scholarly journals Association of High Vitamin D Status with Low Circulating Thyroid-Stimulating Hormone Independent of Thyroid Hormone Levels in Middle-Aged and Elderly Males

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Qingqing Zhang ◽  
Zhixiao Wang ◽  
Min Sun ◽  
Mengdie Cao ◽  
Zhenxin Zhu ◽  
...  
Keyword(s):  
Vitamin D ◽  
Thyroid Hormone ◽  
Smoking Status ◽  
Thyroid Stimulating Hormone ◽  
Vitamin D Status ◽  
Middle Aged ◽  
Hormone Levels ◽  
Elderly Males ◽  
Thyroid Hormone Levels ◽  
Tsh Levels

Background. A recent study has reported that high circulating 25-hydroxyvitamin D [25(OH)D] is associated with low circulating thyroid-stimulating hormone (TSH) levels, but only in younger individuals. The goal of the present study was to explore the relationship between vitamin D status and circulating TSH levels with thyroid autoimmunity and thyroid hormone levels taken into consideration in a population-based health survey of middle-aged and elderly individuals.Methods. A total of 1,424 Chinese adults, aged 41–78 years, were enrolled in this cross-sectional study. Serum levels of 25(OH)D, TSH, thyroid hormones, and thyroid autoantibodies were measured.Results. The prevalence of vitamin D insufficiency was 94.29% in males and 97.22% in females, and the prevalence of vitamin D deficiency was 55.61% in males and 69.64% in females. Vitamin D status was not associated with positive thyroid autoantibodies after controlling for age, gender, body mass index, and smoking status. Higher 25(OH)D levels were associated with lower TSH levels after controlling for age, FT4 and FT3 levels, thyroid volume, the presence of thyroid nodule(s), and smoking status in males.Conclusion. High vitamin D status in middle-aged and elderly males was associated with low circulating TSH levels independent of thyroid hormone levels.

scholarly journals Environmental Factors Affecting Thyroid-Stimulating Hormone and Thyroid Hormone Levels

2021 ◽  
Vol 22 (12) ◽  
pp. 6521
Author(s):  
Mirjana Babić Babić Leko ◽  
Ivana Gunjača ◽  
Nikolina Pleić ◽  
Tatijana Zemunik
Keyword(s):  
Thyroid Hormone ◽  
Environmental Factors ◽  
Thyroid Hormones ◽  
Thyroid Function ◽  
Lifestyle Factors ◽  
Thyroid Stimulating Hormone ◽  
Hormone Levels ◽  
Thyroid Hormone Levels ◽  
The Impact ◽  
Tsh Levels

Thyroid hormones are necessary for the normal functioning of physiological systems. Therefore, knowledge of any factor (whether genetic, environmental or intrinsic) that alters the levels of thyroid-stimulating hormone (TSH) and thyroid hormones is crucial. Genetic factors contribute up to 65% of interindividual variations in TSH and thyroid hormone levels, but many environmental factors can also affect thyroid function. This review discusses studies that have analyzed the impact of environmental factors on TSH and thyroid hormone levels in healthy adults. We included lifestyle factors (smoking, alcohol consumption, diet and exercise) and pollutants (chemicals and heavy metals). Many inconsistencies in the results have been observed between studies, making it difficult to draw a general conclusion about how a particular environmental factor influences TSH and thyroid hormone levels. However, lifestyle factors that showed the clearest association with TSH and thyroid hormones were smoking, body mass index (BMI) and iodine (micronutrient taken from the diet). Smoking mainly led to a decrease in TSH levels and an increase in triiodothyronine (T3) and thyroxine (T4) levels, while BMI levels were positively correlated with TSH and free T3 levels. Excess iodine led to an increase in TSH levels and a decrease in thyroid hormone levels. Among the pollutants analyzed, most studies observed a decrease in thyroid hormone levels after exposure to perchlorate. Future studies should continue to analyze the impact of environmental factors on thyroid function as they could contribute to understanding the complex background of gene–environment interactions underlying the pathology of thyroid diseases.

scholarly journals Thyroid Hormone Levels in Apparently Euthyroid Subjects with Essential Hypertension in a Tertiary Hospital in Nigeria

2013 ◽  
Vol 5 (01) ◽  
pp. 26-29 ◽  
Author(s):  
Abiodun Mathias Emokpae ◽  
Aliyu Abdu ◽  
Humphrey Benedo Osadolor
Keyword(s):  
Essential Hypertension ◽  
Thyroid Hormone ◽  
Medical Information ◽  
Young Patients ◽  
Thyroid Stimulating Hormone ◽  
Overt Hypothyroidism ◽  
Thyroid Disorder ◽  
Major Health Problem ◽  
Hormone Levels ◽  
Thyroid Hormone Levels

ABSTRACT Background: High blood pressure (BP) is a major health problem in Nigeria and the involvement of thyroid hormones in this condition has not been evaluated in this center. Objective: The objective of this study was to evaluate the proportion of patients with an essential hypertension who had abnormal thyroid hormone levels and the type of thyroid disorders commonly observed in this group of patients. Materials and Methods: A retrospective study of 94 patients (30 males, aged 30.4 ± 2 years and 64 females, aged 43.4 ± 1.3 years) with essential hypertension was carried out between January 2005 and December 2007. Demographic and other medical information were obtained from the health records. Analysis of laboratory results of triiodothyronine (T3), Thyroxine (T4), and thyroid stimulating hormone (TSH) were made. Results: Of the 94 patients evaluated, 26 (27.7%) had abnormal thyroid hormone levels, with 23.4% having hyperthyroidism, 4.3% had sub-clinical hypothyroidism and none had overt hypothyroidism. Of the 26 subjects with abnormal thyroid hormone levels, 18 (69.2%) were females while 8 (30.8%) were males. Out of the 18 female subjects with abnormal thyroid hormone levels, 16 had hyperthyroid levels while 2 had sub-clinical hypothyroid levels. Out of the 8 male patients, 6 had hyperthyroid hormone levels while 2 had sub-clinical hypothyroid levels. Conclusion: Thyroid hormone abnormalities are common in patients with essential hypertension. Hyperthyroidism was the most common thyroid disorder observed. Young patients presenting with essential hypertension should be screened for thyroid hormone abnormalities since they can best be managed by treating the underlying causes.

scholarly journals Analysis of Hypothalamic TRH Neurons in Regulating Thyroid Hormone Levels

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A849-A849
Author(s):  
Ricardo H Costa e Sousa ◽  
Rodrigo Rorato ◽  
Anthony Neil Hollenberg ◽  
Kristen R Vella
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormone Receptor ◽  
Designer Drugs ◽  
Mrna Levels ◽  
Hormone Levels ◽  
Males And Females ◽  
Thyroid Hormone Levels ◽  
Hpt Axis ◽  
Tsh Levels

Abstract Thyroid hormone (TH) is a major regulator of development and metabolism. An important mechanism controlling TH production is the negative feedback at the hypothalamic and pituitary level and it has been suggested that thyroid hormone receptor β (TRβ) is the main mediator of TH actions in the hypothalamic paraventricular nucleus (PVN). Nevertheless, the direct actions of TH and TRβ in the negative regulation of TRH have yet to be demonstrated in vivo. Here we used two approaches to investigate the TRH neuron. First, we used a chemogenetic tool to directly investigate the role of TRH neurons on the regulation of thyroid hormone levels. Mice expressing Cre-recombinase in TRH neurons received bilateral injections of the activating designer receptors exclusively activated by designer drugs (DREADD) directly into the PVN. Activation of TRH neurons produced a rapid and sustained increase in circulating TSH levels in both males and females. TSH levels increased approximately 10-fold from baseline within 15 minutes of injection of CNO, returning to baseline within 2.5 hours. TH levels were increased approximately 2-fold in males and females. Therefore, using a chemogenetic approach, we were able to directly evaluated the role of PVN TRH neurons on the control of thyroid activity, for the first time. Next, we generated mice deficient in TRβ specifically in neurons expressing melanocortin 4 receptor (MC4R), which overlaps with TRH expression in the PVN. Knockout mice (KO) developed normally and showed no change in TH and TSH levels. TRH mRNA levels in the PVN of KO mice were similar to control mice. To investigate if the deletion of TRβ in the PVN changes the sensitivity of the HPT axis to T3, mice were rendered hypothyroid and given increasing doses of T3 for 2 weeks. Results show no difference in TRH mRNA or serum TSH between controls and KO. Surprisingly, despite the presence of detectable genomic recombination on the TRβ gene in the PVN, there was no difference in TRβ mRNA expression between control and KO mice, suggesting that either MC4R-positive neurons do not express TRβ or they represent a very small population of TRβ-positive cells in the PVN. Present data show that TRH neuron activation rapidly stimulates TSH release and increases TH levels, demonstrating a major role of these neurons in the regulation of the hypothalamic-pituitary-thyroid (HPT) axis. Nevertheless, deletion of TRβ from MC4R neurons had no major effect on either TRH or TH levels in in mice. Additionally, TRβ in MC4R-positive TRH neurons in the PVN is not necessary for TH-induced suppression of TRH mRNA. Although further studies are necessary, these data suggest that there are distinct populations of hypophysiotropic TRH neurons in the PVN, some of which are not regulated by thyroid hormone and TRβ.

scholarly journals Specific Reference Intervals of Serum Triiodothyronine, Thyroxine, and Thyroid-stimulating Hormone in Normal Pregnant Indian Women as per Trimester

2017 ◽  
Vol 21 (1) ◽  
pp. 17-21
Author(s):  
Nandita Hazra ◽  
Binay Mitra ◽  
Reetika Pal
Keyword(s):  
Thyroid Hormone ◽  
Pregnant Women ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Specific Reference ◽  
Indian Women ◽  
Hormone Levels ◽  
Thyroid Hormone Levels ◽  
Maternal Thyroid ◽  
Stimulating Hormone

ABSTRACT Aim Maternal thyroid hormone levels during pregnancy are vital for the health of the mother as well as the developing child. Fetal growth is affected by maternal thyroid levels. Various physiological changes like alterations of thyroxine-binding globulins, human chorionic gonadotropin level, and changes in iodide metabolism affect maternal thyroid hormone levels. Therefore, reference intervals (RIs) for thyroid hormones in pregnant population require to be established separately from the general population. Materials and methods The RIs of serum triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) were determined in healthy pregnant women by enzyme-linked immunosorbent assay (ELISA) technique after segregating them into three trimesters. This study was conducted in a 492-bedded zonal-level hospital. The reference population was chosen from a study population of pregnant women by strict inclusion and exclusion criteria. The assays were done by the most-commonly used, economical ELISA method employing standard kits. Tests were done using accurate and precise methods with proper quality control measures. Results The RIs were calculated from the central 95% of distribution of total T3, total T4, and TSH values located between 2.5 and 97.5 percentile values. The 0.90 confidence intervals for the upper and lower reference limits were calculated. The values thus obtained were different from those provided by the manufacturer kit literature. Conclusion It is recommended to determine one's own laboratory-specific, method-specific, trimester-wise RIs for maternal thyroid hormone status and use them for screening of pregnant women. How to cite this article Chakrabarty BK, Mitra B, Pal R, Hazra N. Specific Reference Intervals of Serum Triiodothyronine, Thyroxine, and Thyroid-stimulating Hormone in Normal Pregnant Indian Women as per Trimester. Indian J Med Biochem 2017;21(1):17-21.

Serum Thyrotropin and Thyroid Hormone Levels in Elderly and Middle-Aged Euthyroid Persons

1993 ◽  
Vol 41 (8) ◽  
pp. 823-828 ◽  
Author(s):  
Jerome M. Hershman ◽  
A. Eugene Pekary ◽  
Loretta Berg ◽  
David H. Solomon ◽  
Clark T. Sawin
Keyword(s):  
Thyroid Hormone ◽  
Middle Aged ◽  
Hormone Levels ◽  
Thyroid Hormone Levels

scholarly journals Thyroid testing paradigm switch from thyrotropin to thyroid hormones—Future directions and opportunities in clinical medicine and research

Endocrine ◽  
2021 ◽  
Vol 74 (2) ◽  
pp. 285-289
Author(s):  
Stephen P. Fitzgerald ◽  
Nigel G. Bean ◽  
James V. Hennessey ◽  
Henrik Falhammar
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Dysfunction ◽  
Clinical Medicine ◽  
Older Individuals ◽  
Free Triiodothyronine ◽  
Thyroid State ◽  
Peripheral Tissues ◽  
Hormone Levels ◽  
Thyroid Hormone Levels ◽  
Tsh Levels

Abstract Purpose Recently published papers have demonstrated that particularly in untreated individuals, clinical parameters more often associate with thyroid hormone, particularly free thyroxine (FT4), levels than with thyrotropin (TSH) levels. Clinical and research assessments of the thyroid state of peripheral tissues would therefore be more precise if they were based on FT4 levels rather than on TSH levels. In this paper we describe implications of, and opportunities provided by, this discovery. Conclusions The FT4 level may be the best single test of thyroid function. The addition of free triiodothyronine (FT3) and TSH levels would further enhance test sensitivity and distinguish primary from secondary thyroid dysfunction respectively. There are opportunities to reconsider testing algorithms. Additional potential thyroidology research subjects include the peripheral differences between circulating FT4 and FT3 action, and outcomes in patients on thyroid replacement therapy in terms of thyroid hormone levels. Previously performed negative studies of therapy for subclinical thyroid dysfunction could be repeated using thyroid hormone levels rather than TSH levels for subject selection and the monitoring of treatment. Studies of outcomes in older individuals with treatment of high normal FT4 levels, and pregnant women with borderline high or low FT4 levels would appear to be the most likely to show positive results. There are fresh indications to critically re-analyse the physiological rationale for the current preference for TSH levels in the assessment of the thyroid state of the peripheral tissues. There may be opportunities to apply these research principles to analogous parameters in other endocrine systems.

scholarly journals DIAGNOSIS OF ENDOCRINE DISEASE: How reliable are free thyroid and total T3 hormone assays?

2016 ◽  
Vol 175 (6) ◽  
pp. R255-R263 ◽  
Author(s):  
Kerry J Welsh ◽  
Steven J Soldin
Keyword(s):  
Thyroid Hormone ◽  
Reference Method ◽  
Reference Interval ◽  
Thyroid Stimulating Hormone ◽  
Hormone Levels ◽  
Disease States ◽  
Number Of Patients ◽  
Liquid Chromatography Tandem Mass ◽  
Thyroid Hormone Levels

Hypothyroidism is a very common disorder worldwide, for which the usual treatment is monotherapy with levothyroxine (L-T4). However, a number of patients treated with L-T4 continue to report symptoms of hypothyroidism despite seemingly normal levels of thyroid-stimulating hormone (TSH), free-T3 (FT3) and free-T4 (FT4) measured by immunoassay. This review summarizes the limitations of the immunoassays commonly used to measure thyroid hormone levels and emphasizes the advantages of the role of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Immunoassays for free thyroid hormone are affected by alterations in serum binding proteins that occur in many physiological and disease states. Multiple studies show falsely normal values for T3, FT3 and FT4 by immunoassay that are below the reference interval when measured by (ultrafiltration) LC-MS/MS, a reference method. We suggest evaluation of thyroid hormone levels by ultrafiltration LC-MS/MS for patients who continue to experience hypothyroid symptoms on LT-4. This may help identify the approximately 20% subset of patients who would benefit from addition of T3 to their treatment regimen (combination therapy).

scholarly journals Low TSH levels are not associated with osteoporosis in childhood

2007 ◽  
Vol 157 (2) ◽  
pp. 221-223 ◽  
Author(s):  
Anastasios Papadimitriou ◽  
Dimitrios T Papadimitriou ◽  
Anna Papadopoulou ◽  
Polyxeni Nicolaidou ◽  
Andreas Fretzayas
Keyword(s):  
Thyroid Hormone ◽  
Calcium Phosphate ◽  
Bone Metabolism ◽  
Serum Calcium ◽  
Type I ◽  
Normal Range ◽  
Hormone Levels ◽  
Amino Terminal ◽  
Thyroid Hormone Levels ◽  
Tsh Levels

Introduction: A recent study on TSH receptor (TSHR) null mice suggested that skeletal loss occurring in hyperthyroidism is caused by the low TSH rather than high thyroid hormone levels. The aim of this study was to examine whether low TSH results in osteoporosis in the human. Subjects and methods: We determined bone mineral density (BMD) and markers of bone metabolism in two male siblings aged 9.8 and 6.8 years with isolated TSH deficiency, due to a mutation of the TSH β-subunit gene. BMD was measured in the lumbar spine (L1–L4) by dual-energy X-ray absorptiometry. Laboratory investigation included the determination of serum calcium, phosphate, 25-hydroxy-vitamin D, parathyroid hormone concentrations, and urine calcium (Ca)/creatinine (Cr) ratio. Osteoblast activity was measured by serum bone alkaline phosphatase and osteocalcin levels, and osteoclast activity by urine cross-linked amino-terminal, carboxy-terminal telopeptides of type I collagen and deoxypyridinoline concentrations. Results: BMD of both patients was within the normal range for age and sex; z-scores were −0.55 and −0.23 for patients 1 and 2 respectively. Serum calcium, phosphate, urine Ca/Cr ratio, and specific markers of bone metabolism were also within normal range. Conclusion: In childhood, chronic extremely low TSH levels, in the face of normal thyroid hormone levels, are not related to bone loss.

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