Association Of Thyroid-stimulating Hormone Research Articles

Association between subclinical thyroid dysfunction and cognitive decline: findings from the ELSA-Brasil study.

Thyroid dysfunction has been associated with cognitive decline and dementia. However, the role of subtle thyroid hormone alterations in cognitive function is still debatable. Participants without overt thyroid dysfunction aged 35-74 years at baseline were evaluated in three study waves (2008-10, 2012-14, and 2017-19). We assessed baseline thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3). Cognitive performance was evaluated every four years in each wave using 10-word immediate and late recall, word recognition, semantic (animals category) and phonemic (letter f) verbal fluency, and the trail-making B-version tests. A global composite z-score was derived from these tests. The associations of TSH, FT4, and FT3 levels with cognitive decline over time were evaluated using linear mixed-effect models adjusted for sociodemographic, clinical, and lifestyle variables. In 9,524 participants (mean age 51.2±8.9 years old, 51% women, 52% White), there was no association between baseline TSH, FT4, and FT3 levels and cognitive decline during the follow-up. However, increase in FT4 levels over time was associated with faster memory (β=-0.004, 95%CI=-0.007; -0.001, p=0.014), verbal fluency (β=-0.003, 95%CI=-0.007; -0.0005, p=0.021), executive function (β=-0.004, 95%CI=-0.011; -0.003, p<0.001), and global cognition decline (β=-0.003, 95%CI=-0.006; -0.001, p=0.001). Decrease in FT4 levels over time was associated with faster verbal fluency (β=-0.003, 95%CI=-0.007; -0.0004, p=0.025) and executive function (β=-0.004, 95%CI=-0.007; -0.0003, p=0.031) decline. An increase or decrease in FT4 levels over time was associated with faster cognitive decline in middle-aged and older adults without overt thyroid dysfunction during 8 years of follow-up.

The Association of Thyroid-Stimulating Hormone (TSH) Levels and Lipid Profile in Euthyroid Patients with Familial Hypercholesterolemia.

Previous studies reported a relationship between thyroid-stimulating hormone (TSH) and low-density lipoprotein cholesterol (LDL-C) levels. In this study, we aim to evaluate the impact of TSH levels on lipid profile in patients with familial hypercholesterolemia (FH) and euthyroid state. Patients were selected from the Isfahan FH registry. The Dutch Lipid Clinic Network (DLCN) criteria are used to detect FH. Patients were classified into no FH, possible FH, probable FH, and definite FH groups based on the DLCN scores. Patients with any cause of secondary hyperlipidemia, including hypothyroidism, were excluded from this study. The study group consisted of 103 patients with possible FH, 25 patients with definite FH, and 63 individuals with no FH. The mean TSH and LDL-C levels among participants were 2.10 ± 1.22 mU/l and 142.17 ± 62.56 mg/dl, respectively. No positive or negative correlation was found between serum TSH and total cholesterol (P value = 0.438), high-density lipoprotein cholesterol (P = 0.225), triglycerides (P value = 0.863), and LDL-C (P value = 0.203). We found no correlation between serum TSH levels and lipid profiles in euthyroid patients with FH.

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

Diabetic retinopathy (DR) can occur even in well-controlled type 2 diabetes, suggesting residual risks of DR in this population. In particular, we investigated the combined effect of thyroid function and glycaemic control assessed by an emerging metric, time in range (TIR) with DR. In this cross-sectional study, a total of 2740 euthyroid patients with type 2 diabetes were included. Thyroid indicators, including thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, thyroid peroxidase antibody and thyroglobulin antibody, were measured. TIR was measured using continuous glucose monitoring data. Overall, the multivariable-adjusted odds ratios (ORs) for DR across ascending tertiles of TSH were 1.00 (reference), 1.06 (95% confidence interval [CI] 0.85-1.32), and 1.48 (95% CI 1.19-1.85). Even in well-controlled participants who achieved a TIR target of >70% (n=1449), the prevalence of DR was 23.8%, which was significantly related to TSH (OR=1.54, 95% CI 1.12-2.12, highest vs. lowest TSH tertile). Participants were then classified into 6 groups by the joint categories of TIR (>70%, ≤70%) and TSH (tertiles), and the multivariable-adjusted ORs for DR were highest in TIR ≤70% and the highest TSH tertile group (OR=1.96, 95% CI 1.41-2.71) when compared with the TIR >70% and the lowest TSH tertile group. In type 2 diabetic patients with well-controlled glycaemic status, higher TSH within the normal range was associated with an increased risk of DR. The combination of suboptimal TSH and TIR further increased the risk of DR.

Association of Thyroid-Stimulating Hormone With All-Cause Mortality: A 2-Sample Mendelian Randomization Study.

Thyroid-stimulating hormone (TSH), as the most sensitive and specific marker of thyroid status, is associated with multiple health outcomes, including mortality. However, whether TSH levels are causally associated with the risk of mortality remains unclear. This study aims to investigate the causal association between TSH levels and all-cause mortality using Mendelian randomization (MR) analyses. MR analyses using single-nucleotide polymorphisms (SNPs) associated with TSH levels (P < 5 × 10-8) as instruments. Mortality data were obtained from the UK Biobank, including 384 344 participants who were recruited from 22 assessment centers across the UK taken between 2006 and 2010. Cox proportional hazards regression was used to estimate the association of the TSH genetic risk score (GRS) with all-cause and cause-specific mortality. 15 557 individuals died during a median of 9.00 years of follow-up in the UK Biobank. A total of 70 SNPs were included in the MR analysis. The main MR analyses showed that 1 SD increase in TSH was associated with a decreased risk of all-cause mortality (OR 0.972, 95% CI 0.948-0.996), which may be largely attributed to respiratory disease mortality (OR 0.881, 95% CI 0.805-0.963). The multivariable hazard ratios (HRs) (95% CI) of all-cause mortality across 3 TSH GRS categories were 1.00 (reference), 0.976 (0.940-1.014), and 0.947 (0.911-0.985), respectively (P for trend < .01). Moreover, except digestive diseases mortality, genetically predicted TSH levels were negatively associated with mortality from CVD, cancer, noncancer diseases causes, and dementia, although not statistically significant. Higher TSH levels were causally associated with lower risk of all-cause mortality, which may be largely attributed to respiratory disease mortality.

Association of thyroid-stimulating hormone and lipid levels with suicide attempts among adolescents with major depressive disorder in China.

Evidence suggested that thyroid-stimulating hormone (TSH) and lipid levels were associated with major depressive disorder (MDD). However, its role in suicide attempts in adolescents with MDD was unclear. This investigation was to probe into the relationship between TSH, lipid levels, and attempted suicide in adolescents with MDD. A total of 179 adolescents with MDD were included from January 2021 to January 2022. Socio-demographic data and clinical data were obtained through self-made questionnaires. TSH and lipid levels were analyzed by a recognized laboratory. The Epidemiological Studies Depression Scale (CES-D) was used to assess the severity of depression. Questions about whether there was a behavior of suicide attempts were completed through conversation interviews. Results showed that the CES-D total score, TSH, and low-density lipoprotein cholesterol (LDL-C) of suicide attempters were significantly higher than those of non-suicide attempters. Ordinary family relationships were more likely to attempt suicide than good family relationships. The CES-D total score, ordinary family relationships, TSH and LDL-C were still significant in binary logistic regression, with an adjusted odds ratio (OR) of 1.04, 3.42, 5.14, and 1.76, respectively. The area under the receiver operating characteristic (ROC) curve showed that the area under the ROC curve (AUC) ranged from 0.60 to 0.74. Suicide attempts are common among adolescents with MDD and were associated with CES-D total score, ordinary family relationships, TSH, and LDL-C. Given the association between suicide attempts and TSH and LDL-C, the dynamic changes in TSH and LDL-C levels should be detected regularly.

Association of thyroid stimulating hormone and iron profile among patients with subclinical primary hypothyroidism

Introduction: Physiologically, thyroid hormones have a vital role in maintaining metabolic balance of the human body. Subclinical hypothyroidism is often associated with hematological disorders including iron-deficiency anemia. This study aims to correlate thyroid stimulating hormone and iron profile in patients with subclinical primary hypothyroidism. Materials and methods: This is a cross-sectional study conducted in Nepal Medical College and Teaching Hospital, Kathmandu, Nepal among patients with subclinical primary hypothyroidism. The study was conducted from October 2018 to December 2019. Total of 60 patients above the age of 18 years were enrolled for the study. Thyroid function test was done by automated machine using electro chemiluminescent immunoassay technique and iron profile test was done by Immunoassay method using Vitros Analyzer. Pearson’s correlation test was applied to find the correlation between thyroid stimulating hormone and iron profile. Results: Among the 60 participants with subclinical hypothyroidism 23% were males and 77% were females with a mean age of 43 years. The mean serum iron (male =81.14 μg/dl female = 69.5 μg/dl), mean total iron binding capacity (male =470.35 μg/dl, female = 477.94 μg/ dl) and mean ferritin level (male=91.15 μg/dl, female=95.51 μg/dl) were within reference value of our laboratory. A negative correlation was observed between thyroid stimulating hormone levels and serum iron (r=0.376, P=0.003), thyroid stimulating hormone and total iron binding capacity also showed a negative correlation (r=-0.083, P=0.27). Similarly thyroid stimulating hormone and transferrin saturation also showed a negative correlation (r=-0.098, P=0.455) whereas, a positive correlation was observed between thyroid stimulating hormone and ferritin (r=0.037, P=0.779). Conclusions: This study concludes that thyroid stimulating hormone is negatively associated to serum iron, total iron binding capacity and transferrin saturation whereas, positively associated with ferritin among patients with subclinical hypothyroidism.

Association of Thyroid-Stimulating Hormone (TSH) Levels With the Prognosis of Patients Undergoing Heart Transplantation: A Retrospective Study.

Purpose: To investigate the impact of TSH levels using a more stringent cutoff of subclinical hypothyroidism (i.e., TSH > 2.5 mIU/L) on the short-term complications and long-term prognosis in patients who underwent heart transplantation (HTx).Methods: This is a retrospective study of consecutive patients with end-stage heart failure (HF) who underwent HTx. They were divided into three groups: thyroid-stimulating hormone (TSH) ≤ 2.50 mIU/L (L-TSH), 2.50 < TSH ≤ 4.91 mIU/L (M-TSH), and TSH > 4.91 mIU/L (H-TSH). The outcomes are all-cause death and cardiogenic death.Results: There are 63 (70%) males and 27 (30%) females. Nine (10%) patients died within 1 month after surgery, including five cardiogenic deaths. By 1 year, a total of 19 patients total were dead. The survival rate in the M-TSH group was significantly higher than that of the L-TSH group (P = 0.017). After adjusted by variables of sex, age, BMI, diabetes history, hypertension history, the multivariable Cox analysis showed that body mass index (HR = 0.804, 95%CI: 0.680–0.951, P = 0.011), and L-TSH (HR = 8.757, 95%CI: 1.786–42.948, P = 0.007 vs. M-TSH), and H-TSH (HR = 6.427, 95%CI: 1.137–36.327, P = 0.035 vs. M-TSH) were independently associated with all-cause death. The multivariable Cox analysis showed that body mass index (HR = 0.703, 95%CI: 0.564–0.878, P = 0.002), and L-TSH (HR = 17.717, 95%CI: 1.907–164.607, P = 0.011 vs. M-TSH) were independently associated with cardiogenic death.Conclusion: For patients with end-stage HF undergoing HTx, low and high baseline TSH levels are independently associated with 1-year all-cause death and low baseline TSH levels with cardiogenic death.

Association of thyroid-stimulating hormone with corrected QT interval variation: A prospective cohort study among patients with type 2 diabetes

Patients with type 2 diabetes mellitus (T2DM) have a prolonged QT interval and are at high risk of sudden cardiac death. A prolonged QT interval, indicative of impaired ventricular repolarization, is a risk factor for lethal ventricular arrhythmias, such as torsades-de-pointes (TdP). To identify key clinical and biochemical covariates associated with Fridericia's corrected QT interval (QTcF) among euthyroid patients with T2DM, and to describe the temporal relationship between these factors and QTcF. We performed prospective, clinical, biochemical and electrocardiographic measurements among patients with T2DM enrolled in the DIACART study at Pitié-Salpêtrière Hospital, at T1 (baseline) and T2 (follow-up), with a median interval of 2.55 years. Mean age (63.9±8.5 years), sex (22.35% women), drugs with known risk of TdP according to the CredibleMeds website (Cred-drugsTdP) and serum thyroid-stimulating hormone (TSH) concentrations correlated with QTcF in univariate analysis at both T1 and T2. In multivariable analysis, all these covariates except age were significantly associated with QTcF at both T1 (women: standardized β=0.24±0.07, P=0.001; Cred-drugsTdP: β=0.19±0.07, P=0.007; TSH concentration: β=0.18±0.07, P=0.01) and T2 (women: β=0.25±0.08, P=0.002; Cred-drugsTdP: β=0.25±0.08, P=0.001; TSH concentration: β=0.19±0.08, P=0.01). Furthermore, variation in QTcF over the years was associated with variation in TSH concentration (r=0.24, P=0.007) and changes in use of Cred-drugsTdP (r=0.2, P=0.02). Serum TSH concentration and its variation were associated with QTcF and its variation, even after correcting for the main determinants of QTcF. Interventional optimization of TSH concentration in T2DM warrants further investigation to establish its impact on the risk of TdP and sudden cardiac death.

1402Thyroid stimulating hormone (TSH) is associated with general and abdominal obesity in girls during puberty

Abstract Background Childhood is an important public health issue. Although both thyroid hormone and menarche are known to play a role in body metabolism and energy expenditure, no population-based study has been conducted to investigate the impact of TSH on adipogenesis among population-based girls around puberty. Methods A multi-stage cluster sampling method was used to select one junior middle school from each of 4 study areas: Minhang District in Shanghai, Haimen City in Jiangsu Province, Yuhuan City and Deqing County in Zhejiang Province. A total of 474 girls aged 11 to 14 years from 4 schools were enrolled. Information on demographic factors and puberty stage were collected, and anthropometric measurements and thyroid hormones were determined. Multivariate logistic regression models were used to assess the associations of Thyroid stimulating hormone (TSH) with the risk of obesity measured by body mess index (BMI) and waist circumference (WC). Results Of the 474 girls, the prevalences of BMI-based general obesity and WC-based abdominal obesity were 19.8% (94/474) and 21.7% (103/474), respectively. Compared with normal weight girls, the mean serum TSH concentration was significantly higher in BMI-based general overweight or obese girls (P = 0.037), but not in WC-based central overweight or obese girls (P = 0.173). In the multiple logistic regression models, for girls with highest tertile of serum TSH concentration relative to those in the lowest tertile, the odds ratios were 2.58 (95% CI 1.32 to 5.04) and 2.50 (95% CI 1.30 to 4.81) for overweight or obesity based on BMI and WC after adjustment for puberty stage and other covariates. Conclusions Serum TSH concentration was positively associated with both general and abdominal obesity in school-age girls and the association was independent of puberty. Key messages thyroid stimulating hormone; general obesity; central obesity; school-aged girls; puberty

Prognostic significance of low TSH concentration in patients with COVID-19 presenting with non-thyroidal illness syndrome

BackgroundLow free triiodothyronine (FT3) levels are related to a poor prognosis deterioration in patients with COVID-19 presenting with non-thyroidal illness syndrome (NTI). This study was designed to explore whether free thyroxin (FT4) or thyroid stimulating hormone (TSH) levels affected the mortality of patients with COVID-19 presenting with NTI.MethodsPatients with COVID-19 complicated with NTI who were treated at our hospital were included in this retrospective study. Patients were divided into low TSH and normal TSH groups, as well as low and normal-high FT4 group, according to the reference range of TSH or FT4 levels. The 90-day mortality and critical illness rates were compared among patients with low and normal TSH levels, as well as among patients with low FT4 levels and normal-high FT4 levels; in addition, differences in demographic and laboratory data were compared. A Kaplan-Meier analysis and Cox proportional hazards models were used to assess the associations of TSH and FT4 levels with mortality.ResultsOne hundred fifty patients with low FT3 levels and without a history of thyroid disease were included, 68% of whom had normal FT4 and TSH levels. Critical illness rates (74.07% VS 37.40%, P = 0.001) and mortality rates (51.85% VS 22.76%, P = 0.002) were significantly higher in the low TSH group than in the normal TSH group. Although no significant difference in the critical illness rate was found (P = 0.296), the mortality rate was significantly higher in the low FT4 group (P = 0.038). Low TSH levels were independently related to 90-day mortality (hazard ratio = 2.78, 95% CI:1.42–5.552, P = 0.003).ConclusionsLow FT4 and TSH concentrations were associated with mortality in patients with COVID-19 presenting with NTI; moreover, low TSH levels were an independent risk factor for mortality in these patients.

Association between TSH status and prevalence of miscarriages and stillbirth

Thyroid hormones play a significant role in normal human body growth. Abnormalities in thyroid stimulating hormone (TSH) levels can result in pregnancy loss due to miscarriages and intrauterine death (IUD). The objective of the study was to assess the levels of association of thyroid stimulating hormone with miscarriages and IUD. The descriptive study involving 110 samples between 18-40 years of age fulfilling inclusion criteria were sampled for TSH testing (2ml blood) after attaining their written informed consent. The mean age of participants was 29.49±4.26 year. The prevalence of hypothyroidism and hyperthyroidism was 3.64% and 2.73%, respectively. Complications like gestational hypertension, depression and oligomenorrhea were found prevalent in these females. Majority of females were taking high/low iodine than recommended iodine level (150mcg). This work shows that there is a significant association between pregnancy loss and disturbed TSH levels among pregnant females.

Spectrum of thyroid dysfunction and dementia: a dose-response meta-analysis of 344,248 individuals from cohort studies.

Thyroid hormone, as a modifiable risk factor for dementia, promotes neurocognitive function and regulates metabolic processes. Various studies have defined different thyroid-stimulating hormone cutoffs, but the safest thyroid-stimulating hormone concentration was absent. A dose–response meta-analysis describing the overall functional relation and identifying exposure intervals associated with a higher or lower disease risk is thus desirable. Therefore, our current analysis was conducted to understand the influence of thyroid dysfunction on dementia risk. We searched PubMed, Embase, and Web of Science before May 1, 2020 for human studies published in English. Studies were considered for inclusion if they used a cohort study design to measure the risk of dementia in different thyroid function status groups, diagnosed thyroid functional status and all-cause dementia, included participants aged >18 years, and provided quantitative measures of data. The analysis contained 17 articles with 344,248 individuals with a 7.8-year mean follow-up. Ten studies with 329,287 participants indicated that only subclinical hyperthyroidism was associated with an increased risk of dementia. In contrast, subclinical hypothyroidism, clinical hyperthyroidism, and clinical hypothyroidism did not affect dementia. In the dose–response meta-analysis with 46,417 samples from 11 studies, the association of thyroid-stimulating hormone with the risk of dementia exhibited a U-shaped curve. Our study indicated that subclinical hyperthyroidism was associated with the risk of dementia and the thyroid-stimulating hormone concentration at around 1.55–1.60 mU/L as the optimum range for the risk of dementia.

Evaluation of Thyroid Swellings for Incidence of Thyroid Cancer and their Association with Serum Thyroid Stimulating Hormone and Triglyceride Levels: A Cross-sectional Study

Introduction: Earlier, several studies have been evaluated the role of Thyroid Stimulating Hormone (TSH) as a predictor of thyroid cancer in patients presenting with thyroid swelling but it remains unclear. Aim: To evaluate the role of TSH in non neoplastic tumours and neoplastic tumours and its association with various types of thyroid neoplastic tumours. Materials and Methods: In this retrospective cross-sectional study, the records of 138 patients from March 2017 to February 2019 with thyroid swelling were evaluated and analysis was done in October 2020. Examination of following parameters like age, sex, Free Triiodothyronine (FT3), Free Tetraiodothyronine (FT4), Thyroid Stimulating Hormone (TSH), Total Cholesterol (TC), Triglycerides (TGL), Low Density Lipoprotein (LDL) and High Density Lipoprotein (HDL) cholesterol were done. All the patients were divided into two groups viz., neoplastic and non neoplastic on the basis of Fine Needle Aspiration Cytology (FNAC) diagnosis. One-way ANOVA and Student's t-test were used for the analysis of thyroid tumour patients. The p-value of &lt;0.05 was considered to be significant. Results: Out of 138 cases identified, 38 cases (27.5%) were between 10-30 years of age, 90 cases (65.2%) between 31- 50 years and 10 cases (7.3%) between 51-70 years of age. The incidence of thyroid pathology was significantly high in patients with age &gt;30 years of age as compared to ≤30 years of age patients (27.5% vs 72.5%, Υ2=55.7, p-value &lt;0.05). The incidence of thyroid tumours was high in females than in males and is statistically significant (20.3% vs 79.7%, Υ2=97.44, p-value &lt;0.05). Out of 138 patients, euthyroid was observed in 71 patients, overt hypothyroidism in 37, Subclinical Hypothyroidism (SCH) in 14, overt hyperthyroidism in 11 and subclinical hyperthyroidism in four patients. Hypothyroidism was found in 50% of neoplastic tumour patients which is significantly high as compared to non neoplastic tumour patients. Significantly higher levels of TSH were noted in neoplastic group as compared to non neoplastic group (p-value &lt;0.05). Conclusion: The high serum concentrations of TSH in patients with thyroid swellings should be evaluated properly for the early diagnosis of thyroid cancers. The data from our study provided the evidence for a possible association of TSH, TGL with thyroid cancer.

Platelet levels and neutrophil to lymphocyte ratio in thyroid nodules with and without cancer diagnosis

Nodular formation of thyroid tissue is a very common endocrinologic pathology. Approximately 5% of thyroid nodules can prove to be cancerous. The usefulness of mean platelet volume(MPV) and neutrophil to lymphocyte ratio (NLR) is determined as an indicator of immunological response and subclinical inflammation in recent years. In this study we evaluate the association of thyroid stimulating hormone (TSH), platelet, mean platelet volume(MPV) and NLR levels between the thyroid nodules that turn into cancer and do not convert. Our study consisted of patients with thyroid nodules that converted to thyroid cancer (n = 100) and didn’t convert to thyroid cancer (n = 100). These patients were selected retrospectively using the Hospital Information System. The TSH, NLR, platelet and MPV levels were recorded preoperatively and the difference between them was evaluated statistically with SPSS 21. Differences between groups were examined with using Mann Whitney U Test. P

Association of Thyroid-Stimulating Hormone and Thyroid Hormones with Cardiometabolic Risk Factors in Euthyroid Children and Adolescents Aged 10\u201318 Years: A Population-Based Study

Recent evidence indicates that low-normal thyroid function test results within the reference ranges may be related to increased cardiometabolic risk factors. The current study aimed to evaluate the relationship between thyroid function using thyroid-stimulating hormone (TSH) and free thyroxine (FT4) and cardiometabolic risk factors and the clustering of these risk factors (metabolic syndrome) in euthyroid children and adolescents. A total of 250 euthyroid children and adolescents aged 10–18 years were included using data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2015. In the unadjusted correlation analyses, TSH was positively correlated with glucose (r = 0.172, P = 0.006), hemoglobin A1c (HbA1c) (r = 0.149, P = 0.018), insulin (r = 0.144, P = 0.023), homeostatic model assessment for insulin resistance (HOMA-IR) (r = 0.163, P = 0.010), and triglyceride (TG) (r = 0.155, P = 0.014), whereas FT4 was negatively associated with the waist circumference (WC) standard deviation score (SDS) (r = −0.134, P = 0.035), body mass index (BMI) SDS (r = −0.126, P = 0.046), insulin (r = −0.219, P < 0.001), and HOMA-IR (r = −0.211, P < 0.001). In the multiple linear regression analysis, TSH was positively associated with glucose (β = 1.179, P = 0.021), HbA1c (β = 0.044, P = 0.039), and TG (β = 8.158, P = 0.041) after adjustment for possible confounders. FT4 was negatively associated with serum fasting insulin (β = −5.884, P = 0.017) and HOMA-IR (β = −1.364, P = 0.023) in the multiple linear regression analysis. Boys and girls with elevated glucose levels had a higher adjusted mean TSH level compared to those without elevated glucose levels after controlling for confounding factors in the analysis of covariance (2.16 mIU/L vs 3.88 mIU/L, P = 0.004). Our results suggest that higher TSH and/or lower FT4 levels, even within the reference ranges, may be related to increased cardiometabolic risk factors.

The association of thyroid-stimulating hormone (TSH) and free thyroxine (fT4) concentration levels with carbohydrate and lipid metabolism in obese and overweight teenagers.

Obesity has increased rapidly among children and adolescents during the last 30 years. Paediatric patients with a BMI above the 85th centile are more often diagnosed with increased TSH levels than are children with proper body weight. The data of 961 overweight and obese children, aged 13 years, recruited in four cities in Poland as part of PoZdro!, a two-year prophylactic program, were analysed to observe the relationship between serum TSH and fT4 concentration and carbohydrate and lipid metabolism parameters, as well as anthropometric parameters. TSH concentration in the study group was positively correlated, whereas fT4 concentration was negatively correlated with WHR and WHtR values, fasting serum glucose concentrations and one-hour glucose concentration, fasting serum insulin concentrations, one-hour and two-hour insulin concentration, ALT serum activity, as well as total cholesterol, LDL cholesterol, and triglyceride serum concentrations. An increased risk of metabolic syndrome was diagnosed previously in patients with TSH concentrations > 2.5 mUI/L. TSH concentration in the upper half of the current reference range (> 2.50 mIU/L) is associated with an increased risk of lipid and carbohydrate metabolism disorders and therefore increased chances of developing metabolic syndrome. It seems advisable to regularly monitor thyroid function in overweight and obese paediatric patients.

The relationship between thyroid function and cerebral blood flow in mild cognitive impairment and Alzheimer's disease.

The thyroid hormones have been reported to be associated with cognitive decline and Alzheimer’s disease. The relationship between thyroid function within the normal range and cerebral blood flow in Alzheimer’s disease patients has been shown in a recent study. Mild cognitive impairment is often the first stage of Alzheimer’s disease; thus, early diagnosis is important. The present study investigated the relationship between thyroid function and regional cerebral blood flow in patients with mild cognitive impairment and Alzheimer’s disease. A total of 122 memory clinic outpatients who underwent thyroid function testing and single photon emission computed tomography were divided into mild cognitive impairment, Alzheimer’s disease, and Normal groups. Regional cerebral blood flow was calculated using a three-dimensional stereotactic region of interest template in an automated cerebral perfusion single photon emission computed tomography analysis system. Multiple regression analysis adjusted for age and sex was conducted to examine the relationships between thyroid hormones and regional cerebral blood flow. Thyroid stimulating hormone was significantly associated with regional cerebral blood flow in the bilateral temporal, bilateral pericallosal, and bilateral hippocampal regions in the mild cognitive impairment group. In the Alzheimer’s disease group, free triiodothyronine was significantly associated with regional cerebral blood flow in the bilateral parietal, right temporal, and bilateral pericallosal regions. The present study showed the association of thyroid stimulating hormone with regional cerebral blood flow in the mild cognitive impairment group and the association of free triiodothyronine with regional cerebral blood flow in the Alzheimer’s disease group. These study findings could contribute to the early diagnosis of mild cognitive impairment at general memory clinics and the prevention of subsequent progression to Alzheimer’s disease.

Subclinical thyroid dysfunction and circulating thyroid hormones are not associated with bone turnover markers or incident hip fracture in older men

Overt thyroid dysfunction is a risk factor for osteoporosis and fractures. Subclinical hyperthyroidism has also been associated with fracture. It remains unclear whether variation in thyroid hormones within the euthyroid range modulates bone health, particularly among older men. We assessed whether thyroid stimulating hormone (TSH) and free thyroxine (FT4) are associated with bone turnover markers (BTMs) and predict hip fracture risk in community-dwelling older men without known thyroid disease. Prospective cohort study. Four thousand two hundred forty-eight men aged 70-89years. Baseline blood samples were assayed for TSH, FT4, total osteocalcin (TOC), undercarboxylated osteocalcin (ucOC), N-terminal propeptide of type I collagen (P1NP) and collagen type I C-terminal cross-linked telopeptide (CTX). Incidence of hip fracture events was ascertained to 2012. Associations of TSH and FT4 with BTMs were analysed at baseline using Pearson correlation coefficients, and with incident hip fracture using Cox proportional hazards regression. After excluding men with pre-existing thyroid or bone disease, there were 3, 338 men for analysis. Of these, 3, 117 were euthyroid, 135 had subclinical hypothyroidism, and 86 had subclinical hyperthyroidism. Men with subclinical thyroid disease were older, and those with subclinical hyperthyroidism had lower creatinine than the other groups. After multivariate analysis, there were no associations found between FT4, TSH or subclinical thyroid dysfunction and BTMs at baseline. Neither subclinical thyroid dysfunction, TSH nor FT4 were predictive of incident hip fracture in our study population. In euthyroid older men, TSH and FT4 were not associated with BTMs or incident hip fracture. Our findings differ from those previously described in postmenopausal women.

Abstract P197: The Relationship Between Thyroid-Stimulating Hormone Levels and Lipoprotein Subfractions in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Background and purpose: Although the relation between thyroid disorders and heart diseases had been described since decades ago, the association of thyroid-stimulating hormone (TSH) and lipoproteins is not very well elucidated. Hypothesis: to verify if there are associations with TSH levels, lipid and lipoprotein subfractions in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Methods: We evaluated at the ELSA-Brasil baseline (2008-2010) 3,742 middle-aged participants (1,960 women and 1,782 women) without previous cardiovascular disease and people who were taking neither drugs that can interfere with thyroid function nor lipid-lowering agents. All of them had their levels of total-cholesterol and its sub-fractions (LDL, VLDL and HDL subclasses); triglycerides and triglyceride-rich lipoprotein cholesterol [TRL-C (VLDL1+2-C VLDL3-C + IDL-C)] determined by ultracentrifugation (Vertical Auto Profile, Atherotech). We also calculated T-Chol/HDL-C and triglycerides/HDL-C ratios. The application multinomial logistic regression model obtained odds ratios (OR) with its respective 95% confidence interval (95% CI). They are presented as adjusted for age, sex, educational level, hypertension, diabetes, and smoking. Lipids tertiles were evaluated as dependent variables, the quintiles of TSH were considered as an independent variable, using first quintiles of TSH as the reference. Results: The main associations obtained were between the highest levels of TSH (5th quintile) with the highest levels (3rd tertiles) of VLDL-C, OR=1.55 (95%CI, 1.18-2.04); triglycerides, OR=1.71 (95%CI, 1.30-2.24); VLDL-3-C, OR=1.48 (95%CI, 1.13-1.94); TC/HDL-C ratio, OR=1.37 (95%CI; 1.04-1.81) and TG/HDL-C ratio, OR=1.71 (95%CI; 1.29-2.26). A positive association between the lowest levels of HDL3-C (1st tertile) and the highest of TSH was also verified with OR= 1.43 (95%CI, 1.10-1.87). In women, we found positive associations with the 5th TSH quintiles and the 3rd tertiles of VLDL-C, OR 1.68;(95%CI 1.18-2.41); non-HDL-C, OR,1.50; (95%CI,1.04-2.16); Triglyceride-rich Lipoprotein Cholesterol,OR 1.42 (95%CI 1.00-2.02); VLDL3-C (OR,1.68;95%CI 1.16-2.45), TC/HDL-C ratio (OR 1.86;95% CI 1.29-2.69) and TG/HDL-C-ratio (OR 1.62;95%CI 1.12-2.35). In men, we found associations between the 5th quintile of TSH and the 3rd tertiles of TG (OR 1.59; 95%CI 1.07-2.36) and TG/HDL-C-ratio (OR 1.71; 95%CI 1.15-2.55). Conclusions: In this sample of middle-aged participants from ELSA-Brasil, an unfavorable lipid profile, which included triglyceride-rich lipoproteins and their remnants were mostly associated with high levels of TSH. In the other hand, we observed a risky association between the lowest levels of HDL3-C and the highest levels of TSH. The majority of our findings were mainly reproduced among women.

Age- and gender-specific reference intervals of TSH and free T4 in an iodine-replete area: Data from Korean National Health and Nutrition Examination Survey IV (2013-2015).

BackgroundEstablishment of the reference interval of thyroid-stimulating hormone (TSH) is critical in the diagnosis of thyroid dysfunction and is affected by age, gender, iodine nutrition, and ethnicity. The aim of this study was to determine the reference intervals of TSH and free thyroxin (FT4) from a large, nationwide data of Korea where iodine intake is more than adequate.MethodsWe analyzed data from the Korea National Health and Nutrition Examination Survey VI that measured serum TSH, FT4, and thyroid peroxidase antibody from 7,061 individuals (urinary iodine measurement in 6,565). Age- and gender-specific reference intervals were established from 95% confidence limits from the 2.5 to 97.5 percentile of TSH (log-transformed) and FT4 in reference populations.ResultsThe geometric mean of TSH was 2.16 ± 0.01 mIU/L, with the lowest value found in the middle aged group (2.04 ± 0.02 mIU/L) and higher values noted in age groups of 10–19 and over 70 years (2.38 ± 0.02 and 2.32 ± 0.07 mIU/L, respectively). The association of TSH and age was U-shaped. The overall reference interval of TSH was 0.59–7.03 mIU/L. Mean FT4 was 1.25 ± 0.003 ng/dL (16.09 ± 0.039 pmol/L), and it showed a small but continuous decrease after 20 years of age (P < 0.001). There was a significant positive correlation between TSH and urine iodine concentration (r = 0.154, P < 0.001).ConclusionsThe reference interval of TSH in Korea, where iodine intake is above the requirement, was 0.59–7.03 mIU/L and showed U-shaped change with age, which was a similar pattern to iodine intake. The reference interval of FT4 was 0.92–1.60 ng/dL. The geometric mean and upper limit of TSH were higher than those of Western populations, reflecting the paramount importance of iodine intake on thyroid function.