4919510 polymorphisms were evidently associated with the risk of THCA in the Chinese population, which was affected by age, gender, smoking and drinking consumption.

Shared genetics and causal relationships between migraine and thyroid function traits

BACKGROUND

Epidemiological studies have reported a comorbid relationship between migraine and thyroid dysfunction.

METHODS

We investigated the genetic relationship between migraine and thyroid function traits using genome-wide association study (GWAS) data.

RESULTS

We found a significant genetic correlation (r_g) with migraine for hypothyroidism (r_g = 0.0608), secondary hypothyroidism (r_g = 0.195), free thyroxine (fT4) (r_g = 0.0772), and hyperthyroidism (r_g = -0.1046), but not thyroid stimulating hormone (TSH). Pairwise GWAS analysis revealed two shared loci with TSH and 11 shared loci with fT4. Cross-trait GWAS meta-analysis of migraine identified novel genome-wide significant loci: 17 with hypothyroidism, one with hyperthyroidism, five with secondary hypothyroidism, eight with TSH, and 15 with fT4. Of the genes at these loci, six (RERE, TGFB2, APLF, SLC9B1, SGTB, BTBD16; migraine + hypothyroidism), three (GADD45A, PFDN1, RSPH6A; migraine + TSH), and three (SSBP3, BRD3, TEF; migraine + fT4) were significant in our gene-based analysis (p_{Fisher's combined P-value} < 2.04 × 10^-6). In addition, causal analyses suggested a negative causal relationship between migraine and hyperthyroidism (p = 8.90 × 10^-3) and a positive causal relationship between migraine and secondary hypothyroidism (p = 1.30 × 10^-3).

CONCLUSION

These findings provide strong evidence for genetic correlation and suggest complex causal relationships between migraine and thyroid traits.

Modification of TSH-related genetic effects by indicators of socioeconomic position

OBJECTIVE

Thyroid-stimulating hormone (TSH) is influenced by genetic and environmental factors such as socioeconomic position (SEP). However, interactions between TSH-related genetic factors and indicators of SEP have not been investigated to date. The aim of the study was to determine whether education and income as SEP indicators may interact with TSH-related genetic effect allele sum scores (GESTSH_2013 and GESTSH_2020) based on two different GWAS meta-analyses that affect TSH values in a population-based study.

METHODS

In 4085 participants of the Heinz Nixdorf Recall Study associations between SEP indicators, GESTSH and TSH were quantified using sex- and age-adjusted linear regression models. Interactions between SEP indicators and GESTSH were assessed by GESTSH × SEP interaction terms, single reference joint effects and calculating genetic effects stratified by SEP group.

RESULTS

Participants within the highest education group showed the strongest genetic effect with on average 1.109-fold (95% CI: 1.067-1.155) higher TSH values per GESTSH_2013 SD, while in the lowest education group, the genetic effect was less strong (1.061-fold (95% CI: 1.022-1.103)). In linear regression models including interaction terms, some weak indication for a positive GESTSH_2013 by education interaction was observed showing an interaction effect size estimate of 1.005 (95% CI: 1.000-1.010) per year of education and GESTSH_2013 SD. No indication for interaction was observed for using income as SEP indicator. Using the GESTSH_2020, similar results were observed.

CONCLUSION

Our results gave some indication that education may affect the expression of TSH-related genetic effects. Stronger genetic effects in high-education groups may be explained by environmental factors that have an impact on gene expression and are more prevalent in high SEP groups.

Genome-wide association studies for thyroid physiology and diseases

Genetic factors are involved in the etiology of most diseases, but prior to 2000, the methods for identifying such factors were very limited. Genome-wide association study (GWAS), developed in the 2000s, is an analytical method that can be applied to most diseases, including endocrine disorders. GWAS has provided a wealth of information on disease risks and the molecular pathogenesis of many human diseases. This review summarizes key findings from GWAS for thyroid physiology and diseases, and illustrates how GWAS is a powerful research tool to elucidate the molecular mechanisms of the diseases.

Low thyroid function is associated with an increased risk of advanced fibrosis in patients with metabolic dysfunction-associated fatty liver disease

AIMS

Observational studies showed that low thyroid function may perturb liver function. We aimed to evaluate the association of low thyroid function with both metabolic dysfunction-associated fatty liver disease (MAFLD) and advanced hepatic fibrosis.

METHODS

Participants who underwent abdominal ultrasonography and thyroid function test in a Chinese hospital from 2015 to 2021were enrolled. Fibrosis-4 index (FIB-4) > 2.67 and/or non-alcoholic fatty liver disease fibrosis score (NFS) > 0.676 were used to define advanced fibrosis. Descriptive analyses were performed to characterize the epidemiology of MAFLD according to levels of thyroid-stimulating hormone (TSH). The logistic regression model was applied to estimate the association of low thyroid function with MAFLD and advanced fibrosis.

RESULTS

A total of 19,946 participants (52.78% males, mean age: 47.31 years, 27.55% MAFLD) were included, among which 14,789 were strict-normal thyroid function, 4,328 were low-normal thyroid function, 829 were subclinical hypothyroidism. TSH levels were significantly higher in MAFLD patients with a FIB-4 > 2.67 and /or NFS > 0.676 than their counterparts. The logistic regression model adjusted for age and sex showed that low-normal thyroid function increased the risk of MAFLD (odds ratio [OR] = 1.09; 95% confidence interval [CI] 1.01-1.18). Multivariable regression model adjusted for age, sex, body mass index, type 2 diabetes, and hypertension showed low-normal thyroid function increased the risk of advanced fibrosis in patients with MAFLD (FIB-4 > 2.67: OR = 1.41, 95% CI 1.02-1.93; NFS > 0.676: OR = 1.72, 95% CI 1.08-2.72).

CONCLUSION

Elevated TSH concentrations are associated with advanced hepatic fibrosis, even in the euthyroid state.

Cross-Trait Genetic Analyses Indicate Pleiotropy and Complex Causal Relationships between Headache and Thyroid Function Traits

Epidemiological studies have reported a comorbid relationship between headache and thyroid traits; however, little is known about the shared genetics and causality that contributes to this association. We investigated the genetic overlap and associations between headache and thyroid function traits using genome-wide association study (GWAS) data. We found a significant genetic correlation (rg) with headache and hypothyroidism (rg = 0.09, p = 2.00 × 10−4), free thyroxine (fT4) (rg = 0.08, p = 5.50 × 10−3), and hyperthyroidism (rg = −0.14, p = 1.80 × 10−3), a near significant genetic correlation with secondary hypothyroidism (rg = 0.20, p = 5.24 × 10−2), but not with thyroid stimulating hormone (TSH). Pairwise-GWAS analysis revealed six, 14, four and five shared (pleiotropic) loci with headache and hypothyroidism, hyperthyroidism, secondary hypothyroidism, and fT4, respectively. Cross-trait GWAS meta-analysis identified novel genome-wide significant loci for headache: five with hypothyroidism, three with secondary hypothyroidism, 12 with TSH, and nine with fT4. Of the genes at these loci, six (FAF1, TMX2-CTNND1, AARSD1, PLCD3, ZNF652, and C20orf203; headache-TSH) and six (HMGB1P45, RPL30P1, ZNF462, TMX2-CTNND1, ITPK1, SECISBP2L; headache-fT4) were significant in our gene-based analysis (pFisher’s combined p-value < 2.09 × 10−6). Our causal analysis suggested a positive causal relationship between headache and secondary hypothyroidism (p = 3.64 × 10−4). The results also suggest a positive causal relationship between hypothyroidism and headache (p = 2.45 × 10−3) and a negative causal relationship between hyperthyroidism and headache (p = 1.16 × 10−13). These findings suggest a strong evidence base for a genetic correlation and complex causal relationships between headache and thyroid traits.