Serum Thyroid-stimulating Hormone Levels Research Articles

The association between TSH and thyroid hormones in the normal or subclinical dysfunction range with left ventricular diastolic dysfunction

Thyroid hormones modulate the cardiovascular system. However, the effects of subclinical thyroid dysfunction and euthyroidism on cardiac function remain unclear. We investigated the association between left ventricular (LV) diastolic dysfunction and subclinical thyroid dysfunction or thyroid hormones within the reference range. This cross-sectional study included 26,289 participants (22,197 euthyroid, 3,671 with subclinical hypothyroidism, and 421 with subclinical thyrotoxicosis) who underwent regular health check-ups in the Republic of Korea. Individuals with thyroid stimulating hormone (TSH) levels > 4.2 µIU/mL and normal free thyroxine (FT4, 0.78–1.85 ng/dL) and triiodothyronine (T3, 76–190 ng/dL) levels were defined as having subclinical hypothyroidism. Individuals with serum TSH levels < 0.4 µIU/mL and normal FT4 and T3 levels were defined as having subclinical thyrotoxicosis. The cardiac structure and function were evaluated using echocardiography. LV diastolic dysfunction with normal ejection fraction (EF) was defined as follows: EF of > 50% and (a) E/e’ ratio > 15, or (b) E/e’ ratio of 8–15 and left atrial volume index ≥ 34 mL/m2. Subclinical hypothyroidism was significantly associated with cardiac indices regarding LV diastolic dysfunction. The odds of having LV diastolic dysfunction was also increased in participants with subclinical hypothyroidism (adjusted odds ratio [AOR] 1.36, 95% confidence interval [CI], 1.01–1.89) compared to euthyroid participants. Subclinical thyrotoxicosis was not associated with LV diastolic dysfunction. Among the thyroid hormones, only serum T3 was significantly and inversely associated with LV diastolic dysfunction even within the normal range. Subclinical hypothyroidism was significantly associated with LV diastolic dysfunction, whereas subclinical thyrotoxicosis was not. Serum T3 is a relatively important contributor to LV diastolic dysfunction compared to TSH or FT4.

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.

Relationship Between Serum Thyrotropin Levels and Metabolic Diseases in Older Adults.

Subclinical hypothyroidism is associated with metabolic diseases; however, it remains controversial in older individuals. This work aimed to investigate the relationship between thyrotropin (TSH) levels and metabolic diseases. In this cross-sectional study, sampling was conducted from nationally representative general communities from 31 provinces in mainland China. A total of6791 older (aged ≥65 years) and 55 303 young participants (aged 18-64 years) were selected after excluding individuals with overt hyperthyroidism or overt hypothyroidism. According to the kit, TSH reference range (0.27-4.2 mU/L) and the age-specific TSH range previously formulated (an upper limit of 8.86 mU/L for older adults and 6.57 mU/L for young adults), the older adults and young adults were separately divided into 4 groups based on their TSH levels. Main outcome measures included anthropometric assessments, serum concentrations of thyroid functions, and various metabolic parameters. In contrast to young adults, there was no significant increase in the prevalence of any metabolic disorders assessed in the slightly elevated TSH group (TSH 4.21-8.86 mU/L) compared to the euthyroid group (TSH 0.27-4.2 mU/L) among older adults. After adjusting for interference factors, a TSH level higher than 8.86 mU/L was found to be an independent risk factor for low high-density lipoprotein cholesterol (OR, 1.84; 95% CI, 1.14-2.98) and dyslipidemia (OR, 1.49; 95% CI, 1.09-2.04) when compared to the euthyroid group in older adults. Slightly elevated TSH levels are not associated with an increased risk of metabolic diseases in older adults. Therefore, we recommend raising the upper limit of the TSH range for individuals aged 65 years and older.

Corneal topography findings among patients with thyroid dysfunction

Background Hormonal dysregulation impacts the metabolism of the cornea and could be linked to keratoconus. Previous research has suggested an association between keratoconus and autoimmune thyroid disorders. Aim The aim of this study was to compare the topographic corneal changes in patients with thyroid dysfunction. Patients and methods This is a cross-sectional study of 200 patients with thyroid dysfunction attending the Endocrinology Clinic at the Faculty of Medicine, Alexandria University. The corneal topography of patients was examined with TMS. Serum levels of thyroid-stimulating hormone, free thyroxine, and free triiodothyronine were measured. Results Two hundred patients with thyroid dysfunction were enrolled in the study. Of them, 129 were hypothyroid patients and 71 were hyperthyroid patients. The study included 137 females and 63 males with a mean age of 32.4 ± 8.2 years. Corneal keratometry readings, including K1, K2, and K max readings, were measured. The mean value of K1 was 45.86 ± 4.69 D, mean K2 was 47.89 ± 5.08 D and the mean corneal thickness was 475 ± 0.36 µm, no relation was found between any of these parameters and serum thyroid-stimulating hormone, free triiodothyronine, or free thyroxine levels. Conclusion In our study, more topographic changes in favor of a thin cornea and steep cornea rather than a true keratoconus were detected in patients with thyroid dysfunction, making cautious analysis of corneal topography important, especially before refractive surgery.

Association between Iron deficiency and hypothyroxinemia in first-trimester pregnant women: A study from a tertiary care hospital

ABSTRACT Background: Iron deficiency (ID) is a common nutritional concern worldwide. Hypothyroidism during pregnancy also has harmful effects on both mother and child, such as post-partum hemorrhage, pre-eclampsia, low-birth weight, pre-term labour and abruptio placenta. Few articles have shown an association between ID and hypothyroidism. Aims: To evaluate the association between hypothyroidism, hypotriiodothyroninemia and ID in pregnant women. Materials and Methods: This cross-sectional study was conducted between January 2017 and June 2019 at JSS Hospital, a Tertiary Care Teaching and Research Hospital attached to JSS Medical College in Mysuru City, South India. Five hundred consecutive pregnant women aged 18–45 years in the first trimester of pregnancy were recruited. A venous blood sample of approximately 5 mL was drawn and sent for analysis of haemoglobin, thyroid-stimulating hormone (TSH), T3, T4, anti-thyroid peroxidase (TPO) antibodies and serum ferritin. T3, T4, TSH, anti-TPO antibody and serum ferritin levels were measured by chemiluminescence for all pregnant women. Correlation and linear regression analyses were performed to determine the association between ID and T3, T4 and TSH levels. Results: Out of 500 women, nine were excluded because of pre-analytical errors; hence, there were 491 pregnant women in the first trimester. Mean values of T3, T4, TSH and ferritin in the study were 1.45 ± 0.72, 9.29 ± 2.53, 2.37 ± 3.17 and 31.54 ± 30.28. There was a positive correlation between serum ferritin and T4 levels, with a correlation coefficient of 0.135. The scatter plot also showed a linear relationship between serum ferritin and T4 levels. There was no significant correlation between serum ferritin, T3 and TSH levels. Linear regression analysis also showed an association between ferritin and T4 levels, with a significance of 0.003. Linear regression analysis was insignificant for TSH, T3 and serum ferritin levels. Conclusion: ID anaemia (IDA) is associated with hypothyroxinemia in pregnant women. Further extensive studies are needed to evaluate the causal association between hypothyroidism and IDA. Iron therapy might improve thyroid parameters in patients with subclinical hypothyroidism and ID without thyroxine, which requires further research.

A study of the association of lipid ratios with thyroid dysfunction in a tertiary medical college in Eastern India

Background: Thyroid hormones play a crucial role in major metabolic pathways in the body and dyslipidemia is a major metabolic abnormality seen in thyroid disorders. Cardiovascular diseases (CVDs) are now emerging as the leading cause of morbidity and mortality worldwide and the most important risk factor for CVDs is dyslipidemia. The lipid ratios that have a positive association with CVD risk are atherogenic index of plasma (AIP), Castelli’s risk index (CRI)-I and II, and atherogenic coefficient (AC). Clinically, both an excess and deficiency of thyroid hormones can exacerbate or induce CVDs and lipid ratio can be used as an inexpensive marker for predicting CVD risk. Aims and Objectives: This study aims to evaluate the lipid ratios (AIP, CRI-I, CRI-II, AC) in patients with thyroid dysfunction and compare the results with lipid ratios in euthyroid individuals. This study also aims to find any correlation, if exists, between lipid ratios and serum thyroid-stimulating hormone (TSH) levels in thyroid dysfunction. Materials and Methods: The serum TSH and lipid profile were evaluated in fifty euthyroid, fifty hypothyroid, fifty subclinical hypothyroid, and fifty hyperthyroid patients. The lipid ratios (AIP, CRI-I, CRI-II, AC) were calculated from the lipid profile. Results: The mean lipid ratios were higher in hypothyroid, followed by subclinical hypothyroid cases when compared to euthyroid controls and hyperthyroid patients. A positive correlation was observed between the TSH and lipid ratios in euthyroid, hypothyroid, and subclinical hypothyroid subjects. There was no significant correlation between TSH and lipid ratios in hyperthyroid patients. Conclusion: This study demonstrates that the evaluation of lipid ratios along with TSH can provide an effective screening tool to assess the cardiovascular risk in patients with subclinical and overt hypothyroidism, especially in the absence of imaging techniques in resource-limited centers.

Gender difference in the relationship between clinical symptoms, thyroid hormones, and metabolic parameters in young, first-episode and drug-naïve major depressive disorder patients with suicide attempts: A network analysis perspective

BackgroundSuicide attempts are one of the most serious comorbidities in patients with major depressive disorder (MDD), and the prevalence of suicide attempts is higher in younger people compared to older people, with significant gender differences. This study aimed to investigate the relationship between suicide attempts, clinical symptoms, thyroid hormones, and metabolic parameters in young first-episode and drug-naïve (FEND) MDD patients of different genders. MethodsA total of 1289 FEND MDD patients were recruited. Depression, anxiety, and psychotic symptoms were assessed using the Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and the Positive and Negative Syndrome Scale (PANSS) positive subscale, respectively. Thyroid hormones and glucolipid metabolism indicators were also tested. Network analysis was employed to delineate the interplay between thyroid dysfunction, clinical symptoms, and metabolic disorders. ResultsAmong young FEND MDD patients, the rate of suicide attempts was 17.4% in males and 19.8% in females, showing no significant gender difference in the incidence of suicide attempts (χ2 = 1.06, p = 0.303). In the network model, PANSS positive subscale (Expected Influence = 0.578) and HAMD scores (Expected Influence = 0.576) were identified as the individual symptoms that most affected male patients, whereas TSH (Thyroid-Stimulating Hormone) (Expected Influence = 0.972) and PANSS positive subscale (Expected Influence = 0.937) were identified as the individual symptoms that most affected female patients. In addition, we found that TSH (Expected Influence = 0.438) was a pivotal node connecting metabolic disturbances and clinical symptoms. ConclusionOur findings emphasize the important role of psychotic symptoms in young MDD patients with suicide attempts. Moreover, our results highlight the pivotal role of serum TSH levels in the pathophysiology of young female MDD patients with suicide attempts.

Levothyroxine may not adequately prepare hypothyroid women for controlled ovarian hyperstimulation

BackgroundThyroid axis dysregulation during controlled ovarian hyperstimulation (COH) is more pronounced in hypothyroid‐treated women. Whether or not this leads to compromised thyroid hormone levels within the ovarian follicular fluid is not known.AimsTo determine whether ovarian follicular thyroid hormone levels are compromised in adequately replaced hypothyroid women undergoing controlled ovarian hyperstimulation (COH), and/or influence cycle/pregnancy outcomes.Materials and MethodsProspective cohort study involving 46 euthyroid (anti‐thyroid peroxidase antibody negative) and 16 levothyroxine‐replaced women with baseline thyroid‐stimulating hormone (TSH) &lt;2.5 mIU/L attending their first COH cycle. Follicular fluid TSH, free triiodothyronine (T3) and free thyroxine (T4) were recorded at oocyte pick‐up. Serum levels were measured at: (i) baseline; (ii) human chorionic gonadotropin trigger day; and (iii) cycle conclusion. The number of mature oocytes retrieved, fertilisation, early pregnancy loss and live birth rates were compared.ResultsMedian serum TSH levels were similar at baseline (1.76 vs 1.24 mIU/L, P = 0.053), but free T3 levels were lower (4.5 vs 4.8 pmol/L, P = 0.029) in levothyroxine‐replaced compared to euthyroid women, with serum TSH levels increasing across ovarian stimulation (P = 0.006) into pregnancy testing (P = 0.030). Follicular fluid free T3 levels were lower in levothyroxine‐replaced women (median 4.3 vs 4.6 pmol/L, P = 0.032). Fertilisation rates were lower (52% vs 71%, P = 0.043) in women requiring levothyroxine replacement, but numbers of mature oocytes retrieved, early pregnancy loss and live births did not differ.ConclusionAdequately replaced hypothyroid women achieve lower ovarian follicular fluid free T3 levels and poorer fertilisation rates compared to euthyroid women undergoing COH. Optimising T3 levels may be pivotal in improving COH outcomes in hypothyroid women.

The Effect of Antiseizure Medications on Thyroid Functions in Children With Epilepsy

In this study, we aimed to investigate the effects of antiseizure medications on serum thyroid-stimulating hormone (TSH), free thyroxin (fT4) levels, and the frequency of subclinical hypothyroidism in children with epilepsy. One hundred and eighty-one pediatric patients receiving valproate, phenobarbital, carbamazepine, and levetiracetam monotherapy were included. The serum TSH levels were significantly higher at 6th, 12th, and 18th months of the treatment compared with the pre-treatment levels in valproate-treated patients. Serum fT4 levels in carbamazepine group were significantly lower than levetiracetam, valproate, and phenobarbital groups at 12th and 18th months of the treatment. Serum fT4 and TSH levels in levetiracetam group showed no significant changes at any time point. The frequency of subclinical hypothyroidism at 18th month was 16% in valproate, 11% in phenobarbital, 7% in carbamazepine, and 0% in levetiracetam groups. Our data suggest that levetiracetam monotherapy does not cause thyroid dysfunction.

Changes in apoptosis and adipokine biomarkers in the heart tissue of rats with experimental hyperthyroidism

Background and purpose: This study aimed to investigate the effects of hyperthyroidism on heart tissue through adipokines and apoptotic signalling pathways. Materials and Methods: A total of 14 Sprague-Dawley male rats were assigned to 2 groups, a control and a hyperthyroid group. The control group received 0.9% NaCl, while the hyperthyroid group received 1 mg/kg levothyroxine dissolved in 0.9% NaCl throughout the study. Thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels in serum samples, whereas fibronectin type III domain-containing protein 5 (FNDC5), adiponectin, B-cell lymphoma-2 (Bcl-2) and tumour protein 53 (p53) levels in heart tissue were determined by ELISA method. Results: Serum TSH level decreased (p&lt;0.01) while the level of FT4 significantly (p&lt;0.01) increased in the hyperthyroid group compared to the control group. The level of adiponectin in the cardiac tissue of levothyroxinetreated rats was found to be significantly higher than in the control group (p&lt;0.01). Additionally, compared to the control group, the antiapoptotic Bcl-2 level increased (p&lt;0.05) while the proapoptotic p53 level decreased in the hyperthyroid group (p&lt;0.01). Conclusions: In this study, the effects of hyperthyroidism on hormone levels, which are important regulators of energy and metabolic homeostasis, and changes in apoptosis markers were revealed in heart tissue. We consider that apoptosis was potentially prevented by activating mechanisms in order to protect cardiac functions in the beginning, but this scene may be reversed in progressive hyperthyroidism cases. Therefore, their pathways need to be supported by more detailed and time-compared studies.

Subclinical hypothyroidism predicts outcome in heart failure: insights from the T.O.S.CA. registry.

Subclinical hypothyroidism (SH), defined as increased serum thyroid-stimulating hormone (TSH) with normal free T4 (fT4) levels, is frequently observed in the general population. Prevalence ranges from 0.6% to 1.8% in the adult population, depending on age, sex, and iodine intake. Several studies reported a worse prognosis in patients with heart failure with reduced ejection fraction (HFrEF) and SH, but they considered heterogeneous populations suffering mainly from severe SH. Aim of this study was to evaluate if SH was independently associated with the occurrence of cardiovascular death considering 30months of follow-up. 277 HFrEF patients enrolled in the prospective, multicenter, observational T.O.S.CA. (Terapia Ormonale Scompenso CArdiaco) registry, were included in this analysis. Patients were divided into two groups according to the presence of SH (serum TSH levels > 4.5mIU/L with normal fT4 levels). Data regarding clinical status, echocardiography, and survival were analyzed. Twenty-three patients displayed SH (87% mild vs 13% severe), while 254 were euthyroid. No differences were found in terms of age, sex, HF etiology, and left ventricular ejection fraction. When compared with the euthyroid group, SH patients showed higher TSH levels (7.7 ± 4.1 vs 1.6 ± 0.9, p < 0.001), as expected, with comparable levels of fT4 (1.3 ± 0.3 vs 1.3 ± 0.3, p = NS). When corrected for established predictors of poor outcome in HF, the presence of SH resulted to be an independent predictor of cardiovascular mortality (HR: 2.96; 5-95% CI:1.13-7.74; p = 0.03). Since thyroid tests are widely available and inexpensive, they should be performed in HF patients to detect subclinical disorders, evaluate replacement therapy, and improve prognosis.

Hyperthyroidism in Pediatric Patients in a University Hospital: Ten Years of Experience

Although rare in childhood, hyperthyroidism is diagnosed by suppressed serum thyrotropin (TSH) levels and increased levels of free triiodothyronin (fT3) and free thyroxine (fT4) in addition to history and physical examination findings. In this study, we aimed to investigate the causes of hyperthyroidism and the clinical features of the disease in children and to evaluate the treatment. A total of 39 patients with hyperthyroidism diagnosed between 2010 and 2019 in the pediatric endocrinology department were included in the study.Thirty-one (79.5%) patients were female, and the mean age of admission was 14.4 (4.3-17.5) years. Of the cases, 33 (84.6%) were diagnosed with Graves’ diseases and 6 (16.7%) with Hashimoto thyroiditis. The most frequent complaints of patients diagnosed with hyperthyroidism were irritability (24, 61.5%), palpitation (22, 56.9%), and sweating (21, 53.8%). The most frequent findings were goiter in 31 (79.5%) patients and tachycardia in 27 (69.2%) patients. Serum TSH levels were suppressed in all patients, fT3 levels were increased in 94.4% of them, and fT4 levels were increased in 80.5% of them. In patients with Graves’ disease, TSH receptor antagonist was positive in 31 (93.9%) cases, and at least one of the thyroid autoantibodies was positive in all patients. Antithyroid drug treatment was initiated in all patients; 35 of them received methimazole and 4 of them received propylthiouracil. Radioactive iodine treatment was applied to three patients, and two patients were treated surgically who did not respond to antithyroid drug treatment. Antithyroid drug adverse effects were observed in 7 (21.2%) patients, requiring drug discontinuation in 1 patient. Although hyperthyroidism is rare in childhood, its treatment is difficult and requires close follow-up. Treatment options are different for adult patients. There is a need for multicenter studies to evaluate treatment efficacy and long-term outcomes in children.

Association of Anxiety and Depressive Symptoms with Thyroid Hormone Concentrations in Patients with Primary Bone Tumors.

Timely identification and intervention of psychological disorders bear significant import in ameliorating the ensuing therapeutic trajectories in primary bone tumor patients. Moreover, perturbations in thyroxine and thyroid-stimulating hormone (TSH) levels have been linked to manifestations of depressive and anxiety-related symptoms. However, the precise interplay governing the nexus of anxiety, depression, and the levels of thyroxine and TSH within the context of primary bone tumor patients remains presently unexplored. The objective of this study is to investigate the potential correlation between the hypothalamus- pituitary-thyroxine (HPT) axis and the depressive as well as anxious states observed in patients afflicted with bone tumors. Patients with primary bone tumors were required to accept the assessments of anxiety and depressive symptoms as well as thyroid axis hormone concentrations. The depressive and anxiety symptoms were assessed using the Hamilton Depression Rating Scale (HAMD) and the Hamilton Anxiety Scale (HAMA) score. During each follow-up, peripheral venous blood samples were collected for subsequent analysis using radioimmunoassay methods to measure serum- free T3, free T4, and TSH levels, with the calculated free T3 to free T4 ratio indicating peripheral free T4 to free T3 conversion. Tests for trend were conducted to assess thyroid axis hormone concentrations, HAMA scores, and HAMD scores, while the correlation between HAMA or HAMD scores and thyroid axis hormone concentrations was examined through univariate regression analyses. The study included 30 primary bone tumor patients. Initial high HAMA and HAMD scores decreased over a year after surgery (P < 0.05), reflecting diminishing anxiety and depression. TSH levels reduced postoperatively, contrasting with increased free-T3 and free-T4 levels (p < 0.01). Multivariate analysis affirmed that positive correlations were noted between TSH and anxiety/depression scores, while free-T3 correlated negatively, adjusted for demographic factors (p < 0.05). No significant associations emerged between HAMA/HAMD scores and free-T4 or free-T3 to free-T4 ratio (p > 0.05). The early identification of the low T3 syndrome could prove instrumental in both intervening and preventing adverse emotional states associated with primary bone tumors.

Diagnosis and Management of Subclinical Hypothyroidism: The 2023 Clinical Practice Guideline, Korean Thyroid Association

Subclinical hypothyroidism (SCH) is characterized by elevated serum thyroid-stimulating hormone (TSH) levels and normal free thyroxine levels. The Korean Thyroid Association recently issued guidelines for managing SCH. Based on the Korea National Health and Nutrition Examination Survey (2013-2015), a serum TSH level of 6.8 mIU/L is the reference value for SCH. SCH is classified as mild (TSH 6.8-10.0 mIU/L) or severe (TSH &gt; 10.0 mIU/L), and patients are categorized as adult (age &lt; 70 years) or elderly (age ≥ 70 years). Levothyroxine treatment (LT4-Tx) is not recommended for mild or even severe SCH in elderly patients. Immediate LT4-Tx can be given to adults in most cases, but not to women who are pregnant, patients with progressive disease, or patients with underlying coronary artery disease, heart failure, or dyslipidemia.

Effects of levothyroxine treatment on serum thyroid hormone levels in euthyroid patients with papillary thyroid microcarcinoma

We recently reported that lowering serum thyroid stimulating hormone (TSH) levels with levothyroxine (LT4) may be associated with decreased tumor growth during active surveillance (AS) of papillary thyroid microcarcinoma (PTMC). Most clinicians might believe that low serum TSH levels following LT4 therapy indicate subclinical thyrotoxicosis. This study aimed to evaluate the effects of TSH-lowering therapy using small doses of LT4 on serum thyroid hormone levels in euthyroid patients with PTMC. We retrospectively analyzed data from 28 patients with low-risk PTMC who had undergone measurement of both FT4 and FT3 consecutively and received LT4 to achieve serum TSH levels of < 0.5 μIU/mL and > 0.05 μIU/mL between January 2012 and May 2018 at Kuma Hospital. There were 24 females and 4 males (aged 55 ± 12 years [mean ± standard deviation {SD}]). We compared their serum FT4 and FT3 levels at diagnosis with those following TSH-lowering therapy with LT4. Following LT4 therapy, the patients’ serum FT4 levels were significantly increased (P < 0.001). Serum FT3 levels, however, remained unchanged (P = 0.10). The proportions of patients whose FT3 levels increased by more than 1 SD, remained unchanged, and decreased by more than 1 SD were 11 %, 57 %, and 32 %, respectively. Our study indicated that mild TSH-lowering doses of LT4 for euthyroid patients with PTMC increased serum FT4 levels but did not increase serum FT3 levels in most cases, suggesting that a mild TSH-lowering therapy for euthyroid patients may not necessarily cause thyrotoxicosis.

Association Between Dietary Phytochemical Index and Neonatal Thyroid Function.

Background: Thyroid hormones regulate fetal growth and differentiation of several tissues. Maternal dietary patterns may be correlated with changes in the level of neonatal thyroid-stimulating hormone (TSH). We hypothesized that since maternal nutrition affects birth weight and offspring growth, it may also impact endocrine patterns in offspring. This study is aimed at assessing the relationship between maternal dietary phytochemical index (DPI) in the first trimester of pregnancy and neonatal cord blood thyroid hormone levels. Methods: This cross-sectional study is a substudy of a birth cohort. Overall, 216 mothers, aged 16-45 years, were recruited in their first trimester of pregnancy. To calculate DPI, the daily energy percentage of phytochemical-rich foods was divided by the total daily energy intake. At delivery time, TSH and free thyroxine (FT4) levels were measured in cord blood samples using chemiluminescence immunoassay. Results: The mean (standard deviation (SD)) age of mothers was 29.56 (5.50) years, and 47% of newborns were girls. The mean (SD) of DPI in the first, second, third, and fourth quartiles was 25.03 ± 4.67, 33.87 ± 2.18, 40.64 ± 2.10, and 51.17 ± 4.98, respectively. There was not any significant correlation between DPI score with cord serum TSH and FT4 levels in crude and adjusted analysis. Conclusion: No significant relationship between maternal DPI with cord serum TSH and FT4 levels was shown. Limited experience exists about the effect of maternal diet quality indices on neonatal thyroid function, and further studies are needed in this regard.

Clinical inertia in thyrotropin suppressive therapy for low-risk differentiated thyroid cancer: A real-world experience at an endocrine center in Bangkok.

The management of low-risk differentiated thyroid cancer (DTC) has evolved over time toward treatment de-escalation. However, overtreatment with supraphysiological dose of levothyroxine (LT4) continues to be observed despite current clinical guideline. This study aimed to assess the actual thyrotropin suppressive therapy for low-risk DTC patients at an endocrine center in Bangkok. This retrospective study included patients with low-risk DTC who were regularly follow-up for at least 18 months at Theptarin Hospital between 2016 and 2022. The serum thyroid stimulating hormone (TSH) levels were stratified as TSH < 0.1 mIU/L; TSH 0.1 to 0.5 mIU/L; TSH 0.5 to 2.0 mIU/L; and TSH > 2.0 mIU/L. The initial risk stratification (IRS) and dynamic risk stratification were determined at 12 months of follow-up after completing the initial treatment and at the last visit. The clinical factors associated with overtreatment with LT4 were analyzed. A total of 102 patients (83.3% female, age at diagnosis 41.8 ± 13.6 years, mean tumor size 1.6 ± 1.0 cm) were evaluated with a mean follow-up of 5.9 years. The IRS classified 92.2% of patients after the initial treatment and 93.1% of patients at the last follow-up visit into the excellent response category. The mean LT4 daily dosage at the last follow-up was 121.3 ± 44.8 µg/day. Serum TSH levels were in an appropriate target range according to IRS in only 8.8% (9/102) of the patients and then improved to 19.6% (20/102) at the last follow-up visit. Further analysis showed that treating physicians with ≥10 years of practice was associated with severe TSH suppression therapy (TSH < 0.1 mIU/L). Despite the current clinical guideline recommendations and scientific evidences, less than one-fifth of low-risk DTC patients achieved the appropriate serum TSH target. While the proportion of an optimum LT4 suppressive had improved during the study period, further efforts are needed to overcome this clinical inertia.

#742 High TSH and low FT3 levels are associated with chronic kidney disease in three population-based studies from Germany

Abstract Background and Aims High serum thyroid-stimulating hormone (TSH) levels have previously been associated with a low estimated glomerular filtration rate (eGFR), but studies associating thyroid hormone levels with albuminuria revealed inconsistent results. The aim of our study was to investigate associations of serum levels of TSH, fT3 and fT4 with eGFR and albuminuria in population-based cohorts. Method We used cross-sectional data from 7,933 individuals aged 20 to 93 years of the Berlin Aging Study II (BASE II) and the Study of Health in Pomerania (SHIP-START; SHIP-TREND) to associate serum TSH, fT3, and fT4 levels with eGFR and albuminuria. To calculate eGFR, CKD-EPI and FAS equations were used. Albuminuria was defined as an urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. Results In multivariable analyses adjusted for confounding, we found inverse non-linear associations of serum TSH levels with eGFR, while serum fT3 levels showed a positive association with eGFR. High as well as low serum fT4 levels were associated with a lower eGFR. Age but not sex modified the association between thyroid hormone levels and eGFR. The inverse associations between serum TSH levels with eGFR were strongest in the youngest age groups, while the positive associations between serum fT3 levels and eGFR were strongest in older individuals. No significant associations between thyroid hormone levels and albuminuria were found. Conclusion In conclusion, we showed that high TSH, low fT3 as well as low and high fT4 levels were independently associated with a reduced kidney function in a non-linear fashion. Our results indicate that high TSH / hypothyroidism might be associated with a reduced kidney function. Thyroid function might be more tightly related to the eGFR than to albuminuria in the general population.

Elevated thyroid stimulating hormone and metabolic syndrome risk in patients with first-episode and drug-naïve major depressive disorder: a large-scale cross-sectional study

BackgroundMetabolic syndrome (MetS) is common in major depressive disorder (MDD), but its relationship with thyroid hormones remains unclear. We aimed to examine the association of thyroid hormones and MetS in first-episode drug-naïve (FEDN) MDD patients.MethodsWe recruited 1718 unmedicated MDD patients in this cross-sectional study. MetS was defined based on the 2004 Chinese Diabetes Society Criteria. Serum thyroid hormones including free thyroxine (FT4), free triiodothyronine (FT3), thyroid-stimulating hormone (TSH), thyroid peroxidase antibodies (TPOAb), and anti-thyroglobulin (TGAb) were examined. We used the logistic regression model to determine risk factors for MetS and examined the performance of the regression model by using the Area Under the Curve (AUC). In addition, we performed the trend test to test whether the results were robust.ResultsThe prevalence of MetS in unmedicated MDD patients was 34.4%. MDD patients with MetS had higher levels of serum TSH, TGAb, and TPOAb (all P < 0.001). Concurrently, serum TSH levels were independent risk factors for MetS in MDD patients (OR:1.49, 95%CI: 1.40–1.58), which could also distinguish MDD patients with and without MetS (AUC was 0.77). Additionally, in the trend test, the results also indicated a similar trend when TSH was used as a categorical variable (P for trend < 0.001).ConclusionsThis study suggests that TSH levels were independent risk factors for MetS in FEDN MDD patients (OR:1.49). The examination of thyroid function may contribute to the early detection of MetS.

Thyroid status in patients with early stages of cancer of various localization

Purpose of the study. To determine the thyroid status of primary cancer patients in the early stages of uterine body cancer, kidney cancer, breast cancer, skin melanoma and lung cancer without a history of endocrine pathology.Patients and methods. The content levels of thyroid-stimulating hormone (TSH), thyroid hormones (THs) T4 and T3 of total and free forms were determined in the blood serum by RIA method in 132 patients with breast cancer, uterine body cancer, lung cancer, kidney cancer and skin melanoma (average age 55 years). The comparison group consisted of practically healthy donors.Results. Only in skin melanoma, serum TSH levels were reduced by 1.5 times (p &lt; 0.05). The T4 content was reduced by 1.4–1.7 times (p &lt; 0.05) in uterine body cancer and kidney cancer, increased in lung cancer patients and 16 % of breast cancer patients by 1.4–1.7 times though (p &lt; 0.05). A 1.3–1.5‑fold low (p &lt; 0.05) T3 level was found in breast cancer, kidney cancer, and skin melanoma, while an 1.6‑fold increase (p &lt; 0.05) was found in uterine body cancer. The revealed changes in THs by the type of clinical hyperthyroidism are an increase of 1.8 times (p &lt; 0.05) FT3 on the background of low TSH in the blood in patients with skin melanoma, and by the type of hyperthyroxinemia in patients with lung cancer and breast cancer, consisting in increased concentrations of T4 and FT3, and with free and total T3 levels in patients uterine body cancer, as well as FT4, without changes in TSH in the blood serum of patients, may be associated with the features of malignant pathology, since it is known that THs are proliferation stimulants and can build up in tumors.Conclusion. The development of a malignant tumor even in the early stages of the disease is perceived by the body as a threat for homeostasis and the response to the occurrence of neoplasm is the reaction of the hypothalamicpituitary-thyroid regulatory axis. As an outcome, patients develop euthyroid disorder syndrome.