Hypothyroidism

Effect of COVID-19 infection on thyroid function status and clinical indexes among hypothyroid outpatients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly, leading to an Omicron outbreak in Shanghai in mid-December after adjustments to the Coronavirus Disease 2019 (COVID-19) control strategy. To investigate the impact of COVID-19 infection among hypothyroid patients, we gathered data on the hypothyroid outpatients with COVID-19 infection during this time at the Thyroid Disease Center (TDC) of Shanghai Central Hospital. Patients were divided into two groups based on whether their hypothyroidism was caused by Hashimoto's Thyroiditis (HT): the HT and the non-HT group. We assessed the differences between pre-infection and clinical follow-up at one month (day (D) 30) and three months (D90) after COVID-19 infection. In HT group, thyroid-stimulating hormone (TSH) levels decreased significantly compared to pre-infection levels (p = 0.013), while free triiodothyronine (FT3) levels increased at D90 compared to both D30 post-infection and pre-infection levels (p < 0.001 and p = 0.005). Hemoglobin levels also increased after COVID-19 infection (p = 0.033). For non-HT patients, FT3 levels increased at D30 compared to pre-infection levels (p = 0.017). Moreover, inactivated SARS-CoV-2 vaccination can preserve thyroid function stability in patients with hypothyroidism.

Signs and symptoms of vulvovaginal atrophy (VVA) in clinical practice - the possible involvement of thyroid autoimmunity in genitourinary syndrome of menopause (GSM)

BACKGROUND

Thyroid autoimmune disorders (ADs) are common in midlife women and can impact various aspects of health, including sexual function. The effect of thyroid autoimmunity on the clinical manifestations of vulvovaginal atrophy (VVA) remains unclear.

OBJECTIVE

To explore the relationship between thyroid ADs and VVA signs and symptoms in a sample of postmenopausal women.

METHODS

Cross-sectional study including postmenopausal women not using systemic hormone therapy. VVA signs were assessed using the vaginal health index (VHI) and vulvar health index (VuHI); VVA symptoms were rated on a four-point severity scale.

RESULTS

Among 112 women enrolled, 28 had thyroid ADs. A significantly higher percentage of women with thyroid ADs showed vaginal atrophy (75 vs. 45.2%, p < .05). A greater proportion of women with thyroid ADs exhibited vulvar atrophy or both vaginal and vulvar atrophy, though these differences were not statistically significant. Women with thyroid ADs reported significantly higher scores for dryness, burning/itching, irritation/inflammation, and dyspareunia compared to those without it. A higher percentage of women with thyroid ADs experienced severe dyspareunia (45 vs. 20.6%, p < .05), severe burning/itching (33.3 vs. 9.1%, p < .05), and severe stress urinary incontinence (17.9 vs. 3.6%, p < 0.05).

CONCLUSIONS

This study suggests that thyroid ADs may contribute to genital aging, with an apparent greater involvement in vaginal signs of atrophy. Women with thyroid ADs reported more severe VVA symptoms, but specific symptomatological clusters should be investigated in larger samples. Our data support the need to explore further the role of thyroid disorders in VVA.

Risk of hypothyroidism in meat-eaters, fish-eaters, and vegetarians: a population-based prospective study

BACKGROUND

Plant-based diets are gaining popularity due to their well-documented cardiometabolic benefits and environmental sustainability. However, these diets are often lower in specific micronutrients such as iodine, raising concerns about their potential impact on thyroid health. Therefore, we examined the associations between plant-based diets and the risk of hypothyroidism.

METHODS

We analysed data from the UK (United Kingdom) Biobank cohort. Multivariable Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for incident hypothyroidism across vegans, vegetarians, pescatarians, poultry-eaters, low meat-eaters, and high meat-eaters aged 40-69 years. Ancillary to this, we carried out logistic regression analyses to evaluate associations between the diet groups and prevalent hypothyroidism according to International Classification of Diseases (ICD) codes at baseline.

RESULTS

We included 466,362 individuals from the UK Biobank, of which 220,514 followed a high meat, 221,554 a low meat, 5242 a poultry-based, 10,598 a pescatarian, 8057 a vegetarian, and 397 a vegan diet. During a median SD (Standard Deviation) follow-up of 12.7 (± 3.2) years, 10,831 participants developed hypothyroidism. In multivariable Cox regression models without adjustment for body mass index (BMI), none of the diets were significantly associated with the risk of hypothyroidism. However, there was a tendency for a higher risk of hypothyroidism among vegetarians compared to people following a high meat diet (HR = 1.13, 95% CI 0.98-1.30). After controlling for BMI, a potential collider, the association for vegetarians (HR = 1.23, 95% CI 1.07-1.42) became stronger and statistically significant. Furthermore, we observed a positive association between low meat-eaters (OR = 1.05, 95% CI 1.03-1.08), poultry-eaters (OR = 1.15, 95% CI 1.04-1.28), pescatarians (OR = 1.10, 95% CI 1.01-1.19) and vegetarian (OR = 1.26, 95% CI 1.15-1.38) with hypothyroidism prevalence.

CONCLUSIONS

In the present study, we found a moderately higher risk of hypothyroidism among vegetarians, after controlling for BMI, a potential collider. This slightly higher risk of hypothyroidism among vegetarians requires further investigation, taking iodine status and thyroid hormone levels into account.

Thyroid Function Reference Intervals by Age, Sex, and Race : A Cross-Sectional Study

BACKGROUND

Current clinical practice uses a one-size-fits-all approach to define reference intervals for the results of diagnostic tests about thyroid function. This approach does not recognize subgroup differences according to age, sex, or race.

OBJECTIVE

To identify age-, sex-, and race-specific reference intervals for the common diagnostic tests that measure thyroid function and to examine how these new reference intervals reclassify persons into disease categories when compared with current reference intervals.

DESIGN

Cross-sectional analysis.

SETTING

Data from the U.S. NHANES (National Health and Nutrition Examination Survey) supplemented with data from a multicenter Chinese study.

PARTICIPANTS

A nationally representative sample from NHANES aged 20 years or older (n = 8308) supplemented with a Chinese database of routine health checkups from 49 hospitals in 10 provinces aged 18 years or older (n = 314 302).

MEASUREMENTS

The thyroid function reference interval was defined as the interval of diagnostic indicator levels from the 2.5th (lower limit) to the 97.5th (upper limit) percentile by age, sex, and race subgroups.

RESULTS

In 8308 NHANES participants, the 97.5th percentile levels of thyroid-stimulating hormone (TSH) increased with age, whereas total triiodothyronine (TT3) levels declined with age and total thyroxine (TT4) levels were stable across different ages. Women had higher TT4 levels, and White participants had higher TSH levels. Using current reference intervals, the prevalence of subclinical hypothyroidism increased from 2.4% for ages 20 to 29 years to 5.9% for ages 70 years and older. In contrast, using age-, sex-, and race-specific reference intervals reclassified 48.5% of persons with subclinical hypothyroidism as normal, especially women and White participants, and reclassified 31.2% of persons with subclinical hyperthyroidism as normal, especially women, Black participants, and Hispanic participants. When compared with the findings from U.S. participants, many of the findings from 314 302 Chinese participants were similar.

LIMITATION

Cross-sectional data; sample size limitations for subgroup.

CONCLUSION

These findings should help establish more accurate reference intervals for thyroid diseases and facilitate development of a consensus about how to define and manage those diseases.

PRIMARY FUNDING SOURCE

National Key Research and Development Program of China and National Natural Science Foundation.

A causal relationship between hypothyroidism and rheumatoid arthritis, but not hyperthyroidism: evidence from the mendelian randomization study

OBJECTIVE

To investigate the genetic level causal association among hyperthyroidism, hypothyroidism, and rheumatoid arthritis (RA).

METHODS

We utilized the genome-wide association studies (GWAS) summary data for exposure (hyperthyroidism and hypothyroidism) and outcome (RA) from the IEU OpenGWAS database. We used two different sets of data (test cohort and validation cohort) for causal assessment of exposure and outcome. To establish a causal relationship between these conditions, we conducted a two-sample Mendelian randomization (MR) analysis. Subsequently, we evaluated the MR analysis results for heterogeneity, horizontal pleiotropy, and outliers, aiming to assess the validity and reliability of the findings. Moreover, we conducted additional analyses to examine the robustness of the MR results, including a "Leave one out" analysis and the MR robust adjusted profile score (MR-RAPS) method, ensuring the robustness and adherence to normal distribution assumptions.

RESULTS

The findings from the test cohort indicated that hyperthyroidism did not exhibit a genetic causal association with RA (P = 0.702, odds ratio [OR] 95% confidence interval [CI] = 1.021 [0.918-1.135]). Conversely, hypothyroidism displayed a positive genetic causal relationship with RA (P < 0.001, OR 95% CI = 1.239 [1.140-1.347]). The analysis results of the validation cohort are consistent with those of the test cohort. Notably, our MR analysis results demonstrated no evidence of heterogeneity, horizontal pleiotropy, or outliers. Furthermore, our MR analysis results remained unaffected by any single nucleotide polymorphism (SNP) and exhibited a normal distribution.

CONCLUSION

The results of this study showed that hypothyroidism was positively correlated with RA, while hyperthyroidism was not causally correlated with RA. Hypothyroidism may as a risk factor of RA should be paid attention to in clinical work. Future studies are needed to further confirm this finding.

Are liquid levothyroxine formulations comparable? The LETI study

BACKGROUND

Liquid ethanol-containing levothyroxine (e-LT4) is known to circumvent malabsorption induced by food, drugs, or pathological conditions. Recently a new ethanol-free formulation of liquid levothyroxine (ef-LT4) has been commercialized. No studies have compared e-LT4 with ef-LT4. The aim of the present study is to compare thyroid hormone profile in patients treated with e-LT4 and ef-LT4.

MATERIAL AND METHODS

We retrospectively retrieved thyroid hormonal profile and clinical data of 48 patients diagnosed with hypothyroidism who had been on stable treatment with an e- LT4 formulation at the same dosage for at least one year and who decided to switch to ef-LT4 for tasting issue.

RESULTS

A significant increase in TSH levels was observed after 6 months on ef-LT4 treatment (2.5 ± 0.8 mIU/ml vs. 3.1 ± 1.0 mIU/ml, respectively, p < .001), while fT4 decreased [1.2 ng/dl (IQR 1.1-1.4) vs. 1.1 ng/dl (1.0-1.2), respectively, p = .047], maintaining the same dosage of LT4. In 31 patients, for whom data were available 12 months after the switch, TSH further increased (2.50 ± 0.9 mIU/ml at baseline vs 3.2 ± 0.9 mIU/ml after 6 months vs 3.5 ± 0.9 mIU/ml at 12 months, p < .001) and fT4 decreased [1.2 ng/dl (IQR 1.1-1.4) vs. 1.1 ng/dl (IQR 0.9-1.3) vs 1.0 ng/dl (IQR 0.9-1.1), p = .008].

CONCLUSION

ef-LT4 formulation seems to be less effective compared to e-LT4 over time. However, further prospective cross-sectional studies, performed in large sets of patients, even on concomitant therapy with interfering drugs, are needed.

Comparison of incontinent characteristics between women with hypothyroid dysfunction and euthyroidism during pregnancy and the first year postpartum: A prospective observational study

The aim of the study was to evaluate the occurrence and severity of gestational and postpartum urinary incontinence (UI) and the negative impact upon quality of life (QoL) among pregnant women with gestational hypothyroidism. After initial selection 522 eligible subjects with gestational UI were enrolled and distributed into the HUI (hypothyroid UI, n = 155) and EUI (euthyroid UI, n = 367) groups, respectively. Their demographic parameters, clinic characteristics and incontinent profiles evaluated by the validated International Consultation on Incontinence Questionnaire-Urinary Incontinence-Short Form (ICIQ-UI-SF) questionnaire were collected during gestational and postpartum follow-ups. Within the present study the overall prevalence rate of gestational UI was 45.4% (522/1150). The three scored items of ICIQ-UI-SF questionnaire including leakage frequency, leakage amount and negative impact upon incontinence-specific QoL of the HUI group, as well as leakage severity evaluated by the validated ICIQ-UI-SF questionnaire and 1 h pad test, were significantly greater than those of the EUI group during pregnancy, 6-7 weeks postpartum and over the first year postpartum (P < 0.05 or 0.001). No intergroup significant difference regarding leakage frequency and leakage amount, negative impact upon incontinence-specific QoL and leakage severity was observed during 3-4 months postpartum follow-up. Gestational hypothyroidism could elevate the leakage frequency, amount and severity of UI and exacerbate the negative impact of UI upon incontinence-specific QoL among subjects within the HUI group during pregnancy and the first year postpartum, which underlines the potential relationship between gestational hypothyroidism and gestational and postpartum UI.

A long-standing undiagnosed case of vitamin B12 deficiency: a case report

BACKGROUND

Pernicious anemia, an autoimmune disease, presents with gradual, nonspecific symptoms, often leading to delayed diagnosis owing to its overlap with other conditions and variability in laboratory findings, such as neurological symptoms without anemia or macrocytosis.

CASE PRESENTATION

This case describes a 40-year-old Iranian woman with a decade-long history of nonspecific symptoms, including fatigue, widespread musculoskeletal pain, paresthesia, cognitive disturbances, and optic neuritis; misattributed to conditions such as fibromyalgia, hypothyroidism, and autoimmune diseases. Despite annual monitoring for normocytic anemia, her critically low vitamin B12 levels (< 150 pg/mL) and a diagnosis of pernicious anemia were identified only after persistent symptoms prompted further evaluation, revealing atrophic gastritis as the underlying cause. Neurologic improvement with parenteral B12 therapy, alongside management of fibromyalgia, emphasizes the importance of considering vitamin B12 deficiency even in the absence of classic hematologic findings.

CONCLUSION

This case highlights the diagnostic challenges of pernicious anemia, where nonspecific symptoms and overlapping comorbidities obscure diagnosis, underscoring the need for a systematic, multidisciplinary approach and timely recognition of vitamin B12 deficiency to prevent irreversible complications.

Combined LT3 and LT4 therapy for precision medicine: easier with TTCombo system

Hypothyroidism is typically treated with levothyroxine monotherapy. However, despite normalized serum thyroid-stimulating hormone levels, 5-10% of patients continue to experience persistent symptoms, raising concerns about the adequacy of thyroxine monotherapy. Combination therapy with levothyroxine and liothyronine has been proposed as an alternative, but it presents practical challenges, including dosing complexity, the short half-life of triiodothyronine, increased monitoring requirements, and potential adverse effects. Moreover, there is no clear consensus within the medical community regarding the superiority of combination therapy over levothyroxine monotherapy, although some studies indicate potential benefits in specific patient populations. Genetic factors, such as polymorphisms in the DIO2 gene, may influence individual responses to therapy, further complicating treatment. To address the limitations of combination therapy, we propose a novel approach: TTCombo. This digital health technology delivers personalized doses of levothyroxine and liothyronine, improving treatment adherence and optimizing outcomes. By providing individualized, physiologically tailored hormone replacement, TTCombo has the potential to revolutionize hypothyroidism management and enhance patient quality of life.

Thyroid volumes after intensity-modulated radiotherapy as predictors of radiation-induced hypothyroidism in nasopharyngeal carcinoma: A retrospective study

PURPOSE

This study aimed to investigate the ability of thyroid volumes after intensity-modulated radiotherapy (IMRT) to predict the incidence of radiation-induced hypothyroidism/primary hypothyroidism (HT)/(PHT) in nasopharyngeal carcinoma (NPC) patients.

METHODS AND MATERIALS

404 NPC patients were retrospectively enrolled from January 2015 to January 2019. Thyroid volumes were calculated based on magnetic resonance imaging. Volume of thyroid after IMRT within 3 months was defined as Vt-after. Least absolute shrinkage and selection operator (LASSO) regression, random forest analysis, and multivariate Cox proportional hazards were performed to identify optimal predictors of PHT. Then, these predictors were employed to construct the risk stratification using the recursive partitioning analysis (RPA).

RESULTS

A smaller Vt-after was significantly associated with a higher risk of HT/PHT (hazard ratio (HR): 2.046, p < 0.001; HR: 3.214, p < 0.001; respectively). Vt-after and thyroid volumes at 1, 2, and 3 years after IMRT demonstrated superior predictive ability compared to the thyroid volume before IMRT for predicting PHT within the subsequent 2-year period. The combination of Vt-after and thyroid volume spared from 45 Gy (VS45), both of which wereindependent factors for predicting PHT, was incorporated into the RPA risk stratification called PRA-VS45. The PRA-VS45 emerged as a highly discriminative tool, with an area under the curve (AUC) of 0.716 on predicting PHT at 5 years.

CONCLUSIONS

This study identified thyroid volumes after IMRT as valuable parameters to predict radiation-related PHT in NPC patients. The PRA-VS45 has the potential to be clinical applications for predicting PHT.

How Does Thyroid Hormone Profile Differ on and Off Replacement Treatment?

INTRODUCTION

There continues to be much discussion around optimisation of thyroid hormone status in hypothyroid individuals. We here looked the way that free T4(FT4) and thyroid-stimulating hormone (TSH) related to each other in a large laboratory sample of people who underwent a thyroid function test (TFT), split between those on levothyroxine replacement (monitoring test) and those who underwent a test to check for thyroid hormone imbalance (diagnostic test; not on levothyroxine).

METHODS

TFT test (FT4/TSH) results were extracted from the Salford Royal Hospital Laboratory Information Management System during 2009-2012. This was a single site study. Requests includes a tick box for 'on levothyroxine' (yes or no). To minimise comorbidity effects, only samples taken in General Practices were used. For untreated patients only those who had single tests results were used; for treated patients, the median value across all their results was used. Cluster analysis considered an ellipse with centre on median values for log (TSH) and FT4 and the vertex based on 5% and 95% percentile values of both. The percentage of patients falling outside the ellipse boundary was considered for both treated and untreated populations.

RESULTS

The total data set included 290,000 tests on 130,000 individuals. After filtering, FT4/TSH results were used from 12,006 (F 9231/M 2775; age < 60 5850/age ≥ 60 6567) treated patients with 43,846 test results. These were compared to the single results for 43,394 untreated patients (F 24,386/M19,008; age < 60 32,537/age ≥ 60 10,857). Cluster analysis showed for untreated patients, median values for TSH and FT4 were 1.8 mU/L and 15.5 pmol/L, respectively, with 24% of patient results falling outside the untreated 5%/95% percentiles. For treated patients, the median TSH was 2.3 mU/L (+30% vs. untreated) and FT4 was 18.9 pmol/L (+22% vs. untreated), with 22% of treated patients falling outside the treated 5%/95% percentiles. When considered against the untreated limits, 68% of treated results fell outside (split male 63%, female 70% and age < 60 67%, Age ≥ 60 64%).

CONCLUSION

The current treatment regimens of either low or high dose levothyroxine are not delivering the expected laboratory TFT profiles, with significant numbers of treated patients being well outside the expected values: both TSH and FT4 being significantly higher. This effect appears to be more prevalent in women than men.

Hypothyroidism monitoring and control during the first trimester of pregnancy in Catalonia

Objective

This study aims to describe hypothyroidism monitoring and control during the first trimester of pregnancy in women with known hypothyroidism in Catalonia.

Materials and methods

Pregnancies registered in primary care in Catalonia between 2014 and 2016 were retrospectively studied. Women with hypothyroidism were selected for the study. Hypothyroidism was defined if, on the date of the last menstrual period (LMP), there was an updated thyroid hormone prescription (code ATC H03AA -levothyroxine) or any of the following active diagnostic codes: ICD-10: E02, E03, E89.0. To evaluate hypothyroidism monitoring and control, thyrotropin (TSH) tests during the first trimester of pregnancy were considered and categorized according to the reference values of each laboratory.

Results

Out of 111,811 pregnancies, 5,574 had known hypothyroidism. TSH was evaluated in 3,158 (56.65%) of them. The TSH values were within the recommended ranges in 1,146 (36.3%) of the cases, being low abnormal in 53 of them (1.7%) and high abnormal in 1,959 (62%).

Conclusion

TSH testing was not evaluated in almost half of the pregnant women with known hypothyroidism in primary care services in Catalonia during the pregnancy first trimester. Among those tested, more than two-thirds had TSH levels outside the target range. This means that it is essential to improve the management of hypothyroidism during the first trimester of pregnancy in Catalonia.

Shared Decisionmaking in the Treatment of Hypothyroidism

BACKGROUND

Hypothyroidism, a condition characterized by an underactive thyroid gland, affects millions worldwide, leading to cognitive and metabolic slowdowns. It is most prevalent in women and older adults, with causes including autoimmune thyroiditis, surgical thyroidectomy, and certain medications.

STANDARD OF CARE AND LIMITATIONS

The standard treatment involves synthetic levothyroxine (LT4) monotherapy, which alleviates symptoms by converting to the active hormone, T3. However, some patients continue to experience symptoms such as fatigue, mood disturbances, and poor quality of life despite normalized TSH levels. This persistence of symptoms may stem from misdiagnosis, inadequate dosing, or incomplete normalization of thyroid hormone signaling.

NEW FINDINGS

Research suggests that LT4 monotherapy may not fully restore T3 levels, leading to suboptimal symptom control. Consequently, combination therapy with LT4 and liothyronine (LT3) has been proposed as an alternative, aiming to balance T4 and T3 levels more effectively. Although randomized controlled trials have not identified significant differences in patient-reported outcomes between LT4 monotherapy and combination therapy, they indicate that patients may prefer the latter.

CONCLUSION

Guidelines from leading endocrinology organizations now recommend considering combination therapy for patients with persistent symptoms despite adequate LT4 dosing. A patient-centered approach, emphasizing shared decision-making and individualized treatment plans, is essential for optimizing outcomes in hypothyroidism management. Further research is needed to refine dosing strategies and identify the patients who would benefit most from combination therapy.

Bioinspired Long-Acting Mucoadhesive Gastric Patch for Levothyroxine Delivery

The delivery of long-acting therapeutic dosage forms through the oral route is a challenge. A bioinspired mucoadhesive gastric patch was developed as a platform technology for the long-acting delivery of levothyroxine sodium (LT). The mucoadhesive patch was designed to have a three-layer composition, including a core, mucoadhesive, and backing layer. The water contact angle on the mucoadhesive and backing layer sides of the patch was found to be 68 ± 1.4° and 121 ± 0.4°, respectively. The adhesive strength of the mucoadhesive layer, made of a 4-carboxyphenylboronic acid-chitosan conjugate, was found to be 25 ± 1.1 kPa when adhered to the rat stomach mucosa. The LT-containing patch was found to remain adhered to the body region of the rat stomach after 30 days of oral administration. A single dose of the mucoadhesive gastric patch containing 15.8 μg/kg/day of LT was able to provide a constant plasma concentration (87-126 ng/mL) of LT for 38 days in rats. There was no significant (P < 0.05) difference in the concentration of inflammatory markers including tumor necrosis factor-α (TNF-α), interleukins 1β (IL-1 β) and 6 (IL-6), with and without long-acting patch administration. The patches were found to be stable when stored at 5 ± 3 °C for 6 months. Taken together, the bioinspired mucoadhesive gastric patch can be developed for the long-acting delivery of LT through the oral route.

A Rare Complication of Supraglottic Myxedema Secondary to Hypopituitarism and Hypothyroidism

Supraglottic edemas are rare complications of severe hypothyroidism that present significant challenges in management due to their critical location and acute clinical manifestations. The traditional approach of managing hypothyroidism and airway support has been the preferred treatment in the case of supraglottic edema, while glucocorticoids have a controversial therapeutic benefit. Here, we present a case of a 59-year-old male patient with a history of hypothyroidism and pituitary adenoma resection who presented to the emergency department with stridor and shortness of breath, where he underwent ICU admission, was sedated, and received medical treatments. The pre-ICU fiberoptic evaluation suggested supraglottic edema and congestion of the nasopharynx, and neck imaging revealed an inflammatory process of the right side of the oropharynx and right palatine tonsil and ruled out the presence of an abscess in deep neck spaces. Intensive care unit stay and the multidisciplinary treatments were beneficial, resulting in complete remission of the supraglottic edema and the subsequent symptoms. This case highlights the manifestation of supraglottic edema as a complication of hypothyroidism post pituitary adenoma resection and emphasizes the importance of multidisciplinary collaboration in achieving successful outcomes of these challenging presentations.

Construction and validation of a nomogram for predicting fatigue in climacteric women

OBJECTIVE

The aim was to develop and validate a nomogram for evaluating the risk of fatigue in climacteric women and to assess its clinical application value.

METHODS

Clinical information was collected from 402 climacteric women who visited a tertiary hospital in Shanghai between November 2023 and April 2024. Network analysis methods were utilized to analyze the core symptom (fatigue). The study participants were then randomly divided into training and validation cohorts in a 7:3 ratio. Univariate and multivariate logistic regression analyses were conducted to identify independent risk factors for fatigue in climacteric women. A nomogram prediction model was established based on these independent risk factors. The predictive performance of the model was evaluated using the concordance index, area under the curve, receiver operating characteristic curve, Hosmer-Lemeshow test, and calibration curve analysis. Additionally, decision curve analysis was performed to assess the model's performance in clinical applications.

RESULTS

Fatigue is identified as the core symptom in climacteric women. Educational level, chronic diseases, and depression status are independent influencing factors for fatigue in menopausal women. The area under the curve for the training cohort and validation cohort are 0.813 (95% CI, 0.743-0.884) and 0.759 (95% CI, 0.637-0.879), respectively, indicating that the model possesses good discriminative ability. The calibration curve shows good consistency between the predicted probabilities and actual probabilities in both the training and validation cohorts. Additionally, the P values for the Hosmer-Lemeshow test in the training and validation sets are 0.233 and 0.197, respectively, indicating good model calibration. Finally, the decision curve analysis curve demonstrates that the model has good clinical utility.

CONCLUSIONS

A simple nomogram based on three independent factors (educational level, chronic diseases, and depression status) can aid in clinically predicting the risk of fatigue in climacteric women.

Treatment of Hypothyroidism by Age and Sex in the United States: A NHANES and Optum Claims Data Analysis

OBJECTIVE

Recent data using NHANES and Optum Claims data (OCD) showed an increase in primary hypothyroidism (HT) prevalence in the United States following the 2002 NHANES III report. Using these data, we characterized treatment patterns of overt HT (OHT) in the United States.

METHODS

Data on adults with OHT were collected from NHANES (2009-2012) and OCD (2012-2019). Disease status was determined from laboratory results or evidence of HT treatment (levothyroxine or liothyronine). OHT was defined as thyroid-stimulating hormone > 4.0 mIU/L and free thyroxine < 0.8 ng/dL or evidence of OHT treatment. Results were stratified by age group and sex. NHANES data were further stratified by insurance status (private/Medicare vs neither).

RESULTS

Overall, > 72% received treatment, with > 80% of the OCD cohorts receiving treatment. Among the NHANES cohort, treatment rates increased with advancing age and were consistently higher in females than in males (age 18-44: 47.3% vs 39.9%; 45-59: 76.8% vs 51.1%; ≥ 60: 91.9% vs 65.6%, respectively). Among the OCD cohorts, treatment patterns were similar across age group and sex (> 78% treated). Among the NHANES cohort that were not privately/Medicare insured, overall treatment rates were 50%, with those ≥ 60 having highest treatment rates (> 75%). Moreover, < 50% of reproductive-aged women in the NHANES dataset received treatment, which was reduced to 22% among uninsured patients.

CONCLUSIONS

This study provides important updates regarding treatment of OHT and highlights treatment disparities, especially among men and women of reproductive age, using both total and insured population estimates.

Roles of thyroid and leptin hormones and their crosstalk in male reproductive functions: an updated review

PURPOSE

This review aims to provide updated information regarding the role of thyroid and leptin hormones and their crosstalk in affecting the male reproductive function in hypothyroid and obesity conditions.

METHOD

A wide literature search was made using online search engines on published articles using keywords including thyroid hormone, hypothyroidism, leptin hormone, hyperleptinemia, obesity, the relationship between thyroid and leptin hormones and male reproduction, and hypothyroidism, obesity, and male reproduction.

RESULTS

All information pertaining thyroid and leptin hormone effects on male reproduction, hypothyroidism, hyperleptinemia, and obesity effect on male fertility as well as the related molecular mechanisms are obtained.

CONCLUSION

Thyroid and leptin hormones individually play a significant role in male reproduction. Alterations of these hormones' levels could adversely affect the male reproductive functions. PI3K/AKT signaling was found to be the major signaling pathway involved in mediating the effect of both hormones on male reproduction. Impaired crosstalk between the two hormones may occur in hypothyroidism with obesity which would contribute towards male reproductive dysfunction.

Massive Exudative Pleural Effusion With Hypothyroidism: A Case Report

Here, we report the case of a 79-year-old woman with massive exudative pleural effusion and hypothyroidism. The patient underwent total thyroid and parathyroidectomy during pharyngoesophagectomy for hypopharyngeal cancer. She was administered a thyroid hormone preparation (87.5 μg of levothyroxine sodium), calcium supplementation (0.5 g of calcium lactate hydrate), and active vitamin D (2 g of alfacalcidol). Four months after missing her regular medical appointment and discontinuing her medications, she developed a severe exudative pleural effusion, circumferential pericardial effusion, and mild ascites secondary to hypothyroidism. The pleural effusion, which may have been exacerbated by prolonged hypothyroidism and associated heart failure, improved with drainage and did not recur after the initiation of thyroid hormone replacement therapy. The pericardial effusion and ascites improved with hormone replacement alone. Although fluid retention associated with hypothyroidism usually improves with thyroid hormone therapy, drainage may be required to treat severe exudative effusions in diverse body cavities when diuretic treatments are insufficient.

Associations between exposure to sodium/iodide symporter inhibitors and markers of thyroid function: A systematic review and meta-analysis

BACKGROUND

Perchlorate, nitrate, and thiocyanate are well-known sodium/iodide symporter (NIS) inhibitors that disturb iodide uptake at the thyroid, affecting thyroid function. However, the associations between NIS inhibitor exposure and thyroid function are not well summarized in humans.

OBJECTIVE

We aimed to summarize associations between NIS inhibitor exposure and thyroid function markers and to identify key information gaps for future studies.

METHODS

From four databases (Embase, Web of Science, PubMed, CINAHL plus) up to May 31, 2024, we systematically searched studies that examined associations between levels of the three NIS inhibitors and thyroid hormones, including free thyroxine (FT4), total thyroxine (TT4), free triiodothyronine (FT3), and total triiodothyronine (TT3) as well as thyroid-stimulating hormone (TSH). We also conducted a random-effects meta-analysis to estimate the pooled effect size of the associations between NIS inhibitor levels and thyroid function marker levels.

RESULTS

Of 2,588 identified studies, we selected 9 studies for full-text review and 4 studies for a meta-analysis. The association between perchlorate and TSH was primarily studied and only three studies considered iodine concentrations. As a result of a meta-analysis, TSH levels were positively associated with levels of combined NIS inhibitors [β: 0.105; 95% confidence interval (CI): 0.046, 0.160] and perchlorate [β = 0.133; 95% CI: 0.056, 0.211]. We found negative trends between NIS inhibitors and FT3 and TT4 and positive but nonsignificant trends between FT3 and perchlorate and between TT4 and thiocyanate.

CONCLUSIONS

Our study provided comprehensive evidence on the association between exposure to NIS inhibitors and thyroid function markers in humans, aligning with the mechanisms observed in in vivo studies.

The causal relationship between thyroid dysfunction and carpal tunnel syndrome: A Mendelian randomization study

Mendelian randomization was used to investigate the causal relationship between thyroid dysfunction (including hypothyroidism and hyperthyroidism) and carpal tunnel syndrome. Genetic loci independently associated with hypothyroidism and hyperthyroidism were selected as instrumental variables from pooled data from genome-wide association studies. Inverse variance weighting (IVW) was used to analyze the causal effect, supplemented by weighted median and MR-Egger. Heterogeneity test, pleiotropy testing and leave-one-out analysis were used to analyze the sensitivity test to explore the robustness of the results. Both hypothyroidism and hyperthyroidism increase the risk of carpal tunnel syndrome (hypothyroidism: IVW, OR = 1.04, 95% CI = 1.01-1.08, P = .017; hyperthyroidism: IVW, OR = 1.08, 95% CI = 1.05-1.12, P = 9.218E-06, no pleiotropy was found in both tests. Patients with thyroid dysfunction have an increased risk of carpal tunnel syndrome.

Relationship of comprehensive dietary antioxidant index and hypothyroidism risk: evidence from the National Health and Nutrition Examination Surveys 2007-2012

BACKGROUND

Hypothyroidism is a common thyroid disease affecting the health of the global population and oxidative stress and inflammation are involved in the pathophysiological process of hypothyroidism. Comprehensive dietary antioxidant index (CDAI), representing the overall dietary antioxidant capacity, has been proved to be associated with a variety of diseases. However, association between CDAI and hypothyroidism risk remains unclear. This study aims to evaluate the association of CDAI and hypothyroidism risk.

METHODS

Data of this study were extracted from the National Health and Nutrition Examination Surveys (NHANES) database 2007-2012. CDAI, represents the overall dietary nutrients capacity, was calculated by selenium, zinc, magnesium, vitamin A, C and E. Thyroid stimulating hormone (TSH) > 5.6 mIU/L was defined as hypothyroidism. The weighted multivariate logistic regression models and propensity score matching (PSM) analysis were utilized to evaluate the relationship between CDAI and hypothyroidism, with odds ratio (ORs) and 95% confidence intervals (CIs). Subgroup and sensitivity analysis were further evaluated the relationship between CDAI and hypothyroidism. Moreover, the association between the components of CDAI and hypothyroidism was also explored.

RESULTS

Totally, 7,959 subjects with information of complete dietary intake and thyroid function measurement were included. Of whom, 213 (2.68%) subjects had hypothyroidism. After adjusted all covariates, we observed high CDAI was related to low hypothyroidism risk (OR = 0.44, 95%CI: 0.27-0.71). This relationship was prominent in subjects with aged < 65 years old (OR = 0.32, 95%CI: 0.16-0.62), male (OR = 0.39, 95%CI: 0.15-0.99) and BMI ≥ 25 kg/m2 (OR = 0.38, 95%CI: 0.19-0.76). The association between high CDAI and low hypothyroidism risk remained significant when subjects using thyroid hormones were excluded (OR = 0.47, 95%CI: 0.27-0.81).

CONCLUSION

High CDAI was related to low hypothyroidism risk among U.S. adults. Our finding showed that the intake of an antioxidant-rich dietary is a potential method to reduce the risk of hypothyroidism.

Associations between indicators of lipid and glucose metabolism and hypothyroidism

BACKGROUND

Hypothyroidism, a prevalent thyroid hormone abnormality identified by biochemical indicators, is prone to serious consequences because of its insidious clinical manifestations and easy underdiagnosis. This research aimed to elucidate the relationships between indicators of lipid and glucose metabolism and hypothyroidism and to assess the value of metabolic indicators for hypothyroidism.

METHODS

Prevalence surveys were conducted utilizing information from 3254 NHANES individuals who passed screening between 2007 and 2012. Comparisons of baseline characteristics, assessment of logistic regression and subgroup analyses, visualization of restricted cubic splines curves, and validation of causal mediation analyses were performed to obtain a comprehensive view of the relationships between indicators of lipid and glucose metabolism and hypothyroidism.

RESULTS

Lipid and glucose metabolism indicators, especially the unconventional parameters triglyceride‒glucose index (TyG) and remnant cholesterol (RC) and the conventional parameter triglyceride (TG), exhibited robust positive relationships with hypothyroidism and served as crucial mediators in the pathways by which hypothyroidism affects health outcomes. Indicators were varying suggestive for hypothyroidism in distinct populations, with TyG being relatively more valuable.

CONCLUSIONS

Indicators of lipid and glucose metabolism (TyG, TG, and RC) were intimately associated with hypothyroidism, with potential applications in the assessment and management of hypothyroidism.

Effect of thyroid stimulating hormone on the prognosis of coronary heart disease

Introduction

Clinical studies have shown that thyroid stimulating hormone (TSH) is associated with increased cardiovascular disease risk and mortality. Even within normal ranges, elevated TSH levels have an impact on the cardiovascular system and have been associated with cardiac dysfunction. The aim of our study was to evaluate the predictive value of admission fasting serum TSH levels in patients with coronary heart disease in relation to long-term major adverse cardiovascular events (MACE) and all-cause mortality.

Method

A total of 3515 patients with coronary heart disease who met the inclusion criteria were divided into four groups according to the quantile of TSH levels: Group 1 (TSH, 0.34-1.02 mIU/L, n=878); Group 2 (TSH, 1.03-1.71 mIU/L, n=886); Group 3 (TSH, 1.72-2.84 mIU/L, n=880); and Group 4 (TSH, 2.86-5.50 mIU/L, n=873). MACE and all-cause mortality were also compared. TSH concentrations associated with the risk of MACE, all-cause mortality were assessed using continuous scales (restricted quartic splines) and Cox proportional hazards regression models.

Results

A total of 3515 patients with coronary heart disease were eligible for analysis. At a median follow-up of 70 months, patients in group 2 had a lower incidence of MACE compared to the other three groups. All-cause mortality was lower in the 3rd group. Restricted quartic spline analysis also revealed that TSH concentrations were associated with heart failure risk.

Discussion

TSH levels have predictive value for adverse cardiovascular events and heart failure in patients with coronary heart disease.

Subacute thyroiditis in pregnancy: a narrative review

Thyroid dysfunction can adversely affect pregnancy outcomes. Apart from gestational thyrotoxicosis, thyroid dysfunction during pregnancy shares similar etiologies with the non-gravid state. Graves' disease is the most common cause of spontaneous hyperthyroidism in pregnancy, followed by thyroid autonomy. Although subacute thyroiditis is a less common cause of thyrotoxicosis in pregnancy, its associated pain, systemic symptoms, and thyroid dysfunction can present diagnostic and therapeutic challenges. In its painful form, subacute thyroiditis may lead to severe disability, with systemic glucocorticoids being the best effective treatment option. When painless, the condition often comes to medical attention due to thyroid dysfunction. During the thyrotoxic phase, subacute thyroiditis should be differentiated from gestational thyrotoxicosis, Graves' disease, and thyroid autonomy. Additionally, the transient hypothyroid phase may be misdiagnosed as permanent hypothyroidism, such as in Hashimoto's thyroiditis. Once properly diagnosed, management is symptomatic and focused on correcting the predominant abnormality. In this review, we summarize the current reported cases of subacute thyroiditis in pregnancy and discuss the challenges in diagnosis and management. Clinical trial number Not applicable.

Variable transduction of thyroid hormone signaling in structures of the mouse brain

L-thyroxine (L-T4) monotherapy is the standard treatment for hypothyroidism, administered daily to normalize TSH levels. Once absorbed, T4 is converted to T3 to alleviate most symptoms. However, this treatment abnormally elevates plasma T4 levels in over 50% of patients. Using L-T4-treated Thyroid Hormone (TH) Action Indicator mice, which express a T3-regulated luciferase (Luc) reporter, we examined whether these T4 elevations disrupt TH signaling. Hypothyroid mice exhibited reduced Luc expression across brain regions, and L-T4 treatment failed to restore T3 signaling uniformly. There was also variability in the activity of type 2 deiodinase (D2), the enzyme that generates most brain T3. Intracerebroventricular T4 administration achieved higher elevation of Luc expression in the mediobasal hypothalamus compared to the cortex, and studies on cultured cortical astrocytes and hypothalamic tanycytes revealed cell-type-specific responses to T4. In tanycytes, exposure to T4 sustained D2 activity, leading to progressive T3 signaling, whereas in astrocytes, T4 exposure triggered a drop in D2 activity, limiting T3 production through a ubiquitin-dependent, self-limiting mechanism. The sustained D2 activity in tanycytes was linked to rapid deubiquitination by USP33, as confirmed using a ubiquitin-specific protease (USP) pan-inhibitor and USP33 knockout mice. In conclusion, the brain's response to L-T4 treatment is heterogeneous, influenced by cell-specific regulation of D2-mediated T3 production. While cortical astrocytes exhibit limited T3 signaling due to D2 ubiquitination, tanycytes coexpressing USP33 amplify T3 signaling by rescuing ubiquitinated D2 from proteasomal degradation. These findings provide mechanistic insights into the limitations of L-T4 therapy and highlight the need for tailored approaches to managing hypothyroidism.

Thyroid function abnormalities in individuals with sickle cell disease: a meta-analysis

BACKGROUND

There has been an increasing comprehension and recognition of endocrine dysfunction among both pediatric and adult patients with sickle cell disease (SCD). Thyroid disorders can have significant clinical consequences, including growth retardation and impaired cognitive function. However, there is a disparity in the available data concerning the magnitude and spectrum of thyroid abnormalities in this population. This review aimed to provide a systematic summary and analyses on the status of thyroid function abnormalities in individuals with SCD.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted across Medline/PubMed, Google Scholar, World Health Organization Virtual Health Library Regional Portal, and ScienceDirect. Pooled prevalence and standardized mean difference (SMD) estimates with 95% confidence intervals (CIs) were calculated using Comprehensive Meta-Analysis Software version 3.3.

RESULTS

Nineteen studies met the inclusion criteria and were incorporated into the analyses. Serum thyroid-stimulating hormone (TSH) levels were significantly higher in SCD patients compared to controls (SMD = 1.184; 95% CI, 0.269-2.099; p = 0.011). While non-significant, there was a trend towards lower levels of triiodothyronine (T3), thyroxin (T4), free T3, and free T4 in the SCD group (T3: SMD = -1.746; 95% CI, -3.561-0.070; p = 0.059; T4: SMD = -1.365; 95% CI, -3.030-0.300; p = 0.108; free T3: SMD = -0.384; 95% CI, -1.128-0.356; p = 0.311; free T4: SMD = -1.205; 95% CI, -2.522-0.111; p = 0.073). The pooled prevalence of hypothyroidism and subclinical hypothyroidism among SCD patients was found to be 4.9% and 8.7%, respectively.

CONCLUSION

Individuals with SCD exhibit a tendency towards elevated TSH levels compared to the general population, with a subset potentially developing thyroid abnormalities, particularly subclinical hypothyroidism. Although not highly prevalent in the SCD population, monitoring thyroid function remains essential due to the potential for progression to overt hypothyroidism and its associated adverse health outcomes.

Thyroid hormone receptor-β analogues for the treatment of metabolic dysfunction-associated steatohepatitis (MASH)

The association between suboptimal thyroid function ((sub)clinical hypothyroidism or low-normal thyroid function) and the metabolic syndrome and MASLD (metabolic dysfunction-associated steatotic liver disease) has been clearly established. Furthermore, in MASLD, intracellular thyroid hormone concentrations are low and the activation of the thyroid hormone receptor (THR) is reduced. Administration of thyroid hormone has been shown to reduce liver triglycerides by stimulating fatty acid disposal through lipophagy and beta-oxidation, and to lower LDL-cholesterol. As thyroid hormone exerts its effects in many different organs, including the heart and bone, several drug candidates have been developed as selective thyromimetics for the THR-β nuclear receptor with potent and liver-targeted activity. Importantly, these compounds have reduced affinity for the THR-α nuclear receptor and tissue distribution profiles that differ from endogenous thyroid hormones, thereby reducing unwanted cardiovascular side effects. The most advanced compound, resmetirom, is an oral drug that demonstrated, in a large phase III trial in patients with MASH (metabolic dysfunction-associated steatohepatitis), the ability to reduce liver fat, decrease aminotransferase levels and improve atherogenic dyslipidaemia with a good tolerability profile. This translated into histological improvement that led to accelerated approval of this drug for active fibrotic steatohepatitis, a milestone achievement as a first MASH drug.

Association Between FOXP3 rs2232368 Variant and Hashimoto's Thyroiditis Risk: A Case-Control Study

Background and aim Hashimoto's thyroiditis (HT) pathogenesis is characterized by a dysregulation of immune tolerance, which may be influenced by genetic variations in the FOXP3 gene, a key regulator of T-regulatory cell function. However, the role of specific FOXP3 polymorphisms in HT susceptibility is not yet fully understood, particularly in Middle Eastern populations. This study aims to explore the association between the FOXP3 rs2232368 polymorphism and HT susceptibility in an Iraqi population while also examining its relationship with thyroid function parameters. Methods This case-control study included 60 HT patients and 40 healthy controls from the Medical City Educational Laboratories in Baghdad (October 2022 to September 2023). HT diagnosis was based on established clinical and laboratory criteria. Thyroid function (thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4)) was measured using the mini VIDAS® system (bioMérieux, Craponne, France). FOXP3 rs2232368 genotyping was performed using ARMS-PCR. Genetic associations were assessed through ORs with 95% CIs, adjusting for demographic and clinical variables. Results HT patients exhibited significant thyroid dysfunction compared to controls (median TSH: 18.82 vs. 2.66 mIU/L, p < 0.001; T3: 0.53 vs. 2.33 nmol/L, p < 0.001; T4: 8.12 vs. 43.5 μg/dL, p < 0.001). The AA genotype was associated with a significantly increased risk of HT (OR = 4.66, 95% CI: 1.32-16.44, p = 0.017), while the heterozygous GA genotype showed a nonsignificant trend (OR = 2.28, 95% CI: 0.84-6.19, p = 0.108). The A allele was strongly associated with HT susceptibility (OR = 2.98, 95% CI: 1.54-5.77, p = 0.001). These associations remained significant after adjusting for BMI and thyroid parameters. Conclusions This study identifies FOXP3 rs2232368 as a significant genetic risk factor for HT in the Iraqi population, with the AA genotype associated with nearly a five-fold increased susceptibility. These findings enhance our understanding of the genetic basis of HT and may inform risk stratification strategies for Middle Eastern populations. Further research is needed to explore the functional implications of this polymorphism in thyroid autoimmunity.

Autoimmune thyroiditis incidence in a large population-based study in northeastern Italy

PURPOSE

An improvement in iodine status in the Veneto region (Italy) in the last decade has been documented. Our aim was to estimate the incidence of autoimmune thyroiditis (AT) in this region over the period 2012-2022.

METHODS

A retrospective population-based study conducted in Veneto using the population registry and administrative health databases. We documented incident hyperthyroidism from 2013 to 2022 to exclude prevalent cases and calculated standardised incidence rates (IR) per 10,000 person-years by age and sex.

RESULTS

We identified 65,379 incident cases (IR: 13.38), 5.44-fold higher in females than in males. IR decreased from 15.86 (95% CI: 15.50, 16.21) in 2013 to 12.35 (95% CI: 12.04, 12.67) in 2022. The decline was evident only in females, with a documented reduction in IR from 27.26 (95% CI: 26.61, 27.91) in 2013 to 20.49 (95% CI: 19.92, 21.07) in 2022 (P = 0.002). The decrease was sharper in females aged 15-54 years (IR from 37.86 (95%CI: 36.79, 38.94) in 2013 to 27.40 (95% CI: 26.44, 28.36) in 2022; P < 0.001) than in those aged ≥55 years (IR from 20.06 (95% CI: 19.13, 20.99) in 2013 to 16.56 (95% CI: 15.78, 17.35) in 2022; P = 0.034). In 2020, an out-of-trend decrease in AT incidence was documented, corresponding with the SARS-CoV-2 pandemic, with a realignment to the trend in the subsequent years.

CONCLUSIONS

A decline in AT was documented in the Veneto region in the last decade, paralleling improvement in the iodine status. The reduction was significant only among females, particularly in reproductive age.

Acquired hypothyroidism, iodine status and hearing impairment in adults: A pilot study

OBJECTIVES

Hearing impairment can have major impacts on behavior, educational attainment, social status, and quality of life. In congenital hypothyroidism, the incidence of hearing impairment reaches 35-50%, while in acquired hypothyroidism there is a reported incidence of 25%. Despite this, knowledge of the pathogenesis, incidence and severity of hearing impairment remains greatly lacking. The aim of our study was to evaluate hearing in patients with acquired hypothyroidism.

METHODS

30 patients with untreated and newly diagnosed peripheral hypothyroidism (H) and a control group of 30 healthy probands (C) were enrolled in the study. Biochemical markers were measured, including median iodine urine concentrations (IUC) µg/L. The hearing examination included a subjective complaint assessment, otomicroscopy, tympanometry, transitory otoacoustic emission (TOAE), tone audiometry, and brainstem auditory evoked potential (BERA) examinations. The Mann-Whitney U test, Fisher's Exact test and multivariate regression were used for statistical analysis.

RESULTS

The H and C groups had significantly different thyroid hormone levels (medians with 95% CI) TSH mU/L 13.3 (8.1, 19.3) vs. 1.97 (1.21, 2.25) p =  0 and fT4 pmol/L 10.4 (9.51, 11.1) vs. 15 (13.8, 16.7) p =  0. The groups did not significantly differ in age 39 (34, 43) vs. 41 (36,44) p =  0.767 and IUC 142 (113, 159) vs. 123 (101, 157) p =  0.814. None of the hearing examinations showed differences between the H and C groups: otomicroscopy (p =  1), tympanometry (p =  1), TOAE (p =  1), audiometry (p =  0.179), and BERA (p =  0.505).

CONCLUSIONS

We did not observe any hearing impairment in adults with acquired hypothyroidism, and there were no associations found between hearing impairment and the severity of hypothyroidism or iodine status. However, some forms of hearing impairment, mostly mild, were very common in both studied groups.

Novel Biomarkers Reveal Mismatch Between Tissue and Serum Thyroid Hormone Status in Amiodarone-Induced Hyperthyroidism

CONTEXT

Serum thyrotropin and thyroid hormone (TH) levels are routine markers of thyroid function. However, their diagnostic performance is limited under special conditions, such as in amiodarone-induced hyperthyroidism (AIH). Such cases would require the assessment of tissue TH action, which is currently unfeasible.

OBJECTIVE

Development of an approach that determines how well serum parameters are reflected in tissue TH action of patients.

METHODS

TH-responsive marker genes were identified from human hair follicles (HFs) with next-generation sequencing, validated by quantitative polymerase chain reaction. A classification model was built with these markers to assess tissue TH action and was deployed on amiodarone-treated patients. The impact of amiodarone on tissue TH action was also studied in thyroid hormone action indicator (THAI) mice.

RESULTS

The classification model was validated and shown to predict tissue TH status of subjects with good performance. Serum- and HF-based TH statuses were concordant in hypothyroid and euthyroid amiodarone-treated patients. In contrast, amiodarone decreased the coincidence of serum-based and HF-based TH statuses in patients with hyperthyroidism, indicating that AIH is not unequivocally associated with tissue hyperthyroidism. This was confirmed in the THAI model, where amiodarone prevented tissue hyperthyroidism in THAI mice despite high serum free thyroxine.

CONCLUSION

We developed a minimally invasive approach using HF markers to assess tissue TH economy that could complement routine diagnostics in controversial cases. We observed that a substantial proportion of patients with AIH do not develop tissue hyperthyroidism, indicating that amiodarone protects tissues from thyrotoxicosis. Assessing tissue TH action in patients with AIH may be warranted for treatment decisions.

A disturbed communication between hypothalamic-pituitary-ovary axis and gut microbiota in female infertility: is diet to blame?

Female infertility is a multifactorial condition influenced by various genetic, environmental, and lifestyle factors. Recent research has investigated the significant impact of gut microbiome dysbiosis on systemic inflammation, metabolic dysfunction, and hormonal imbalances, which can potentially impair fertility. The gut-brain axis, a bidirectional communication system between the gut and the brain, also plays a significant role in regulating reproductive functions. Emerging evidence suggests that the gut microbiome can influence brain functions and behavior, further emphasizing the importance of the microbiota-gut-brain axis in reproduction. Given their role as a major modulator of the gut microbiome, diet and dietary factors, including dietary patterns and nutrient intake, have been implicated in the development and management of female infertility. Hence, this review aims to highlight the impact of dietary patterns, such as the Western diet (WD) and Mediterranean diet (MD), and to decipher their modulatory action on the microbiota-gut-brain axis in infertile women. By contrasting the detrimental effects of WD with the therapeutic potential of MD, we emphasize the pivotal role of a balanced diet rich in nutrients in promoting a healthy gut microbiome. These insights underscore the potential of targeted dietary interventions and lifestyle modifications as promising strategies to enhance reproductive outcomes in subfertile women.

Interpretable Machine Learning Model for Predicting Postpartum Depression: Retrospective Study

Background

Postpartum depression (PPD) is a prevalent mental health issue with significant impacts on mothers and families. Exploring reliable predictors is crucial for the early and accurate prediction of PPD, which remains challenging.

Objective

This study aimed to comprehensively collect variables from multiple aspects, develop and validate machine learning models to achieve precise prediction of PPD, and interpret the model to reveal clinical implications.

Methods

This study recruited pregnant women who delivered at the West China Second University Hospital, Sichuan University. Various variables were collected from electronic medical record data and screened using least absolute shrinkage and selection operator penalty regression. Participants were divided into training (1358/2055, 66.1%) and validation (697/2055, 33.9%) sets by random sampling. Machine learning-based predictive models were developed in the training cohort. Models were validated in the validation cohort with receiver operating curve and decision curve analysis. Multiple model interpretation methods were implemented to explain the optimal model.

Results

We recruited 2055 participants in this study. The extreme gradient boosting model was the optimal predictive model with the area under the receiver operating curve of 0.849. Shapley Additive Explanation indicated that the most influential predictors of PPD were antepartum depression, lower fetal weight, elevated thyroid-stimulating hormone, declined thyroid peroxidase antibodies, elevated serum ferritin, and older age.

Conclusions

This study developed and validated a machine learning-based predictive model for PPD. Several significant risk factors and how they impact the prediction of PPD were revealed. These findings provide new insights into the early screening of individuals with high risk for PPD, emphasizing the need for comprehensive screening approaches that include both physiological and psychological factors.

Effects of levothyroxine therapy on bone and mineral metabolism in hypothyroidism: a systematic review and meta-analysis

BACKGROUND

Thyroid hormone plays an important role in accumulating bone development and regulating bone metabolism. It is established that hypothyroidism is linked to increased risk of osteoporosis and fracture. However, the effects of levothyroxine (LT4) treatment on bone for hypothyroid patients remain controversial.

METHODS

A systematical search was conducted of several databases, from inception until December 9, 2022, and updated the search using the same search strategy on October 30, 2024, for studies evaluating the effects of LT4 treatment on bone in hypothyroidism including subclinical hypothyroidism (SCH) and overt hypothyroidism (OH). The data were reported using a random-effects model with a standardized mean difference (SMD) and 95% conference interval (CI).

RESULTS

Thirteen of the 5996 published articles were included in this meta-analysis. No significance was found in bone mineral density (BMD) at the lumbar spine between SCH patients treated with LT4 and control group either at baseline or after intervention. For OH, BMD at the lumbar spine was statistically lower in LT4 treatment group compared with healthy controls (HCs) (SMD: -0.28, 95%CI: -0.55, -0.02, P = 0.040, I2 = 52%). There were no differences in BMD at the femoral neck, trochanter, and Ward's triangle between OH patients treated with LT4 and HCs. In addition, BMD at the lumbar spine was significantly lower in males with OH undergoing LT4 treatment for a duration of less than five years compared to those treated over five years. Nevertheless, no significant differences were found in bone metabolism biomarkers between OH patients treated with LT4 and HCs.

CONCLUSION

This systematic review and meta-analysis demonstrated that there is a slight adverse effect of LT4 replacement therapy on bone and mineral metabolism in patients with OH, while no observed effect was found in SCH patients.

Effects of Thioglycolate Compounds in an Emerging Technique in the World of Cosmetics-Brow Lamination

BACKGROUND

The side effects of two related chemicals, ammonium thioglycolate (ATG) and thioglycolic acid (TGA) have been widely highlighted in the world of cosmetics. These thioglycolate compounds are considered essential ingredients in a new technique known as brow lamination. This technique is widely used nowadays, with the aim of changing the eyebrow shape.

AIMS

To our knowledge, this is the first study to address the possible side effects of brow lamination.

RESULTS

The hydrophilic characteristic of ATG and TGA reflects their transdermal absorption through the intracellular and transappendageal pathways. These compounds can affect the skin through allergic contact dermatitis (ACD), characterized by skin irritation, dryness, and erythema. Moreover, these thioglycolates can alter several mechanical and chemical reactions in the eyebrows' hair, therefore affecting their shape, structure, and pigmentation. In addition, these chemicals contained in brow lamination can exert systemic manifestations, at the level of the reproductive, ocular, respiratory, and endocrine systems.

CONCLUSION

More studies should be elaborated to shed light on the possible side effects of this trend. Additionally, further regulations should be taken into consideration to ensure the concentration and the measures applied are convenient to minimize these side effects.

Thyroid hormone and the Liver

It is known that thyroid hormone can regulate hepatic metabolic pathways including cholesterol, de novo lipogenesis, fatty acid oxidation, lipophagy, and carbohydrate metabolism. Thyroid hormone action is mediated by the thyroid hormone receptor (THR) isoforms and their coregulators, and THRβ is the main isoform expressed in the liver. Dysregulation of thyroid hormone levels, as seen in hypothyroidism, has been associated with dyslipidemia and metabolic dysfunction-associated fatty liver disease. Given the beneficial effects of thyroid hormone in liver metabolism and the advances illuminating the use of thyroid hormone analogs such as resmetirom as therapeutic agents in the treatment of metabolic dysfunction-associated fatty liver disease, this review aims to further explore the relationship between TH, the liver, and metabolic dysfunction-associated fatty liver disease. Herein, we summarize the current clinical therapies and highlight future areas of research.

More Than Under-Eye Bags: Treatment of Formidable Festoons

A 64-year-old male with no medical care over the last decade was transferred from his local emergency room to a level 1 trauma center following an unwitnessed fall. Upon ophthalmic evaluation, he was noted to have significant lethargy and bilateral large festoons with secondary ectropion. Laboratory workup revealed severe hypothyroidism, consistent with myxedema coma, and his lethargy improved with medical treatment. The festoons were surgically removed to address the ectropion, and the patient was satisfied with the results following a single procedure. This case report features the largest reported festoons to date in the literature and emphasizes the importance of balancing cosmesis with function during surgical excision and correction of ectropion.

Frequency and characteristics of anemia in hypothyroid patients: A cross-sectional study

BACKGROUND

Hypothyroidism leads to a metabolic slowdown that affects all body systems and significantly impacts the hematopoietic system, resulting in anemia in 20%-60% of patients. This study aims to evaluate the prevalence of anemia in hypothyroid patients and describe the factors associated with anemia in those patients.

MATERIALS AND METHODS

We reviewed the electronic health records (EHRs) of all the patients attending the Outpatient Department of King Abdulaziz University Hospital, Jeddah, Saudi Arabia, during January 1, 2018, to December 31, 2022. All patients aged 18-70 years who had received a diagnosis of hypothyroidism, ICD-10 code E03.9, and had undergone simultaneous blood tests for complete blood count and iron profile along with thyroid function tests were included in the study. Data on demographic characteristics, laboratory test results, and comorbidities was retrieved from EHRs. Anemia was defined according to WHO as Hb levels <12.0 g/dL in women and <13.0 g/dL in men. Data was analyzed using SPSS version 28.0. Categorical variables were presented as frequencies and percentages while continuous variables were described by mean and standard deviation. Multiple logistic regression was applied to determine the risk factors for hypothyroidism.

RESULTS

Study included a total of 413 patients with hypothyroidism; 40% of hypothyroid patients were found to be anemic and most had microcytic normochromic anemia. Logistic regression revealed that males had much lower risk of anemia compared to females (adjusted odds ratio [AOR] = 0.14; 95% confidence interval [CI]: 0.05-0.39), while obesity was associated with a higher risk of anemia (AOR = 1.67; 95% CI: 1.11-2.50).

CONCLUSION

A higher proportion of anemia was seen in patients with hypothyroidism, indicating a significant relationship between anemia, obesity, and gender. This highlights the importance of monitoring anemia in patients with hypothyroidism, especially in females and obese individuals.

Add on effect of Whole System Ayurveda protocol in suboptimal controlled Primary Hypothyroidism - A randomized controlled trial

BACKGROUND

Primary hypothyroidism (PH) is a common chronic life style disorder. Whole system Ayurveda protocol on PH (WSAPH) is explored for it's possible complimentary role in the management of suboptimal controlled PH on stable levothyroxine therapy.

OBJECTIVE

To evaluate the efficacy of whole system Ayurveda protocol on Primary hypothyroidism with suboptimal response to stable levothyroxine therapy.

MATERIAL AND METHODS

Study was a randomized controlled trial. Total 46 known patients of suboptimal response to stable levothyroxine therapy, age group 20-60 years of either sex participated in the study. They were randomly placed in two groups, Group KG received Kanchanara guggulu two tablets of 500 mg each, thrice a day with water and group WSAPH was on whole system Ayurveda protocol for primary hypothyroidism (WSAPH). Interventions were for 60 days. Assessments were done through various parameters like Thyroid profiles (TSH, T3, T4, Free T4), Weight, BMI, Skin fold thickness (SFT), Body fat index (BFI), Waist hip ratio (WHR), Lipid profile, Zulewskis clinical score for hypothyroidism (ZUL), WHO Quality of Life- BREF (WHOQOL-BREF), Clinical Global Improvement scales (CGI). Clinical assessments were done on every 15th day and biochemical were done before and after interventions.

RESULTS

Study showed that WSAPH group produced significant outcome improvement compared to KG group in TSH (p = 0.02), weight (p = 0.02), SFT (p = 0.04), BFI (p = 0.01), WHOQOL-BREF (p = 0.004) and ZUL (p = 0.02). Both the group showed improvements in BMI, WHR, BFI, SFT, WHOQOL-BREF, ZUL, CGI scales. Effect size was medium in TSH, weight, BFI, SFT and ZUL.

CONCLUSION

WSAPH was effective in management of PH and normalized TSH and ZUL scores in patients with suboptimal response to stable levothyroxine therapy. Further studies are needed.

Thyroid function, autoimmunity, thyroid volume, and metabolic profile in people with Hashimoto thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is associated with high cardiovascular risk. Thyroid volume has a notable dispersion of values in these patients. This study aims to clarify the association between thyroid antibodies, thyroid morphology, insulin resistance, and lipid profile in patients with HT.

METHODS

Cross-sectional study that includes 409 subjects diagnosed with HT. We assessed thyroid function, markers of autoimmunity, and markers of cardiovascular risk. We also evaluated thyroid ultrasound and studied the correlation between all factors.

RESULTS

Among the study population, 9.8% were male, the mean age was 56.4 ± 17.4 years, 63.7% had dyslipidemia, and 29.5% had diabetes. Patients with hypothyroidism had higher levels of anti-thyroperoxidase antibodies (TPOab), and the decreased thyroid dimensions subgroup had a higher percentage of patients taking levothyroxine (98.7%). Positive correlations were found between TPOab and volume, and negative correlations were observed between thyroid-stimulating hormone (TSH) and volume.

CONCLUSION

The current study reveals a complex interrelationship between cardiovascular disease risk factors, thyroid function, autoimmunity, and thyroid volume in HT. These associations may be of clinical relevance, and further studies are needed to elucidate how these findings may be used clinically to reduce the cardiovascular risk in patients with HT.

Evaluation of the hematological parameters, inflammatory biomarkers, and thyroid hormones in hypothyroidism patients

AIM

Hypothyroidism is created by disruption of thyroid hormone production, which can destroy the emotional, relational, social, and working life of patients if left untreated. Hypothyroidism has multiple etiologies. We evaluated the relationship of hematological parameters and inflammatory biomarkers with thyroid hormones to find the potential use of these items in patients screening and prognosis.

METHODS

This is a cross-sectional study, which was done on 88 individuals of both genders (32 male and 56 female), over 18 years old with a mean age of 45 years old. These patients were referred by physicians after examination to our laboratories of Qaem Medical Laboratory of Kuhchenar and Jahrom University of Medical Sciences, Fars, Iran. The patients had recent symptoms and signs of hypothyroidism with increased TSH above the normal range, and negative serum anti-TPO antibody. To determine ABO, Rh, and Lewis (Le) blood groups was used anti-A, anti-B, anti-D, anti-Lea, and anti-Leb monoclonal antibodies. Serum T3, T4, and TSH was measured by direct chemiluminescent immunoassay. Anti-TPO antibody was measured by ELISA. CRP was determined using an immunoturbidimetric assay. CBC count assessment was done via an automated cell counter. Exclusion criteria were patients with acute or chronic inflammatory diseases. Herein, we evaluated the correlation of hematological parameters consisting ABO, Rh, and Le blood groups, RBC and WBC parameters, and platelet count as well as inflammatory biomarkers including ESR, CRP, IL-8, and NLR with T3, T4, and TSH in hypothyroid patients.

RESULTS

Our study showed a significant correlation between Lea blood group (non-secretor) in comparison with Leb blood group (secretor) with TSH (P = 0.01). There was no correlation between Leb and Lea blood groups with T3 and T4. We did not observe the correlation between Rh and ABO blood groups with T3, T4, and TSH. We observed significant correlations between Hb, Hct, and MCH with T3 (PHb = 0.012, PHct = 0.021, and PMCH = 0.032) and also, with T4 in hypothyroidism (PHb = 0.023 and PHct = 0.026). We revealed significant correlations between Hb, Hct, and MCH with TSH in hypothyroidism (PHb = 0.017, PHct = 0.019, and PMCH = 0.007). The significant correlations between CRP and IL-8 with T3, T4, and TSH was not explored. The significant correlations between ESR with T3 and TSH was not detected. ESR showed a significant correlation with T4 (PESR = 0.020). There were also no significant correlations between the counts of neutrophils, lymphocytes, monocytes, and eosinophils, as well as NLR with T4. There was only significant correlation between monocyte count with T3 (PMono = 0.029) and also lymphocyte count with TSH (PLymph = 0.041).

CONCLUSION

In this investigation, we observed a significant relationship between Lea blood group in comparison with Leb blood group with TSH. We demonstrated significant correlations between Hb and Hct with T3, T4, and TSH, and also correlations between MCH with T3 and TSH. In conclusion, the assessment of Hb, Hct, MCH, and Le blood groups as hematological parameters can help physicians in the management of hypothyroidism.

Relationship between hypothyroidism and chronic kidney disease: Results from the National Health and Nutrition Examination Survey 2007 to 2012 and Mendelian randomization study

Chronic kidney disease (CKD) and hypothyroidism are prevalent chronic conditions with a generally believed correlation between them. However, large-scale population studies and investigations into causation are lacking. This study analyzed CKD and thyroid function data from the National Health and Nutrition Examination Survey database spanning 2007 to 2012 using multiple regression analyses to examine the correlation between CKD and hypothyroidism. Bidirectional Mendelian randomization analysis was employed to investigate the causal association between the two conditions. As CKD stages deteriorated, there was a significant decrease in total triiodothyronine (TT3) and free triiodothyronine (P < .05). However, no significant decrease was observed in total thyroxine and free thyroxine. Notably, there was a significant increase in thyroid-stimulating hormone levels (P < .05). However, no significant changes were observed in thyroglobulin, thyroglobulin antibody, and thyroid peroxidase antibody levels. A causal relationship between CKD and reduced thyroid function was observed (odds ratio [OR] = 1.0041, 95% confidence interval [CI]: 1.0007-1.0075, P = .0186). Conversely, reverse causality was not statistically significant (OR = 2.540, 95%CI: 0.8680-4.8603, P = .1014). As CKD progressed, the risk of hypothyroidism increased. A causal correlation was observed between CKD and reduced thyroid function. Chronic kidney disease (CKD) and hypothyroidism are prevalent chronic conditions with a generally believed correlation between them. There is no large-scale population studies and the causation relationship between CKD and hypothyroidism are lacking. The finding of the causal relationship between CKD and hypothyroidism may be beneficial to the prevention of the disease and the prognosis of the patients.

Association between hypothyroidism and obstructive sleep apnea: a bidirectional Mendelian randomization study combined with the geo database

Background

The causal relationship between hypothyroidism and obstructive sleep apnea (OSA) remains controversial. Therefore, our research used a bidirectional Mendelian randomization (MR) method in an attempt to determine the causal relationship between hypothyroidism and OSA.

Methods

From the publicly accessible genome-wide association analysis (GWAS) summary database, we obtained single nucleotide polymorphism (SNPs) data pertaining to hypothyroidism and OSA. Inverse variance weighting (IVW) was the principal method of analysis utilized, with validation also conducted via weighted median, MR-Egger, simple model, and weighted model approaches. To further evaluate the robustness of the results, heterogeneity testing, pleiotropy testing, and the "leave-one-out" sensitivity analysis were performed. Differentially expressed genes (DEGs) from the OSA dataset (GSE135917) and hypothyroidism dataset (GSE176153) derived from the Gene Expression Omnibus (GEO) database were screened using the "limma" package. The "clusterProfiler" and "GO plot" packages were used for further enrichment analysis in order to validate the findings of the MR study. The Cytoscape software was utilized to build a protein-protein interaction (PPI) network of DEGs and to screen for hub genes.

Results

The MR analysis showed that genetically predicted hypothyroidism was associated with an increased risk of OSA [IVW odds ratio (OR) = 1.734; 95% confidence interval (CI) = 1.073-2.801; p = 0.025]. The trend of the outcomes of the other approaches is consistent with the trend of the IVW outcome. However, the reverse MR analysis suggested no evidence for the causal effect of OSA on hypothyroidism (IVW OR = 1.002, 95% CI: 0.996-1.009, p = 0.454). The robustness of the results was confirmed by the sensitivity analysis. Bioinformatics analysis revealed that there were DEGs that hypothyroidism and OSA have in common.

Conclusion

Our findings suggested that hypothyroidism may increase the risk of OSA, while the effect of OSA on hypothyroidism was not found in this MR study. Thus, patients with hypothyroidism should be enhanced with screening for OSA for early diagnosis and appropriate treatment.

Rising Incidence and Comorbidities of Endogenous Hypothyroidism in Republic of Korea from 2004 to 2018: A Nationwide Population Study

BACKGRUOUND

Hypothyroidism, a prevalent endocrine disorder, results from insufficient thyroid hormone production or release, affecting metabolism. However, disparities in comorbidities and treatment trajectories may exist between endogenous and exogenous hypothyroidism.

METHODS

Data from the Korean National Health Insurance Service from 2004 to 2018. Endogenous hypothyroidism was defined as cases with two or more diagnostic codes for hypothyroidism coupled with a history of thyroid hormone intake exceeding 60 days. To eliminate iatrogenic hypothyroidism, individuals with diagnosis codes for thyroid cancer, treatment codes for thyroid surgery, or radiotherapy were excluded. Hypothyroidism-related comorbidities were defined as new occurrences of the corresponding diagnosis code after the diagnosis of hypothyroidism during the entire study period.

RESULTS

The age-standardized incidence of endogenous hypothyroidism among men was 0.2 per 1,000 person-years in 2004, increasing to 0.8 in 2018. Among women, the incidence increased from 1.6 per 1,000 person-years in 2004 to 3.7 in 2018. When comparing age groups of 20s-50s and 60s-90s, both sexes in the 60s-90s demonstrated a more rapid increase in incidence than those in the 20s-50s age range. Patients with endogenous hypothyroidism demonstrated a higher incidence of mood disorders across all age groups and cerebrovascular disease in individuals ≥60 years old, regardless of sex.

CONCLUSION

In Republic of Korea, endogenous hypothyroidism incidence has been increased in recent years. The incidence of endogenous hypothyroidism is increasing more rapidly in men than in women, especially in the elderly. Patients with endogenous hypothyroidism seem to have a heightened risk for cerebrovascular disease and mood disorders.

Causality of Hashimoto's Thyroiditis to Thyroid Cancer: A 2-S Mendelian Randomization Study

BACKGROUND

Observational studies have indicated an association between Hashimoto's thyroiditis (HT) and the risk of thyroid cancer (TC); however, the causality and direction of these effects in genetics remain unclear. Therefore, our study aims to investigate the relationship between genetic susceptibility to HT and TC through a bidirectional Mendelian randomization (MR) approach using twin samples.

METHODS

MR analysis was conducted using genetic instruments associated with HT, selected from a comprehensive genome-wide association meta-analysis involving a total of 756 000 individuals of European and East Asian descent. The data set for TC comprised 1.486 million individuals, including both European and East Asian populations. Single nucleotide polymorphisms closely linked to HT were derived from genome-wide association studies. Two-sample bidirectional MR analyses were applied to assess the causal association between HT and TC, using inverse-variance weighted methods, and MR Egger, weighted median, simple mode, and weighted mode. Furthermore, sensitivity analyses were conducted employing the MR-Egger regression model, weighted median method, MR pleiotropy residual sum and outlier, and leave-one-out technique.

RESULTS

MR analyses revealed no evidence of a causal relationship between HT and TC in either European or East Asian populations (all P > .1). However, bidirectional MR analysis demonstrated a causal relationship between TC and HT in the European population (odds ratio = 1.0838, 95% confidence interval: 1.0346, 11 354, P = .000686).

CONCLUSION

This MR analysis indicates a lack of evidence supporting an association between genetically predicted HT and the risk of developing TC. In contrast, there is evidence of a causal relationship between genetically predicted TC and HT.

Causal relationship between hypothyroidism and peripheral neuropathy: a Mendelian randomization study of European ancestry

Background

Metabolic disorders are significant risk factors for peripheral neuropathy (PN) diseases. However, current clinical observational studies cannot fully determine the causal relationships between hypothyroidism (HT) and PN diseases.

Methods

We performed univariate Mendelian randomization (MR) analyses using single nucleotide polymorphisms (SNPs) associated with hypothyroidism and two diseases clinically presented as HT (autoimmune thyroid disease and benign neoplasm of the pituitary gland and craniopharyngeal duct) as instrumental variables. We selected eight peripheral neuropathy diseases (diabetic neuropathy, nerve root/plexus disorder, carpal tunnel syndrome, polyneuropathies, sciatica with lumbago, trigeminal neuralgia, postherpetic neuralgia, small fiber neuropathy) as outcomes. Genetic data were sourced from authoritative genome-wide association study (GWAS) datasets. We primarily used the inverse variance-weighted (IVW) method and conducted a comprehensive sensitivity analysis to ensure robustness.

Results

The IVW results indicated that HT was significantly associated with an increased risk of diabetic peripheral neuropathy (OR = 1.22, p = 6.49E-05). HT was also significantly linked to nerve root/plexus disorder (OR = 1.04, p = 6.43E-06) and carpal tunnel syndrome (OR = 1.04, p = 0.004), but appeared to be a potential protective factor for polyneuropathies (OR = 0.93, p = 0.0009). Additionally, autoimmune thyroid disease (AITD) was identified as a potential risk factor for carpal tunnel syndrome (OR = 13.79, p = 0.006) and a protective factor for polyneuropathies (OR = 0.0011; p = 4.44E-5).

Conclusions

This study provides genetic evidence supporting potential causal links between hypothyroidism and various peripheral neuropathy diseases.

Higher Parametric Thyroid Feedback Quantile-based Index Is a Predictor of Type 2 Diabetes in a German Population Sample

CONTEXT

Type 2 diabetes has been described to be associated with hypothyroidism but we recently found that a decrease in pituitary sensitivity to thyroid hormone is associated with diabetes, obesity, and metabolic syndrome.

OBJECTIVE

We aimed to assess the longitudinal nature of this association in the population-based Study of Health in Pomerania (SHIP) in Germany.

METHODS

Among a population-based sample of 4308 participants aged 20 to 79 years, 77% were followed for a period of 5 years. We studied 2542 participants without diabetes or thyroid medication at baseline and complete data in the variables of interest. Data of baseline free thyroxine (fT4) and thyrotropin (TSH) were used to calculate the Parametric Thyroid Feedback Quantile-based Index (PTFQI), which measures whether TSH remains elevated despite fT4 being high. It uses the average population response as reference. PTFQI association with incidence of type 2 diabetes over 5 years was estimated with Poisson regression models adjusted for age, sex, and body mass index (BMI).

RESULTS

Compared with the first PTFQI quartile, incidence rate ratios for diabetes were 1.54 (95% CI, 0.97-2.46), 1.55 (0.94-2.57), and 1.97 (1.27-3.10) for the upper quartiles (P trend = .004) after adjusting for age and sex. The association remained statistically significant after additionally adjusting for BMI: 1.64 (1.05-2.59) for the fourth vs the first quartile (P trend = .043).

CONCLUSION

An elevation of the pituitary TSH-inhibition threshold is associated with incident type 2 diabetes independently of BMI. The PTFQI might have clinical potential for prognosis and metabolic status monitoring.

Leveraging nuclear receptor mediated transcriptional signaling for drug discovery: Historical insights and current advances

Nuclear receptors (NRs) are ligand-activated transcription factors that regulate gene expression in response to physiological signals, such as hormones and other chemical messengers. These receptors either activate or repress the transcription of target genes, which in turn promotes or suppresses physiological processes governing growth, differentiation, and homeostasis. NRs bind to specific DNA sequences and, in response to ligand binding, either promote or hinder the assembly of the transcriptional machinery, thereby influencing gene expression at the transcriptional level. These receptors are involved in a wide range of pathological conditions, including cancer, metabolic disorders, chronic inflammatory diseases, and immune system-related disorders. Modulation of NR function through targeted drugs has shown therapeutic benefits in treating such conditions. NR-targeted drugs, which either completely or selectively activate or block receptor function, represent a significant class of clinically valuable therapeutics. However, the pathways of NR-mediated gene expression and the resulting physiological effects are complex, involving crosstalk between various biomolecular components. As a result, NR-targeted drug discovery is challenging. With improved understanding of how NRs regulate physiological functions and deeper insights into their molecular structure, the process of NR-targeted drug discovery has evolved. While many traditional NR-targeting drugs are associated with side effects of varying severity, new drug candidates are being designed to minimize these adverse effects. Given that NR activity varies according to the tissue in which they are expressed and the specific isoform that is activated or repressed, achieving selectivity in targeting specific tissues and isoform classes may help reduce systemic side effects. In a recent breakthrough, the isoform-selective, hepato-targeted thyroid hormone-β agonist, Resmetirom (marketed as Rezdiffra), was approved for the treatment of non-alcoholic steatohepatitis. This chapter explores the structural and mechanistic principles guiding NR-targeted drug discovery and provides insights into recent developments in this field.