Normal Thyroid-stimulating Hormone Research Articles

The Relationship Between TSH and Indirect Bilirubin Levels in Neonates Suspected of Having Jaundice

Background: Congenital hypothyroidism (CH) is a condition of thyroid hormone deficiency that occurs at birth. The TSH (thyroid-stimulating hormone) test is crucial for diagnosing hypothyroidism. CH is known to cause prolonged unconjugated hyperbilirubinemia. Therefore, this study aimed to analyze the relationship between TSH and indirect bilirubin levels in neonates suspected of having jaundice. Methods: This is a non-experimental, retrospective study conducted at Lombok Dua Dua Lontar Mother and Child Hospital in Surabaya. The study involved data collection on neonates aged 2–7 days suspected of jaundice, whose TSH and indirect bilirubin levels were measured between November 2022 to April 2024. Results: Among 100 neonates, 62% were aged 2-4 days, while 38% were aged 5-7 days. The majority were male (56%), with female comprising 44%. Of the 100 neonates, only 1 (1%) had borderline TSH levels, while 99% had normal TSH levels. Hyperbilirubinemia was observed in 94% of the neonates, while 6% had normal indirect bilirubin levels. Statistical analysis using the Spearman correlation showed no significant link between TSH and indirect bilirubin levels (p = 0.802). Conclusions: While this study did not find a clear connection between TSH and indirect bilirubin levels in neonates suspected of having jaundice, one case of borderline TSH was identified. This neonate required referral to pediatric endocrinology, as untreated congenital hypothyroidism can lead to mental retardation. Despite limited research linking TSH and bilirubin levels in jaundiced neonates, routine screening for congenital hypothyroidism using TSH testing should be reconsidered. Future studies could benefit from focusing on specific causes of neonatal jaundice to help narrow down research questions in this area.

The influence of calibration on bias in quality control and patient results for TSH on Vitros XT 7600 analyzer.

Thyroid-stimulating hormone (TSH) is a glycoprotein secreted by the anterior pituitary gland and is regulated by negative feedback from the serum free thyroid hormones. In this study we aimed to quantitate the relative bias caused by calibration drifting as seen in our TSH Levey-Jennings quality control (QC) charts and assess the magnitude of bias on patients' samples. In the period from October 2021 to August 2022 we looked at the QC results of ten 28-days' calibration time intervals and calculated relative bias compared to the mean. For each time interval the mean from three QC points before and after calibration was calculated. The average from 10 pre- and post-calibration means was calculated and the relative bias, pre- and post-calibration, was then calculated. We used 5 patient samples with low, normal and high TSH concentrations and calculated relative bias pre- and post-calibration. The allowed relative bias for TSH is ± 6.7%. At both QC levels, with the respective means of 5.14 mIU/L (coefficient of variation, CV% = 3.1%) and 27.80 mIU/L (CV% = 3.2%) had their respective relative bias - 8.2% and - 7.9%. The patient samples with low (0.586 mIU/L), normal (2.89 mIU/L and 5.19 mIU/L) and high (20.5 mIU/L and 39.8 mIU/L) TSH had - 4.1%, - 4.0%, - 3.5%, - 5.1% and - 4.1%, respectively. Even though the relative bias exceeded allowable criteria for the QC samples, this was not manifested on the patients' samples.

Long-term retreatment outcomes after definitive management of Graves’ disease with radioactive iodine versus surgery

BackgroundCommon treatments for Graves’ disease include antithyroid drugs (ATD), radioactive iodine (RAI), and surgery. RAI avoids surgical morbidity, but rate and durability of remission varies across studies. This study directly compared the long-term results of Graves’ disease treated by surgery versus RAI and hypothesized that RAI would be associated with lower rates of long-term biochemical remission and higher likelihood of retreatment. MethodsThis retrospective cohort study included individuals diagnosed with Graves’ disease who were treated surgically, with RAI, or both at a tertiary referral center. Definitive retreatment was defined as additional RAI or surgery after index treatment, and retreatment was defined as requiring ATD or a second definitive treatment after index treatment. Remission was defined by normalization of thyroid stimulating hormone without retreatment at 6 months. ResultsIndex definitive therapy was total thyroidectomy for 72 patients and RAI for 104 patients. The median follow-up time was 3.6 years. The rate of remission at 6 months in the RAI group (68.8%) was lower than that in the surgery group (98.6%) (odds ratio: 0.03, P < .001). Patients who underwent index RAI experienced a significantly higher cumulative incidence of any retreatment at all time points than those who underwent index surgery (P < .001). Among RAI patients who achieved euthyroidism within 6 months, 19% developed subsequent relapse requiring ATD therapy or retreatment. ConclusionThe need for retreatment after index therapy for Graves’ disease is significantly lower after thyroidectomy than after RAI.

Investigating thyroid function and iodine status in adolescents with and without paediatric major depressive disorder.

Depression has been associated with subclinical hypothyroidism and altered hypothalamic-pituitary-thyroid axis functioning. Adequate iodine nutrition is essential for healthy thyroid functioning. We therefore determined associations of iodine and thyroid status with paediatric major depressive disorder (pMDD) among Swiss adolescents and explored whether associations are sex-specific and mediated by stress. We conducted a matched case-control study in 95 adolescents with diagnosed pMDD and 95 healthy controls. We assessed depression severity using the Children's Depression Rating Scale-Revised and stress using the perceived stress scale (PSS) and measuring hair cortisol levels. We determined iodine status by measuring urinary iodine concentrations (UIC) and thyroid status by thyroid-stimulating hormone (TSH) and free thyroxine (FT4) in serum. Median (IQR) UIC did not differ between cases (121 (87, 174) µg/l) and controls (114 (66, 183) μg/l, P = 0·3). Median TSH and FT4 were lower in cases than controls (TSH: 1·36 (0·91, 2·00) mlU/l v. 1·50 (1·18, 2·06) mlU/l, P = 0·039; FT4: 14·7 (12·9, 16·9) pmol/l v. 15·7 (14·3, 17·2) pmol/l, P = 0·004). The prevalence of hypothyroxinaemia (normal TSH; low FT4) was higher among female cases than controls (21 % v. 4%, P = 0·006). PSS scores were higher while hair cortisol was lower in cases than controls (PSS: 25 (20, 28) v. 11 (7, 15), P < 0·001; cortisol: 2·50 (1·34, 3·57) pg/mg v. 3·23 (1·79, 4·43) pg/mg, P = 0·044). After adjusting for confounders, the associations of TSH and hair cortisol with pMDD were no longer significant. Furthermore, TSH and FT4 were not associated with PSS scores and hair cortisol levels. Summarising, iodine nutrition was adequate for adolescents with and without pMDD. However, FT4 concentrations were lower in those with pMDD, and 1 in 5 female adolescents with pMDD were hypothyroxinaemic.

6602 Classification of TSH Trajectories During Levothyroxine Treatment in the ELSA-Brasil Cohort

Abstract Disclosure: M.D. Ettleson: None. G.C. Penna: Consulting Fee; Self; Ipsen, Bayer, Inc.. W. Wan: None. I.M. Bensenor: None. N. Laiteerapong: None. A.C. Bianco: Consulting Fee; Self; Abbvie. Classification of TSH Trajectories During Levothyroxine Treatment in the ELSA-Brasil Cohort Introduction: Hypothyroidism is a common endocrine disorder for which levothyroxine (LT4) serves as the primary treatment. Periods during which thyroid stimulating hormone (TSH) levels are outside the normal range have been associated with adverse cardiovascular outcomes, including mortality. In practice, serial TSH levels are measured over time to ensure therapeutic LT4 treatment is maintained. However, there is no measure of the quality of treatment maintenance over time. TSH trajectory classification represents a novel approach to define the adequacy of LT4 treatment for hypothyroidism over time utilizing multiple observation points. Methods: With longitudinal clinical data, including thyroid function from a large prospective study, we aimed to define classes of TSH trajectories and examine changes in cardiovascular (CV) health markers over a 9 year study period with three observation points. Growth mixture modeling (GMM), including latent class growth analysis (LCGA), was used to classify LT4-treated individuals participating in the Longitudinal Study of Adult Health in Brazil (ELSA-Brasil) based on serial TSH levels. Repeated measure analyses were then utilized to measure within-class changes in blood pressure, lipid levels, hemoglobin A1c, and CV-related medication utilization. Results: From the 621 LT4-treated study participants, the best-fit GMM approach identified four TSH trajectory classes, as defined by their relationship to the normal TSH range: 1) High-high normal TSH, 2) Normal TSH, 3) Normal-to-low TSH, and 4) Low-to-normal TSH. Notably, the average baseline LT4 dose was lowest in the high-high normal TSH group (77.7 mcg, p &amp;lt;0.001). There were no significant differences in CV health markers between the classes at baseline. At least one significant difference in CV markers occurred in all classes, highlighted by the low-to-normal class, in which total and HDL cholesterol, triglycerides, and A1c all increased significantly (p = 0.049, p &amp;lt;0.001, p &amp;lt;0.001, and p = 0.001, respectively). Medication utilization increased in all classes over the study period. Conclusion: GMM/LCGA represents a viable approach to define and examine LT4 treatment by TSH trajectory. In the future, more comprehensive datasets will allow for more complex trajectory modeling and analysis of clinical outcome differences between trajectory classes. Defining the adequacy of LT4 treatment using a longitudinal scope could allow clinicians to more accurately communicate treatment progress and identify patients at risk for adverse CV outcomes. Presentation: 6/3/2024

8412 Resolution of Central Hypothyroidism shortly after Transsphenoidal Surgery For Cushing’s Disease

Abstract Disclosure: L. Esper: None. A. Ibrahim: None. N. El Asmar: None. Background: Cushing's disease is a rare endocrine disorder characterized by excessive cortisol production, resulting in various metabolic disturbances. Hypercortisolism is known to cause central hypothyroidism. The mechanism is complex and involves hypercortisolism mediated decreased TRH and TSH secretion in addition to inhibition of peripheral deiodination. This case details the successful management and recovery of a patient with Cushing's disease and reversal of central hypothyroidism after pituitary surgery.Case:A 43-year-old man was evaluated for central hypogonadism, 20 pound weight gain with central weight distribution, and the development of purple abdominal striae for the past year. He had a normal thyroid exam and appeared euthyroid. He was alsodiagnosed with hypertension and prediabetes in the past yearrequiring medical therapy.A low dose dexamethasone suppression test (DST) resulted in AM cortisol of 12.9 mcg/dl. Two adequate 24hr Urinary cortisol measurements showed elevated cortisol excretion at 458 and 378mcg/24. Lab evaluation revealed elevated cortisol levels along with elevated adrenocorticotropic hormone (ACTH) levels(ACTH of 172 pg/ml with a cortisol level of 23.9 mcg/dl). A high dose DST demonstrated suppression of cortisol to 3.4 mcg/dl. MRI pituitary was performed which showed a clearright sided 7mm pituitary adenoma.Thyroid function tests performed were consistent with central hypothyroidism, with low levels of free thyroxine (FT4) at 0.67ng/dl along with an inappropriately low normal thyroidstimulating hormone (TSH) at 0.596 uIU/ml. Total T4 was low at 4 ug/dl in addition to a low total T3 of 66 ng/dl. Remaining labs revealed central hypogonadism along with slightly elevated prolactin of 16 ng/ml. He was not started on thyroid hormone.He then underwent transsphenoidal surgery for tumor removal. He developed post-operative adrenal insufficiency (cortisol 2.12 mcg/dl) 16 hours post-op after which he was started on hydrocortisone replacement, indicating remission. 12 hours post-op, his TSH was 0.656 uIU/ml with a free t4 of 0.79 ng/dl, both in the normal range. 36 hours post-op, TSH was 0.524 uIU/ml and free t4 was 1.15 ng/dl. Histopathological examination confirmed the diagnosis of an ACTH-secreting pituitary adenoma.At 4 weeks post-op, thyroid labs showed normal FT4 (1.07ng/dl) and TSH (2.06uIU/ml). Conclusion: Hypercortisolism causes a global inhibition of the thyroid axis, with decreased levels of TSH, T4, and T3 (1). Previous studies suggest the monitoring of thyroid function at 6 and 12 months after surgical cure of hypercortisolism. Our case suggests that the resolution of hypothyroidism occurs shortly after surgery for Cushing’s disease and the need for earlier monitoring. Presentation: 6/3/2024

7527 Subacute Thyroiditis in First Trimester of Pregnancy: Rare Cause of Thyrotoxicosis

Abstract Disclosure: K. Wilcher: None. A. Gupta: None. Background: Subacute thyroiditis (SAT) is extremely rare in pregnancy with only 8 prior cases reported in the literature. SAT can result in maternal and fetal complications. In this case report, we describe a case of subacute thyroiditis presenting in the first trimester of pregnancy. Case Presentation: A 38-year-old female with past medical history of stillbirth presented with thyrotoxicosis in gestational week 10 of her pregnancy. The patient has a history of stillbirth in gestational week 38 of her first pregnancy requiring cesarean section one year prior to presentation. She was in the process of getting in vitro fertilization (IVF) and had an egg retrieval. During the process, she started on thyroxine 50 mcg daily for blood thyroid-stimulating hormone (TSH) 3.77 mcIU/mL. She became pregnant without the help of IVF and stopped thyroxine. One month later, labs showed low TSH 0.022 mcIU/mL (reference range: 0.4-4.5 mcIU/mL) and high blood free thyroxine (FT4) 1.87 ng/dL (reference range: 0.7-1.8 ng/dL). Repeat labs two weeks later showed low blood TSH 0.012 mcIU/mL, high FT4 2.08 ng/dL, and high blood free triiodothyronine (FT3) 5.2 pg/mL (reference range: 2.3-4.2 pg/mL). She was referred to endocrinology for evaluation. She reported mild intermittent right sided neck pain since diagnosis of pregnancy. She denied any history of viral infection, cough, or fever. She reported symptoms of severe nausea, mild constipation, and mild anxiety. She denied diarrhea, tremors, changes in voice, palpitations, or weight loss. Her family history is significant for hypothyroidism in her father. Physical exam demonstrated a non-tender, symmetric thyroid without enlargement or nodules. Ultrasound showed heterogenous thyroid with an ill-defined heterogenous area in the right lobe appearing pseudo-nodule, and increased vascularity. At this time, the patient was diagnosed with mild gestational hyperthyroidism with a plan to monitor thyroid hormone levels. Repeat labs two weeks later showed low blood TSH 0.005 mcIU/mL, high FT4 2.35 ng/dL, and high FT3 6.4 pg/mL. TSH-receptor antibodies, thyroid stimulating immunoglobulin, and thyroid peroxidase antibodies were normal on testing. In gestational week 16, labs showed normal TSH 2.76 mcIU/mL, low FT4 0.56 ng/dL, and low FT3 2.1 pg/mL. At that time, she started on levothyroxine 75 mcg daily and was diagnosed with subacute thyroiditis. Follow up labs in gestational weeks 18, 20, and 24 showed improvement in TSH and FT4 on thyroid hormone supplementation. Conclusion: This case report discusses the findings of SAT in first trimester pregnancy. Currently, she is in gestational week 28 and still requiring thyroid hormone supplementation. SAT in pregnancy is very rare. This case report significantly contributes to the literature and current knowledge of the prevalence, presentation, and disease process of subacute thyroiditis in first trimester pregnancy. Presentation: 6/2/2024

Management of immune-checkpoint inhibitor (ICI)-related thyroid dysfunction: An avenue for quality improvement.

309 Background: Hypothyroidism is a common immune-related adverse effect (irAE) with ICI therapy, occurring in 4-9% of patients treated with PD-1 ICI, and 10-15% of patients treated with dual PD-1/CTLA-4 ICI therapy. Prolonged thyroid dysfunction increases risk for cardiovascular and cerebrovascular events. Consensus guidelines recommend weight-based dosing for thyroid repletion in younger patients and/or without cardiovascular comorbidities. We observed that patients on thyroid repletion are often underdosed compared to guideline recommendations. To formally evaluate this, we performed a retrospective study to determine the percentage of ICI-treated cancer patients who are receiving guideline-recommended thyroid repletion at an urban comprehensive cancer center. Methods: We identified patients who received PD-1 ICI, either singly or in combination with chemotherapy, TKI, or other ICI to identify patients who met the consensus guideline criteria for weight-based dosing of thyroid repletion. Analysis was restricted to ICI-treated patients who had a thyroid stimulating hormone (TSH) level above 10 mU/L following initiation of therapy. For each patient, we collected the patient’s age, weight, and initial prescribed dose of levothyroxine. We also obtained the date of abnormality and normalization for TSH and free thyroxine (T4). Results: 402 patients received ICI, either singly or in combination. 55 patients had TSH &gt; 10 mU/L. 15 patients who did not have documentation of hypothyroidism or developed it prior to immunotherapy were excluded. The proportion of patients who were eligible for, and who received weight-based repletion is summarized in the table. The proportion of patients who received guideline-recommended thyroid repletion was: 6/17 (35%) SITC-guideline recommended dose, 18/27 (67%) NCCN-guideline recommended dose and 6/22 (28%) ASCO-guideline recommended dose. The median time to free T4 normalization was 9 weeks (IQR 6-15 weeks) and TSH normalization was 13 weeks (IQR 9-30 weeks). Conclusions: At an urban comprehensive cancer center, the incidence of hypothyroidism in ICI-treated cancer patients is 10%. The compliance with guideline recommended weight-based dosing is low, with 33-72% of patients not receiving appropriate therapy, translating into prolonged time to thyroid function normalization. We aim to develop a quality improvement intervention to improve thyroid dosing in this patient population. Proportion of patients receiving guideline-recommended thyroid repletion. Criteria Per SITC Guidelines Per NCCN Guidelines (if lower end of dosing range) Per ASCO Guidelines Patients eligible for weight-based dosing 17 27 22 # of patients who received appropriate initial dosing 6 (35%) 18 (67%) 6 (28%) Average initial dose prescribed 81 mcg 78 mcg 76 mcg Average initial dose per guidelines (based on ideal body weight) 107 mcg 71 mcg 109 mcg

Associative Learning in Subclinical Hypothyroidism at Different Ranges of Thyroid Stimulating Hormone: A Cambridge Neuropsychological Test Automated Battery (CANTAB) Study of Visual Paired Association Learning Task.

Associative learning deficits are constantly found in subclinical hypothyroidism (SCH). Despite achieving normal thyroid stimulating hormone (TSH) levels, a considerable number of patients undergoing levothyroxine (LT-4) treatment frequently complain about memory retrieval. The Paired Association Learning (PAL) task involves computerised testing on the CANTAB- Cambridge Neuropsychological Test Automated Battery, also considered a screening tool for Alzheimer's disease (AD). This study aimed to investigate the impact of different levels of TSH on visual associative learning in SCH and determine if these impairments were reversed with LT-4. A total of 134 participants were included in this cross-sectional study. Group 1: 35 healthy controls; patients with SCH (Group 2: 33 newly identified cases; Group 3: 32 patients on LT-4 with elevated TSH; Group 4: 34 euthyroid but on LT-4). A thyroid profile and a neuropsychological clinical assessment were done. The visual PAL task was performed on CANTAB. PAL was significantly impaired (p = <0.05) in all 3 patient groups as compared to Group 1. The PAL total errors (adjusted) scores were significantly higher in Groups 2 and 3, indicating that associative learning is definitely impaired in SCH, reaching levels previously seen in patients with AD. Our findings encourage screening for visual associative learning or memory retrieval in patients with SCH. The study present has established a more reasonable threshold of TSH 2.5mIU/L to encourage examination of associative learning and the initiation of LT-4 in SCH. Poor PAL task performance in patients with SCH may have significant implications in clinical settings for suspecting AD.

The Association Between Hypothyroidism and Cognitive Function Change in Women across the Menopause Transition: The Study of Women's Health Across the Nation.

Background: Patients treated for hypothyroidism with levothyroxine (LT4) monotherapy may present with persistent hypothyroidism symptoms, including cognitive symptoms, despite having a normal thyroid stimulating hormone (TSH) level. It remains unclear whether LT4 monotherapy is sufficient to normalize cognitive function outcomes over time. Methods: This is a multisite longitudinal study of a diverse group of women during midlife representing 5 ethnic/racial groups from 7 enrollment sites across the United States in the Study of Women's Health Across the Nation. Women were screened for a history of thyroid disease and the use of LT4. The study consisted of two primary groups: women with LT4-treated hypothyroidism and control women without thyroid disease. Each participant completed up to 9 cognitive assessments over the study period testing processing speed, working memory, and episodic memory (immediate and delayed recall). Multivariable generalized linear mixed models of scores for each cognitive assessment were developed to determine the association between LT4-treated hypothyroidism and cognitive function trajectories. Covariates included sociodemographic, clinical characteristics, and menopausal status (pre/early peri, late peri, and surgical/post). Sensitivity analyses were conducted to assess the impact of abnormal TSH levels and practice effects (i.e., improvements in scoring after repeated testing). Results: Of the 2033 women who were included in the study, 227 (11.2%) met criteria for LT4-treated hypothyroidism. At baseline, both processing speed and working memory scores were higher in LT4-treated women (mean processing speed scores: 56.5 vs 54.4; p value = 0.006; mean working memory scores: 6.8 vs 6.4; p value = 0.018). However, when considering the effect of LT4-treated hypothyroidism over time, there were no significant differences in the rate of cognitive decline (in any measure) between the hypothyroidism and control groups with or without covariate adjustment. The results were similar when considering LT4-treated women with abnormal TSH levels or after minimizing practice effects. Conclusions: We observed no difference in cognitive decline between women with LT4-treated hypothyroidism and women without thyroid disease. For similar aged patients with cognitive complaints, if thyroid function testing is normal, clinicians should consider causes other than inadequate thyroid hormone treatment to explain these symptoms.

A confusing situation in the clinic: isolated maternal hypothyroxinemia

Isolated maternal hypothyroxinemia (IMH) is a common problem in the clinic. There is a normal maternal thyroid stimulating hormone (TSH) level with a low maternal free thyroxine (FT4) level. The aim of this review is to explain IMD in the light of current literature and to contribute to clinicians in the management of IMH. Iodine deficiency is the most important factor in etiology. The effects of IMH on the pregnant woman and the fetus are not clear. However, it is a serious concern among serious clinicians, especially considering the importance of the effect of thyroid hormones on fetal brain development. As for the treatment of IMH, the number of studies conducted is not sufficient and there is no consensus and evidence on levothyroxine treatment. However, there is a consensus on iodine supplementation and it is recommended to take 250 mg of iodine daily. As a result, IMH is a problem that should be taken seriously during pregnancy and care should be taken regarding its diagnosis and treatment. Additionally, more research is needed on the effects and treatment of IMH on pregnant and fetal health

Analysis of Inflammatory and Thyroid Hormone Levels Based on Hepatitis A and B Virus Immunity Status: Age and Sex Stratification.

This study investigated the potential associations between hepatitis virus antibody status and thyroid and inflammatory function. The C-reactive protein (CRP), thyroid-stimulating hormone (TSH), and free thyroxine (FT4) levels were measured in individuals with and without antibodies to the hepatitis A virus (HAV) and hepatitis B virus (HBV). Participants were stratified by age, sex, and HAV/HBV antibody status. Participants with and without antibodies to HAV and HBV had normal CRP, TSH, and FT4 levels. However, notable discrepancies were observed in FT4 levels among participants with HAV antibodies and in CRP and FT4 levels among those with both HAV and HBV antibodies, suggesting potential associations between viral immunity and thyroid function, especially in younger participants. Significant variations in thyroid hormone levels were noted when the sample was stratified by sex and HAV and HBV antibody status, indicating that the association between antibody status and thyroid hormone levels varied by sex. This study underscores the need for further research on the effect of viral immunity on inflammatory parameters and thyroid hormone levels.

The importance and prognostic effect of thyroid hormones in patients with transposition of the great arteries

Objectives: Transposition of the great arteries (TGA) is a rare congenital heart disease that occurs in 3 in 10,000 newborns and is rapidly fatal (90%) within one year if left untreated. The prognosis of this pathology changed after introducing an early arterial switch operation (ASO), while the left ventricle could still adapt to systemic high-pressure conditions. Appropriate regulation of thyroid hormones positively impacts metabolism, cardiac function, and postoperative recovery. Therefore, regular thyroid hormone monitoring and thyroid function monitoring of TGA patients may help to improve the health status and prognosis of this group of postoperative patients. Methods: In our study, 127 patients who underwent ASO at our pediatric cardiac surgery clinic between 01.01.2014 and 18.09.2021 were retrospectively analyzed and included. Among the patients, 43% (n=54) were females, and 57% (n=73) were males. Results: The coronary arteries were normal in 89.7% (n=114) and abnormal in 10.3% (n=13) of the patients. Twenty-one of the patients exited, and mortality was calculated to be 16.5%. There were no significant differences in mortality or thyroid stimulating hormone (TSH), free thyroxine (T4), or free triiodothyronine (T3) values (P=0.674, P=0.345, P=0.478). In our study, in which we investigated the effect of thyroid hormone levels on prognosis in neonatal patients with TGA with normal free T3, T4, and TSH values, we found that TSH levels were greater in the group with advanced aortic regurgitation and exitus, although the effect of thyroid hormones on postoperative results was not statistically significant. Conclusions: Congenital hypothyroidism is a common disease with cardiac effects. During the neonatal period, this disease may conceal itself. Careful, expert clinical follow-up and clinical trials are crucial to improve outcomes in the surgical treatment of transposition of the great arteries, a complex congenital heart disease.

Association Between Particulate Matter Exposure and Preterm Birth in Women With Abnormal Preconception Thyrotropin Levels: Large Cohort Study.

Prior research has linked exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM2.5) with preterm birth (PTB). However, the modulating effect of preconception thyroid stimulating hormone (TSH) levels on the relationship between PM2.5 exposure and PTB has not been investigated. This study aimed to assess whether preconception TSH levels modulate the impact of PM2.5 exposure on PTB. This cohort study was conducted in Guangdong, China, as a part of the National Free Pre-Pregnancy Checkups Project. PM2.5 exposure was estimated by using the inverse distance weighting method. To investigate the moderating effects of TSH levels on trimester-specific PM2.5 exposure and PTB, we used the Cox proportional hazards model. Additionally, to identify the susceptible exposure windows for weekly specific PM2.5 exposure and PTB, we built distributed lag models incorporating Cox proportional hazards models. A total of 633,516 women who delivered between January 1, 2014, to December 31, 2019, were included. In total, 34,081 (5.4%) of them had abnormal preconception TSH levels. During the entire pregnancy, each 10-μg/m3 increase in PM2.5 was linked to elevated risks of PTB (hazard ratio [HR] 1.559, 95% CI 1.390-1.748), early PTB (HR 1.559, 95% CI 1.227-1.980), and late PTB (HR 1.571, 95% CI 1.379-1.791) among women with abnormal TSH levels. For women with normal preconception TSH levels, PM2.5 exposure during the entire pregnancy was positively associated with the risk of PTB (HR 1.345, 95% CI 1.307-1.385), early PTB (HR 1.203, 95% CI 1.126-1.285), and late PTB (HR 1.386, 95% CI 1.342-1432). The critical susceptible exposure windows were the 3rd-13th and 28th-35th gestational weeks for women with abnormal preconception TSH levels, compared to the 1st-13th and 21st-35th gestational weeks for those with normal preconception TSH levels. PM2.5 exposure was linked with a higher PTB risk, particularly in women with abnormal preconception TSH levels. PM2.5 exposure appears to have a greater effect on pregnant women who are in the early or late stages of pregnancy.

A Critical Investigation of Sick Euthyroid Syndrome in Chronic Heart Failure Patients: Addressing the Need for Accurate Thyroid Assessment.

Background The body undergoes numerous metabolic changes during severe illness or physiological stress to protect itself by lowering metabolism and reducing overall demands. This evolutionary adaptation dates back to early human development, long before the advent of ICU facilities and advanced treatments. One such protective mechanism is Sick Euthyroid Syndrome (SES), also known as Non-thyroidal Illness Syndrome (NTIS). SES commonly occurs in critically ill patients and is frequently observed in conditions such as heart failure, chronic kidney disease, and severe sepsis. This syndrome is characterized by abnormal thyroid function tests in patients with acute or chronic systemic illnesses who do not have intrinsic thyroid disease. Typically, these patients exhibit low serum levels of triiodothyronine (T3), normal or low levels of thyroxine (T4), and normal or low thyroid-stimulating hormone (TSH) levels. SES is believed to be an adaptive response to illness, aimed at reducing the body's metabolic rate and conserving energy during severe physiological stress. This original article delves into SES's prevalence and clinical impact in these settings. Materials and methods The study aims to determine the prevalence of SES in patients with long-standing heart failure, elucidate the relationship between thyroid function and heart failure severity, and assess its impact on various hematological and clinical parameters. This observational, cross-sectional study was conducted at Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pune, India, a 2011-bed hospital, over one and a half years. This study included 70 patients with chronic heart failure, aged 18 years and above, defined by a left ventricular ejection fraction of 40% or less and a Boston criteria score of 8 or more. Patients were excluded if they had a history of thyroid dysfunction, clinical sepsis, or were taking thyroid-affecting drugs. Results The study provides important insights into the prevalence and impact of SES in long-standing heart failure patients. It found that a significant 44.29% of these patients exhibited low T3 levels, highlighting the substantial occurrence of SES in this population. Additionally, the study revealed a negative correlation between N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels, Boston score, and total T3, suggesting that as indicators of heart failure severity worsen, total T3 levels may decrease further. Another key finding is the high prevalence of anemia among heart failure patients, with a notable gender disparity: 92.11% of male patients were affected compared to 50% of female patients. Conclusion The study concluded that SES is significantly prevalent among long-standing heart failure patients, further indicating that thyroid suppression increases with the severity of heart failure. Recognizing SES can guide tailored treatments, prompting intensive monitoring and optimized heart failure management.Additionally, the study found a high prevalence of anemia, particularly among male patients, highlighting the need for gender-specific considerations in managing heart failure. These findings underscore the importance of routine thyroid function assessments and regular monitoring of anemia in heart failure patients. Future research should focus on improving clinical outcomes through comprehensive management of both thyroid function and anemia in these patients.

Epidemiologic changes in thyroid disease.

To analyze the evolving epidemiologic trends in thyroid disease, focusing on risk factors, underlying drivers of these changes, and their implications on clinical practice and research priorities. Thyroid disease remains one of the most prevalent groups of disorders globally, and the shift in its frequency and distribution is multifactorial. The prevalence of hypothyroidism increases with age, although normal thyrotropin ranges appear to be age-dependent, raising concern for potentially inappropriate levothyroxine use. Hyperthyroidism and Graves' disease continue to be predominant in reproductive-age women but exhibit a milder phenotype at diagnosis. Thyroid nodules are increasingly found in asymptomatic patients, likely from more widespread use of neck and chest imaging. Thyroid cancer incidence has risen exponentially over the years, mostly driven by overdiagnosis of low-risk tumors; however, a small rise in incidence of higher risk tumors has been noted. Obesity appears to be a risk factor for thyroid cancer occurrence and more aggressive forms of the disease. Understanding epidemiologic trends in thyroid disease is crucial for guiding clinical practice and research efforts, aiming to optimize patient outcomes while preventing unnecessary and potentially harmful interventions.

The role of non-invasive oscillometric method to detect aortic stiffness in patients with subclinical hypothyroidism

Introduction Subclinical hypothyroidism (SCH) is a biochemical condition that is diagnosed when peripheral free thyroid hormone levels are within normal reference laboratory range but serum thyroid-stimulating hormone (TSH) levels are mildly elevated. The aim of this study was to investigate the relationship between SCH and arterial stiffness using two different non-invasive methods, including echocardiography and oscillometric arteriography. Material and Methods The study included 33 newly diagnosed SCH patients and 34 age- and gender-matched healthy controls. Systolic and diastolic diameters and elastic parameters of the aorta were calculated by 2D Transthoracic echocardiography (TTE). Central blood pressure and aortic stiffness values of patient groups were measured noninvasively from the brachial artery using Mobil-O-Graph arteriography. Pulse wave velocity (PWV) and augmentation index (AIx) were used as arterial stiffness indicators. Results There was no significant difference between SCH and control groups with regard to age, gender, and body mass index (BMI). Aortic strain and aortic distensibility, were significantly lower in the SCH group than in the control group (p < 0.001). PWV and AIx which measured by Mobil-O-Graph arteriography were found to be significantly higher in the subclinical hypothyroid group compared to the control group (p < 0.05). Conclusion Aortic stiffness assessed by TTE and Mobil-O-Graph arteriography deteriorated in patients with SCH after excluding other cardiovascular risk factors. The assessment of aortic stiffness by the oscillometric method was easy and useful for widespread clinical use.

O-304 Is there any association between thyroid-stimulating hormone (TSH) levels and semen parameters? A retrospective study in a European fertility clinic

Abstract Study question Is there any association between TSH levels and semen parameters considering age, body mass index (BMI), and life style? Summary answer In line with the results of logistic regression, normal TSH values increase the probability of having a higher sperm count. What is known already To date, association between TSH levels, semen parameters and other hormones have not been thoroughly investigated in European andrology labs. However, while andrology guidelines do not support a systematic evaluation of thyroid function, some studies reported that men in infertility clinics have higher risks of presenting thyroid disorders than in the general population. Study design, size, duration Both partners investigated for sterility are routinely checked for TSH in the work up of our clinic. We examined for 2021 – 2023 all 347 male patients (infertile/fertile) with complete records of demographic data, semen analysis and hormone analysis. Patients suffering from azoospermia, genital tract infections, hormonal supplementation or heavy medical treatments (radiotherapy, chemotherapy), as well as those receiving iodine supplements or drugs that could potentially affect testicular or thyroid physiology, were excluded. Participants/materials, setting, methods Age, BMI, smoking and detailed alcohol intake were recorded. A blood sample was taken from each patient in connection with the sperm collection to measure TSH, FSH, LH, prolactin and testosterone levels. Spearman’s correlation coefficients were used to determine correlations among hormones. Statistical analyses were performed using semen parameters as dichotomized using WHO reference values. Men above the reference values for count, concentration and motility were used as comparison subjects in multivariate logistic regression. Main results and the role of chance The analysis explored relationships between age, BMI, smoking, alcohol consumption and semen parameters with TSH hormone levels. The mean age of the participants was 35.8 ±7.43 years and BMI was 27.2 ±4.54 kgm-2. Of all participants, 37% reported being smokers, alcohol consumption was 3% regularly, 35% occasionally, 44% rarely, 18% none. Considering a TSH level (0.4-4 mIU/l) as normal, the prevalence of thyroid dysfunction in the cohort was 0.9% (TSH &amp;lt;0.4) and 1.1% (TSH &amp;gt;4) implying that most patients had normal TSH levels. In this cohort, TSH levels were not found to be significantly affected by age, BMI, smoking or alcohol consumption despite being known as putative confounding factors influencing TSH levels. Among the various hormones evaluated, only one significant positive correlation was found between TSH and Prolactin (r = 0.199, p = 0.0001), while a trend towards a negative correlation between TSH and LH (r=-0.101, p = 0.073) was suggested. Multivariate logistic regression analysis showed, not surprisingly, that age was a factor influencing sperm count, sperm concentration as well as total and progressive sperm motility. Logistic regression also showed that when TSH values were within the normal range, sperm counts were significantly higher (OR:1.302, P = 0.043; CI95%:1.009-1.681). Limitations, reasons for caution Sperm morphology and viability were not recorded. Evaluation of thyroxine (T4) and triiodothyronine (T3) levels could be useful. The crucial role of iodine and the complex relationship between iodine and selenium status (which depends on geographical location) in affecting thyroid function should be taken into account in future studies. Wider implications of the findings Male patients with abnormal TSH levels are not very common in this region. Normal TSH level is associated with a higher sperm count. TSH assessment in infertile couples should be routine in both partners, given the recorded worldwide increase in thyroid dysfunction and iodine deficiency. Trial registration number not applicable

The association of higher thyroid stimulating hormone levels in the normal range with unexplained infertility: A cross-sectional study.

Since thyroid hormones have an essential role in energy production, early development of the human placenta, embryo development, and implantation, abnormalities in thyroid function can significantly affect pregnancy outcomes. The present study aimed to investigate the effect of higher thyroid-stimulating hormone (TSH) levels in the normal range in euthyroid women with unexplained infertility. In this cross-sectional study, we evaluated the data for 300 euthyroid women aged between 18 and 39 yr with normal TSH levels ( 5 mIU/L) referred to Yazd Reproductive Sciences Institute, Yazd, Iran from December 2018-March 2021 in 2 groups: the case group (with unexplained infertility) and the control group (with male factor infertility). Finally, age, body mass index, and serum levels of TSH were extracted from participants' medical records and compared between groups. The mean age and TSH level of participants were 31.52 3.52 yr and 1.24 2.59 mIU/L, respectively. 142 women (47.3%) had TSH 2.5, and 158 women (52.7%) had TSH 2.5 mIU/L. The women with unexplained infertility had significantly higher TSH levels than controls in the same normal range (0.62 vs. 0.64 mIU/L, p 0.001). Although a more significant proportion of women in the case group had TSH levels 2.5 mIU/L, we did not find a significant association between TSH levels and age or body mass index. Women with unexplained infertility have a higher level of serum TSH in the normal range ( 2.5 mIU/L) than the control group. So, the effect of TSH treatment on these women should be considered.

Impact of Subclinical Hypothyroidism on Lipid Profile in Jeddah: A Retrospective Cohort Study.

Background Patients with subclinical hypothyroidism (SCH) have a high serum concentration of thyroid-stimulating hormone (TSH), whereas their serum-free thyroxine concentrations are normal. Lipid metabolism is regulated in large part by thyroid hormones. It could be connected to a changed lipid profile. This study aimed to evaluate the relationship between SCH and alterations in the lipid profile. Methodology Data from 99 patients with SCH and 109 euthyroid cases were collected from King Abdulaziz Medical City, Jeddah, Saudi Arabia, from 2016 to 2022. Patients older than 18 years were included in the study. The groups were matched in terms of gender, age, and body mass index. SCH was defined as a TSH value of 4.5 to 10 mIU/L, and normal T4 as 5 to 18 μg/dL. Control cases had a normal TSH ranging from 0.45 to 4.5 mIU/L. The total serum cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride (TG) levels in both groups were examined and the results were recorded. Results In comparison to the control group, SCH patients had greater median glycated hemoglobin (HbA1C) (p = 0.001) and lower median vitamin D levels (p = 0.004) before therapy. Before therapy, SCH patients also showed considerably lower HDL levels and significantly higher LDL and TG levels (p < 0.001). Conclusions There is a substantial correlation between SCH and reduced HDL and vitamin D levels. It was linked to increased TG, LDL, and HbA1c levels. Only vitamin D and LDL were pathologically high. Treatment with levothyroxine raised total and LDL cholesterol levels. Future research should look into the affordability of treating SCH.