Higher FT4 Levels Research Articles

Relationship of thyroid parameters with chronic inflammation in patients with euthyroid type 2 diabetes

AimsWe evaluated the association of multiple thyroid parameters with the levels interleukin 6 (IL6) and interleukin 8 (IL8) in patients with euthyroid type 2 diabetes (T2D).MethodsA total of 166 adults with euthyroid T2D were examined. Serum IL6, IL8, triiodothyronine (FT3), free thyroxin (FT4), thyroid-stimulating hormone (TSH), five thyroid sensitivity indexes (FT3/FT4, TSH index [TSHI], thyrotroph T4 resistance index [TT4RI], thyroid feedback quantile-based index by FT3 [TFQIFT3], and TFQIFT4), and biochemical parameters were determined.ResultsThe median age was 64 years (IQR: 54.75,70) and the median duration of diabetes was 10 years (IQR: 3,18). Patients with high levels of IL6 (≥2.38 pg/mL) had lower levels of FT3 and TFQIFT3 (P<0.05). Patients with high levels of IL8 (≥18.1 pg/mL) had lower levels of TSH and higher levels of FT4 (P<0.05). IL6 was negatively correlated with FT3 (r=−0.359, P<0.001), TFQIFT3 (r=−0.273, P=0.009), and FT3/FT4 (r=−0.22, P=0.037). IL8 was negatively correlated with TSH (r=−0.256, P=0.01), TSHI (r=−0.226, P=0.033), and TT4RI (r=−0.244, P=0.021). Binary logistic regression analysis with multiple adjusted models showed that a high level of IL6 was negatively associated with FT3 (aOR: 0.529; 95%CI: 0.302, 0.926, P=0.026), and that a high level of IL8 was negatively associated with TSH (aOR: 0.343; 95%CI: 0.155, 0.759; P=0.008) and TT4RI (aOR: 0.398;95%CI: 0.191, 0.831; P=0.014).ConclusionPatients with euthyroid T2D who had lower levels of FT3 had significantly higher levels of IL6, and those with lower levels of TSH and TT4RI had significantly higher levels of IL8.

Understanding Hypothyroidism: Causes, Symptoms, Diagnosis, and Treatment Options for Optimal Thyroid Health

Hypothyroidism is a condition where your thyroid gland doesn’t produce enough thyroid hormone leading to symptoms like fatigue, weight gain, and feeling cold. Globally, the lack of iodine in the environment is the leading cause of hypothyroidism. However, in regions where there is enough iodine, Hashimoto’s thyroiditis, an autoimmune disorder is the most common cause. Risk factors include having a family history of thyroid disease, being over 6o years and being female. Diagnosis done with a simple blood test that measures the levels of serum free thyroxine (FT4) and thyroid-stimulating hormone (TSH). High TSH and FT4 levels usually indicate Hypothyroidism. Even daily medication with synthetic thyroid hormone (levothyroxine), regular follow up with your doctor is important to monitor your TSH level and adjust the dosage of medication as needed.

Increased cardiovascular morbidity and reduced life expectancy in a large Italian cohort of patients with resistance to thyroid hormone β (RTHβ).

Decreased survival and higher cardiovascular morbidity have been recently reported in a UK cohort of 61 RTHβ patients, but there is no evidence from other countries. Retrospective cohort study from an historical group of 284 Italian RTHβ patients, diagnosed between 1984 and 2023. We collected data on diagnosis of 284 cases and longitudinal data of 249 RTHβ who carried heterozygous pathogenic variants in the THRB gene. We studied how thyroid function and recognized risk factors for cardiovascular disease, such as hypertension and diabetes, affected overall mortality and major cardiovascular events. The cumulative prevalence of sinus/supraventricular tachycardia and atrial fibrillation was 40% and 18%, respectively. FT4 values 57% higher than the upper limit of normal were associated with premature cardiovascular manifestations. Major cardiovascular events (MACEs) occurred in RTHβ patients at a median age (IQR) of 59.4 years (50.4-66.4) and early mortality resulted in a mean of 11 years of life lost. While at univariable analysis hypertension, dyslipidemia, high fasting glucose/diabetes were also associated with MACEs, at multivariable analysis only age at diagnosis, increased fT4 levels, and male gender remained significantly associated with MACEs and age at diagnosis and higher fT4 levels with mortality. Previous thyroidectomy or radioiodine therapy had no statistically significant effect in the prevention of major cardiovascular events or all-cause mortality. These data should raise the general awareness on the cardiovascular risk and prompt a proactive cardiovascular monitoring in RTHβ, especially in men and those with fT4 levels above 30 pmol/L.

Thyroid dysfunction in the wake of Omicron: understanding its role in COVID-19 severity and mortality.

SARS-CoV-2 can invade the thyroid gland. This study was to delineate the risk of thyroid dysfunction amidst the prevalence of the Omicron variant, and to investigate the correlation between thyroid function and Coronavirus disease 2019 (COVID-19) outcomes. The study also aimed to ascertain whether thyroid dysfunction persisted during COVID-19 recovery phase. This was a retrospective cohort study. COVID-19 patients from the Renmin Hospital of Wuhan University, China during the epidemic of Omicron variants were included, and their thyroid function were analyzed in groups. A history of thyroid disease was not associated with COVID-19 outcomes. COVID-19 can lead to a bimodal distribution of thyroid dysfunction. The severity of COVID-19 was inversely proportional to the levels of thyroid- stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4), leading to a higher prevalence of thyroid dysfunction. Severe COVID-19 was a risk factor for euthyroid sick syndrome (ESS) (OR=22.5, 95% CI, 12.1 - 45.6). Neutrophil to lymphocyte ratio mediated the association between severe COVID-19 and ESS (mediation effect ratio = 41.3%, p < 0.001). ESS and decreased indicators of thyroid function were associated with COVID-19 mortality, while high levels of FT3 and FT4 exhibited a protective effect against death. This effect was more significant in women (p < 0.05). During the recovery period, hyperthyroidism was quite uncommon, while a small percentage of individuals (7.7%) continued to exhibit hypothyroidism. COVID-19 severity was linked to thyroid dysfunction. Severe COVID-19 increased the risk of ESS, which was associated with COVID-19 mortality. Post-recovery, hyperthyroidism was rare, but some individuals continued to have hypothyroidism.

Association of Serum Thyroxine and Atrial Fibrillation in Patients on Levothyroxine.

Excess thyroid hormone is a well-documented risk factor for the development of atrial fibrillation (AF). The purpose of the study is to assess incidence of AF in patients taking levothyroxine for hypothyroidism and correlate it with biochemical thyroid function. This was a retrospective cohort study of patients aged 18 years and older who were treated with levothyroxine. Exclusion criteria were pre-existing diagnosis of AF and use of amiodarone in the prior year. Patients were followed 2012 through 2019 and stratified into 4 groups based on mean thyroid-stimulating hormone (TSH) value or mean fT4 value in 2012. Primary outcome was incidence of AF. Rates of AF between groups were assessed via Poisson regression with control of underlying confounders. Of 21,035 patients, 1091 (5.2%) developed AF during follow-up. Thyroid-stimulating hormone at baseline was not significantly associated with incident AF. Higher fT4 levels at baseline were associated with increased AF risk in age- and sex-adjusted analyses (hazard ratio 1.22; 95% CI, 1.03-1.44) for the highest quartile versus the lowest quartile of fT4. In hypothyroid patients treated with levothyroxine, higher circulating fT4 levels are associated with increased risk of incident AF. There is no association of serum TSH with risk of AF. In patients at risk for AF, consideration should be given to avoiding fT4 levels in the highest quartile.

Selenium Status Associates with Thyroid Hormone and Thyroid Dysfunction in Older Chinese Adults.

Selenium (Se) is physiologically essential for thyroid function. However, epidemiological studies on the association between Se status and thyroid function are limited and the results are inconsistent. Therefore, we explored this association in an elderly Chinese population sample. Participants in the cross-sectional study were people aged 65 years or older who provided fingernail and whole blood samples. Hyperthyroidism and hypothyroidism were defined by serum thyroid hormones concentrations, including thyroid stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free thyroxine (FT3), and free thyrotropin (FT4). Significant positive association was observed between whole blood and fingernail Se concentrations (r = 0.672, P < 0.001). Compared with the lowest Se quartile (Q1), the other fingernail Se quartile groups had lower TSH, higher FT3 and FT4 levels, and Q2 had higher TT3 levels after adjusting for covariates; the other whole blood Se quartile groups had lower TSH levels, Q2 had higher FT3, FT4 and TT3 levels, Q3 had higher FT3 levels, and Q4 had higher FT4 levels after adjusting for covariates. Compared with Q1, the adjusted odds ratios (OR) and 95% confidence intervals (95%CIs) of hypothyroidism for Q4 of whole blood Se was 0.141 (0.029,0.675), and the adjusted OR (95%CIs) of hyperthyroidism for Q2 and Q3 of fingernail Se were 4.121 (1.233,13.733) and 3.614 (1.095,11.926). Higher Se levels were significantly associated with lower TSH levels and higher levels of TT3, FT3 and FT4. Meanwhile, higher Se levels were associated with lower risk of hypothyroidism and higher risk of hyperthyroidism.

#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.

Protective effect of higher free thyroxine levels within the reference range on biliary tract cancer risk: a multivariable mendelian randomization and mediation analysis.

Hepatobiliary cancer (HBC), including hepatocellular carcinoma (HCC) and biliary tract cancer (BTC), is currently one of the malignant tumors that mainly cause human death. Many HBCs are diagnosed in the late stage, which increases the disease burden, indicating that effective prevention strategies and identification of risk factors are urgent. Many studies have reported the role of thyroid hormones on HBC. Our research aims to assess the causal effects and investigate the mediation effects between thyroid function and HBC. Utilizing the Mendelian randomization (MR) approach, the study employs single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) to explore causal links between thyroid function [free thyroxine (FT4), thyroid stimulating hormone (TSH), hyperthyroidism and hypothyroidism] and HBC. Data were sourced from the ThyroidOmic consortium and FinnGen consortium. The analysis included univariable and multivariable MR analysis, followed by mediation analysis. The study found a significant causal association between high FT4 levels and the reduced risk of BTC, but not HCC. However, TSH, hyperthyroidism and hypothyroidism had no causal associations with the risk of HBC. Notably, we also demonstrated that only higher FT4 levels with the reference range (FT4-RR) could reduce the risk of BTC because this protective effect no longer existed under the conditions of hyperthyroidism or hypothyroidism. Finally, we found that the protective effect of FT4-RR on BTC was mediated partially by decreasing the risk of metabolic syndrome (MetS) and reducing the waist circumference (WC). The findings suggest that higher FT4-RR may have a protective effect against BTC, which is partially mediated by decreased risk of MetS and a reduction in WC. This study highlights the potential role of FT4 in the pathogenesis of BTC and underscores that MetS and WC may play mediation effects as two mediators in this process.

Gestational thyroid hormones and autism-related traits in the EARLI and HOME studies.

Thyroid hormones are essential for neurodevelopment. Few studies have considered associations with quantitatively measured autism spectrum disorder (ASD)-related traits, which may help elucidate associations for a broader population. Participants were drawn from two prospective pregnancy cohorts: the Early Autism Risk Longitudinal Investigation (EARLI), enrolling pregnant women who already had a child with ASD, and the Health Outcomes and Measures of the Environment (HOME) Study, following pregnant women from the greater Cincinnati, OH area. Gestational thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured in mid-pregnancy 16 (±3) weeks gestation serum samples. ASD-related traits were measured using the Social Responsiveness Scale (SRS) at ages 3-8 years. The association was examined using quantile regression, adjusting for maternal and sociodemographic factors. 278 participants (132 from EARLI, 146 from HOME) were included. TSH distributions were similar across cohorts, while FT4 levels were higher in EARLI compared to HOME. In pooled analyses, particularly for those in the highest SRS quantile (95th percentile), higher FT4 levels were associated with increasing SRS scores (β = 5.21, 95% CI = 0.93, 9.48), and higher TSH levels were associated with decreasing SRS scores (β = -6.94, 95% CI = -11.04, -2.83). The association between TSH and SRS remained significant in HOME for the 95% percentile of SRS scores (β = -6.48, 95% CI = -12.16, -0.80), but not EARLI. Results for FT4 were attenuated when examined in the individual cohorts. Our results add to evidence that gestational thyroid hormones may be associated with ASD-related outcomes by suggesting that relationships may differ across the distribution of ASD-related traits and by familial likelihood of ASD.

Correlation Between Thyroid-Related Hormones and Diabetic Retinopathy in Type 2 Diabetes Mellitus Patients with Normal Thyroid Function: A Retrospective Study.

To investigate the correlation between thyroid-related hormones and diabetic retinopathy (DR) in euthyroid patients with type 2 diabetes mellitus (T2DM). Patients with T2DM admitted to our hospital between January 2023 and June 2023 were retrospectively analyzed. The patients were divided into DR and non-diabetic retinopathy (NDR) groups according to whether DR occurred. Thyroid function-related hormones (TSH, FT3, and FT4), blood glucose indices (FBG and HbA1c), and blood lipid indices (HDL-C, LDL-C, TC, and TG) of the two groups were analyzed by univariate and multivariate logistic regression to explore the risk factors for DR. Pearson correlation analysis and multiple stepwise regression analysis were used to investigate the correlation of TSH or FT3 with FBG, HbA1c, and TG in DR patients. Of the 286 patients with T2DM included in this study, 101 (35.31%) developed DR and 185 (64.69%) did not. High TG, FBG, HbA1c, and TSH and low FT3 levels were independent risk factors for DR in T2DM patients. TSH positively correlated with TG, whereas FT3 negatively correlated with TG and HbA1c in T2DM patients with DR. Higher TSH and lower FT3 in T2DM patients with normal thyroid function may affect glucose and lipid metabolism, thereby increasing the risk of DR.

Predictive value of thyroid function in severe aplastic anemia patients treated with immunosuppressive therapy.

To explore the predictive value of thyroid function in severe aplastic anemia (SAA) patients treated with immunosuppressive therapy (IST), 149 SAA patients in our center were enrolled between February 2015 and June 2020 in this study. We assessed the thyroid function of 134 patients without primary thyroid diseases, and discovered that 89 patients were accompanied by abnormal thyroid hormone, especially low triiodothyronine (T3). Patients with higher pretreatment-free T3 (FT3) levels (>5 pmol/L) demonstrated superior response rates at 3 and 6 months after IST compared to those with lower FT3 levels (54.5% vs 35.4%, P = .020; 67.3% vs 46.9%, P = .020). Multivariate analysis indicated that shorter disease duration (≤56 days) and response at 6 months were independent favorable factors of overall survival (relative risk [RR] = 2.66, 95% confidence interval [CI] = 1.03-6.90, P = .040; RR = 30.10, 95% CI = 4.02-225.66, P = .001). The 6-year failure-free survival (FFS) was 53.8% (95% CI = 40.9%-65.1%). Multivariate analysis revealed that patients with a response at 6 months, shorter duration (≤56 days) and receiving rabbit antithymocyte globulin (ATG) had better FFS outcomes than those without a response at 6 months, with a longer duration and receiving porcine ATG (RR = 22.6, 95% CI = 7.9-64.9, P < .001; RR = 2.4, 95% CI = 1.3-4.5, P = .006; RR = 2.5, 95% CI = 1.1-5.8, P = .030). In conclusion, FT3 levels reflect the severity of SAA, and patients with higher FT3 levels (>5 pmol/L) had superior response rates than those with lower ones.

Associations between peripheral thyroid sensitivity and all-cause and cardiovascular mortality in the US adults with metabolic syndrome.

The relationship between peripheral sensitivity to thyroid hormones, as indicated by the ratio of free triiodothyronine (fT3) to free thyroxine (fT4) (fT3/fT4), and the prognosis of metabolic syndrome (MetS) remains unclear. This study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2012. MetS was defined based on the criteria established by the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III). Kaplan-Meier survival curves, restricted cubic spline (RCS) analysis, and Cox proportional hazards models were employed to investigate the association between peripheral thyroid sensitivity and mortality outcomes among adults with MetS. A total of 3,101 adult participants (1,594 males and 1,507 females; median age: 52.00 years) with MetS were included in the analysis. Multivariate Cox regression analysis revealed that elevated levels of fT4 were positively associated with increased risks of both all-cause and cardiovascular mortality in the MetS population [adjustedhazard ratio (aHR): 2.74, 95% confidence interval (CI): 1.94-3.87, p < 0.001 for all-cause mortality; aHR: 3.93, 95% CI: 2.07-7.45, p < 0.001 for cardiovascular mortality]. Conversely, higher levels of fT3 and the fT3/fT4 ratio were found to be protective factors, reducing the mortality risk in the MetS population (fT3: aHR: 0.76, 95% CI: 0.57-0.99, p = 0.046 for all-cause mortality; fT3/fT4 ratio: aHR: 0.75, 95% CI: 0.67-0.85, p < 0.001 for all-cause mortality; aHR: 0.66, 95% CI: 0.52-0.83, p < 0.001 for cardiovascular mortality). The fT3/fT4 ratio exhibited a nonlinear association with all-cause mortality, but a linear and inverse association with cardiovascular mortality. The findings of this study suggest that higher peripheral thyroid sensitivity, as indicated by the fT3/fT4 ratio, may be associated with reduced mortality risks among adults with MetS. Further research is warranted to validate these associations.

Measurement of salivary thyroid hormones using the LC-MS/MS technique in a clinical setting.

Saliva could be an attractive alternative to blood for assessing thyroid hormonal function. Our goal was to determine if the levels of thyroid hormones in saliva can accurately reflect a person's thyroid status and if they consistently correlate with the levels of the same hormones in the blood. We conducted a cross-sectional study. We enrolled a total of 109 participants with different thyroid conditions. We measured TSH (Thyroid-Stimulating Hormone), free T3 (fT3), and free T4 (fT4) in the blood using two different immunoassay methods: electrochemiluminescence immunoassay (ECLIA) and chemiluminescence immunoassay (CLIA). Saliva samples were collected using Salivette® tubes, and then we analyzed the levels of thyroid hormones in the saliva using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Comparing salivary and serum levels of thyroid hormones, we observed significantly lower fT4 and higher fT3 levels in saliva (p < 0.001), regardless of the measurement method. We also found that salivary fT3 and fT4 levels were positively correlated in the entire group of participants (p < 0.001, R 0.575), as well as in those with TSH values within the normal reference range (p < 0.001, R 0.570). We further divided participants based on their TSH reference intervals and assessed the correlations between serum and salivary thyroid hormones within these groups. We also discovered that taking exogenous levothyroxine influenced the correlations between serum and salivary thyroid hormones. Thyroid antibodies did not have a significant impact on the levels of thyroid hormones in both serum and saliva. This study demonstrates that salivary thyroid hormones can partially reflect the levels of these hormones in the blood. Saliva may be a useful tool in a clinical setting for patients with thyroid antibodies, but it may not be as effective for those who are taking levothyroxine as a treatment.

Atrial Fibrillation and Associated Factors Among Hyperthyroidism Patients Attending at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia.

The most prevalent heart symptom of hyperthyroidism is atrial fibrillation. Other than sinus tachycardia, which occurs with hyperthyroidism, atrial fibrillation is the most prevalent cardiac arrhythmia. Hyperthyroidism results in excess mortality from increased incidence of circulatory diseases and dysrhythmias. The aims of the study was prevalence and associated factors of atrial fibrillation among hyperthyroidism adult patients attending the University of Gondar Referral Hospital, Northwest Ethiopia. This study aimed to determine the prevalence and associated factors of atrial fibrillation among adult hyperthyroid patients attending the University Of Gondar Referral Hospital, Ethiopia. Using a consecutive sampling technique, 228 patients with hyperthyroidism participated in an institution-based cross-sectional study. A standardized questionnaire that had been pretested was used to gather the data that was designed to include socio-demographic data, clinical presentation, biochemical profile, and electrocardiography findings through chart review and interviews. The data were manually curated. Atrial fibrillation was present in 32 (14%) patients, with a 95% CI of 9.6 to 19.2. The identified predictor variables were age >61 years (Adjusted Odd Ratio = 4.2, 95% CI = 1.5-11.7), female sex (Adjusted Odd Ratio = 4.0, 95% CI = 1.4-12.0), and high serum FT4 >23.9 pmol/l (Adjusted Odd Ratio = 8.0, 95% CI = 2.1-30.0). The prevalence of atrial fibrillation among hyperthyroidism patients was 14%. Being female, being older, and having high serum FT4 levels were significantly associated with AF in hyperthyroid patients.

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

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

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

An association of thyroid function with mood disorders has been widely suggested, but very few studies have examined this association longitudinally. We assessed the cross-sectional and longitudinal association between thyroid function and depression in a population-based cohort. 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. 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. 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.

Association of exposure to perfluoroalkyl substances (PFAS) and phthalates with thyroid hormones in adolescents from HBM4EU aligned studies

BackgroundPerfluoroalkyl substances (PFAS) and phthalates are synthetic chemicals widely used in various types of consumer products. There is epidemiological and experimental evidence that PFAS and phthalates may alter thyroid hormone levels; however, studies in children and adolescents are limited. AimTo investigate the association of exposure to PFAS and phthalate with serum levels of thyroid hormones in European adolescents. MethodsA cross-sectional study was conducted in 406 female and 327 male adolescents (14–17 years) from Belgium, Slovakia, and Spain participating in the Aligned Studies of the HBM4EU Project (FLEHS IV, PCB cohort, and BEA, respectively). Concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), free thyroxine (FT4), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) were measured in sera from study participants, and urinary metabolites of six phthalates (DEP, DiBP, DnBP, BBzP, DEHP, and DiNP) and the non-phthalate plasticizer DINCH® were quantified in spot urine samples. Associations were assessed with linear regression and g-computational models for mixtures. Effect modification by sex was examined. ResultsIn females, serum PFOA and the PFAS mixture concentrations were associated with lower FT4 and higher FT3 levels; MEP and the sums of DEHP, DiNP, and DINCH® metabolites (∑DEHP, ∑DiNP, and ∑DINCH) were associated with higher FT4; ∑DEHP with lower FT3; and the phthalate/DINCH® metabolite mixture with higher FT4 and lower FT3. In males, PFOA was associated with lower FT4 and the PFAS mixture with higher TSH levels and lower FT4/TSH ratio; MEP and ∑DiNP were associated with higher FT4; and MBzP, ∑DEHP, and the phthalate/DINCH® metabolite mixture with lower TSH and higher FT4/TSH. PFOA, mono-(2-ethyl-5-hydroxyhexyl) phthalate (OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (oxo-MEHP), and monocarboxyoctyl phthalate (MCOP) made the greatest contribution to the mixture effect. ConclusionsResults suggest that exposure to PFAS and phthalates is associated with sex-specific differences in thyroid hormone levels in adolescents.

Lower free triiodothyronine levels are associated with higher all-cause and cardiovascular mortality in people with diabetes-NHANES 2007–2012

ObjectiveThyroid hormone plays a key role in maintaining cardiovascular system homeostasis. However, there is limited evidence regarding the correlation between normal range thyroid hormone levels and all-cause mortality or cardiovascular mortality among individuals with diabetes. MethodThis retrospective study analyzed data from 1,208 individuals with diabetes who participated in the National Health and Nutrition Survey (NHANES) conducted in the United States between 2007 and 2012. Weighted Kaplan-Meier (KM) analysis and Cox proportional hazards models were used to explore the association between thyroid hormone indices and mortality. ResultsThe Weighted Kaplan-Meier (KM) analysis revealed statistically significant differences in survival probabilities across free triiodothyronine (FT3), free thyroxine (FT4), FT3/FT4 ratio and thyroid-stimulating hormone (TSH) groups (p < 0.05 or < 0.001). In the multivariate adjusted Cox proportional hazards models, higher levels of FT3 were founded to be associated with decreased all-cause mortality (HR (95% CI), 0.715 (0.567, 0.900)), cardio-cerebrovascular mortality (0.576 (0.408, 0.814)) and cardiovascular mortality (0.629 (0.438, 0.904)). Notably, this correlation was more significant among individuals over the age of 60, as indicated by the results of the nonlinear regression analysis. ConclusionFT3 is an independent predictor of all-cause death, cardio-cerebrovascular and cardiovascular death in euthyroid subjects with diabetes.

ACE Question

Article| June 2023 ACE Question ASA Monitor June 2023, Vol. 87, 12. https://doi.org/10.1097/01.ASM.0000938796.60441.09 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Search Site Citation ACE Question. ASA Monitor 2023; 87:12 doi: https://doi.org/10.1097/01.ASM.0000938796.60441.09 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll PublicationsASA Monitor Search Advanced Search Topics: anesthesiology continuing education (ace) Which of the following combinations of free thyroxine (FT4) level and thyroid-stimulating hormone (TSH) level is MOST likely in a patient with subclinical hypothyroidism? About 5% of patients older than 65 years have hypothyroidism. Primary hypothyroidism is due to thyroid gland dysfunction, while secondary hypothyroidism is due to pituitary dysfunction. In primary hypothyroidism, thyroid-stimulating hormone (TSH) is increased due to a negative feedback loop that stimulates the failing gland, while free thyroxine (FT4) is low or low-normal. Low levels of both FT4 and TSH suggest secondary hypothyroidism, often associated with pituitary dysfunction. High FT4 levels with low TSH levels suggest primary hyperthyroidism (Figure). Subclinical hypothyroidism is characterized by normal FT4 and high TSH. High TSH ranges from 5 to 15 mU/L, while normal TSH ranges from 0.3 to 4.5 mU/L. Generally, subclinical hypothyroidism is thought to have little or no perioperative significance. An increasing TSH level is the... You do not currently have access to this content.

Association between thyroid function and obesity phenotypes in healthy euthyroid individuals: an investigation based on Tehran Thyroid Study

AimsWe investigated whether thyroid function could be associated with obesity phenotypes amongst euthyroid individuals.Materials and methodsA cross-sectional analysis was conducted among healthy, euthyroid subjects. The study participants were chosen from the Tehran Thyroid Study (TTS). We analyzed 2988 euthyroid adults and classified them into four obesity phenotype groups: metabolically healthy normal weight (MHNW), metabolically healthy obese (MHO), metabolically unhealthy normal weight (MUNW), and metabolically unhealthy obese (MUO). The statistical differences between thyroid hormones between various obesity phenotypes according to age and sex was compared using analysis of covariance (ANCOVA).ResultsIt was found that MHNW participants had higher levels of FT4 when compared with metabolically healthy or unhealthy obese subjects (P < 0.001), even after adjustment for the confounding variables. No difference was observed in the levels of TSH (P = 0.260) among obesity phenotypes. In the subgroup analysis according to the age, a significant difference was observed in the level of FT4 only in subjects with age < 55 years (P = 0.001). However, analyzing men and women separately did not show a significant difference in the FT4 level among obesity phenotypes (P > 0.05).Conclusion“Metabolically abnormality” was independently related to low normal FT4 levels in overweight/obese euthyroid individuals. There is a need for further research to understand how low FT4 levels are linked to metabolically unhealthy states in euthyroid individuals.