The incidence and prevalence of thyroid dysfunction in Europe: a meta-analysis

Risk of Incident Thyroid Dysfunction in the Post-Acute Phase of COVID-19: A Population-Based Cohort Study in Hong Kong

OBJECTIVE

The evidence of thyroid dysfunction in the post-acute phase of SARS-CoV-2 infection is limited. This study aimed to evaluate the risk of incident thyroid dysfunction in the post-acute phase of COVID-19.

METHODS

This retrospective, propensity-score matched, population-based study included COVID-19 patients and non-COVID-19 individuals between January 2020 and March 2022, identified from the electronic medical records of the Hong Kong Hospital Authority. The cohort was followed up until the occurrence of outcomes, death, or 31 January 2023, whichever came first. Patients with COVID-19 were 1:1 matched to controls based on various variables. The primary outcome was a composite of thyroid dysfunction (hyperthyroidism, hypothyroidism, initiation of antithyroid drug or levothyroxine, and thyroiditis). Cox regression was employed to evaluate the risk of incident thyroid dysfunction during the post-acute phase.

RESULTS

A total of 84 034 COVID-19 survivors and 84 034 matched controls were identified. Upon a median follow-up of 303 days, there was no significant increase in the risk of diagnosed thyroid dysfunction in the post-acute phase of COVID-19 (hazard ratio [HR] 1.058, 95% confidence interval 0.979-1.144, P = .154). Regarding the secondary outcomes, patients with COVID-19 did not have increased risk of hyperthyroidism (HR 1.061, P = .345), hypothyroidism (HR 1.062, P = .255), initiation of antithyroid drug (HR 1.302, P = .070), initiation of levothyroxine (HR 1.086, P = .426), or thyroiditis (P = .252). Subgroup and sensitivity analyses were largely consistent with the main analyses.

CONCLUSION

Our population-based cohort study provided important reassuring data that COVID-19 was unlikely to be associated with persistent effects on thyroid function.

A nationwide registry-based observational study of thyroid disease incidence in the Faroe Islands

OBJECTIVE

The occurrence of thyroid disease varies among populations. While the iodine nutrition level of the Faroese seems to have been decreasing over the past decades, there is no systematic evaluation of the thyroid disease pattern in the Faroe Islands. Such knowledge of thyroid disease occurrence in the North Atlantic region may support healthcare planning and prevention. To investigate incidence rates, including subtypes of thyroid diseases, and demographic characteristics of thyroid disease patients in the Faroe Islands, to improve understanding of the patterns and trends of these disorders.

DESIGN AND METHOD

A registry-based observational study was conducted over 10 years, encompassing all adult Faroese individuals.

PATIENTS AND MEASUREMENTS

Health records from general practitioners and hospitals were used to identify incident cases of thyroid diseases. Validation was performed using multiple data sources. The incidence rates were standardised using population data from the middle of the study period 2006-2018.

RESULTS

Among the 1152 individuals diagnosed with thyroid disease, the standardised incidence rates per 100,000 person-years were 55 for hyperthyroidism and 112 for hypothyroidism, and around four times higher in women than in men. Hashimoto's thyroiditis was the dominant cause of hypothyroidism, while Graves' disease was the leading cause of hyperthyroidism. The incidence of hypothyroidism increases with age. A decreasing trend was observed over time for both hypothyroidism and hyperthyroidism.

CONCLUSION

Considering the decrease in iodine nutrition levels over the past decades, we were surprised by the high incidence of autoimmune thyroid disease. The findings highlight the need for continuous monitoring of thyroid disease occurrence in coastal areas of the North Atlantic Ocean.

Proton Pump Inhibitors Do Not Affect the Bioavailability of a Novel Liquid Formulation of Levothyroxine

OBJECTIVE

This study evaluates the impact of a representative proton pump inhibitor (PPI) (omeprazole), administered simultaneously or staggered, on the pharmacokinetics of levothyroxine (LT4) solution (Tirosint-SOL).

METHODS

This was a randomized, 3-way crossover, comparative bioavailability study in 36 healthy adults under fasting conditions. Omeprazole 40 mg delayed-release capsule was administered once daily from Day 1 to 6 (mornings, Treatment-A; evenings, Treatment-B; none, Treatment-C) to increase and stabilize gastric pH. In the morning of Day 5, a single dose of LT4 solution 600 mcg was administered. Blood samples were collected 0 to 48 hours post-LT4 administration. Noncompartmental pharmacokinetic parameters were calculated for total serum thyroxine using baseline-corrected data. Maximum concentration (Cmax) and area under the concentration-time curve (AUC0-48) were included in an analysis of variance to obtain geometric mean ratios and 90% confidence intervals.

RESULTS

For both comparisons (A/C and B/C), geometric mean ratios and 90% confidence intervals for all parameters were within the equivalence boundaries (80%-125%), indicating bioequivalence: for A/C, AUC0-48 98.98% [94%-104%], and Cmax 91.68% [87%-97%]; for B/C, AUC0-48 98.94% [95%-103%], and Cmax 94.90% [90%-100%]. Median Tmax (time associated with Cmax) was similar across treatments.

CONCLUSION

This study demonstrated that Tirosint-SOL bioavailability is unaffected by coadministration of a representative PPI, given simultaneously or staggered by about 12 hours, compared to administration of LT4 solution alone. For hypothyroid patients on PPI therapy, administration of LT4 solution may reduce variations in thyroid stimulating hormone levels related to intermittent use of acid-reducing drugs and consequently the need for dose adjustments.

Air pollution exposure, accelerated biological aging, and increased thyroid dysfunction risk: Evidence from a nationwide prospective study

BACKGROUND

Long-term air pollution exposure is a major health concern, yet its associations with thyroid dysfunction (hyperthyroidism and hypothyroidism) and biological aging remain unclear. We aimed to determine the association of long-term air pollution exposure with thyroid dysfunction and to investigate the potential roles of biological aging.

METHODS

A prospective cohort study was conducted on 432,340 participants with available data on air pollutants including particulate matter (PM2.5, PM10, and PM2.5-10), nitrogen dioxide (NO2), and nitric oxide (NO) from the UK Biobank. An air pollution score was calculated using principal component analysis to reflect joint exposure to these pollutants. Biological aging was assessed using the Klemera-Doubal method biological age and the phenotypic age algorithms. The associations of individual and joint air pollutants with thyroid dysfunction were estimated using the Cox proportional hazards regression model. The roles of biological aging were explored using interaction and mediation analyses.

RESULTS

During a median follow-up of 12.41 years, 1,721 (0.40 %) and 9,296 (2.15 %) participants developed hyperthyroidism and hypothyroidism, respectively. All air pollutants were observed to be significantly associated with an increased risk of incident hypothyroidism, while PM2.5, PM10, and NO2 were observed to be significantly associated with an increased risk of incident hyperthyroidism. The hazard ratios (HRs) for hyperthyroidism and hypothyroidism were 1.15 (95 % confidence interval: 1.00-1.32) and 1.15 (1.08-1.22) for individuals in the highest quartile compared with those in the lowest quartile of air pollution score, respectively. Additionally, we noticed that individuals with higher pollutant levels and biologically older generally had a higher risk of incident thyroid dysfunction. Moreover, accelerated biological aging partially mediated 1.9 %-9.4 % of air pollution-associated thyroid dysfunction.

CONCLUSIONS

Despite the possible underestimation of incident thyroid dysfunction, long-term air pollution exposure may increase the risk of incident thyroid dysfunction, particularly in biologically older participants, with biological aging potentially involved in the mechanisms.

Farming activity and risk of treated thyroid disorders: Insights from the TRACTOR project, a nationwide cohort study

BACKGROUND

Epidemiological data regarding thyroid diseases are lacking, in particular for occupationally exposed populations.

OBJECTIVES

To compare the risk of hypothyroidism and hyperthyroidism between farming activities within the complete population of French farm managers (FMs).

METHODS

Digital health data from retrospective administrative databases, including insurance claims and electronic health/medical records, was employed. This cohort data spanned the entirety of French farm managers (FMs) who had undertaken work at least once from 2002 to 2016. Survival analysis with the time to initial medication reimbursement as timescale was used to examine the association (hazard ratio, HR) between 26 specific farming activities and both treated hypothyroidism and hyperthyroidism. A distinct model was developed for each farming activity, comparing FMs who had never engaged in the specific farming activity between 2002 and 2016 with those who had. All analyses were adjusted for potential confounders (e.g., age), and sensitivity analyses were conducted.

RESULTS

Among 1088561 FMs (mean age 46.6 [SD 14.1]; 31% females), there were 31834 hypothyroidism cases (75% females) and 620 hyperthyroidism cases (67% females), respectively. The highest risks were observed for cattle activities for both hyperthyroidism (HR ranging from 1.75 to 2.42) and hypothyroidism (HR ranging from 1.41 to 1.44). For hypothyroidism, higher risks were also observed for several animal farming activities (pig, poultry, and rabbit), as well as fruit arboriculture (HR = 1.22 [1.14-1.31]). The lowest risks were observed for activities involving horses. Sex differences in the risk of hypothyroidism were observed for eight activities, with the risk being higher for males (HR = 1.09 [1.01-1.20]) than females in viticulture (HR = 0.97 [0.93-1.00]). The risk of hyperthyroidism was two times higher for male dairy farmers than females.

DISCUSSION

Our findings offer a comprehensive overview of thyroid disease risks within the FM community. Thyroid ailments might not stem from a single cause but likely arise from the combined effects of various causal agents and triggering factors (agricultural exposome). Further investigation into distinct farming activities-especially those involving cattle-is essential to pinpoint potential risk factors that could enhance thyroid disease monitoring in agriculture.

Adequacy of thyroid hormone replacement for people with hypothyroidism in real-world settings: A systematic review and meta-analysis of observational studies

OBJECTIVE

Thyroid hormone under-replacement and over-replacement are associated with adverse health outcomes. This systematic review aimed to evaluate the extent of thyroid hormone replacement adequacy for patients with known hypothyroidism in real-word settings, excluding those receiving thyroid hormone suppressive therapy as thyroid cancer treatment.

DESIGN

Four electronic databases (Embase [Ovid], Medline [Ovid], PubMed and SCOPUS) were searched for published and unpublished observational studies until 12 December 2022. The results of the studies were meta-analysed to calculate pooled prevalence estimates for thyroid hormone supplementation adequacy, over-replacement and under-replacement. Quality assessment of studies was performed using the Joanna-Briggs appraisal tool for prevalence studies.

RESULTS

Seven studies with a total of 4230 patients were eligible for quantitative synthesis. The pooled prevalence estimates of adequate thyroid replacement, over-replacement and under-replacement were 0.55 (95% confidence interval [CI]: 0.49-0.60, p = .001), 0.20 (95% CI: 0.14-0.27, p = .001) and 0.24 (95% CI: 0.13-0.36, p = .001), respectively. Four studies subclassified hypothyroidism and hyperthyroidism into overt and subclinical. The pooled prevalence of overt and subclinical hyperthyroidism was 0.04 (95% CI: 0.00-0.11, p = .01) and 0.17 (95% CI: 0.09-0.27 p = .001), respectively. For overt and subclinical hypothyroidism, the pooled prevalence was 0.02 (95% CI: 0.01-0.03, p = .001) and 0.20 (95% CI: 0.12-0.29, p = .001), respectively.

CONCLUSIONS

On average, approximately half of patients with hypothyroidism are only treated to target euthyroidism. In real-world practice, a significant number of patients are over-treated or under-treated, leading to adverse healthcare outcomes. It is imperative that more effective thyroid monitoring strategies be implemented, with an emphasis on primary care thyroid function monitoring, to minimise inappropriate thyroid replacement treatments and optimise healthcare outcomes at a population level.

Thyroid disease in ANCA-associated vasculitis: a clinical and epidemiological study

OBJECTIVES

To describe clinical and laboratory characteristics and outcomes in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and thyroid disease (TD). We also aimed to calculate incidence and identify predictors of TD in two large cohorts of patients with AAV.

METHODS

The study comprised 644 patients with AAV in a population-based cohort from southern Sweden (n=325) and a cohort from a specialised vasculitis centre in Cambridge, UK (n=319). Diagnosis and classification of AAV and TD were confirmed by medical record review. Person-years (PY) of follow-up were calculated from AAV diagnosis to the earliest of TD, death or the end of study. Cox-regression analysis was employed to study predictors of TD.

RESULTS

At AAV diagnosis, 100 individuals (15.5%, 77 females) had TD, 59 had myeloperoxidase (MPO)-ANCA+ and 34 had proteinase-3 (PR3)-ANCA+. Patients with TD tended to have lower C reactive protein, lower haemoglobin and fewer constitutional symptoms. Survival and renal survival was greater in those patients with AAV with pre-existing TD. During 4522 PY of follow-up, a further 29 subjects developed TD, yielding an incidence rate of 641/100 000 PY. No analysed factor predicted de novo TD in AAV. The prevalence of TD among patients with AAV in southern Sweden was 18%.

CONCLUSION

TD is a common comorbidity in AAV, affecting nearly one in five. While TD diagnosis is more common in females and MPO-ANCA+, these factors do not predict de novo TD after initiation of AAV treatment, necessitating monitoring of all patients with AAV with respect to this comorbidity.

Exploring the link between obesity and hypothyroidism in autoimmune thyroid diseases: a metabolic perspective

Background: The management of primary hypothyroidism demands a comprehensive approach that encompasses both the implications of autoimmune thyroid disease and the distinct effects posed by obesity and metabolic irregularities. Despite its clinical importance, the interplay between obesity and hypothyroidism, especially in the context of metabolic perspectives, is insufficiently explored in existing research. This study endeavors to classify hypothyroidism by considering the presence of autoimmune thyroid disease and to examine its correlation with various metabolic obesity phenotypes. Method: This research was conducted by analyzing data from 1,170 individuals enrolled in the Thyroid Disease Database of Shandong Provincial Hospital. We assessed four distinct metabolic health statuses among the participants: Metabolically Healthy No Obese Metabolically Healthy Obese Metabolically Unhealthy No Obese and Metabolically Unhealthy Obese Utilizing logistic regression, we investigated the association between various metabolic obesity phenotypes and hypothyroidism. Results: The study revealed a significant correlation between the Metabolically Unhealthy Obese (MUO) phenotype and hypothyroidism, particularly among women who do not have thyroid autoimmunity. Notably, the Metabolically Unhealthy No Obese (MUNO) phenotype showed a significant association with hypothyroidism in individuals with thyroid autoimmunity, with a pronounced prevalence in women. Furthermore, elevated levels of triglycerides and blood glucose were found to be significantly associated with hypothyroidism in men with thyroid autoimmunity and in women without thyroid autoimmunity. Conclusion: Effective treatment of hypothyroidism requires a thorough understanding of the process of thyroid autoimmune development. In patients without concurrent thyroid autoimmunity, there is a notable correlation between obesity and metabolic issues with reduced thyroid function. Conversely, for patients with thyroid autoimmunity, a focused approach on managing metabolic abnormalities, especially triglyceride levels, is crucial.

The genetic association between hyperthyroidism and heart failure: a Mendelian randomization study

Background and aims

Hyperthyroidism is an endocrine disease with multiple etiologies and manifestations. Heart failure (HF) is a common, costly, and deadly medical condition in clinical practice. Numerous studies have suggested that abnormal thyroid function can induce or aggravate the development of heart disease. However, no study has demonstrated a causal relationship between hyperthyroidism and heart failure. Therefore, the purpose of this study was to explore the causal link between hyperthyroidism and HF.

Methods

Summary data for genetically predicted hyperthyroidism were obtained from a genetic association study. The data examined for genetically determined all-cause heart failure came from 218,208 individuals from the FinnGen Consortium. Two-sample Mendelian randomization (MR) analysis was used to estimate the causal link between hyperthyroidism and heart failure. Statistical analyses were conducted using the inverse variance-weighted, weighted median, simple median, weighted mode, MR-PRESSO (number of distribution = 5000), MR-Egger, and leave-one-out.

Results

The results of the inverse-variance weighted analysis indicated a causal association between hyperthyroidism and an increased risk of all-cause heart failure (IVW: β=0.048, OR=1.049, 95%CI: [1.013 to 1.087], P=0.007). Similarly, the weighted median approach demonstrated a positive correlation between hyperthyroidism and all-cause heart failure (OR=1.049, [95% CI, 1.001-1.100]; P=0.044). Additionally, no horizontal pleiotropy or heterogeneity was observed. The leave-one-out analysis revealed that the majority of the SNP-driven associations were not influenced by a single genetic marker.

Conclusion

Our study observed a causal relationship between hyperthyroidism and all-cause heart failure. Hyperthyroidism may associate with heart failure genetically.

Prevalence and risk factors of thyroid nodules in breast cancer women with different clinicopathological characteristics: a cross-sectional study

BACKGROUND

Association between breast cancer (BC) and thyroid nodules (TNs) is still unclear. This research was to estimate the prevalence and risk factors of TN in Chinese BC women at initial diagnosis.

METHODS

1731 Chinese early-stage BC women at initial diagnosis underwent thyroid ultrasound and 1:1 age-matched Chinese healthy women underwent health examination in corresponding period were enrolled for analysis.

RESULTS

Prevalence of TN and TI-RADS ≥ 4 TN in BC patients (56.27% and 9.76%) were higher than healthy people (46.04% and 5.49%), respectively, P < 0.001. Among BC patients, prevalence of TN and TI-RADS ≥ 4 TN in hormone receptor (HR)-positive patients (59.57% and 11.81%) were higher than HR-negative patients (48.77% and 5.10%), respectively, P < 0.001, while without difference between HR-negative patients and healthy people. After adjusting for age and BMI, HR-positive patients had higher risk of TN (OR = 1.546, 95%CI 1.251-1.910, P < 0.001) and TI-RADS ≥ 4 TN (OR = 3.024, 95%CI 1.943-4.708, P < 0.001) than HR-negative patients. Furthermore, the risk of TI-RADS ≥ 4 TN was higher in patients with estrogen receptor (ER) positive (OR = 2.933, 95%CI 1.902-4.524), progesterone receptor (PR) positive (OR = 1.973, 95%CI 1.378-2.826), Ki-67 < 20% (OR = 1.797, 95%CI 1.280-2.522), and tumor size < 2 cm (OR = 1.804, 95%CI 1.276-2.552), respectively, P < 0.001.

CONCLUSIONS

Prevalence of TN, especially TI-RADS ≥ 4 TN, in Chinese early-stage BC women was higher than healthy people. HR-positive patients had higher prevalence and risk of TN, while without difference between HR-negative patients and healthy people. The increased risk of TN was correlated with ER-positive, PR-positive, lower Ki-67 expression, and smaller tumor size.

Thyroid diseases and female sexual dysfunctions

INTRODUCTION

Female sexual dysfunctions (FSDs) have received little attention in the context of thyroid diseases, despite the high prevalence of both conditions.

OBJECTIVES

This review aims to update and summarize the state of knowledge on the association between thyroid diseases and FSDs and to investigate the complex mechanisms through which thyroid hormone imbalance can impact female sexual health in the context of the biopsychosocial model.

METHODS

A comprehensive literature search was performed through the PubMed, MEDLINE, and Scopus databases, using the following keywords: "female sexual function," "sexual dysfunction," "hypoactive sexual desire disorder," "thyroid disease," "thyroiditis," "hypothyroidism," and "hyperthyroidism."

RESULTS

To date, well-designed studies that describe the relationship between FSDs and thyroid disorders are lacking. However, despite the limitations on available studies, current data indicate that sexual alterations are frequently associated with thyroid diseases in women. A complex interplay of direct and indirect hormonal and nonhormonal mechanisms has been hypothesized, including hormonal changes, neurotransmitter imbalance, reduced nitric oxide release, mood disorders, and other systemic consequences of both hypothyroidism and hyperthyroidism. Thyroid hormone receptors have also been identified in the genitourinary system.

CONCLUSIONS

In a clinical setting, physicians should investigate the sexuality of patients consulting for thyroid disease. At the same time, an evaluation of thyroid function should be performed in patients presenting with FSD, especially after menopause, when the risk of thyroid diseases and FSDs increases strongly.

Treatment of Hypothyroidism and Stress Using Neuro-Emotional Technique (NET): A Case Study

Hypothyroidism is generally considered an autoimmune condition, and typical medical management involves taking levothyroxine (synthetic thyroid hormone) for life. This case report details the results of a mind-body intervention (MBI) called the Neuro-Emotional Technique (NET) used to treat a 28-year-old Caucasian female presenting with symptoms and bloodwork markers associated with two years of hypothyroidism and a long history of stress. The patient's medical doctor provided a diagnosis of hypothyroidism after blood tests showed that thyroid-stimulating hormone (TSH) levels were high at 6.87 mIU/L (where the acceptable range is 0.40-3.50 mIU/L) and free T4 (FT4) levels were low at 8.6 pmol/L (where the acceptable range is 9.0-19.0 pmol/L). Psychometric tests were completed at baseline and after 12 weeks of treatment to evaluate changes in mental health and emotional well-being. The Adverse Childhood Experiences Questionnaire (ACE-Q) revealed a high degree of childhood trauma that may have predisposed to the underlying autoimmune thyroid dysfunction. At the conclusion of the treatment period, serum thyroid-stimulating hormone (TSH) and free T4 were within normal ranges and psychometric indicators normalized. We hypothesize that these changes may be due to the stress-reducing mechanism of NET and outline possible mechanisms via the Psycho-Immune-Neuroendocrine (PINE) network. The PINE network model asserts that chronic stress acts as a potential driver of pathophysiology that can lead to one or more medical and mental health conditions. While further studies with larger sample sizes are required to establish whether these results could be extrapolated to a wider population, the results of this case suggest that it may be pertinent to consider co-management of subclinical hypothyroidism with a relatively quick and cost-effective MBI such as NET.

Does thyroid diseases contribute to the natural history of idiopathic adult-onset dystonia? Data from the Italian Dystonia Registry

A few earlier observations and recent controlled studies pointed to the possible contribution of thyroid diseases in idiopathic adult-onset dystonia (IAOD). The aim of this study was to investigate the association between thyroid status and clinical characteristics of IAOD, focusing on dystonia localization, spread, and associated features such as tremors and sensory tricks. Patients were identified from those included in the Italian Dystonia Registry, a multicentre dataset of patients with adult-onset dystonia. The study population included 1518 IAOD patients. Patients with hypothyroidism and hyperthyroidism were compared with those without any thyroid disease. In the 1518 IAOD patients, 167 patients (11%; 95% CI 9.5-12.6%) were diagnosed with hypothyroidism and 42 (2.8%; 95% CI 1.99-3.74) with hyperthyroidism. The three groups were comparable in age at dystonia onset, but there were more women than men in the groups with thyroid disease. Analysing the anatomical distribution of dystonia, more patients with blepharospasm were present in the hyperthyroidism group, but the difference did not reach statistical significance after the Bonferroni correction. The remaining dystonia-affected body sites were similarly distributed in the three groups, as did dystonia-associated features and spread. Our findings provided novel information indicating that the high rate of thyroid diseases is not specific for any specific dystonia subpopulation and does not appear to influence the natural history of the disease.

HLA Class II Allele Groups Involved in Autoimmune Thyroid Diseases: Hashimoto's Thyroiditis and Basedow-Graves Disease

Autoimmune thyroid diseases (AITD), particularly Hashimoto's thyroiditis (HT) and Basedow-Graves disease (BGD) are diseases of global public health concern, characterized by autoimmune attacks on the thyroid gland, leading to hypothyroidism in HT and hyperthyroidism in BGD. We conducted a study between 2019 and 2021 in northwestern Transylvania (Romania) on patients with HT and with BGD compared to the control group. The aim of the study was to investigate the correlations of HLA class II alleles with AITD by identifying potential genetic susceptibility factors such as HLA-DRB1 and HLA-DQB1 genes in patients diagnosed with HT and BGD. Various molecular biology methods, including SSP-PCR low-resolution and PCR-SSO were employed to analyze DNA samples from patients and control subjects. Our study revealed the influence of the HLA-DRB1*03/*16 genotype as a genetic susceptibility factor for HT, a similar influence regarding BGD being observed for the HLA-DRB1*03 allele group, DRB1*03/*16 genotype, and the DRB1*03/DQB1*06 haplotype. The only protective factor detected in our study was the HLA-DRB1*13 allele group, for both HT and BGD. By elucidating any specific allele or genotype associations that might contribute to the development of AITD, our study can contribute to the prevention and early detection of these diseases.

Causal association between thyroid dysfunction and sepsis: a two-sample mendelian randomization study

Background

The causal association between thyroid dysfunction (including hyperthyroidism and hypothyroidism) and sepsis is controversial in previous studies. Therefore, we used Mendelian randomization (MR) to explore the causal association between hyperthyroidism or hypothyroidism and the susceptibility to four distinct subtypes of sepsis (streptococcal sepsis, puerperal sepsis, asthma-associated pneumonia or sepsis, and other sepsis).

Methods

In our research, we conducted two-sample Mendelian randomization (MR) analyses utilizing publicly available genome-wide association studies (GWAS) data from Sakaue et al. and the Finnish database to investigate the potential causal associations between hyperthyroidism, hypothyroidism, and each of the four distinct subtypes of sepsis, in addition to reverse MR analyses of the positive results to examine the existence of reverse causality.

Results

Genetic hypothyroidism was causally related to the development of asthma-associated pneumonia or sepsis (ORIVW: 1.097, 95% CI: 1.024 to 1.174, P = 0.008); hypothyroidism was significantly associated with the development of other sepsis (ORIVW: 1.070, 95% CI: 1.028 to 1.115, P < 0.001). In addition, sensitivity analysis substantiated the robustness of these two MR findings, with no evidence of horizontal pleiotropy observed (P > 0.05). MR Egger regression analysis demonstrated no heterogeneity between instrumental variables (IVs). Inverse MR results confirmed no reverse causality between hypothyroidism and asthma-associated pneumonia or sepsis, or between hypothyroidism and other sepsis. The findings of this study also unveiled that there is no evidence of a causal link between hypothyroidism and the development of streptococcal sepsis or puerperal sepsis. Additionally, the research provided evidence indicating the absence of a causal relationship between hyperthyroidism and streptococcal sepsis, puerperal sepsis, asthma-associated pneumonia or sepsis, and other sepsis.

Conclusions

This study identified a causal link between hypothyroidism and the occurrence of asthma-associated pneumonia or sepsis, and other sepsis, but not with the development of streptococcal sepsis and puerperal sepsis. Moreover, our findings did not reveal any causal association between hyperthyroidism and streptococcal sepsis, puerperal sepsis, asthma-associated pneumonia or sepsis, and other sepsis.

GRADE-ADOLOPMENT of hyperthyroidism treatment guidelines for a Pakistani context

INTRODUCTION

The prevalence of hyperthyroidism in Pakistan is 2.9%, which is two times higher than in the United States. Most high-quality hyperthyroidism clinical practice guidelines (CPGs) used internationally originate from high-income countries in the West. Local CPGs in Pakistan are not backed by transparent methodologies. We aimed to produce comprehensive, high-quality CPGs for the management of hyperthyroidism in Pakistan.

METHODS

We employed the GRADE-ADOLOPMENT approach utilizing the 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis as the source CPG. Recommendations from the source guideline were either adopted as is, excluded, or adapted according to our local context.

RESULTS

The source guideline included a total of 124 recommendations, out of which 71 were adopted and 49 were excluded. 4 recommendations were carried forward for adaptation via the ETD process, with modifications being made to 2 of these. The first addressed the need for liver function tests (LFTs) amongst patients experiencing symptoms of hepatotoxicity while being treated with anti-thyroid drugs (ATDs). The second pertained to thyroid status testing post-treatment by radioactive iodine (RAI) therapy for Graves' Disease (GD). Both adaptations centered around the judicious use of laboratory investigations to reduce costs of hyperthyroidism management.

CONCLUSION

Our newly developed hyperthyroidism CPGs for Pakistan contain two context-specific modifications that prioritize patients' finances during the course of hyperthyroidism management and to limit the overuse of laboratory testing in a resource-constrained setting. Future research must investigate the cost-effectiveness and risk-benefit ratio of these modified recommendations.

Autoimmune Thyroid Diseases

Autoimmune thyroid diseases (AITDs) include a wide spectrum of thyroid diseases affecting more commonly women than men. The most frequent forms are Graves' Disease (GD) and Hashimoto's thyroiditis / Autoimmune Thyroiditis (AIT), but there are also other immunogenic destructive forms of thyroiditis, that is, silent and postpartum thyroiditis. In the last decade, AITDs and other inflammatory thyroid diseases related to anti-tumor molecular drugs are more frequently seen due to the widespread use of tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICPIs). Autoimmune thyroiditis related to SARS-CoV-2 infection has been a novel entity in recent years. Graves' Disease and AIT may shift from hyperthyroidism to hypothyroidism, which may complicate the differential diagnosis and further treatment strategy. Moreover, all AITDs may manifest with thyrotoxicosis (a clinical condition marked with high serum levels of thyroid hormones) which has to be distinguished from hyperthyroidism (increased thyroid hormone production and secretion as a result of hyperfunctioning thyroid gland) due to different therapeutic approaches. Nuclear medicine techniques, such as radioiodine uptake (RAIU) and thyroid scintigraphy, using 99mTc- pertechnetate (Na[99mTc]TcO4) or 123-Iodine (Na[123I]I), have a crucial role in the differential diagnosis. Measurement of thyroid antibodies, e.g. thyroid peroxidase antibodies (TPO) and thyrotropin receptor antibodies (TRAb), as well as thyroid ultrasound, are complementary methods in the evaluation of thyroid disorders.

Elevated TSH Levels: A Database Study of General Practitioners' Course of Action

OBJECTIVE

To investigate general practitioners' course of action after detection of elevated thyroid stimulating hormone (TSH) levels regarding repeat testing, direct levothyroxine replacement, or neither.

METHODS

We conducted a retrospective study of adults without prior evidence of thyroid disease and with a first detection of elevated TSH levels from January 1, 2015, to December 31, 2020, using data from electronic medical records of a Swiss primary care database. We determined the occurrence of either repeat TSH testing or direct levothyroxine initiation in primary care during 12-month follow-up and determined associations with demographic and clinical factors.

RESULTS

Of the 1 591 patients included (median age 65 years, 64.4% female, median TSH 5.7 mIU/L), 34.3% received repeat TSH testing and 12.4% received direct levothyroxine replacement in primary care during follow-up. Repeat TSH testing showed the strongest association with overt hypothyroidism and was more common among patients with high primary care utilization and among patients aged 40-64 years compared to patients aged <40 years. Direct levothyroxine initiation was more likely for TSH levels >7 mIU/L, overt hypothyroidism, female patients, and nonurban practices.

CONCLUSIONS

While the degree of thyroid dysfunction was the main driver of follow-up, we identified important gaps in the primary care-based monitoring of elevated TSH levels in young patients and in patients with infrequent consultations. We also observed potential overtreatment of women and patients in nonurban areas. Our findings highlight the need for standardization and dissemination of guidelines for the management of elevated TSH levels among general practitioners.

Causal effect of gut microbiota of Defluviitaleaceae on the clinical pathway of "Influenza-Subacute Thyroiditis-Hypothyroidism"

Introduction

Hypothyroidism has been found to be influenced by gut microbiota. However, it remains unclear which a taxon of gut microbiota plays a key role in this function. Identifying the key bacteria affects hypothyroidism and through what mechanism will be helpful for the prevention of hypothyroidism through specific clinical pathways.

Materials and methods

In Study A, 35 families and 130 genera of gut microbiota are used as exposures, with hypothyroidism as the outcome. The causal effect of the gut microbiota on hypothyroidism is estimated through two-sample Mendelian randomization. Combining the results of the two taxonomical levels, key taxa are selected, which in Study B are investigated for their causal association with multiple generally admitted causes of hypothyroidism and their more upstream factors. For validating and revealing the potential mechanism, enrichment analyses of the related genes and interacting transcription factors were performed.

Results

In Study A, Defluviitaleaceae (OR: 0.043, 95% CI: 0.005-0.363, P = 0.018)/Defluviitaleaceae_UCG_011 (OR: 0.385, 95% CI: 0.172-0.865, P = 0.021) are significantly causally associated with hypothyroidism at both taxonomical levels. In Study B, Defluviitaleaceae family and Defluviitaleaceae_UCG_011 genus show the causal association with decreased thyroiditis (Family: OR: 0.174, 95% CI: 0.046-0.653, P = 0.029; Genus: OR: 0.139, 95% CI: 0.029-0.664, P = 0.043), decreased subacute thyroiditis (Family: OR: 0.028, 95% CI: 0.004-0.213, P = 0.007; Genus: OR: 0.018, 95% CI: 0.002-0.194, P = 0.013), decreased influenza (Family: OR: 0.818, 95% CI: 0.676-0.989, P = 0.038; Genus: OR: 0.792, 95% CI: 0.644-0.974, P = 0.027), and increased anti-influenza H3N2 IgG levels (Family: OR: 1.934, 95% CI: 1.123-3.332, P = 0.017; Genus: OR: 1.675, 95% CI: 0.953-2.943, P = 0.073). The results of the enrichment analysis are consistent with the findings and the suggested possible mechanisms.

Conclusion

Defluviitaleaceae of the gut microbiota displays the probability of causally inhibiting the clinical pathway of "Influenza-Subacute Thyroiditis-Hypothyroidism" and acts as the potential probiotics to prevent influenza, subacute thyroiditis, and hypothyroidism.

Hyperthyroidism

Thyrotoxicosis causes a variety of symptoms and adverse health outcomes. Hyperthyroidism refers to increased thyroid hormone synthesis and secretion, most commonly from Graves' disease or toxic nodular goitre, whereas thyroiditis (typically autoimmune, viral, or drug induced) causes thyrotoxicosis without hyperthyroidism. The diagnosis is based on suppressed serum concentrations of thyroid-stimulating hormone (TSH), accompanied by free thyroxine and total or free tri-iodothyronine concentrations, which are raised (overt hyperthyroidism) or within range (subclinical hyperthyroidism). The underlying cause is determined by clinical assessment, detection of TSH-receptor antibodies and, if necessary, radionuclide thyroid scintigraphy. Treatment options for hyperthyroidism include antithyroid drugs, radioactive iodine, and thyroidectomy, whereas thyroiditis is managed symptomatically or with glucocorticoid therapy. In Graves' disease, first-line treatment is a 12-18-month course of antithyroid drugs, whereas for goitre, radioactive iodine or surgery are preferred for toxic nodules or goitres. Evidence also supports long-term treatment with antithyroid drugs as an option for patients with Graves' disease and toxic nodular goitre.

From Viral Infection to Autoimmune Reaction: Exploring the Link between Human Herpesvirus 6 and Autoimmune Diseases

The complexity of autoimmunity initiation has been the subject of many studies. Both genetic and environmental factors are essential in autoimmunity development. Among others, environmental factors include infectious agents. HHV-6 is a ubiquitous human pathogen with a high global prevalence. It has several properties suggestive of its contribution to autoimmunity development. HHV-6 has a broad cell tropism, the ability to establish latency with subsequent reactivation and persistence, and a range of immunomodulation capabilities. Studies have implicated HHV-6 in a plethora of autoimmune diseases-endocrine, neurological, connective tissue, and others-with some studies even proposing possible autoimmunity induction mechanisms. HHV-6 can be frequently found in autoimmunity-affected tissues and lesions; it has been found to infect autoimmune-pathology-relevant cells and influence immune responses and signaling. This review highlights some of the most well-known autoimmune conditions to which HHV-6 has been linked, like multiple sclerosis and autoimmune thyroiditis, and summarizes the data on HHV-6 involvement in autoimmunity development.

Thyroid ultrasound and its ancillary techniques

Ultrasound (US) of the thyroid has been used as a diagnostic tool since the late 1960s. US is the most important imaging tool for diagnosing thyroid disease. In the majority of cases a correct diagnosis can already be made in synopsis of the sonographic together with clinical findings and basal thyroid hormone parameters. However, the characterization of thyroid nodules by US remains challenging. The introduction of Thyroid Imaging Reporting and Data Systems (TIRADSs) has improved diagnostic accuracy of thyroid cancer significantly. Newer techniques such as elastography, superb microvascular imaging (SMI), contrast enhanced ultrasound (CEUS) and multiparametric ultrasound (MPUS) expand diagnostic options and tools further. In addition, the use of artificial intelligence (AI) is a promising tool to improve and simplify diagnostics of thyroid nodules and there is evidence that AI can exceed the performance of humans. Combining different US techniques with the introduction of new software, the use of AI, FNB as well as molecular markers might pave the way for a completely new area of diagnostic accuracy in thyroid disease. Finally, interventional ultrasound using US-guided thermal ablation (TA) procedures are increasingly proposed as therapy options for benign as well as malignant thyroid diseases.

Clinical and molecular impact of concurrent thyroid autoimmune disease and thyroid cancer: From the bench to bedside

The recent incorporation of immune checkpoint inhibitors targeting the PD-1 (programmed cell death receptor 1) and CTLA-4 (cytotoxic T lymphocyte antigen 4) pathways into the therapeutic armamentarium of cancer has increased the need to understand the correlation between the immune system, autoimmunity, and malignant neoplasms. Both autoimmune thyroid diseases and thyroid cancer are common clinical conditions. The molecular pathology of autoimmune thyroid diseases is characterized by the important impact of the PD-1/PD-L1 axis, an important inhibitory pathway involved in the regulation of T-cell responses. Insufficient inhibitory pathways may prone the thyroid tissue to a self-destructive immune response that leads to hypothyroidism. On the other hand, the PD-1/PD-L1 axis and other co-inhibitory pathways are the cornerstones of the immune escape mechanisms in thyroid cancer, which is a mechanism through which the immune response fails to recognize and eradicate thyroid tumor cells. This common mechanism raises the idea that thyroid autoimmunity and thyroid cancer may be opposite sides of the same coin, meaning that both conditions share similar molecular signatures. When associated with thyroid autoimmunity, thyroid cancer may have a less aggressive presentation, even though the molecular explanation of this clinical consequence is unclear. More studies are warranted to elucidate the molecular link between thyroid autoimmune disease and thyroid cancer. The prognostic impact that thyroid autoimmune disease, especially chronic lymphocytic thyroiditis, may exert on thyroid cancer raises important insights that can help physicians to better individualize the management of patients with thyroid cancer.

The causal relationship between 41 inflammatory cytokines and hypothyroidism: bidirectional two-sample Mendelian randomization study

Objective

Investigating the association between inflammatory cytokines and hypothyroidism remains challenging due to limitations in traditional observational studies. In this study, we employed Mendelian randomization (MR) to assess the causal relationship between 41 inflammatory cytokines and hypothyroidism.

Method

Inflammatory cytokines in 30,155 individuals of European ancestry with hypothyroidism and in a GWAS summary containing 8,293 healthy participants were included in the study for bidirectional two-sample MR analysis. We utilized inverse variance weighting (IVW), weighted median (WM), and Mendelian randomization-Egger (MR-Egger) methods. Multiple sensitivity analyses, including MR-Egger intercept test, leave-one-out analysis, funnel plot, scatterplot, and MR-PRESSO, were applied to evaluate assumptions.

Results

We found evidence of a causal effect of IL-7 and macrophage inflammatory protein-1β (MIP-1β) on the risk of hypothyroidism, and a causal effect of hypothyroidism on several cytokines, including granulocyte colony-stimulating factor (G-CSF), IL-13, IL-16, IL-2rα, IL-6, IL-7, IL-9, interferon-γ-inducible protein 10 (IP10), monokine induced by interferon (IFN)-γ (MIG), macrophage inflammatory protein-1β (MIP-1β), stem cell growth factors-β (SCGF-β), stromal cell derived factor-1α (SDF-1α), and tumor necrosis factor-α (TNF-α).

Conclusion

Our study suggests that IL-7 and MIP-1β may play a role in the pathogenesis of hypothyroidism, and that hypothyroidism may induce a systemic inflammatory response involving multiple cytokines. These findings may have implications for the prevention and treatment of hypothyroidism and its complications. However, further experimental studies are needed to validate the causal relationships and the potential of these cytokines as drug targets.

Association of prolonged occupational co-exposures to electromagnetic fields, noise, and rotating shift work with thyroid hormone levels

The purpose of this study was to determine the association of prolonged occupational co-exposure to extremely low-frequency electromagnetic fields (ELF-EMFs), noise, and rotating shift work with the levels of thyroid hormones (triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH). From 2016 to 2017, we enrolled all male workers without a history of thyroid disorders and followed them until 2020. To measure ELF-EMFs and noise exposures, we calculated the 8-hour equivalent sound pressure levels (Leq) and the 8-hour average of ELF-EMFs, respectively. Shift work schedules involved 8-hr fixed day and 8-hr clockwise 3-rotating night schedules. The participant's thyroid hormone levels were obtained from blood test results in their medical records. The percentage change in the levels of T3, T4, and TSH was estimated by using different mixed-effects linear regression models. The TSH levels were significantly elevated per a 10-dB increment of noise. The levels of T4 hormone were significantly changed per a unit increase in the levels of ELF-EMFs. Compared to the fixed-day workers, we observed workers exposed to shift work had a significantly lower T4 level. For T4 and TSH hormones, we found significant interactions among noise, ELF-EMFs, and shift work variables. In summary, this study warranted that prolonged exposure to ELF-EMFs, noise, and rotating shift work might be associated with thyroid dysfunction.

Effect of probiotics or prebiotics on thyroid function: A meta-analysis of eight randomized controlled trials

BACKGROUND

Microbiome-directed therapies are increasingly utilized to optimize thyroid function in both healthy individuals and those with thyroid disorders. However, recent doubts have been raised regarding the efficacy of probiotics, prebiotics, and synbiotics in improving thyroid function. This systematic review aimed to investigate the potential relationship between probiotics/prebiotics and thyroid function by analyzing the impact on thyroid hormone levels.

METHODS

We conducted a comprehensive systematic review and meta-analysis of randomized controlled trials that investigated the effects of probiotics, prebiotics, and synbiotics on free triiodothyronine (fT3), free thyroxine (fT4), thyroid stimulating hormone (TSH), and thyroid stimulating hormone receptor antibody (TRAb) levels. We searched for articles from PubMed, Scopus, Web of Science, and Embase up until April 1st, 2023, without any language restriction. Quantitative data analysis was performed using a random-effects model, with standardized mean difference (SMD) and 95% confidence interval as summary statistics. The methods and results were reported according to the PRISMA2020 statement.

RESULTS

A total of eight articles were included in this review. The meta-analysis showed no significant alterations in TSH (SMD: -0.01, 95% CI: -0.21, 0.20, P = 0.93; I2: 0.00%), fT4 (SMD: 0.04, 95% CI: -0.29, 0.21, P = 0.73; I2: 0.00%) or fT3 (SMD: 0.45, 95% CI: -0.14, 1.03, P = 0.43; I2: 78.00%), while a significant reduction in TRAb levels was observed (SMD: -0.85, 95% CI: -1.54, -0.15, P = 0.02; I2: 18.00%) following probiotics/prebiotics supplementation. No indication of publication bias was found.

CONCLUSIONS

Probiotics/prebiotics supplementation does not influence thyroid hormone levels, but may modestly reduce TRAb levels in patients with Graves' disease.

Causal association between obesity and hypothyroidism: a two-sample bidirectional Mendelian randomization study

Introduction

Previous observational studies have reported a positive correlation between obesity and susceptibility to hypothyroidism; however, there is limited evidence from alternative methodologies to establish a causal link.

Methods

We investigated the causal relationship between obesity and hypothyroidism using a two-sample bidirectional Mendelian randomization (MR) analysis. Single-nucleotide polymorphisms (SNPs) associated with obesity-related traits were extracted from a published genome-wide association study (GWAS) of European individuals. Summarized diagnostic data of hypothyroidism were obtained from the UK Biobank. Primary analyses were conducted using the inverse variance-weighted (IVW) method with a random-effects model as well as three complementary approaches. Sensitivity analyses were performed to ascertain the correlation between obesity and hypothyroidism.

Results

MR analyses of the IVW method and the analyses of hypothyroidism/myxedema indicated that body mass index (BMI) and waist circumference (WC) were significantly associated with higher odds and risk of hypothyroidism. Reverse MR analysis demonstrated that a genetic predisposition to hypothyroidism was associated with an increased risk of elevated BMI and WC, which was not observed between WC adjusted for BMI (WCadjBMI) and hypothyroidism.

Discussion

Our current study indicates that obesity is a risk factor for hypothyroidism, suggesting that individuals with higher BMI/WC have an increased risk of developing hypothyroidism and indicating the importance of weight loss in reducing the risk of hypothyroidism.

Subclinical thyroid dysfunction and the risk of incident atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Thyroid hormones act on the cardiovascular system directly by modulating its function and indirectly by transcriptional regulation of gene expression in the heart and the vasculature. Studies have shown associations between overt and subclinical thyroid disorders and cardiovascular outcomes. The aim of this study was to perform a systematic review and meta-analysis to assess the potential relationships between subclinical hyper- and hypothyroidism and risk of atrial fibrillation (AF), and post-operative AF.

METHODS

MEDLINE and Scopus databases were searched from inception to 18th February 2023 for randomised controlled trials, case-control studies, and cohort studies which assessed the relationship between subclinical thyroid dysfunction and incident AF events. Risk of bias and the quality of evidence were assessed using the RoBANS tool and GRADE approach, respectively. Meta-analysis was conducted in Review Manager 5.4 using the Mantel-Haenszel statistical method and a random-effects model. Data are presented as risk ratios with 95% confidence intervals. Statistical heterogeneity amongst studies was assessed by the chi-squared (χ2) test and I2 statistic. p≤0.05 were considered significant.

RESULTS

A total of 6467 records were identified, of which 10 cohort studies met the inclusion criteria. Both subclinical hyperthyroidism and subclinical hypothyroidism were associated with an increased risk of incident AF (risk ratio (RR), 1.99; 95% confidence interval (CI), 1.43-2.77; n = 5 studies; p<0.0001 and RR, 1.19; CI, 1.03-1.39; n = 7 studies; p = 0.02, respectively). Subgroup analysis for post-operative AF revealed marked heterogeneity between studies (I2 = 84%) and association with subclinical hypothyroidism was not significant (RR, 1.41; CI, 0.89-2.22; n = 3 studies; p = 0.15).

CONCLUSIONS

The current evidence suggests that both subclinical hyperthyroidism and subclinical hypothyroidism are associated with increased risk of incident AF. Further investigation is required to determine potential causal links that would guide future clinical practice.

Influence of silver nanoparticles on mRNA expression of thyroid hormone-related genes in the thyroid gland and liver of laying hens

The widespread use of silver nanoparticles (AgNPs) in consumer products and animal husbandry raises the need to study their impact on living organisms. This study was conducted on Hy-Line Brown hens at the age of 25 weeks with an average weight of 1.58 kg. Hens for 2 weeks received a solution of 50 nm AgNPs at a concentration of 100 pm (experimental group; n = 6) or a solution in which the nanoparticles were suspended (control group; n = 6). Thyroid hormones (thyroxine - T4, triiodothyronine - T3) were evaluated in the blood plasma and expression profiles of genes involved in thyroid hormone (TH) synthesis (TSHR, NIS, TPO, TG), metabolism (DIO1, DIO2, DIO3) and transport (MCT8, MCT10, LAT1) were determined in the chicken thyroid gland. Furthermore, iodothyronine deiodinase, TH transporter and TH receptor (THRA, THRB) mRNA expressions were evaluated in the livers isolated from the same chickens. AgNPs did not affect serum T4 levels but elevated serum T3 concentration. The results showed that AgNPs increased DIO3 mRNA in the thyroid gland. In turn, in the liver AgNPs administration significantly upregulated DIO2 and downregulated MCT10 mRNA levels. These results indicate that exposure to AgNPs leads to a tissue-specific alternative expression of genes engaged in TH metabolism. Moreover, the mRNA expression of DIO2 in the liver showed a positive correlation with plasma T3 levels. In conclusion, AgNPs may have an impact on TH metabolism by affecting deiodinases and TH transporter MCT10 mRNA expression.

The prevalence of subclinical hypothyroidism in a pre-diabetes population and an analysis of related factors

BACKGROUND

To investigate the prevalence and related influencing factors of subclinical hypothyroidism (SCH) in a pre-diabetes (PreDM) population.

PATIENTS AND METHODS

A multi-stage stratified cluster random sampling method was used to select the adult Han population in Gansu Province for investigation. General data and related biochemical indices were recorded and SPSS software was used for statistical analyses.

RESULTS

This study selected 2876 patients, including 548 with SCH and 433 with PreDM. In the PreDM population, the levels of thyroid stimulating hormone (TSH), serum phosphorus, TPOAb and TgAb in the SCH group were higher than those in the euthyroid group (P < 0.05). The level of TPOAb in females of SCH group was higher than that in males (P < 0.05). The positive rates of TPOAb and TgAb in females were higher than those in males in the total population and SCH population. The prevalence of SCH in the PreDM group under 60 was significantly higher than that in the normal glucose tolerance (NGT) group (26.02% vs. 20.40%, χ² = 5.150, P < 0.05). We defined SCH as a TSH level of >4.20 mIU/L. Using this criterion, the prevalence of SCH in the total population of PreDM was higher than that in the NGT population (χ² = 8.611, P < 0.05), the prevalence of SCH in the PreDM population generally showed an upward trend. However, we performed a separate analysis considering the accepted impact of age on TSH redefining SCH as TSH >8.86 mIU/L (for individuals over age 65). However, allowing for the expected rise in TSH levels in individuals over age 65, the prevalence of SCH in the elderly over 65 years of age decreased significantly (NGT population from 27.48% to 9.16%, PreDM population from 34.18% to 6.33%, P < 0.05). Logistic regression analysis showed that the risk factors for SCH in the PreDM population were female gender, fasting plasma glucose and TSH (all P < 0.05). Risk factors for SCH in the impaired fasting glucose (IFG) population were female gender, OGTT 2 h, TSH and TPOAb (all P < 0.05).

CONCLUSION

The prevalence of SCH in the PreDM population not considering the known physiological increase in age related TSH was relatively high and was significant in female and the IFG population. However, the effect of age on these findings needs to attract more attention.

Association study of urinary iodine concentrations and coronary artery disease among adults in the USA: National Health and Nutrition Examination Survey 2003-2018

Iodine is a vital trace element in the human body and is associated with several important coronary artery disease (CAD) risk factors. We aimed to explore the correlation between urinary iodine concentration (UIC) and CAD. Data from 15 793 US adults in the National Health and Nutrition Examination Survey (2003-2018) were analysed. We conducted multivariable logistic regression models and fitted smoothing curves to study the correlation between UIC and CAD. Furthermore, we performed subgroup analysis to investigate possible effect modifiers between them. We found a J-shaped association between UIC and CAD, with an inflection point at Lg UIC = 2·65 μg/l. This result indicated a neutral association (OR 0·89; 95 % CI 0·68, 1·16) between UIC and CAD as Lg UIC < 2·65 μg/l, but the per natural Lg [UIC] increment was OR 2·29; 95 % CI 1·53, 3·43 as Lg UIC ≥ 2·65 μg/l. An interaction between diabetes and UIC might exist. The increase in UIC results in an increase in CAD prevalence (OR 1·84, 95 % CI 1·32, 2·58) in diabetes but results in little to no difference in non-diabetes (OR 0·98, 95 % CI 0·77, 1·25). The J-shaped correlation between UIC and CAD and the interaction between diabetes and UIC should be confirmed in a prospective study with a series of UIC measurements. If excessive iodine precedes CAD, then this new finding could guide clinical practice and prevent iodine deficiency from being overcorrected.

Correlation of subclinical hypothyroidism with sarcopenia and its components in the Chinese older adults

OBJECTIVE

To identify the correlation of thyroid function and subclinical hypothyroidism (SCH) with sarcopenia and its components in the older Chinese adults.

METHODS

Older adults were recruited and divided into SCH group and non-SCH group. Free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured by electrochemiluminescence. Appendicular skeletal muscle mass (ASM) was measured, and skeletal muscle index (SMI) was further calculated. Grip strength was measured. Physical performance was graded by the Short Physical Performance Battery (SPPB) scores of the gait speed test, chair stand test and balance test.

RESULTS

Of the 240 older adults included, 48 (20.00%) presented with SCH. The prevalence of sarcopenia in SCH group was higher than that in non-SCH group (33.33% v.s. 18.75%). Grip strength was significantly lower in patients with SCH than those without sarcopenia. In terms of physical performance, 6-meter gait speed and SPPB score were lower in subjects with SCH than those without SCH, while 5 sit-to-stand movements was longer score in subjects with SCH than those without SCH. SCH was significantly correlated with sarcopenia, while FT3, FT4, and TSH levels were not. SCH was significantly correlated with low muscle strength and low muscle mass, but not with low physical performance. FT3 level was positively correlated with grip strength and SMI. TSH level was negatively correlated with grip strength, 6-meter gait speed, and SPPB score, but positively correlated with the time of 5 sit-to-stand movements.

CONCLUSION

SCH is a risk factor for sarcopenia in the older adults and correlated with low muscle strength and low muscle mass, but not with low physical performance. FT3, FT4 and TSH levels are associated with sarcopenia components, but not with sarcopenia.

Multiparametric ultrasound-based assessment of overt hyperthyroid diffuse thyroid disease

Introduction

Hyperthyroidismis a prevalent condition affecting global populations, with an overall prevalence of 1.2%. Our research aimed to establish a systematic diagnostic approach using multiparametric ultrasound (MPUS) to diagnose hyperthyroid diffuse thyroid disease (DTD).

Methods

We conducted a retrospective study from June 2021 to June 2023 at a specialized endocrinology center in Timisoara, Romania, enrolling subjects presenting with clinical hyperthyroidism. Using the Mach 30 Aixplorer ultrasound equipment, evaluations were performed initially in B-mode US, followed by Color Doppler and Spectral Doppler measurements, and finally, 2D Shear wave elastography (SWE).

Results

From the 218 patients analyzed, the diagnosis of DTD with hyperthyroidism was confirmed through biochemical assessment, subgrouping various pathologies such as subacute thyroiditis, Graves' disease, painless thyroiditis, Hashimoto's thyroiditis, iatrogenic, as well as healthy controls. In the first step, B-mode hypoechogenicity had an AUC of 0.951 for DTD detection. In the second step, the peak systolic velocity differentiated Graves' disease with a median of 42.4 cm/s and an AUC of 1. Lastly, the third step consisted of SWE evaluation, revealing a mean elasticity index in the SAT subgroup significantly higher from other subgroups (p<0.001) with an AUC of 1.

Conclusion

Our study offers a step-by-step evaluation algorithm for DTD diagnosis, with a very good overall diagnostic performance (AUC of 0.946).

Prevalence of thyroid dysfunction among Iranian older adults: a cross-sectional study

There is limited data on the prevalence of thyroid dysfunction in the older population. This study aimed to determine the prevalence of thyroid dysfunction among a sample of Iranian older adults. A cross-sectional analysis of older adults who aged 60 years and over was conducted. A total of 363 subjects were randomly selected from Birjand longitudinal aging study (BLAS) cohort study. Serum thyroid-stimulating hormone (TSH) level, total thyroxine (T4) and total triiodothyronine (T3) were measured by the enzyme-linked immunosorbent assay (ELISA). Based on thyroid function tests and history of taking medicines used to treat thyroid disorders, participants were classified into the following groups: euthyroid, overt/subclinical hypothyroidism, and overt/subclinical hyperthyroidism. Subsequently, the crude and World Health Organization (WHO) age-standardized prevalence were estimated for different thyroid function categories. A total of 171 men and 192 women, aged 60-94 years, were randomly selected. The crude prevalence of total hypothyroidism was 22.31% (subclinical [18.46%], overt [3.86%]), and that of hyperthyroidism was 1.66% (subclinical [1.38%], overt [0.28%]). The crude prevalence of total thyroid dysfunction was, therefore, 23.97%. A female preponderance was noticed in both total (P-value = 0.035) and overt (P-value = 0.035) hypothyroidism. An increasing trend with age was noticed in the prevalence of total hypothyroidism (P-value = 0.049). Age-standardized prevalence of total hypothyroidism and hyperthyroidism was 26.63% (95% confidence interval [CI] 20.58-33.69%) and 1.11% (95% CI 0.49-2.51%), respectively. A considerable proportion of our study population demonstrated evidence of thyroid dysfunction, particularly subclinical hypothyroidism. Our findings highlight the importance of further investigation of thyroid disorders among older Iranian adults.

Increased prevalence of thyroid dysfunction in Tehran - HAMRAH study

BACKGROUND

The aim of the current study is to assess the prevalence of different categories of thyroid dysfunction and their associated risk factors among the modern urban population of Tehran, the capital of Iran.

METHODS

The present investigation is a sub-study of the HAMRAH study, a population-based prospective study designed to assess the prevalence of traditional cardiovascular risk factors and their changes through a 10-year follow-up. 2228 (61% female) adults aged between 30 and 75 years old and with no overt cardiovascular diseases were selected through a multistage cluster randomized sampling. Blood levels of thyroid-stimulating hormone (TSH), thyroxin (T4), and triiodothyronine (T3) were measured with the aim of assessing the prevalence of abnormal thyroid function status among the modern urban Iranian population, and in order to report the total prevalence of participants with clinical hypo- or hyperthyroidism, the number of individuals taking thyroid-related drugs were added to the ones with overt thyroid dysfunction. A subgroup analysis was also performed to determine the associated risk factors of thyroid dysfunction.

RESULTS

The prevalence of thyroid dysfunction among the total population was 7% (95%CI: 5.9 - 8%) and 0.4% (95% CI: 0.1 - 0.6%) for subclinical and overt hypothyroidism, and 1.6% (95% CI: 1 - 2%) and 0.2% (95% CI: 0 - 0.3%) for subclinical and overt hyperthyroidism, respectively. Clinical thyroid dysfunction was detected in 10.3% of the study population (9.4% had clinical hypo- and 0.9% had clinical hyperthyroidism). In the subgroup analysis, thyroid dysfunction was significantly more prevalent among the female participants (P-value = 0.029).

CONCLUSIONS

In the current study, the prevalence of different categories of abnormal thyroid status, and also the rate of clinical hypo- and hyperthyroidism was assessed using the data collected from the first phase of the HAMRAH Study. In this study, we detected a higher prevalence of clinical and subclinical hypothyroidism among the Iranian population compared to the previous studies.

Thyroid function and opium use disorder: a cross-sectional study on the Fasa adults cohort study (FACS), 2017

BACKGROUND

Addiction increases the risk of different lifelong disorders. However, there are limited studies evaluating the effects of opioid use disorder (OUD) on thyroid function. The present study aimed to compare the thyroid function of individuals with and without OUD.

METHODS

This cross-sectional study was conducted on 700 eligible participants of the Persian Cohort of Fasa, Iran. Pregnant women and participants with false or missing data were excluded from the study. Remained participants were divided into case and control groups based on the recorded history of OUD. Frozen plasma samples of the cohort bank were used to determine the levels of T3, T4, and thyroid-stimulating hormone (TSH). The thyroid function was compared between the two groups using the Mann-Whitney test (P < 0.05).

RESULTS

The mean age of the final studied population (n = 648) was 54.0 ± 9.8 years, including 336 men (49.1%) and 197 participants with OUD (28.8%). The median levels of TSH, T4, and T3 were 2.91 ± 4.61, 9.26 ± 3.65, and 1.22 ± 0.49, respectively. The case group had significantly higher TSH (3.72 ± 6.2 vs. 2.58 ± 3.75, P < 0.001) and lower T4 (8 ± 3.6 vs. 9.8 ± 3.5, P < 0.001). Also, T3 was slightly lower in the case group (1.1 ± 0.5 vs. 1.3 ± 0.5; P = 0.369), although this association was only significant in female opium users (P < 0.001).

CONCLUSIONS

The present findings revealed that OUD caused a reduction in T4 while increasing TSH. Therefore, OUD may lead to the development of primary hypothyroidism, which needs to be investigated in future studies.

Thyroid dysfunction and risk of cutaneous malignant melanoma: a bidirectional two-sample Mendelian randomization study

Background

Epidemiologic and observational data have found a risk association between thyroid dysfunction and cutaneous malignant melanoma (CMM), however, the cause and direction of these effects are yet unknown. By using a bidirectional two-sample Mendelian randomization (MR) methodology, we hoped to further investigate the causal link between thyroid dysfunction and CMM in this work.

Methods

A genome-wide association study (GWAS) of 9,851,867 single nucleotide polymorphisms (SNPs) in a European population was used to develop genetic tools for thyroid dysfunction. Hypothyroidism was linked to 22,687 cases and 440,246 controls. For hyperthyroidism, there were 3545 cases and 459,388 controls. A total of 3751 cases and 372016 controls were included in the genetic data for CMM from UK Biobank (http://www.nealelab.is/uk-biobank) (the Dataset: ieu - b - 4969). Among them, inverse variance weighting (IVW) is the main MR Analysis method for causality assessment. MR-Egger method, MR Pleiotropic residual and outlier test (MR-PRESSO), and simple and weighted median (VM) were used to supplement the IVW method. Sensitivity analyses, mainly Cochran's Q test, leave-one-out analysis, and MR Egger intercept test were performed to assess the robustness of the outcomes.

Results

The two-sample MR Analysis results revealed a negative correlation between genetically predicted hypothyroidism and the probability of CMM (OR=0.987, 95%CI =0.075-0.999, p=0.041). The supplemental MR Analysis did not reveal any statistically significant differences, although the direction of the effect sizes for the other approaches was consistent with the IVW effect sizes. The results of the causal analysis were relatively robust, according to a sensitivity analysis. The risk of CMM was unaffected by hyperthyroidism (p>0.05). No correlation between CMM and thyroid dysfunction was seen in the reverse MR analysis.

Conclusion

Although the magnitude of the causal association is weak and further investigation of the mechanism of this putative causal relationship is required, our findings imply that hypothyroidism may be a protective factor for CMM.

Causal relationship between rheumatoid arthritis and hypothyroidism or hyperthyroidism: a bidirectional two-sample univariable and multivariable Mendelian randomization study

Objective

The causal relationship between Rheumatoid arthritis (RA) and hypothyroidism/hyperthyroidism remains controversial due to the limitations of conventional observational research, such as confounding variables and reverse causality. We aimed to examine the potential causal relationship between RA and hypothyroidism/hyperthyroidism using Mendelian randomization (MR).

Method

We conducted a bidirectional two-sample univariable analysis to investigate the potential causal relationship between hypothyroidism/hyperthyroidism and RA. Furthermore, we performed a multivariate analysis to account for the impact of body mass index (BMI), smoking quantity, and alcohol intake frequency.

Results

The univariable analysis indicated that RA has a causative influence on hypothyroidism (odds ratio [OR]=1.07, 95% confidence interval [CI]=1.01-1.14, P=0.02) and hyperthyroidism (OR=1.32, 95% CI=1.15-1.52, P<0.001). When hypothyroidism/hyperthyroidism was considered as an exposure variable, we only observed a causal relationship between hypothyroidism (OR=1.21, 95% CI=1.05-1.40, P=0.01) and RA, whereas no such connection was found between hyperthyroidism (OR=0.91, 95% CI=0.83-1.01, P=0.07) and RA. In the multivariate MR analyses, after separately and jointly adjusting for the effects of daily smoking quantity, alcohol intake frequency, and BMI, the causal impact of RA on hypothyroidism/hyperthyroidism and hypothyroidism on RA remained robust. However, there is no evidence to suggest a causal effect of hyperthyroidism on the risk of RA (P >0.05).

Conclusion

Univariate and multivariate MR analyses have validated the causal association between RA and hypothyroidism/hyperthyroidism. Hypothyroidism confirmed a causal relationship with RA when employed as an exposure variable, whereas no such relationship was found between hyperthyroidism and RA.

Epidemiological, Pathophysiological, and Clinical Considerations on the Interplay between Thyroid Disorders and Type 2 Diabetes Mellitus

Thyroid disorders (TD) and diabetes mellitus (DM) are the two endocrinopathies with the highest prevalence in the general population that frequently coexist. Thyroid dysfunction is more common in people with type 2 diabetes mellitus (T2DM) compared to normoglycemic individuals. Untreated TD can impair glycemic control, increasing the risk of diabetes complications. Hyperinsulinemia can affect the morphology of the thyroid gland by promoting the proliferation of thyroid tissue and increasing the size of thyroid nodules. Metformin can confer benefits in both endocrinopathies, while other antidiabetics, such as sulfonylureas, can negatively affect thyroid function. Animal and human observational data suggest an increased risk of medullary thyroid carcinoma after treatment with glucagon-like peptide-1 receptor agonists. However, randomized trials have so far been reassuring. Furthermore, some observational studies suggest an association between thyroid cancer and T2DM, especially in women. This narrative review aims to shed light on the epidemiological, pathophysiological, and clinical aspects of the interplay between TD and T2DM. Taking into account the important clinical implications of the coexistence of T2DM and TD, proper screening and management strategies are needed for both endocrinopathies to ensure optimal patient care.

Cerebral Venous Thrombosis during Thyrotoxicosis: Case Report and Literature Update

Cerebral venous thrombosis (CVT) is a rare cause of stroke, particularly in young adults. Several known thrombophilic conditions may lead to an increased CVT risk. Interestingly, few cases in the literature have reported an association between CVT and thyrotoxicosis. Here, we describe the case of a young woman with CVT and concomitant thyrotoxicosis, without any other known prothrombotic conditions. We also performed a literature review of CVT cases and hyperthyroidism, searching for all articles published in peer-reviewed journals. We identified 39 case reports/case series concerning patients with CVT associated with thyrotoxicosis, highlighting, in most cases, the association with additional known prothrombotic factors. We then discussed the possible mechanisms by which hyperthyroidism could underlie a pro-coagulative state resulting in CVT. Thyroid disease might be a more common prothrombotic risk factor than expected in determining CVT. However, in most cases, a coexistence of multiple risk factors was observed, suggesting a multifactorial genesis of the disorder. We hope that this work may alert clinicians to consider thyrotoxicosis as a potential risk factor for CVT, even in patients who apparently have no other pro-coagulative conditions.

Therapeutic Management and Long-Term Outcome of Hyperthyroidism in Patients with Antithyroid-Induced Agranulocytosis: A Retrospective, Multicenter Study

BACKGROUND

Antithyroid drug-induced agranulocytosis (AIA) (neutrophils <500/µL) is a rare but serious complication in the treatment of hyperthyroidism.

METHODOLOGY

Adult patients with AIA who were followed up at 12 hospitals in Spain were retrospectively studied. A total of 29 patients were studied. The etiology of hyperthyroidism was distributed as follows: Graves' disease (n = 21), amiodarone-induced thyrotoxicosis (n = 7), and hyperfunctioning multinodular goiter (n = 1). Twenty-one patients were treated with methimazole, as well as six patients with carbimazole and two patients with propylthiouracil.

RESULTS

The median (IQR) time to development of agranulocytosis was 6.0 (4.0-11.5) weeks. The most common presenting sign was fever accompanied by odynophagia. All of the patients required admission, reverse isolation, and broad-spectrum antibiotics; moreover, G-CSF was administered to 26 patients (89.7%). Twenty-one patients received definitive treatment, thirteen patients received surgery, nine patients received radioiodine, and one of the patients required both treatments. Spontaneous normalization of thyroid hormone values occurred in six patients (four patients with amiodarone-induced thyrotoxicosis and two patients with Graves' disease), and two patients died of septic shock secondary to AIA.

CONCLUSIONS

AIA is a potentially lethal complication that usually appears around 6 weeks after the initiation of antithyroid therapy. Multiple drugs are required to control hyperthyroidism before definitive treatment; additionally, in a significant percentage of patients (mainly in those treated with amiodarone), hyperthyroidism resolved spontaneously.

Hypothyroidism in Adult Women: The Utility of Targeted vs Universal Thyroid Screening

Hypothyroidism is a common disease that is more prevalent in female populations. The purpose of this paper is to discuss the evidence, risks, and benefits of screening asymptomatic women for hypothyroidism. There is lack of evidence to support clinical management of asymptomatic individuals with an elevated TSH and normal serum thyroxine levels. Patients with subclinical hypothyroidism, especially the elderly, are at risk of overtreatment. Given these considerations, the majority of US and UK professional organizations do not support universal screening. Many do offer caveats for special groups, including pregnant people, who may need screening if there are clinical symptoms or family history of autoimmune disease. In conclusion, targeted screening may be best recommended based on risk factors, symptoms, and clinical suspicion, rather than at a universal level.

Thyroid Cancer Knowledge and Awareness in Saudi Arabia: A Cross-Sectional Study

Background Thyroid cancer incidence has been increasing worldwide over the last few decades. It is the most common endocrine cancer and is most common among females. The study contributes to filling the knowledge gap among Saudi people regarding thyroid cancer. Objectives This research aims to investigate the level of thyroid cancer knowledge and awareness in Saudi Arabia, identify potential knowledge gaps, and develop targeted strategies for enhancing public awareness and education. Methods A cross-sectional, voluntary online survey was conducted from 1st August 2023 to 1st October 2023 among residents living in Saudi Arabia over 18 years of age. The participants included were 2030 respondents. Data analysis was performed using RStudio (R version 4.3.0; R Foundation for Statistical Computing, Vienna, Austria). Results Among the participants, the majority were female (60.4%). A total of 49.7% of the individuals reported having a moderate to high level of knowledge about thyroid cancer. While 63.9% knew the association of a lump in the neck to thyroid cancer, 82.6% affirmed to consult a doctor upon discovering a lump, 72.1% knew that regular monitoring of neck lumps is crucial for early diagnosis and treatment of precancerous conditions, 38.7% were aware of females being prone to thyroid cancer, and 59.2% were aware of the link between lifestyle and increased risk. Higher awareness scores were positively associated with female gender, previously having thyroid function tests done, and previously undergoing a US scan of the thyroid. Conclusion In this study, Saudi individuals are reported to lack some aspects of knowledge and perception of thyroid cancer. This study emphasizes filling the existing knowledge gap in thyroid cancer awareness in the Saudi population.

Adherence to levothyroxine treatment among patients with hypothyroidism in Oman: a national cross-sectional study

OBJECTIVE

Hormone replacement therapy with levothyroxine is considered the treatment of choice for hypothyroidism; however, non-adherence is a major contributor to poor treatment outcomes. This study aimed to evaluate levels of drug adherence (DA) to levothyroxine therapy among Omani adults with hypothyroidism and to explore related sociodemographic and clinical factors.

METHODS

A national, multi-center, cross-sectional survey was carried out from August to December 2021 at 18 primary healthcare centers across all governorates of Oman. A total of 415 Omani adults were recruited. Data were collected using a pre-tested, Arabic-language questionnaire completed by trained researchers during face-to-face interviews with the participants. Level of DA was determined using the 8-item Morisky Medication Adherence Scale (MMAS-8).

RESULTS

A total of 400 Omani adults participated in the study (response rate: 96.4%). The mean age was 41.9 ± 12.4 years old (range: 18-78 years) and 90.3% were female. According to their MMAS-8 scores, 157 (39.2%), 139 (34.8%), and 104 (26.0%) participants demonstrated low, medium, and high DA, respectively. No significant correlations were observed between level of DA and any sociodemographic or clinical characteristics, including age, gender, education, duration of treatment, and family history of thyroid disease (p > 0.050).

CONCLUSIONS

Only a quarter of Omani patients with hypothyroidism reported high levels of adherence to levothyroxine treatment, likely as a result of lack of awareness of the disease and the importance of maintaining an euthyroid state. Further studies using more objective measures of DA are recommended to determine correlates of non-compliance to levothyroxine therapy among Omani patients.

Impact of Hypothyroidism on Tomography and Biomechanics in Keratoconus - Cross-Sectional and Longitudinal Assessment within the Homburg Keratoconus Center at the Time of Inclusion and after 1 Year

BACKGROUND AND PURPOSE

The etiology of keratoconus (KC) is probably multifactorial but remains essentially unknown. Previous scientific observations have suggested that hypothyroidism might play a role in the development and progression of KC. The purpose of this study was to analyze the tomographic and biomechanical parameters in KC patients with or without hypothyroidism.

METHODS

Twenty-eight patients with KC and hypothyroidism (HT group) and fifty-six KC patients without thyroid dysfunction (WHT group) with matching gender and age were analyzed. Mean age was 40.3 years (range 14 - 57) in the HT group and 40.3 years (range 14 - 57) in the WHT group. Routine ophthalmic examinations consisted of corneal tomography and biomechanical parameters. We extracted the following KC parameters from the Pentacam (Pentacam HR, Oculus, Wetzlar, Germany): Keratoconus Index (KI), maximum keratometry (Kmax), astigmatism, and thinnest pachymetry (TP). From the ocular response analyzer (ORA, Reichert Ophthalmic Instruments, Depew, NY, USA), we extracted corneal hysteresis (CH), corneal resistance factor (CRF), and KC match index (KMI).

RESULTS

The comparison of the tomographic and biomechanical values from cross-sectional and longitudinal analyses showed no significant differences between the HT and WHT groups.

CONCLUSION

The severity of KC based on tomographical and biomechanical parameters does not seem to depend on the presence of hypothyroidism.

Thyroid function test variability and cardiovascular morbidity in hyperthyroidism

OBJECTIVE

The variability of thyroid function tests (TFTs) during antithyroid drug (ATD) therapy and its association with adverse health outcomes have not been previously studied. The aim of this study was to evaluate the association of TFT variability and cardiovascular morbidity during ATD therapy.

DESIGN

Retrospective cohort study.

PATIENTS AND MEASUREMENTS

Hyperthyroid patients (n = 394) treated with ATD therapy at Tampere University Hospital between March 2016 and December 2018 were followed up for a median time of 1.5 years (interquartile range 0.8-2.0). The coefficients of variation (CVs) of the follow-up thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) measurements were determined. The associations of TFT variability and baseline clinical factors with cardiovascular disease (CVD) -associated hospital visits were assessed with logistic regression analyses.

RESULTS

In the multivariable analyses, age (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.03-1.09), male gender (OR: 2.33, 95% CI: 1.03-5.28) and fT4-CV (OR: 1.02, 95% CI: 1.01-1.04) were independent risk factors for cardiovascular morbidity, whereas baseline positive thyrotropin receptor antibodies (TRAbs) were associated with lower cardiovascular morbidity (OR: 0.29, 95% CI: 0.14-0.61). When the patients with baseline TRAb positivity were studied separately, fT4-CV was associated with cardiovascular morbidity (OR: 1.03, 95% CI: 1.00-1.05).

CONCLUSIONS

During ATD therapy, fT4 variability is associated with an increased cardiovascular morbidity. Although positive TRAbs are associated with a lower cardiovascular morbidity compared with hyperthyroidism with negative autoantibodies, the variability of fT4 is associated with cardiovascular morbidity also in patients with positive TRAbs.

Use of Thyroid Hormones in Hypothyroid and Euthyroid Patients: A THESIS questionnaire survey of members of the Irish Endocrine Society

BACKGROUND

Replacement of thyroid hormones (TH) with Levothyroxine (LT4) is the treatment of choice for hypothyroidism, however, there are aspects of treatment where uncertainties exist and practice varies. Factors influencing initiation and choice of TH replacement may impact patient satisfaction, safety, and health care costs.

METHODS

The aim of the study was to examine the attitudes of Irish endocrinologists regarding the treatment of hypothyroid and euthyroid patients with TH. Members of the Irish Endocrine Society (IES) were invited to participate in an online survey.

RESULTS

Forty-eight invitations were sent, and 39 (81.3%) participants responded. All respondents favoured LT4 tablet therapy for treatment of hypothyroidism, but 20.5% prescribed combination therapy (LT4 and liothyronine), and 13% regularly used desiccated thyroid extract. A significant proportion (51%) might prescribe TH in euthyroid patients; 41% for thyroid auto-antibody positive women seeking pregnancy, 18% for goitre and 5% for unexplained fatigue. Many (38%) consider combination therapy in patients with persistent symptoms. Respondents reported seeing LT4 treated patients with persistent symptomatology more frequently and perceive psychosocial factors and comorbidities to be the most common reasons for such symptoms.

CONCLUSION

LT4 tablets are the treatment of choice for hypothyroidism in Ireland. Approximately a third of Irish endocrinologists either regularly use, or would consider, liothyronine for hypothyroid patients. A significant proportion would give TH to euthyroid individuals in specific circumstances. The prescription of TH amongst Irish endocrinologists was generally in keeping with recommended practice, and areas where practice deviated from guidance were typically where evidence was conflicting or insufficient.

Understanding the Relationship between Nonalcoholic Fatty Liver Disease and Thyroid Disease

The prevalence of hypothyroidism in patients with nonalcoholic fatty liver disease (NAFLD) is high (22.4%). Thyroid hormones (THs) regulate many metabolic activities in the liver by promoting the export and oxidation of lipids, as well as de novo lipogenesis. They also control hepatic insulin sensitivity and suppress hepatic gluconeogenesis. Because of its importance in lipid and carbohydrate metabolism, the involvement of thyroid dysfunction in the pathogenesis of NAFLD seems plausible. The mechanisms implicated in this relationship include high thyroid-stimulating hormone (TSH) levels, low TH levels, and chronic inflammation. The activity of the TH receptor (THR)-β in response to THs is essential in the pathogenesis of hypothyroidism-induced NAFLD. Therefore, an orally active selective liver THR-β agonist, Resmetirom (MGL-3196), was developed, and has been shown to reduce liver fat content, and as a secondary end point, to improve nonalcoholic steatohepatitis. The treatment of NAFLD with THR-β agonists seems quite promising, and other agonists are currently under development and investigation. This review aims to shine a light on the pathophysiological and epidemiological evidence regarding this relationship and the effect that treatment with THs and selective liver THR-β agonists have on hepatic lipid metabolism.

Comprehensive analysis of chemokine gene polymorphisms in Korean children with autoimmune thyroid disease

Chemokines are chemotactic cytokines that can cause directed migration of leukocytes. The aim of this study was to examine differences in single nucleotide polymorphisms (SNP) of chemokine in AITD patients compared to normal controls. A total of 86 Korean pediatric patients were included in the patient group and 183 adults were included in the normal control group. To compare influences of several chemokine gene polymorphisms, 25 SNPs in 16 chemokine genes were analyzed. Genotype frequencies of CCL11(rs3744508)AA(OR = 6.9) and CCR2(rs1799864)AA(OR = 3.8) were higher in the AITD patients than in the controls, whereas CCL17(rs223828)CC was lower in the AITD patients than in the controls(OR = 0.4). In comparison between Graves' disease (GD) patients and controls, genotype frequency of CCL17(rs223828)CC(OR = 0.4) was lower in the GD group, whereas those of CCR2(rs1799864)AA(OR = 4.8) were higher in the GD group. The genotype frequency of CCL11(rs3744508)AA(OR = 11.3) was higher in Hashimoto's thyroiditis (HT) patients, whereas that of CXCL8(rs2227306)CC(OR = 0.4) was lower in HT patients. Polymorphisms of CCL11(rs3744508), CCL17(rs223828), and CCR2(rs1799864) might be associated with AITD, with CCL17(rs223828), CCR2(rs1799864) and CXCR2(rs2230054, rs1126579) affecting GD and CCL11(rs3744508) and CXCL8(rs2227306) affecting HT in Korean children.