Management of Subclinical Hypothyroidism: A Focus on Proven Health Effects in the 2023 Korean Thyroid Association Guidelines

Incidence and risk factors for early thyroxin supplementation therapy after hemithyroidectomy for benign conditions in Europe. A Eurocrine® registry-based study

The incidence and risk factors of hypothyroidism after hemithyroidectomy (HT) remain poorly defined. Regarding its management, national or local policies may influence on early (first visit) prescription of replacement therapy (EPRT). Our aim was to identify factors influencing and explaining different prescription patterns across European countries. We conducted a retrospective, multicenter study using the Eurocrine® database, focusing on patients undergoing HT for histologically-proven benign conditions. Analyzed variables included the country where surgery was performed, as well as epidemiological, clinical, surgical and pathological data. The dependent variable was EPRT, assessed 30-45 days after surgery. Associations between qualitative variables and the likelihood of receiving EPRT were tested using Chi-square or Fisher's exact tests. A multivariate logistic regression model was developed to identify independent predictors. 14,484 patients undergoing HT between 2015 and 2022 were included. Median age was 52 years, and 11,345 (78.3%) were female. The most common indication for surgery was excluding malignancy in 7873 cases (54.3%). Overall, 4653 patients (32.1%) received EPRT, with significant variability among countries, ranging from 3 to 95%. Independent risk factors for EPRT included female sex, older age, malignancy and thyrotoxicosis as surgical indications, Bethesda III cytology, thyroiditis on histology, and the country where HT was performed. One-third of European patients undergoing HT for confirmed benign conditions required EPRT. That prescription was more likely among older patients, those with suspected malignancy or thyrotoxicosis as surgical indications, suspicious cytology, and thyroiditis on histology. Additionally, the country where surgery was done played a significant role.

Long-term forecasting and evaluation of medicine consumption for the ATC class H with a focus on thyroid hormones in OECD countries using ARIMA models

Thyroid hormones are among the most prescribed medicines. In many countries, there are shortages combined with evidence of overuse and irrational prescribing. An analysis was conducted for ATC class H with a focus on thyroid hormones for OECD countries. This study aims to evaluate prescribing behaviours, forecast long-term developments and promote rational prescribing behaviour. The ARIMA(2,1,2) (autoregressive integrated moving average) model successfully predicted the future for 30 OECD countries and the non-OECD country Croatia until 2040. An upward trend is forecast for 18 countries, including Austria (+ 5.7%), Chile (+ 220.0%), Czechia (+ 52.8%), Denmark (+ 15.6%), Estonia (+ 87.8%), Greece (+ 238.7%), Hungary (+ 5.7%), Iceland (+ 18.6%), Italy (+ 42.9%), Latvia (+ 83.7%), Lithuania (+ 131.2%), Portugal (+ 106.7%), Slovakia (+ 182.1%), Slovenia (+ 57.4%), Spain (+ 162.8%), Turkey (+ 168.7%), the United Kingdom (+ 138.1%) and Croatia (+ 190.6%). A downward trend is forecast for 13 countries, including Australia (-3.4%), Belgium (-38.8%), Canada (-95.1%), Costa Rica (-79.5%), Finland (-14.7%), France (-100.0%), Germany (-16.4%), Israel (-21.6%), Korea (-100.0%), Luxembourg (-100.0%), the Netherlands (-35.9%), Norway (-23.6%) and Sweden (-43.6%). The reliability and accuracy of the forecasts varies, being influenced by data quality. While a downward trend is favoured, an upward trend is seen as problematic. Increasing trends predominate in Southern and Eastern Europe and Latin America, while decreasing trends predominate in Northern and Western Europe and the Asia-Pacific Region. Some external factors affect all countries, like an increasing prevalence of thyroid disease. There is evidence of cultural influences on prescribing behaviour. While there is evidence of inappropriate use in countries where prescriptions are predicted to increase, measures to restrict the use of thyroid hormones are more common in countries with a recently reported and predicted declining trend.

Macro-Thyrotropin Syndrome: Prevalence and Clinical Profile of an Under-Recognised Rare Entity in Thyroidology

Introduction

Macro-thyrotropin syndrome (macro-TSH) is a rare condition characterised by the formation of a complex between thyroid-stimulating hormone (TSH) and an unknown component, resulting in elevated TSH levels that do not accurately reflect thyroid status. This study aimed to investigate the prevalence and clinical profile of macro-TSH among patients with subclinical hypothyroidism (SCH).

Methods

A total of 1500 patients were evaluated, with 135 exhibiting elevated TSH levels (>10 IU/mL) and normal free-thyroxine levels. Macro-TSH was diagnosed based on persistent elevated TSH levels despite serial dilutions and confirmed by less than 60% TSH recovery following polyethylene glycol (PEG) precipitation.

Results

Finally, 115 were diagnosed with SCH, 15 with macro-TSH, and 1245 were categorised into non-thyroid groups. The prevalence of macro-TSH, SCH, and heterophilic antibodies interfering with immunoassay was 1.09%, 8.36%, and 0.36%, respectively. Among macro-TSH patients, 13.33% exhibited classical hypothyroid features, contrasting with the 52.0% observed in SCH patients. Female gender and a family history of hypothyroidism were associated with higher odds of having macro-TSH. Diabetes mellitus, clinical symptoms of hypothyroidism (except lethargy), higher TSH level, and post-PEG TSH recovery were significantly associated with SCH compared to macro-TSH. The mean TSH level was five times higher in macro-TSH compared to SCH.

Conclusion

Macro-TSH syndrome represents a distinct clinical entity within the spectrum of SCH, characterised by disproportionately high TSH levels. Recognising macro-TSH is crucial for accurate diagnosis and appropriate management of SCH.

Evaluation of the effects of thyroid functions on frailty in geriatric patients using the Edmonton, SOF and FRAIL Scales

BACKGROUND AND RATIONALE: Thyroid dysfunction in older adults often mimics the signs of aging, impacting metabolism and overall physiological balance. While age-related chronic conditions have been extensively studied, the relationship between thyroid function and frailty remains underexplored.

OBJECTIVE

This study aimed to evaluate the effects of thyroid dysfunction on frailty among individuals aged 65 years and older. Thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and thyroid peroxidase antibody (anti-TPO) levels were analyzed. The study further examined the correlation between thyroid dysfunction, chronic diseases, sociodemographic factors, and optimal TSH levels in relation to frailty, using the Study of Osteoporotic Fractures (SOF), Edmonton Frail Scale (EFS), and FRAIL scales.

METHODS

This cross-sectional study included 220 older adults with either treated or untreated thyroid dysfunction. Comprehensive geriatric assessments were conducted, including detailed medical histories, sociodemographic data collection, and thyroid function tests. Frailty was assessed using the SOF, EFS, and FRAIL scales. Multivariate logistic regression analyses were performed to identify significant associations between thyroid parameters and frailty.

RESULTS

The median age of participants was 73 years, and 68.2% (n = 150) were women. Frailty prevalence was significantly higher in individuals with abnormal TSH levels (outside the 0.5-6 mIU/L range). Lower fT3 levels and the fT3/fT4 ratio were significantly associated with frailty, particularly as assessed by the SOF and EFS scales. In contrast, the FRAIL scale revealed a significant association between increased frailty and lower fT3 levels only. Subgroup analysis indicated that in individuals aged ≥ 80 years, a lower fT3/fT4 ratio was consistently associated with frailty across all frailty scales, whereas in those aged < 80 years, lower TSH levels showed a strong association with frailty as assessed by the FRAIL scale. These findings underscore age-specific variations in the relationship between thyroid function and frailty.

CONCLUSION

This study highlights the significant impact of thyroid dysfunction on frailty in older adults. Lower fT3 levels and the fT3/fT4 ratio emerged as key indicators of increased frailty, particularly on the SOF and EFS scales. Subgroup analysis further emphasized the importance of age-specific assessments, with a lower fT3/fT4 ratio being a critical indicator of frailty in individuals aged ≥ 80 years, while lower TSH levels were significant in those aged < 80 years. Abnormal TSH levels were strongly associated with frailty on the SOF scale, suggesting the need to consider thyroid dysfunction as a modifiable risk factor. Additionally, factors such as age, sex, education, thyroid medication use, and comorbidities influenced frailty status. Incorporating thyroid function tests into frailty assessments could enhance early identification and targeted interventions for at-risk older adults, particularly when age-specific thresholds are applied.

Severe Symptomatic Anemia as a Rare Initial Manifestation of Type 3 Polyglandular Autoimmune Syndrome: A Case Report

Autoimmune polyglandular syndrome type 3 (APS-3) is an uncommon condition marked by autoimmune thyroid disease (ATD) linked with other autoimmune issues, excluding Addison's disease. We report a case of a 41-year-old man who was hospitalized due to exhaustion and macrocytic anemia, later diagnosed with APS-3, which included Hashimoto's thyroiditis, pernicious anemia resulting from autoimmune gastritis, and pre-existing vitiligo. Diagnostic results indicated positive intrinsic factor antibodies, a gastric biopsy compatible with gastritis, elevated thyroid peroxidase antibodies, and significant findings from a thyroid ultrasound. Treatment included parenteral vitamin B12, which improved anemia, while for mild hypothyroidism, a watchful waiting approach was taken. This case report highlights the importance of conducting a systematic evaluation of anemia in the diagnosis and management of APS-3. Although anemia is not typically recognized as a characteristic feature of APSs, it can present as pernicious anemia secondary to autoimmune gastritis. These anemias can be significant and severely limiting, often causing pronounced symptoms that greatly impact patients' daily lives, further emphasizing the need for timely diagnosis and appropriate management.

Serum Vitamin B12 and Holotranscobalamin Levels in Subclinical Hypothyroid Patients in Relation to Thyroid-Stimulating Hormone (TSH) Levels and the Positivity of Anti-thyroid Peroxidase Antibodies: A Case-Control Study

Background Subclinical hypothyroidism (SCH) is characterized by elevated thyroid-stimulating hormone (TSH) levels, while thyroid hormones (free thyroxine (T4) and free triiodothyronine (T3)) remain within the reference ranges. Vitamin B12 (cobalamin) deficiency is common in patients with autoimmune disorders, including autoimmune hypothyroidism. The study was aimed at evaluating serum vitamin B12 levels and holotranscobalamin (HoloTC) levels in SCH patients and ascertaining their association with a risky level of TSH and the positivity of anti-thyroid peroxidase (anti-TPO) antibodies. Methodology A case-control study was conducted at Azadi Teaching Hospital, Duhok, a city in the Kurdistan region of Iraq, involving 153 participants, including 72 newly diagnosed SCH patients and 81 healthy controls. Serum levels of vitamin B12, HoloTC, TSH, free T4, free T3, and anti-TPO antibodies were measured based on different principles. Results The mean age of patients with SCH was 32.87±8.7 years, with predominantly females comprising 75% and 77.8% being less than 40 years of age. Moreover, the mean levels of serum TSH (6.96±2.68 µIU/L), anti-TPO antibodies (53.31±81.32 IU/ml), and HoloTC (41.93±19.42 pmol/l) were significantly higher in patients with SCH compared to healthy control participants (p < 0.05), whereas there was a non-significantly higher level of vitamin B12(320.72±98.42 pg/ml) among SCH patients compared to healthy control participants (p = 0.220). The mean levels of vitamin B12 (345.33±103.22 pg/ml) and HoloTC (40.14±18.16 pmol/l) were insignificantly lower in SCH patients with TSH levels more than 7 µIU/L (p > 0.05), as well as the mean levels of vitamin B12 (308.82±96.12 pg/ml) and HoloTC (41.14±19.29 pmol/l) insignificantly lower in SCH patients with positive anti-TPO antibodies (p > 0.05).  Conclusions This study highlights the potential association between SCH and altered vitamin B12 status, particularly evident in HoloTC levels. The presence of positive anti-TPO antibodies and the degree of elevation in TSH levels may exacerbate vitamin B12 deficiency in SCH patients.