Urinary haloacetic acid concentrations and thyroid function among women: Results from the TREE study

BACKGROUND

Disinfection byproducts (DBPs) have been shown to impair thyroid function in experimental models. However, epidemiological evidence is scarce.

METHODS

This study included 1190 women undergoing assisted reproductive technology (ART) treatment from the Tongji Reproductive and Environmental (TREE) cohort from December 2018 to August 2021. Serum thyrotropin (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were measured as indicators of thyroid function. FT4/FT3 and TSH/FT4 ratios were calculated as markers of thyroid hormone homeostasis. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), the two most abundant HAAs, in urine were detected to assess individual DBP exposures.

RESULTS

After adjusting for relevant covariates, positive associations were observed between urinary TCAA concentrations and serum TSH and TSH/FT4 levels (e.g., percent change = 5.82 %, 95 % CI: 0.70 %, 11.21 % for TSH), whereas inverse associations were found for serum FT3 and FT4 (e.g., percent change = -1.29 %, 95 % CI: -2.49 %, -0.07 % for FT3). There also was a negative association between urinary DCAA concentration and serum FT4/FT3 (percent change = -2.49 %, 95 % CI: -4.71 %, -0.23 %). These associations were further confirmed in the restricted cubic spline and generalized additive models with linear or U-shaped dose-response relationships.

CONCLUSION

Urinary HAAs were associated with altered thyroid hormone homeostasis among women undergoing ART treatment.

The Cross-sectional and Longitudinal Association Between Thyroid Function and Depression: A Population-Based Study

CONTEXT

An association of thyroid function with mood disorders has been widely suggested, but very few studies have examined this association longitudinally.

OBJECTIVE

We assessed the cross-sectional and longitudinal association between thyroid function and depression in a population-based cohort.

METHODS

A total of 9471 individuals were included in cross-sectional analyses, of whom 8366 had longitudinal data. At baseline, we assessed thyroid function using serum samples (thyrotropin [TSH], free thyroxine (FT4), and thyroid peroxidase antibodies) and depressive symptoms using the Centre for Epidemiologic Studies Depression (CES-D) scale. Incident depressive events (n = 1366) were continuously followed up with the CES-D and clinical interviews. We analyzed the cross-sectional association of thyroid function and thyroid disease with depressive symptoms using linear and logistic regression, and the longitudinal association with Cox proportional hazard models for depressive events.

RESULTS

Lower TSH levels and lower and higher FT4 levels were cross-sectionally associated with more depressive symptoms with a B value of -0.07 per 1 unit increase of natural log-transformed TSH (95% CI -0.11; -0.04). Furthermore, hypothyroidism was cross-sectionally associated with less depressive symptoms and hyperthyroidism with more depressive symptoms. Longitudinally, there was a U-shaped association between FT4 and incident depressive events but only in euthyroid participants.

CONCLUSION

We show a cross-sectional association between thyroid (dys)function with depressive symptoms, and a U-shaped association between FT4 and incident depressive events in euthyroid individuals. Our findings suggest an association of thyroid function with the risk of developing depression, albeit small. Reverse causation and additional underlying factors may also contribute to the association.

Free triiodothyronine to free thyroxine ratio as a marker of poor prognosis in euthyroid patients with acute coronary syndrome and diabetes after percutaneous coronary intervention

Objectives

In recent years, the free triiodothyronine/free thyroxine (FT3/FT4) ratio, a new comprehensive index for evaluating thyroid function, which could reflect thyroid function more stably and truly than serum thyroid hormone level, has been demonstrated to correlate with the risks of diabetes and cardiovascular disease in euthyroid adults. However, the correlation between thyroid hormone sensitivity and long-term prognosis in euthyroid patients with acute coronary syndrome (ACS) and diabetes after percutaneous coronary intervention (PCI) remains unclear.

Methods

A total of 1,786 euthyroid patients with ACS who successfully underwent PCI at Beijing Anzhen Hospital from August 2021 to April 2022 were included in our study, which was divided into three groups according to tertiles of thyroid hormone sensitivity index. Cox regression, Kaplan-Meier, and receiver operating characteristic analyses were applied to analyze the associations between the FT3/FT4 ratio with ACS and diabetes after PCI.

Results

Our analysis indicated that a lower level of FT3/FT4 ratio in euthyroid patients with acute coronary syndrome (ACS) and diabetes after PCI showed significantly higher incidences of major adverse cardiac and cerebrovascular events (MACCE) when compared with a higher level of FT3/FT4 ratio. After adjusting for other covariates, patients with a lower level of FT3/FT4 ratio were negatively associated with the risk of MACCE than those with a higher level of FT3/FT4 ratio (adjusted OR =1.61, 95% CI 1.05-2.47, P = 0.028). In subgroup analyses, individuals were stratified by age, sex, BMI, ACS type, hypertension, and dyslipidemia, showing that there were no significant interactions between the FT3/FT4 ratio and all subgroups for MACCE. In addition, the FT3/FT4 ratio performed better on ROC analyses for cardiac death prediction [area under the curve (AUC), 0.738].

Conclusion

A reduced level of FT3/FT4 ratio was a potential marker of poor prognosis in euthyroid patients with ACS and diabetes after PCI.

Approach to the Patient With Raised Thyroid Hormones and Nonsuppressed TSH

Measurement of free thyroid hormones (THs) and thyrotropin (TSH) using automated immunoassays is central to the diagnosis of thyroid dysfunction. Using illustrative cases, we describe a diagnostic approach to discordant thyroid function tests, focusing on entities causing elevated free thyroxine and/or free triiodothyronine measurements with nonsuppressed TSH levels. Different types of analytical interference (eg, abnormal thyroid hormone binding proteins, antibodies to iodothyronines or TSH, heterophile antibodies, biotin) or disorders (eg, resistance to thyroid hormone β or α, monocarboxylate transporter 8 or selenoprotein deficiency, TSH-secreting pituitary tumor) that can cause this biochemical pattern will be considered. We show that a structured approach, combining clinical assessment with additional laboratory investigations to exclude assay artifact, followed by genetic testing or specialized imaging, can establish a correct diagnosis, potentially preventing unnecessary investigation or inappropriate therapy.

Higher serum free thyroxine levels are associated with increased risk of hip fractures in older men

Overt and subclinical hyperthyroidism are associated with an increased fracture risk, but whether thyroid hormones are associated with fracture risk in individuals with normal thyroid-stimulating hormone (TSH) has mostly been investigated in women. Therefore, we investigated if serum levels of free thyroxine (FT4) or TSH are associated with fracture risk in Swedish men. We followed (median 12.2 yr) elderly men (n = 1825; mean age 75, range 69-81 yr) participating in the Gothenburg and Malmö subcohorts of the prospective, population-based MrOS-Sweden study. The statistical analyses included Cox proportional hazards regression. Men receiving levothyroxine treatment were excluded. In our total cohort, serum FT4 (per SD increase) was associated with increased risk of major osteoporotic fractures (MOFs; n = 479; fully adjusted hazard ratio [HR] 1.14, 95% CI, 1.05-1.24) and hip fractures (n = 207; HR 1.18, 95% CI, 1.04-1.33). Also, in men with normal TSH (n = 1658), FT4 (per SD increase) was significantly associated with increased risk of MOF and hip fractures. Furthermore, men in the highest FT4 quartile had a 1.5-fold increase in hip fracture risk compared with men in the three lower FT4 quartiles, both in the total population and in men with normal TSH (fully adjusted: HR 1.45, 95% CI, 1.04-2.02 and HR 1.51, 95% CI, 1.07-2.12, respectively). In contrast, the risk of MOF was not statistically different in the highest FT4 quartile compared with the three lower FT4 quartiles. Finally, serum TSH was not associated with fracture risk after full adjustment for covariates. In conclusion, serum FT4, but not serum TSH, is a predictor of hip fracture risk in elderly Swedish men. Additionally, there was an association between FT4 (per SD increase) and the risk of MOF.

Isolated central hypothyroidism: Underlying pathophysiology and relation to antidepressant and antipsychotic medications-A multi-centre South Wales study

OBJECTIVE

Isolated biochemical central hypothyroidism is a presentation we are experiencing more frequently as endocrinologists, with variation in levels of investigation between physicians. We therefore conducted research to investigate the final diagnosis and clinical outcome of patients across multiple hospitals in South Wales with biochemical isolated central hypothyroidism; namely to establish whether this isolated biochemical picture was clinically significant. We also analysed whether there is an association between this biochemical picture and treatment with antidepressant and antipsychotic medications, and how common this is.

DESIGN

We performed a retrospective observational study of patients across nine different hospitals in South Wales. We analysed patients referred to endocrinology at each site over a 6-year period with unexplained isolated biochemical central hypothyroidism.

MATERIALS AND METHODOLOGY

1022 individual patients' thyroid function test results were identified from our biochemical database using our inclusion criteria. After exclusion criteria were applied, 71 patients' results were analysed as to the final pathophysiology of their central hypothyroidism.

RESULT

Of the 71 patients included in the study, none were found to have any clinically significant pathology on pituitary imaging. On reviewing their medications, 46/71 (65%) were found to be taking psychotropic medications.

CONCLUSIONS

Our study strongly suggests isolated central hypothyroidism, in the absence of other pituitary hormone dysfunction or visual field defect, does not require further investigation, saving resources as well as sparing patients unnecessary anxiety. It also strongly supports a relationship between patients taking psychotropic medications and biochemical isolated central hypothyroidism, an association only described in a very limited amount of literature before this, and further supporting our previous single-centre study findings. The mechanism behind this is likely to be the suppression of thyrotropin secretion via antagonism of the dopamine-serotoninergic pathway. In our opinion, patients found to have isolated biochemical central hypothyroidism who are taking psychotropic medications can therefore be regarded to have a recognised cause for this biochemical finding and do not require further radiological investigation.

Can artificial intelligence replace biochemists? A study comparing interpretation of thyroid function test results by ChatGPT and Google Bard to practising biochemists

BACKGROUND

Public awareness of artificial intelligence (AI) is increasing and this novel technology is being used for a range of everyday tasks and more specialist clinical applications. On a background of increasing waits for GP appointments alongside patient access to laboratory test results through the NHS app, this study aimed to assess the accuracy and safety of two AI tools, ChatGPT and Google Bard, in providing interpretation of thyroid function test results as if posed by laboratory scientists or patients.

METHODS

Fifteen fictional cases were presented to a team of clinicians and clinical scientists to produce a consensus opinion. The cases were then presented to ChatGPT and Google Bard as though from healthcare providers and from patients. The responses were categorized as correct, partially correct or incorrect compared to consensus opinion and the advice assessed for safety to patients.

RESULTS

Of the 15 cases presented, ChatGPT and Google Bard correctly interpreted only 33.3% and 20.0% of cases, respectively. When queries were posed as a patient, 66.7% of ChatGPT responses were safe compared to 60.0% of Google Bard responses. Both AI tools were able to identify primary hypothyroidism and hyperthyroidism but failed to identify subclinical presentations, non-thyroidal illness or secondary hypothyroidism.

CONCLUSIONS

This study has demonstrated that AI tools do not currently have the capacity to generate consistently correct interpretation and safe advice to patients and should not be used as an alternative to a consultation with a qualified medical professional. Available AI in its current form cannot replace human clinical knowledge in this scenario.

Anaemia-based screening for resistance to thyroid hormone alpha in children

BACKGROUND

The hypothyroid phenotype associated with resistance to thyroid hormone alpha (RTH-α) is associated with a diverse clinical picture. On the other hand, thyroid-stimulating hormone (TSH) levels are normal. Free triiodothyronine (fT3) and free thyroxine (fT4) levels can also be normal; however, normo- or macrocytic anaemia is usually present in reported cases. Diagnosis is challenging and there is limited data regarding screening methods.

OBJECTIVE

The study aimed to assess the efficiency of a screening strategy for RTH-α.

SUBJECTS AND METHODS

Out of a total of 6540 children evaluated at the outpatient clinics of paediatric neurology over 2 years and who underwent complete blood count and thyroid function tests, 432 were found to have anaemia. Within this group, we identified 42 children without an underlying specific neurological aetiology who exhibited normo- or macrocytic anaemia, normal TSH levels, fT3 levels in the upper half of the normal range or high, and fT4 levels in the lower half of the normal range or low. We excluded one patient who had already been diagnosed with RTH-α and nine patients could not be reached. Subsequently, clinical evaluation, biochemical assessment, and THRA sequencing analysis were conducted on 32 children. The findings were compared with those of the known RTH-α patients in our unit.

RESULTS

The median age of the patients was 5.7 (5.1-7.4) years, and 22 of them were males (69%). The main reasons for assessment in paediatric neurology clinics were autism spectrum disorder (n = 12, 38%), epilepsy (n = 11, 34%), and delay in developmental stages (n = 8, 25%). Constipation was present in five of the cases (16%), while the closure of the anterior fontanelle and tooth eruption were delayed in two cases (6%) and one case (3%), respectively. The median length/height and weight standard deviation (SD) scores were 0.3 [(-0.8)-(1.1)] and -0.1 [(-0.8)-(0.3)], respectively. The median fT3, fT4, and TSH levels were 4.6 (4.2-5.0) pg/mL, 0.9 (0.8-1.0) ng/dL, and 2.2 (1.8-3.1) uIU/mL, respectively. Thirteen of the patients (41%) had high fT3 levels, while none of them had low fT4 levels. The normo- or macrocytic anaemia rate was 47% (normocytic/macrocytic, n = 8/7) at the time of reassessment. Serum creatine kinase (CK) was elevated in five patients (16%; one had anaemia). None of the subjects had a pathological variant in THRA. Known RTH-α patients had significantly lower median height SD score, higher rates of delayed tooth eruption and closure of the anterior fontanelle, lower haemoglobin levels, and higher mean corpuscular volume (MCV) and CK levels as compared to those found without RTH-α.

CONCLUSIONS

This approach found one known patient with RTH-α but did not reveal any new cases. Notably, normo- or macrocytic anaemia did not persist in nearly half of the screened patients. A screening strategy that takes clinical findings and prominent laboratory features suggestive of RTH-α into account could lower unnecessary genetic analysis of THRA in patients presenting with neurological problems.

TSH and FT4 Reference Interval Recommendations and Prevalence of Gestational Thyroid Dysfunction: Quantification of Current Diagnostic Approaches

CONTEXT

Guidelines recommend use of population- and trimester-specific thyroid-stimulating hormone (TSH) and free thyroxine (FT4) reference intervals (RIs) in pregnancy. Since these are often unavailable, clinicians frequently rely on alternative diagnostic strategies. We sought to quantify the diagnostic consequences of current recommendations.

METHODS

We included cohorts participating in the Consortium on Thyroid and Pregnancy. Different approaches were used to define RIs: a TSH fixed upper limit of 4.0 mU/L (fixed limit approach), a fixed subtraction from the upper limit for TSH of 0.5 mU/L (subtraction approach) and using nonpregnancy RIs. Outcome measures were sensitivity and false discovery rate (FDR) of women for whom levothyroxine treatment was indicated and those for whom treatment would be considered according to international guidelines.

RESULTS

The study population comprised 52 496 participants from 18 cohorts. Compared with the use of trimester-specific RIs, alternative approaches had a low sensitivity (0.63-0.82) and high FDR (0.11-0.35) to detect women with a treatment indication or consideration. Sensitivity and FDR to detect a treatment indication in the first trimester were similar between the fixed limit, subtraction, and nonpregnancy approach (0.77-0.11 vs 0.74-0.16 vs 0.60-0.11). The diagnostic performance to detect overt hypothyroidism, isolated hypothyroxinemia, and (sub)clinical hyperthyroidism mainly varied between FT4 RI approaches, while the diagnostic performance to detect subclinical hypothyroidism varied between the applied TSH RI approaches.

CONCLUSION

Alternative approaches to define RIs for TSH and FT4 in pregnancy result in considerable overdiagnosis and underdiagnosis compared with population- and trimester-specific RIs. Additional strategies need to be explored to optimize identification of thyroid dysfunction during pregnancy.

Trends and Components of Thyroid Status Evaluation in Commercially Insured Adults in the United States, 2006-2020

CONTEXT

Thyroid-stimulating hormone (TSH) is one of the most ordered laboratory tests.

OBJECTIVE

Determine trends of TSH testing rates and components of thyroid function testing.

METHODS

This was a retrospective analysis of adults 18-64 years old without evidence of thyroid disease with at least 365 days of continuous enrollment between 2006 and 2020 in the IBM MarketScan Claims Database. The main outcome measures were trends of TSH tests/1000 eligible patient-months stratified by age, sex, and region and composition of thyroid function testing.

RESULTS

Among 67 353 280 patients meeting eligibility criteria, we identified 25 606 518 TSH tests and 15 138 211 patients with ≥1 TSH test. Patients contributing an episode of TSH testing were most commonly 45-54 years old (29.8%) and female (63.6%). TSH testing rates remained consistent throughout the study period with 11.4 and 11.7 TSH tests/1000 person-months in the first and last study months, respectively (mean 12.2 TSH tests/1000 person-months). TSH testing rates dropped sharply in the spring of 2020 (4.2 TSH tests/1000 person-months). Females showed a nearly 2-fold higher rate of TSH testing than males (16.1 TSH tests/1000 person-months vs 8.6 TSH tests/1000 person-months). TSH testing rates increased with age (8.2 TSH tests/1000 person-months among individuals 18-34 years old vs 15.4 TSH tests/1000 person-months among individuals 55-64 years old). No difference in TSH testing rates was noted between regions. Thyroid function testing episodes included only TSH in most cases (70.8%).

CONCLUSION

TSH testing rates among commercially insured individuals without known thyroid disease appears stable over time, with higher frequency in females and with increasing age.

Assessment of Individual and Mixed Effects of Six Minerals on Thyroid Hormones in Chinese Pregnant Women

The biosynthesis of thyroid hormones is essential for brain and neurological development. It requires iodine as a key component but is also influenced by other nutrients. Evidence for the combined nutrient status in relation to thyroid hormones during pregnancy is limited. We aimed to investigate the joint associations of iodine, selenium, zinc, calcium, magnesium and iron with maternal thyroid functions in 489 pregnant women from Hangzhou, China. Serum levels of six essential minerals and thyroid function parameters were measured during the first antenatal visit. Linear regression, quantile g-computation and Bayesian kernel machine regression were used to explore the individual and joint relationships between the six minerals and thyroid hormones. Linear regression analyses revealed that calcium was positively associated with free triiodothyronine (FT3). Zinc was positively associated with free thyroxine (FT4). Iodine was negatively associated with thyroid-stimulating hormone (TSH) and positively associated with FT3 and FT4. The quantile g-computation and BKMR models indicated that the joint nutrient concentration was negatively associated with TSH and positively associated with FT3 and FT4. Among the six minerals, iodine contributed most to thyroid function. The findings suggested that maintaining the appropriate concentration of minerals, either as individuals or a mixture, is important for thyroid health during pregnancy.

Promoting Choosing Wisely Thyroid Function Test Guidelines in a Large Pediatric Hospital System

BACKGROUND

Free thyroxine (fT4) is often ordered when not indicated. The goal of the current study was to use quality improvement tools to identify and implement an optimal approach to reduce inappropriate fT4 testing throughout a large pediatric hospital system.

METHODS

After reviewing evidence-based guidelines and best practices, a thyroid-stimulating hormone with reflex to fT4 test and an outpatient thyroid order panel with clinical decision support at order entry, along with several rounds of provider education and feedback, were implemented. Outpatient and inpatient order sets and system preference lists were reviewed with subject matter experts and revised when appropriate. Tracking metrics were identified. Automated monthly run charts and statistical process control charts were created using data retrieved from the electronic health record. Charts established baseline data, balancing measure data, monitored the impact of interventions, and identified future interventions.

RESULTS

Over a 44-month period, among nonendocrinology providers, a reduction in fT4 and thyroid-stimulating hormone co-orders from 67% to 15% and an increase in reflex fT4 tests from 0% to 77% was obtained in inpatient and outpatient settings. Direct cost savings as a result of performing 5179 fewer fT4 tests over 3 years was determined to be $45 800.

CONCLUSIONS

After implementation of a reflex fT4 test, a novel order panel with clinical decision support, provider education, and changes to ordering modes, a large and sustainable reduction in fT4 tests that was associated with significant cost savings was achieved among nonendocrinology providers.

The Combined Effect of Immune Checkpoint Inhibitors and Tyrosine Kinase Inhibitors on Thyroid Function

Background: Recent successes with immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs) for the treatment of solid malignancies have paved the way for a new era of combined therapy. A common side effect seen with each of these classes of treatment is thyroid dysfunction, with rates estimated at 30-40% for TKI and 10-20% for ICI. However, little is known about the effect of combined ICI+TKI therapy on thyroid function. Therefore, this study evaluated the incidence, clinical features, and risk factors for developing thyroid abnormalities during ICI+TKI therapy and the relationship to cancer outcomes. Methods: We conducted a retrospective cohort study of patients treated with combination ICI+TKI cancer therapy at City of Hope Comprehensive Cancer Center from 2017 to 2023 who had pretreatment normal thyrotropin (TSH) levels. Primary analyses assessed the frequency, timing, and severity of thyroid function test abnormalities during ICI+TKI cancer therapy, and the requirement for thyroid hormone replacement. Secondary analyses evaluated risk factors for the development of thyroid dysfunction, including sex and drug regimen, and the association with cancer progression-free survival or overall survival. Univariable and multivariable models were used. Results: There were 106 patients who received ICI+TKI therapy with a median age of 63.5 years and a median follow-up of 12.8 months (interquartile range [IQR] 5.9-20.9). Notably, 63.2% (67/106) developed thyroid function abnormalities during ICI+TKI therapy, including 11 (10.4%) with hyperthyroidism, 42 (39.6%) with subclinical hypothyroidism (SCHypo), and 14 (13.2%) with overt hypothyroidism. The onset of thyroid dysfunction occurred at a median of 7 weeks (IQR 3.1-9.0) after start of ICI+TKI treatment for hyperthyroidism, 8.0 weeks (IQR 3.0-19.0) for SCHypo, and 8.1 weeks (IQR 5.9-9.1) for overt or worsening hypothyroidism. Hyperthyroidism resolved to hypothyroidism or normal TSH without intervention in all subjects, suggesting thyroiditis, and hypothyroidism was readily treated with thyroid hormone replacement. Conclusions: Thyroid dysfunction is a frequent adverse event in individuals treated with combination ICI+TKI therapy, with our data suggesting a rapid onset and higher incidence than previously seen with ICI or TKI therapy alone. Therefore, close monitoring of thyroid function during initial therapy and multidisciplinary care with endocrinology are recommended to facilitate early detection and initiation of thyroid hormone replacement in these patients.

The impact of quetiapine monotherapy or in combination with lithium on the thyroid function in patients with bipolar depression: A retrospective study

OBJECTIVE

This study aims to investigate whether quetiapine monotherapy or in combination with lithium significantly disturbs thyroid function in depressed patients with bipolar disorder (BD), and whether difference exists in the post-treatment thyroid function between the two therapies.

METHODS

Based on the electric medical records, outpatients and inpatients with a current depressive episode of BD from January 2016 to December 2022 were screened. All patients were treated with quetiapine monotherapy or in combination with lithium. In addition to the demographic data and depression scale, thyroid profiles including total thyroxine (TT4), total triiodothyronine (TT3), free thyroxine (FT4), free triiodothyronine (FT3), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), and antithyroglobulin antibody (TGAb) were recorded, analyzed, and compared before and after the treatment.

RESULTS

Totally, 73 eligible patients were enrolled, including 53 in the monotherapy group (MG) and 20 in the combined therapy group (CG). No significant differences in thyroid profiles were detected between the two groups at the baseline (p > 0.05). After one-month treatment, in the MG, serum levels of TT4, TT3, FT4, and FT3 reduced significantly (p < 0.05), while TSH, TPOAb, and TGAb increased significantly (p < 0.05). In the CG, serum levels of TT4, TT3, and FT4 reduced and TSH increased following one-month treatment (p < 0.05), with no significant change in FT3, TPOAb, or TGAb (p > 0.05). After one-month treatment, no difference of TT4, TT3, FT4, FT3, and TSH was found between the two groups (p > 0.05).

CONCLUSION

Both quetiapine monotherapy and a combined therapy with lithium significantly disturbed thyroid function in patients with bipolar depression, while quetiapine monotherapy seems to be associated with immune dysregulation in the thyroid.

Interference against a newly labeled substance with ruthenium sulfonate complexes showing discrepant thyroid function test results

We report here two patients exhibiting a combination of falsely elevated serum levels of free thyroxine (FT4), free triiodothyronine (FT3), and thyrotropin receptor antibodies (TRAb), measured using Elecsys assay kits (Roche Diagnostics GmbH). The first patient was a 74-year-old man misdiagnosed with Graves' disease and treated with methimazole. The second patient was a 48-year-old woman whose serum FT4 and FT3 concentrations were found to be high during a blood test. These patients denied taking biotin or any other supplements. Further detailed examination, including a heterophilic blocking tube test, revealed the presence of serum antibodies. The abnormal reactions were observed only using the improved assay kits using ruthenium (Ru) sulfonate instead of Ru as a chemiluminescent agent. Therefore, serum antibodies to the Ru sulfonate complex caused the pseudo-high levels of FT4, FT3, and TRAb. To our knowledge, this is the first report showing that antibodies to the Ru sulfonate complex in the electrochemiluminescence immunoassay can cause falsely elevated levels of the combination, leading to discrepant thyroid function test results. We emphasize that in cases of abnormal test results, alternative assay methods should be considered for further examination; unusual test results should not be impulsively interpreted, even when using revised assay kits.

A Novel TSH Receptor Gene Variant Associated with Non-Autoimmune Hyperthyrotropinemia: A Case Report

BACKGROUND

Resistance to TSH is defined as reduced sensitivity to normal, biologicallyactive TSH, and abnormally high levels of TSH are needed to achieve normal levels of thyroid hormones.

CASE PRESENTATION

A 15-year-old female patient, having been treated since childhood with levothyroxine for hyperthyrotropinemia was referred to our institution complaining of tachycardia after the levothyroxine therapy had been increased. Thyroid ultrasound features were normal, and thyroid antibodies were negative. The therapy was gradually tapered in light of the symptoms, although subclinical hypothyroidism was evident at thyroid function tests. First-degree relatives were tested for thyroid function, and the father was also found to have a previously-unknown subclinical hypothyroidism. The patient underwent genetic testing for TSH receptor (TSHR) gene mutations, which revealed a gene variant hitherto not described: p.C598R (c.1792T>C). The father was also tested and was found to carry the same mutation, while other first-degree relatives were wild-type for the TSHR gene. An in-silico analysis was performed, which revealed a loss-of-function phenotype corresponding to the described variant, suggesting a novel loss-of-function TSH receptor gene mutation.

CONCLUSION

In this case report, we present a novel loss-of-function gene mutation in the TSH receptor gene associated with a TSH resistance phenotype.

Evaluation of patients diagnosed with congenital hypothyroidism by newborn screening between 2011-2019 in Diyarbakir, Turkey

This study aimed to determine the incidence of congenital hypothyroidism in Turkey's Diyarbakir Province and assess the development and growth conditions of people with congenital hypothyroidism. Patients born between 2011-2019 and diagnosed with congenital hypothyroidism within the scope of the newborn screening program were included. The medical records of these patients were retrospectively reviewed. The length and weight for age, weight for length, and body mass index standard deviation scores were calculated. We investigated the treatment status of the patients, whether their relatives had a similar disorder, and the presence of consanguinity between parents. Blood samples were collected from 380,592 newborns. As a result of further tests, 498 newborns were diagnosed with congenital hypothyroidism (incidence: 1/764). Demographic and anthropometric data of 241 patients were analyzed. The patients comprised 46.9% (n = 113) females and 53.1% (n = 128) males. It was determined that 44.4% of the individuals had transient congenital hypothyroidism and 53.6% had permanent congenital hypothyroidism. The parents of 29.8% of the individuals diagnosed with transient congenital hypothyroidism and 44.2% of the individuals diagnosed with permanent congenital hypothyroidism were consanguineous (P = .02). According to the latest anthropometric assessment, 6.8% of individuals diagnosed with congenital hypothyroidism had a weight z-score below -2 SD and 16.9% had a length z-score below -2 SD. The incidence of congenital hypothyroidism was higher in our region. The ratio of consanguinity between parents was higher in patients diagnosed with permanent congenital hypothyroidism than in those diagnosed with transient congenital hypothyroidism. According to the most recent follow-up, weight and age were found to be similar in patients with transient and permanent congenital hypothyroidism.

Low levels of free triiodothyronine are associated with risk of cognitive impairment in older euthyroid adults

Accumulated evidence showed that thyroid diseases induced cognitive decline. However, the relationship between thyroid hormones (THs) and cognition in older euthyroid people is still unclear. Our study aimed to estimate the association between THs within the euthyroid range and cognition in community-dwelling older adults in China. Data were extracted from a cohort study on the health status of rural older adults from the Guizhou province in China (HSRO). Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were measured using the electrochemiluminescence immunoassay. Cognitive function was evaluated by the Mini-Mental State Examination (MMSE). Linear regression and a binary logistic regression model were used to explore the relationship between THs and cognition in euthyroidism (TSH level of 0.27 ~ 4.20mIU/L). A total of 957 euthyroidism individuals were included in this study, with a mean (SD) age of 71.34 (6.35) years. In individuals with euthyroidism, serum TSH and FT3 levels were positively associated with cognition (TSH:β = 0.06, 95% CI  0.01 ~ 0.11, P = 0.03; FT3:β = 0.07, 95% CI  0.01 ~ 0.12, P = 0.01); and serum FT3 and TSH levels were significantly associated with cognitive domains (P < 0.05). Further, euthyroid individuals in the lowest serum FT3(OR = 1.96; 95% CI 1.27 ~ 3.03) quartile had a twofold increased risk of cognitive impairment compared to those in the highest quartile after adjusting for potential confounding factors. These findings suggested that low levels of FT3 could be an independent risk factor for cognitive impairment in older euthyroid adults. Additionally, a positive linear association exists between serum FT3 levels and cognitive domains (such as immediate memory, language, and attention). Further studies are needed to determine the underlying mechanisms and the community significance of these findings.

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

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

Gestation-suppressed serum TSH levels during early pregnancy are not associated with altered maternal and neonatal outcomes

Objective

The aim of the study was to investigate the impact of suppressed serum TSH levels (sTSH) during early pregnancy on maternal and neonatal outcomes.

Methods

In this single-centre, retrospective cohort study 1081 women were screened at 11.8 ± 2.4 weeks of pregnancy for TSH, free T4 (FT4) and TPOAb. Exclusion criteria were twin- and assisted- reproduction pregnancies, women with TSH levels >3.74 mIU/L, severe hyperthyroidism, treated for thyroid dysfunction before or after screening and gestational blood sampling <6 or >16 weeks of pregnancy. The prevalence of adverse pregnancy outcomes was compared between the study group sTSH (TSH: < 0.06 mIU/L; n = 36) and euthyroid controls (TSH: 0.06-3.74 mIU/L; n = 1045), and the impact of sTSH on pregnancy outcomes verified in logistic regression analyses.

Results

Median (IQR) serum TSH level in women with sTSH was 0.03 (0.03-0.03) vs 1.25 (0.81-1.82) mIU/L in controls and FT4 levels 18.0 (14.4-20.3) vs 14.2 (12.9-15.4) pmol/L; both P < 0.001. None of the women with sTSH had thyrotropin receptor antibodies. Compared with controls, the prevalence of TPOAb positivity (TAI) was comparable between groups (5.6% vs 6.6%; P = 0.803). The prevalence of maternal and neonatal pregnancy outcomes was comparable between the study and control group. The logistic regression analyses with corrections for TAI, FT4 and demographic parameters confirmed the absence of an association between sTSH, and the following outcomes: iron deficient anaemia (aORs (95% CI)): 1.41 (0.64-2.99); P = 0.385, gestational diabetes: 1.19 (0.44-2.88); P = 0.713, preterm birth: 1.57 (0.23-6.22);P = 0.574 and low Apgar-1' score: 0.71 (0.11-2.67); P = 0.657.

Conclusions

Suppressed serum TSH levels during the first to early second trimester of pregnancy were not associated with altered maternal or neonatal outcomes.

The Effects of Maternal Smoking on Thyroid Function: Findings from Routine First-Trimester Sonographic Anomaly Screening

AIM

This study aimed to assess the effect of tobacco exposure on maternal thyroid function and investigate its relationship to subclinical hypothyroidism in pregnant women during the first trimester.

SUBJECTS AND METHOD

A comparison of maternal thyroid function was made on 45 smokers, who composed the study group, and 72 non-smokers, pregnant women, who constituted the control group. After determining smokers by questionnaire, carbon monoxide (CO) levels in the expiratory air of the participants in both groups were measured and recorded, and the smokers' exposure was objectively confirmed.

RESULTS

Smoking and non-smoking pregnant women were similar regarding body mass index (BMI). While the TSH and fT4 levels were respectively 1.48 mlU/L and 11.43 pmol/L in pregnant women who smoked, that ratio changed to 1.72 mlU/L and 11.17 pmol/L in the non-smokers' group. But the differences between the groups were not statistically significant (p=0.239, p=0.179). Even though the rate of subclinical hypothyroidism was 8.9% in the smoking group, it was approximately 19.4% in the non-smoker group; the difference was not statistically significant (p=0.187).

CONCLUSION

This study proved that there is no statistically significant difference between maternal serum TSH and fT4 levels and the rate of subclinical hypothyroidism in smokers during pregnancy in the first trimester.

Thyroid hormone profile in preeclampsia patients: a case control study

Objective: Preeclamptic women are reported to have a higher incidence of thyroid dysfunction that correlates with the severity of preeclampsia. The aim of this study was to assess thyroid hormone profiles in in pregnant women with preeclampsia and gestational hypertension and the risk for thyroid dysfunction.Methods: In this study, age-matched pregnant females in the second trimester of pregnancy, diagnosed with preeclampsia (PE), gestational hypertension (GH), as cases, and apparently healthy normotensive (NT) pregnant woman as controls were recruited. Blood samples were drawn for the assessment of thyroid hormone (TSH, FT3 and FT4) levels and thyroid dysfunction.Results: Out of the total of 133 pregnant women recruited for this study, sub-clinical hypothyroidism was the only thyroid dysfunction common to all study groups, with a prevalence of 3.3% in both PE and NT groups, and 4.3% in the GH group. 1% of women in the PE group had sub-clinical hyperthyroidism, compared to 3.3% in the NT group. Although TSH and FT3 were elevated in normotensives, mean differences between the three groups were not statistically significant. However, mean FT4 levels in the GH group (12.99 ± 1.24) and PE group (12.33 ± 2.26), when compared to the control group (11.55 ± 1.94), were significantly higher (p < 0.05).Conclusion: Undiagnosed subclinical hypothyroidism was found in all the categories of pregnant women studied, which if uncontrolled, could increase the risk of pregnancy-related complications, especially in pregnant women with preeclampsia and gestational hypertension.

Reference Intervals for Thyroid Hormones and Thyroid Volume in Children Aged 7 ~ 13 Years from Iodine-Sufficient Areas in Tianjin, China

Reference intervals (RIs) for serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) suitable for local children are urgently needed in northern China. The reference interval for thyroid volume (Tvol) in Chinese children also differed greatly from that recommended by the WHO. This study aimed to establish TSH, FT3, FT4, and Tvol RIs suitable for children in northern China. A total of 1070 children aged 7 ~ 13 were recruited from iodine nutrition-sufficient areas in Tianjin, China, from 2016 to 2021. Four hundred fifty-eight children aged 7 ~ 13 years, and 815 children aged 8 ~ 10 years were eventually included to study RIs for the thyroid hormones and Tvol. RIs for thyroid hormones were established in accordance with the Clinical Laboratory Standards Institute (CLSI) document C28-A3 guidelines. Quantile regression was used to analyze the influencing factors of Tvol. RIs for TSH, FT3, and FT4 were 1.23 (1.14 ~ 1.32) to 6.18 (5.92 ~ 7.26) mIU/L, 5.43 (5.29 ~ 5.52) to 7.89 (7.66 ~ 7.98) pmol/L, and 13.09 (12.85 ~ 13.73) to 22.22 (21.61 ~ 22.51) pmol/L. There was no need to establish RIs by age and gender. Our RIs could increase the prevalence of subclinical hyperthyroidism (P < 0.001) and reduce the prevalence of subclinical hypothyroidism (P < 0.001). Body surface area (BSA) and age are correlated with the 97th percentile of Tvol (both P < 0.001). Our reference interval could increase the goiter rate in children from 2.97 to 4.96% (P = 0.007). The thyroid hormones' reference intervals suitable for local children should be established. In addition, BSA and age should be considered when establishing Tvol reference interval.

Biological variation in thyroid function tests in older adults and clinical implications

OBJECTIVE

Interpreting thyroid function tests can be challenging due to inherent variation, and the need for tests rises with age. While age-related changes in thyrotropin (TSH) levels are known, the biological variation in older adults remains unclear.

DESIGN

We recruited nineteen 65-99-year-old (older adults) without thyroid disease for monthly blood sampling for 1 year.

PATIENTS AND MEASUREMENTS

Serum was stored at -20C°, and TSH, total thyroxine (TT4) and total triiodothyronine (TT3) were analysed in random order in a single batch for each participant. Results were compared to test results from 15 euthyroid men aged 24-53 years (younger adults) collected previously using a similar methodology.

RESULTS

Interindividual coefficients of variation in older/younger adults were 46.7%/44.0% for TSH, 12.7%/19.5% for TT4 and 14.6%/22.4% for TT3. Intraindividual coefficients of variation (CVI ) were 19.0%/25.4% for TSH, 5.5%/10.8% for TT4 and 6.9%/13.2% for TT3. The index of individuality was below 0.6 for all hormones in all age groups. The number of samples required to determine the homoeostatic set-point at 10% precision in older adults was 14-21 for TSH and 2 for TT4 and TT3. TT4 in older adults was the only parameter in any group with comparable CVI between individuals (p = .22).

CONCLUSIONS

CVI for TT4 and TT3 was halved in older compared to younger adults with two tests of TT4 needed to describe the individual set-point. Similar CVI between older adults caused TT4 to provide a reliable estimate of thyroid function, and the added value of measuring thyroxine could improve clinical practice.

A machine learning-assisted system to predict thyrotoxicosis using patients' heart rate monitoring data: a retrospective cohort study

Previous studies have shown a correlation between resting heart rate (HR) measured by wearable devices and serum free thyroxine concentration in patients with thyroid dysfunction. We have developed a machine learning (ML)-assisted system that uses HR data collected from wearable devices to predict the occurrence of thyrotoxicosis in patients. HR monitoring data were collected using a wearable device for a period of 4 months in 175 patients with thyroid dysfunction. During this period, 3 or 4 thyroid function tests (TFTs) were performed on each patient at intervals of at least one month. The HR data collected during the 10 days prior to each TFT were paired with the corresponding TFT results, resulting in a total of 662 pairs of data. Our ML-assisted system predicted thyrotoxicosis of a patient at a given time point based on HR data and their HR-TFT data pair at another time point. Our ML-assisted system divided the 662 cases into either thyrotoxicosis and non-thyrotoxicosis and the performance was calculated based on the TFT results. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of our system for predicting thyrotoxicosis were 86.14%, 85.92%, 52.41%, and 97.18%, respectively. When subclinical thyrotoxicosis was excluded from the analysis, the sensitivity, specificity, PPV, and NPV of our system for predicting thyrotoxicosis were 86.14%, 98.28%, 94.57%, and 95.32%, respectively. Our ML-assisted system used the change in mean, relative standard deviation, skewness, and kurtosis of HR while sleeping, and the Jensen-Shannon divergence of sleep HR and TFT distribution as major parameters for predicting thyrotoxicosis. Our ML-assisted system has demonstrated reasonably accurate predictions of thyrotoxicosis in patients with thyroid dysfunction, and the accuracy could be further improved by gathering more data. This predictive system has the potential to monitor the thyroid function status of patients with thyroid dysfunction by collecting heart rate data, and to determine the optimal timing for blood tests and treatment intervention.

Age and Gender Adjusted FT3 Levels as Novel Predictors of Survival

CONTEXT

Lower levels of free T3 (FT3) occur during acute illness, as part of "euthyroid sick syndrome." A chronic form of this syndrome also exists.

OBJECTIVE

To determine whether thyroid hormone levels predict long-term survival.

DESIGN AND SETTING

This was a "big-data" study of thyroid function tests from samples taken between 2008 and 2014. Data were crossed with electronic health records for morbidity and mortality. Test results were converted to age- and gender-adjusted percentiles (AGAPs). The hazard ratio for death was crossed with ranges of initial AGAPs and change in AGAPs for 2 subgroups: "not healthy" (subjects with at least 1 of 5 chronic conditions registered in their electronic health chart) and "healthy" (all others).

PARTICIPANTS

2 453 091 sets of thyroid function tests from 365 965 distinct patients were evaluated. 258 695 sets remained after excluding patients registered as taking thyroid preparations or anti-thyroid drugs.

MAIN OUTCOME MEASURE

Hazard ratio for death, planned before data collection.

RESULTS

The cohort included 151 868 not healthy and 106 827 healthy people. After a median of 6.8 years, 5865/151 868 (10.4%) of the not healthy had died and 2504/106 827 (2.3%) of healthy participants. Low initial FT3 AGAPs were predictive of poor survival. The hazard ratio for survival compared between the lowest 5 and highest 50 percentiles of initial FT3 AGAPs for not healthy participants was 5.71 [confidence interval (CI) 5.23-6.26, P < .001] and for healthy was 3.92 (CI 3.06-5.02, P < .001).

CONCLUSION

Low FT3 AGAPs predicted poor survival, most strongly among not healthy people.

Relationship between Iron Deficiency and Thyroid Function: A Systematic Review and Meta-Analysis

Objective: Iron deficiency (ID) is the most prevalent nutritional deficiency worldwide. Low levels of serum ferritin (SF) could affect the thyroid gland and its functioning. The purpose of this systematic review and meta-analysis is to summarize the main currently available evidence and analyze data on the relationship between ID and thyroid function. Methods: This study included all articles evaluating the relationship between ID and thyroid function. Quality assessment was performed using Cambridge Quality Checklists. The search strategy included the following combination of Medical Subjects Headings terms and keywords: "iron deficiency", "thyroid function", "thyroid disease", "thyroid dysfunction", and "hypothyroidism". A meta-analysis was performed to evaluate whether thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) levels differed between patients with ID and healthy controls without ID. For statistical comparison between cases and controls, the mean difference (MD) was calculated, and a subgroup analysis of pregnant and non-pregnant women was performed. Cochran's Q testing and heterogeneity indices (I2) were used to assess statistical heterogeneity. Sensitivity analysis and publication bias analyses were also performed, both qualitatively and quantitatively. Finally, a meta-regression analysis was performed to evaluate the correlation between serum TSH or FT4 levels and SF in the study population. Results: Ten cross-sectional studies were identified and reviewed. Patients with ID showed TSH (MD: -0.24 mIU/L; 95% CI -0.41, -0.07; I2 = 100%, p = 0.005), FT4 (MD: -1.18 pmol/L; 95% CI -1.43, -0.94; I2 = 99%, p < 0.000001), and FT3 (MD: -0.22 pmol/L; 95% CI -0.32, -0.12; I2 = 99%, p < 0.00001) levels that were significantly lower. Subgroup analysis confirmed significantly lower TSH, FT4, and FT3 levels in pregnant women. Non-pregnant women showed significantly lower serum FT4 and FT3 levels but no difference in TSH values. Meta-regression analysis showed that serum TSH and FT4 levels were positively correlated with SF levels. Our systematic review of the literature found that ID significantly increases the prevalence of thyroid autoantibody (anti-thyroglobulin antibodies and anti-thyroid peroxidase antibodies) positivity both individually and collectively. Conclusion: Studies currently published in the literature indicate a possible relationship between ID, thyroid function, and autoimmunity, especially in some patient groups. Data analysis shows that thyroid hormone levels are lower in patients with ID and, in particular, in pregnant women. Further studies are needed to understand the role played by iron in thyroid metabolism.

Rare case of central congenital hypothyroidism due to a TSHβ mutation presenting with macro-orchidism

A male infant was brought to our paediatric endocrine unit with typical clinical features of congenital hypothyroidism (CH) and striking macro-orchidism. On evaluation, free T3, free T4 and thyroid stimulating hormone (TSH) were found to be low, suggestive of congenital CH. Cortisol was within reference range and prolactin was mildly elevated. No suspicious lesions were encountered on neurosonography. On commencing treatment with thyroxine, clinical features of hypothyroidism showed dramatic improvement with regression of testicular enlargement. Genetic analysis revealed deletion of the TSHβ gene.Our case highlights a rare presentation of central CH with macro-orchidism in a genetically proven deletion of TSHβ gene. Macro-orchidism has been widely reported in IGSF-1 mutations leading to central CH; however, central CH and macro-orchidism have not been reported in association with TSHβ deletions.

Subclinical hypothyroidism in pregnancy - assessment of offspring thyroid status and mitochondrial robustness to stress

Subclinical hypothyroidism's clinical implications on pregnancy are controversial. Consequently, thyrotropin (TSH) cutoff-values for pregnancy are continuously a subject for debate. In subclinical hypothyroidism, altered levels of thyroid hormones may affect mitochondrial function.Objectives were i) to analyze thyroid hormone levels in offspring of women with and without subclinical hypothyroidism ii) to analyze mitochondrial "robustness" in terms of MTG/TMRM ratio in pregnant women and their offspring in relation to thyroid function and iii) to perform differentiate analyses on different TSH thresholds to determine the importance of cutoff-values to results.Pregnant women were included by blood collections prior to a planned cesarean section, and cord samples were collected after delivery. Thyroid status (analyzed by Siemens Healthcare Diagnostics by an electrochemical luminescent immunoassay based on LOCI-technology) grouped the women and their offspring in euthyroid or subclinical hypothyroid, with groups established from previous recommended third-trimester cutoff-value (TSH > 3.0 mIU/L) and the recently recommended cutoff-value in Denmark (TSH > 3.7 mIU/L). Flow cytometric measurements of mitochondrial function in mononuclear blood cells with the fluorophores TetraMethylRhodamine Methyl Ester (TMRM) and Mitotracker Green (MTG) were used to evaluate mitochondrial robustness as the MTG/TMRM ratio.No significant differences in mitochondrial robustness between euthyroid and subclinical hypothyroid cohorts were observed, irrespective of TSH-cutoff applied. Maternal and cord MTG/TMRM ratios were positively correlated. Cord-TSH was elevated in subclinical hypothyroid offspring, independent of TSH cutoff applied. Cord-TSH was associated with maternal TSH-level, maternal smoking and cord arterial-pH.

Thyroid dysfunction and glycaemic control among Type 2 diabetes mellitus patients in Ghana: A comparative cross-sectional study

INTRODUCTION

Thyroid disorders and diabetes mellitus coexist and are prevalent endocrinopathies among adult population. Thyroid dysfunction contributes to metabolic imbalances, increase beta-cell apoptosis and glucose intolerance. There is paucity of data and contradicting findings on how thyroid dysfunction influence glycaemic control. Therefore, we evaluated thyroid dysfunction and glycaemic control among Type 2 diabetes mellitus (T2DM) patients in Ghana.

METHODS

A comparative cross-sectional study was conducted among 192 T2DM patients from Effia Nkwanta Regional Hospital. Three consecutive monthly fasting plasma glucose (FBG) and glycated haemoglobin (HbA1c) were analysed and the results were classified as, moderate hyperglycaemia (MH) (FBG = 6.1-12.0 mmol/L, HbA1c < 7%), severe hyperglycaemia (SH) (FBG ≥ 12.1 mmol/L, HbA1c > 7%) and good glycaemic controls (GC) (FBG = 4.1-6.0 mmol/L, HbA1c < 7%). Thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4), body mass index (BMI) and other clinical parameters were measured. Data analysis was done using R language version 4.0.2 and p < .05 was considered statistically significant.

RESULTS

There were no significant differences in age (years) between patients in the various glycaemic groups (p = .9053). The overall prevalence of thyroid disorders was 7.8% among T2DM patients. The prevalence of thyroid disorders was higher in patients with SH (11.7%) followed by those with MH (7.5%) and then those with GC (5.4%). Serum levels of TSH and FT3/FT4 ratio were significantly lower in T2DM patients with SH compared to those with MH and the GC (p < .0001). However, FT4 was significantly higher in SH patients compared to the good glycaemic controls (p < .01). The first tertiles of TSH [aOR = 10.51, 95% CI (4.04-17.36), p < .0001] and FT3 [aOR = 2.77, 95% CI (1.11-6.92), p = .0290] were significantly and independently associated with increased odds of hyperglycaemia.

CONCLUSION

The prevalence of thyroid dysfunction is high in T2DM and increases with hyperglycaemia. Reduced TSH and T3 may worsen glycaemic control. Periodic monitoring of thyroid function should be incorporated into management guidelines among T2DM patients in Ghana.

Thyroid Function Tests in Children and Adolescents With Trisomy 21: Definition of Syndrome-Specific Reference Ranges

CONTEXT

The lack of syndrome-specific reference ranges for thyroid function tests (TFT) among pediatric patients with Down syndrome (DS) results in an overestimation of the occurrence of hypothyroidism in this population.

OBJECTIVE

To (a) outline the age-dependent distribution of TFT among pediatric patients with DS; (b) describe the intraindividual variability of TFT over time; and (c) assess the role of elevated thyrotropin (TSH) in predicting the future onset of overt hypothyroidism.

METHODS

In this retrospective, monocentric, observational analysis, we included 548 patients with DS (0-18 years) longitudinally assessed between 1992 and 2022. Exclusion criteria were abnormal thyroid anatomy, treatments affecting TFT, and positive thyroid autoantibodies.

RESULTS

We determined the age-dependent distribution of TSH, FT3, and FT4 and outlined the relative nomograms for children with DS. Compared with non-syndromic patients, median TSH levels were statistically greater at any age (P < .001). Median FT3 and FT4 levels were statistically lower than controls (P < .001) only in specific age classes (0-11 for FT3, 11-18 years for FT4). TSH levels showed a remarkable fluctuation over time, with a poor (23%-53%) agreement between the TSH centile classes at 2 sequential assessments. Finally, the 75th centile was the threshold above which TSH values predicted future evolution into overt hypothyroidism with the best statistical accuracy, with a satisfactory negative predictive value (0.91), but poor positive predictive value (0.15).

CONCLUSION

By longitudinally assessing TFT in a wide pediatric DS population, we outlined the syndrome-specific reference nomograms for TSH, FT3, and FT4 and demonstrated a persistent upward shift of TSH compared to non-syndromic children.

Preconception Management of Hyperthyroidism and Thyroid Status in Subsequent Pregnancy: A Population-Based Cohort Study

CONTEXT

Optimal thyroid status in pregnancy is essential in reducing the risk of adverse outcomes. The management of hyperthyroidism in women of reproductive age poses unique challenges and it is unclear how preconception treatment strategies impact on thyroid status in subsequent pregnancy.

OBJECTIVE

We aimed to determine trends in the management of hyperthyroidism before and during pregnancy and to assess the impact of different preconception treatment strategies on maternal thyroid status.

METHODS

We utilized the Clinical Practice Research Datalink database to evaluate all females aged 15-45 years with a clinical diagnosis of hyperthyroidism and a subsequent pregnancy (January 2000 to December 2017). We compared thyroid status in pregnancy according to preconception treatment, namely, (1) antithyroid drugs up to or beyond pregnancy onset, (2) definitive treatment with thyroidectomy or radioiodine before pregnancy, and (3) no treatment at pregnancy onset.

RESULTS

Our study cohort comprised 4712 pregnancies. Thyrotropin (TSH) was measured in only 53.1% of pregnancies, of which 28.1% showed suboptimal thyroid status (TSH >4.0 mU/L or TSH <0.1 mU/L plus FT4 >reference range). Pregnancies with prior definitive treatment were more likely to have suboptimal thyroid status compared with pregnancies starting during antithyroid drug treatment (odds ratio 4.72, 95% CI 3.50-6.36). A steady decline in the use of definitive treatment before pregnancy was observed from 2000 to 2017. One-third (32.6%) of first trimester carbimazole-exposed pregnancies were switched to propylthiouracil while 6.0% of propylthiouracil-exposed pregnancies switched to carbimazole.

CONCLUSION

The management of women with hyperthyroidism who become pregnant is suboptimal, particularly in those with preconception definitive treatment, and needs urgent improvement. Better thyroid monitoring and prenatal counseling are needed to optimize thyroid status, reduce teratogenic drug exposure, and ultimately reduce the risk of adverse pregnancy outcomes.

Iron deficiency and thyroid dysfunction among sudanese women in first trimester of pregnancy: a cross-sectional study

BACKGROUND

Pregnant women are more susceptible to iron deficiency (ID), and it can lead to several maternal and perinatal adverse effects. There are some published data on the effect of ID on thyroid function, but none of the studies were conducted in sub-Saharan African countries including Sudan. This study was conducted to investigate association between ID (ferritin < 15 µg/L) and thyroid functions [thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4)] among Sudanese women in the first trimester of pregnancy.

METHOD

A cross-sectional study was conducted in Saad Abuelela Maternity Hospital, Sudan. Obstetric/sociodemographic characteristics were gathered through questionnaires. Hemoglobin, serum ferritin, TSH, FT3, and FT4 were measured in all pregnant women. Continuous variables were compared with either independent sample t-test if they were normally distributed, or with Mann-Whitney U- test if they were not-normally distributed. Spearman correlations were performed between the continuous variables.

RESULTS

In total, 127 pregnant women with mean [standard deviation (SD)] age of 27.0 (5.5) years and gestational age of 10.5 (3.0) weeks, respectively, were enrolled in this study. Forty-seven (37.0%) of these 127 women had ID. While the median [interquartile range (IQR)] of the parity, TSH, and FT3 were not different between women with ID and women without ID, the median (IQR) of FT4 was significantly lower in women with ID compared with women without ID [1.020 (0.910‒1.120) vs. 1.095 (0.990‒1.217) pmol, P = 0.014]. Serum ferritin was inversely correlated with FT3, (r = -0.225, P = 0.011). There was no significant correlation between serum ferritin, TSH, and FT4.

CONCLUSIONS

Iron deficiency was common during the first trimester of pregnancy and was associated with thyroid dysfunctions. Therefore, ID should be evaluated to avoid thyroid dysfunction.

The prognostic Value of Thyroid Hormone Levels in Immunotherapy-Treated Patients With Metastatic Urothelial Carcinoma

INTRODUCTION

A low fT3/fT4 ratio has been associated with a poorer prognosis in patients treated for different solid malignancies. However, the prognostic role of baseline thyroid function in patients with metastatic urothelial carcinoma (mUC) has not yet been established.

PATIENTS AND METHODS

We analyzed 72 consecutive immunotherapy-treated patients with mUC from a single institution. We recorded clinical data, baseline blood test results, and oncological outcomes. We stratified patients into three groups according to the fT3/fT4 ratio value and analyzed differences in progression-free survival (PFS), overall survival (OS), and radiological response in the three groups. We also conducted univariate and multivariate analyses to identify prognostic factors for PFS and OS.

RESULTS

The median PFS in the low, intermediate, and high fT3/fT4 ratio groups was 2.2, 4.1, and 8.2 months, respectively (P < 0.01). The median OS in the low, intermediate, and high fT3/fT4 groups was 3.6, 10.3, and 19.1 months, respectively (P < .01). The low fT3/fT4 ratio maintained its prognostic role independently of other prognostic factors. Patients with a high fT3/fT4 ratio had an increased radiological response.

CONCLUSION

Thyroid hormone impairment, as measured by the fT3/fT4 ratio, is a strong prognostic factor in patients treated with immunotherapy for urothelial carcinoma.

An update: maternal iodine supplementation, thyroid function tests, and child neurodevelopmental outcomes

PURPOSE OF REVIEW

The impact of maternal iodine supplementation (MIS) during pregnancy on thyroid function and child neurodevelopmental outcomes in areas of mild-to-moderate iodine deficiency (MMID) remains unclear.

RECENT FINDINGS

Despite growing success of salt iodization programs, a 2022 meta-analysis found that 53% of pregnant patients worldwide continue to have insufficient iodine intake during pregnancy. A 2021 randomized controlled trial (RCT) found that MIS in women with mild iodine deficiency led to iodine sufficiency and positive effects on maternal thyroglobulin. A 2021 cohort study of MIS initiated prior to pregnancy was associated with lower thyroid-stimulating hormone (TSH), higher FT3, and FT4. Other cohort studies, however, found that neither salt iodization nor MIS were adequate to meet pregnancy iodine needs. Data have been mixed regarding maternal iodine status and pregnancy outcomes in patients of MMID. Meta-analyses have not shown any clear benefit on infant neurocognitive outcomes with MIS of MMID patients. A 2023 meta-analysis found that the prevalence of excess iodine intake in pregnancy was 52%.

SUMMARY

MMID continues to exist during pregnancy. Salt iodization alone may be insufficient to ensure adequate iodine status during pregnancy. There is an absence of high-quality data to support routine MIS in areas of MMID. However, patients with specialized diets (vegan, nondairy, no seafood, noniodized salt, and so on) may be at risk for inadequate iodine status in pregnancy. Excess iodine intake can be detrimental to the fetus and should be avoided during pregnancy.

Renal function changes in patients with subclinical hyperthyroidism: a novel postulated mechanism

BACKGROUND

Subclinical hyperthyroidism (SCH) is found to be associated with renal dysfunction. Hyperthyroidism is a well-known cause of secondary systolic hypertension. However, the effect of SCH on the kidney and its vasculature is still unknown.

AIM

To assess the presence of renal function changes and renal vasodysfunction in SCH patients and their relation to hypertension.

METHODS

The study included 321 patients with SCH and 80 healthy matched controls. Laboratory investigations included thyroid function tests, anti-TSH receptor antibody (TRAb), creatinine, estimated glomerular filtration rate (eGFR), serum osmolarity (S. Osmol), urine osmolarity (U. Osmol), Fractional Excretion of Sodium (FeNa), Fractional Excretion of Potassium (FeK), copeptin (CPP), and aldosterone/renin ratio (ARR). Ultrasound for the thyroid gland, echocardiography, total peripheral resistance (TPR), flow-mediated dilatation (FMD), and Renal Arterial distensibility (RAD) was also done.

RESULTS

Serum creatinine was significantly lower while eGFR was significantly higher in SCH patients compared to euthyroid subjects (mean 0.59 ± 0.11 mg/dl Vs mean 0.8 ± 0.1 mg/dl, p = 0.001 and mean 128.28 ± 14.69 ml/min/1.73m2 Vs mean 100.49 ± 14.9 ml/min/1.73m2, p = 0.013, respectively). The TPR and FMD showed a significant decrease in SCH group compared to controls (mean 975.85 ± 159.33 mmHg.min/L Vs mean 1120.24 ± 135.15 mmHg.min/L, p = 0.045 and mean 7.03 ± 4.02% Vs mean 13.48 ± 4.57%, p = 0.003, respectively). RAD was significantly higher in hypertensive SCH patients compared to normotensive SCH patients (mean 17.82 ± 2.46 mmHg Vs mean 11.98 ± 3.21 mmHg, p = 0.001).

CONCLUSION

SCH patients showed vascular resistance reduction. Alterations in thyroid hormones and blood pressure could be the driving mechanisms for the change in renal functions in patients with SCH.

Characterisation of an interference affecting the triiodothyronine measurement on two different immunoassays

We report a case of falsely elevated triiodothyronine (T3) due to anti-T3 antibody interference in two immunoassays (Cobas 8000 e602® module (Roche Diagnostics) and Architect® i2000 (Abbott)). The interference was investigated using various laboratory methods including the search for heterophilic antibodies, biotin detection and the polyethylene glycol precipitation of potential interfering macromolecules. The presence of anti-T3 autoantibodies was detected and measured by radioimmunoprecipitation. Our investigations confirmed the clinical suspicion of a falsely elevated free T3. No further explorations or unnecessary treatments were conducted for this patient after identification of the interference. This underlines the importance of implementing systematic analytical procedures in laboratories for the search of suspected interferences.

Thyroid function test variability and cardiovascular morbidity in hyperthyroidism

OBJECTIVE

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

DESIGN

Retrospective cohort study.

PATIENTS AND MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

The optimal healthy ranges of thyroid function defined by the risk of cardiovascular disease and mortality: systematic review and individual participant data meta-analysis

BACKGROUND

Reference intervals of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) are statistically defined by the 2·5-97·5th percentiles, without accounting for potential risk of clinical outcomes. We aimed to define the optimal healthy ranges of TSH and FT4 based on the risk of cardiovascular disease and mortality.

METHODS

This systematic review and individual participant data (IPD) meta-analysis identified eligible prospective cohorts through the Thyroid Studies Collaboration, supplemented with a systematic search via Embase, MEDLINE (Ovid), Web of science, the Cochrane Central Register of Controlled Trials, and Google Scholar from Jan 1, 2011, to Feb 12, 2017 with an updated search to Oct 13, 2022 (cohorts found in the second search were not included in the IPD). We included cohorts that collected TSH or FT4, and cardiovascular outcomes or mortality for adults (aged ≥18 years). We excluded cohorts that included solely pregnant women, individuals with overt thyroid diseases, and individuals with cardiovascular disease. We contacted the study investigators of eligible cohorts to provide IPD on demographics, TSH, FT4, thyroid peroxidase antibodies, history of cardiovascular disease and risk factors, medication use, cardiovascular disease events, cardiovascular disease mortality, and all-cause mortality. The primary outcome was a composite outcome including cardiovascular disease events (coronary heart disease, stroke, and heart failure) and all-cause mortality. Secondary outcomes were the separate assessment of cardiovascular disease events, all-cause mortality, and cardiovascular disease mortality. We performed one-step (cohort-stratified Cox models) and two-step (random-effects models) meta-analyses adjusting for age, sex, smoking, systolic blood pressure, diabetes, and total cholesterol. The study was registered with PROSPERO, CRD42017057576.

FINDINGS

We identified 3935 studies, of which 53 cohorts fulfilled the inclusion criteria and 26 cohorts agreed to participate. We included IPD on 134 346 participants with a median age of 59 years (range 18-106) at baseline. There was a J-shaped association of FT4 with the composite outcome and secondary outcomes, with the 20th (median 13·5 pmol/L [IQR 11·2-13·9]) to 40th percentiles (median 14·8 pmol/L [12·3-15·0]) conveying the lowest risk. Compared with the 20-40th percentiles, the age-adjusted and sex-adjusted hazard ratio (HR) for FT4 in the 80-100th percentiles was 1·20 (95% CI 1·11-1·31) for the composite outcome, 1·34 (1·20-1·49) for all-cause mortality, 1·57 (1·31-1·89) for cardiovascular disease mortality, and 1·22 (1·11-1·33) for cardiovascular disease events. In individuals aged 70 years and older, the 10-year absolute risk of composite outcome increased over 5% for women with FT4 greater than the 85th percentile (median 17·6 pmol/L [IQR 15·0-18·3]), and men with FT4 greater than the 75th percentile (16·7 pmol/L [14·0-17·4]). Non-linear associations were identified for TSH, with the 60th (median 1·90 mIU/L [IQR 1·68-2·25]) to 80th percentiles (2·90 mIU/L [2·41-3·32]) associated with the lowest risk of cardiovascular disease and mortality. Compared with the 60-80th percentiles, the age-adjusted and sex-adjusted HR of TSH in the 0-20th percentiles was 1·07 (95% CI 1·02-1·12) for the composite outcome, 1·09 (1·05-1·14) for all-cause mortality, and 1·07 (0·99-1·16) for cardiovascular disease mortality.

INTERPRETATION

There was a J-shaped association of FT4 with cardiovascular disease and mortality. Low concentrations of TSH were associated with a higher risk of all-cause mortality and cardiovascular disease mortality. The 20-40th percentiles of FT4 and the 60-80th percentiles of TSH could represent the optimal healthy ranges of thyroid function based on the risk of cardiovascular disease and mortality, with more than 5% increase of 10-year composite risk identified for FT4 greater than the 85th percentile in women and men older than 70 years. We propose a feasible approach to establish the optimal healthy ranges of thyroid function, allowing for better identification of individuals with a higher risk of thyroid-related outcomes.

FUNDING

None.

High Time to Consider the Role of Thyroid Function in Single Ventricle Heart Disease

Herein we respond to the controversial United States Food and Drug Administration (FDA) recommendation to perform thyroid function testing in children up to 3 years of age within 3 weeks of exposure to iodinated contrast media (ICM). Considering the many effects of thyroid hormone on the cardiovascular system, the increased risk of thyroid disease in patients with congenital heart disease, the hemodynamic consequences of the Fontan circulation on the thyroid gland, and the potential clinical significance of subclinical hypothyroidism, we share our perspective that the cardiovascular effects of thyroid hormone may carry more influence for patients with single ventricle heart disease. In our opinion, the FDA statement prompts us to consider routine thyroid hormone surveillance testing in the long-term management of patients with single ventricle heart disease.

Association of thyroid stimulating hormone and time in range with risk of diabetic retinopathy in euthyroid type 2 diabetes

AIMS

Diabetic retinopathy (DR) can occur even in well-controlled type 2 diabetes, suggesting residual risks of DR in this population. In particular, we investigated the combined effect of thyroid function and glycaemic control assessed by an emerging metric, time in range (TIR) with DR.

MATERIALS AND METHODS

In this cross-sectional study, a total of 2740 euthyroid patients with type 2 diabetes were included. Thyroid indicators, including thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, thyroid peroxidase antibody and thyroglobulin antibody, were measured. TIR was measured using continuous glucose monitoring data.

RESULTS

Overall, the multivariable-adjusted odds ratios (ORs) for DR across ascending tertiles of TSH were 1.00 (reference), 1.06 (95% confidence interval [CI] 0.85-1.32), and 1.48 (95% CI 1.19-1.85). Even in well-controlled participants who achieved a TIR target of >70% (n = 1449), the prevalence of DR was 23.8%, which was significantly related to TSH (OR = 1.54, 95% CI 1.12-2.12, highest vs. lowest TSH tertile). Participants were then classified into 6 groups by the joint categories of TIR (>70%, ≤70%) and TSH (tertiles), and the multivariable-adjusted ORs for DR were highest in TIR ≤70% and the highest TSH tertile group (OR = 1.96, 95% CI 1.41-2.71) when compared with the TIR >70% and the lowest TSH tertile group.

CONCLUSIONS

In type 2 diabetic patients with well-controlled glycaemic status, higher TSH within the normal range was associated with an increased risk of DR. The combination of suboptimal TSH and TIR further increased the risk of DR.

Longitudinal trajectories of maternal TSH in healthy pregnant women in Catalonia

Objective

Longitudinal evaluation of thyroid function throughout pregnancy in the same subject could offer precise information about its dynamics as a physiological mechanism of adaption to the requirements. In this study, we evaluated longitudinal trajectories of maternal thyroid function during pregnancy by a latent class growth analysis and explored their association with maternal-fetal outcomes.

Methods

A prospective observational study was carried out, including 414 healthy pregnant women, from the first trimester to delivery. Thyroid function and autoimmunity were measured in the three trimesters. Clinical data during pregnancy were obtained. Longitudinal mixed model techniques were performed to explore trajectories of gestational thyroid function.

Results

Three different longitudinal trajectories were obtained from maternal thyrotropin (TSH) levels: low-increasing TSH (class 1) in 86% of cases, high-increasing TSH (class 2) in 9.7%, and decreasing TSH (class 3) in 4.3%. No statistical differences in free thyroxine levels were found among the three classes. Differences in maternal age (P = 0.027) and initial maternal weight (P = 0.043) were observed among the groups. In logistic regression analysis, maternal age correlated with longitudinal trajectories. The three longitudinal classes remain when women with thyroid autoimmunity (TAI) are excluded. Multinomial logistic regression showed maternal age correlated with longitudinal trajectories independently of TAI status.

Conclusions

Three differentiated TSH trajectories were found in healthy pregnant women living in Catalonia, as previously described. No association with obstetric outcomes was observed in these different chronological thyroid pathways, but maternal age might condition the longitudinal mechanism of thyroid function regulation throughout pregnancy.

Genetic determinants of thyroid function in children

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical Features of Children With Serology Negative, Biopsy Positive Celiac Disease

The prevalence of pediatric serological negative celiac disease (SNCD) is poorly described, with few recognized clinical predictors beyond immunoglobulin A (IgA) deficiency or reduced gluten intake. The purpose of this retrospective review was to describe the prevalence of SNCD at the Stollery Children's Hospital and identify clinical features to help in recognition of these cases. Patients with a positive biopsy and negative serology (SNCD) were compared to those with positive biopsy and serology. SNCD diagnosis required clinical correlation and either confirmatory genetics or follow up endoscopy on a gluten-free diet. Of the 424 patients who met celiac disease (CD) criteria, 4.7% (n = 20) fulfilled our criteria for SNCD. There was a significant difference in the rates of IgA deficiency between the 2 groups, but no other clinical features were found that allowed for ready identification of SNCD patients.

The impact of juvenile hypothyroidism on stature

Short stature with different alterations in the skeletal appearance usually results from juvenile hypothyroidism. The present case-control study was conducted to assess the effect of thyroid hormone deficiency on the height of young people and the prevalence of short stature in juvenile hypothyroidism. The research was conducted at the Al-Waffa Diabetic Centre between May and September 2022. The study group included 90 children with short stature, while the control group included 58 children. The statistical analysis was conducted using Minitab version 20. The results revealed that a low serum level of triiodothyronine (T3) was present in 2.2% of participants, while a low serum level of thyroxin (T4) was present in 36.7%. All subjects had elevated serum thyroid stimulating hormone (TSH). Female children had increased rates of short stature. Juvenile hypothyroidism results in various skeletal manifestations, including reduced height. Low serum thyroxin coupled with high serum thyroid stimulating hormone are common findings in juvenile hypothyroidism.