scholarly journals AMIODARONE-INDUCED THYROTOXICOSIS AFTER TOTAL THYROIDECTOMY FOR METASTATIC FOLLICULAR THYROID CANCER

2020 ◽  
Vol 6 (2) ◽  
pp. e70-e72
Author(s):  
Christerlyn Charles ◽  
Ketan K. Dhatariya
Keyword(s):  
Myocardial Infarction ◽  
Thyroid Cancer ◽  
Total Thyroidectomy ◽  
Reference Range ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Follicular Thyroid Cancer ◽  
Free Triiodothyronine ◽  
Positron Emission

Objective: To describe the case of a man who developed amiodarone-induced thyrotoxicosis (AIT) after a total thyroidectomy for metastatic follicular thyroid cancer because of the effect of the drug on metastasis. To the best of our knowledge this is the first reported case of this condition. Methods: We completed a retrospective review of medical records and laboratory results including thyroid function tests as well as imaging reports including plain radiographs, positron emission tomographs, computed tomographs, and histology reports. Results: A 78-year-old man had undergone a total thyroidectomy for follicular thyroid cancer. He had meta-static disease in his chest and vertebrae, and after the operation he was started on suppressive levothyroxine treatment prior to ablative radioactive iodine treatment. Prior to thyroidectomy, his thyroid-stimulating hormone (TSH) concentration was 3.21 mU/L (reference range is 0.35 to 3.50 mU/L). On suppressive thyroxine replacement, his TSH concentration was 0.02 mU/L, his free thyroxine was 13 pmol/L (reference range is 8 to 12 pmol/L), and free triiodothyronine was 5.8 pmol/L (reference range is 3.8 to 6.0 pmol/L). He subsequently had a myocardial infarction and required antiarrhythmic treatment with amiodarone. Eleven days later he developed the clinical and biochemical features of thyrotoxicosis (TSH <0.01 mU/L, free thyroxine of 41 pmol/L, and free triiodothyronine of 14.7 pmol/L). His thyroxine dose was reduced and then discontinued 3 days later. AIT was the principal differential diagnosis, but before being able to determine the nature of the condition he died 18 days after his myocardial infarction. Conclusion: AIT can still occur after total thyroidectomy if metastatic tissue is present.

Subclinical hypothyroidism

2011 ◽  
pp. 543-547
Author(s):  
Jayne A. Franklyn
Keyword(s):  
Thyroid Function ◽  
Subclinical Hypothyroidism ◽  
Expert Panel ◽  
Elevated Serum ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Free Triiodothyronine ◽  
Function Tests ◽  
Serum Tsh

Subclinical hypothyroidism is defined biochemically as the association of a raised serum thyroid-stimulating hormone (TSH) concentration with normal circulating concentrations of free thyroxine (T4) and free triiodothyronine (T3). The term subclinical hypothyroidism implies that patients should be asymptomatic, although symptoms are difficult to assess, especially in patients in whom thyroid function tests have been checked because of nonspecific complaints such as tiredness. An expert panel has recently classified individuals with subclinical hypothyroidism into two groups (1): (1) those with mildly elevated serum TSH (typically TSH in the range 4.5–10.0 mU/l) and (2) those with more marked TSH elevation (serum TSH >10.0 mU/l).

Effects of Age and Health on the Euthyroid Reference Ranges for Serum Free Thyroxine and Free Triiodothyronine

1985 ◽  
Vol 24 (02) ◽  
pp. 57-65 ◽  
Author(s):  
J. E. M. Midgley ◽  
K. R. Gruner
Keyword(s):  
Lower Limit ◽  
Healthy Subjects ◽  
Thyroid Dysfunction ◽  
Reference Range ◽  
Free Thyroxine ◽  
Reference Ranges ◽  
Free Triiodothyronine ◽  
Serum Free ◽  
Young Subjects ◽  
Age Range

SummaryAge-related trends in serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations were measured in 7248 euthyroid subjects (age-range 3 months to 106 years). 5700 were patients referred to hospitals for investigation of suspected thyroid dysfunction, but who were diagnosed euthyroid. 1548 were healthy blood donors (age-range 18-63 years) with no indication of thyroid dysfunction. FT4 concentrations were little affected by the age, the sex or the state of health of the subjects in either group. Serum FT3 concentrations were significantly affected by both age and health factors. The upper limit of the euthyroid reference range for young subjects up to 15 years was about 20% higher (10.4 pmol/1) than for adult subjects older than 25 years (8.8 pmol/1). The change in the upper limits typical of young subjects to that typical of adults occurred steadily over the decade 15–25 years. After this age, little further change occurred, especially in healthy subjects. Additionally, the lower limit of the euthyroid range for FT3 was extended by the inclusion in the reference group of patients referred to hospitals. Compared with the lower limit of the FT3 range for healthy subjects (5 pmol/1), the corresponding limit for referred subjects (young or adult) was 3.5–3.8 pmol/1. Broadening of the FT3 reference range was probably brought about by a significant number of patients in the hospital-referred group with the “1OW-T3 syndrome” of mild non-thyroidal illness. Accordingly, FT3 was inferior to FT4 in the discrimination of hypothyroidism, as FT4 was unaffected by this phenomenon. Effects of age and non-thyroidal illness on serum FT3 concentrations require great care when selecting subjects for a laboratory euthyroid reference range typical of the routine workload. Constraints on the choice of subjects for FT4 reference ranges are less stringent.

scholarly journals Interconversion of Plasma Free Thyroxine Values from Assay Platforms with Different Reference Intervals Using Linear Transformation Methods

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 45
Author(s):  
Fanwen Meng ◽  
Jacqueline Jonklaas ◽  
Melvin Khee-Shing Leow
Keyword(s):  
Linear Transformation ◽  
Piecewise Linear ◽  
Equilibrium Dialysis ◽  
Accurate Method ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Linear Transformations ◽  
Transformation Methods

Clinicians often encounter thyroid function tests (TFT) comprising serum/plasma free thyroxine (FT4) and thyroid stimulating hormone (TSH) measured using different assay platforms during the course of follow-up evaluations which complicates reliable comparison and interpretation of TFT changes. Although interconversion between concentration units is straightforward, the validity of interconversion of FT4/TSH values from one assay platform to another with different reference intervals remains questionable. This study aims to establish an accurate and reliable methodology of interconverting FT4 by any laboratory to an equivalent FT4 value scaled to a reference range of interest via linear transformation methods. As a proof-of-concept, FT4 was simultaneously assayed by direct analog immunoassay, tandem mass spectrometry and equilibrium dialysis. Both linear and piecewise linear transformations proved relatively accurate for FT4 inter-scale conversion. Linear transformation performs better when FT4 are converted from a more accurate to a less accurate assay platform. The converse is true, whereby piecewise linear transformation is superior to linear transformation when converting values from a less accurate method to a more robust assay platform. Such transformations can potentially apply to other biochemical analytes scale conversions, including TSH. This aids interpretation of TFT trends while monitoring the treatment of patients with thyroid disorders.

Subclinical Hyperthyroidism: Diagnostic Criteria and Principles of Treatment

2016 ◽  
pp. 75-79
Author(s):  
Vita Galitskaya
Keyword(s):  
Hormone Receptors ◽  
Color Doppler ◽  
Specific Treatment ◽  
Nodular Goiter ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Subclinical Hyperthyroidism ◽  
Mineral Density ◽  
Free Triiodothyronine ◽  
Stimulating Hormone

This article presents the European Thyroid Association guidelines for diagnosis and treatment of subclinical hyperthyroidism, 2015. Determination of thyroid1stimulating hormone levels can help to diagnose a variety of pathological conditions: hypertension, cardiac fibrillation, atrial fibrillation, mineral density reduction in bones, menstrual irregularities, infertility, which require specific treatment after detection of hormonal status disorders (subclinical, overt), taking into account the patient’s age. Diagnosis of endogenous subclinical hyperthyroidism is based solely on the results of laboratory tests, not clinical criteria. Endogenous subclinical hyperthyroidism is defined by the presence of sub-normal levels of thyroid-stimulating hormone with normal levels of free thyroxine, total triiodothyronine, and/or free triiodothyronine. There are two categories of endogenous subclinical hyperthyroidism: stage 1 – the level of thyroid-stimulating hormone is 0,1–0,39 mIU/l; stage 2 – the level of thyroid-stimulating hormone is <0.1 mIU/l. The levels of free thyroxine and free triiodothyronine, as a rule, are medium-high value at a subclinical level of thyroid hormone and can help differentiate between endogenous subclinical hyperthyroidism from overt hyperthyroidism. It is recommended to study the thyroid-stimulating hormone level as the first test for the diagnosis of subclinical hyperthyroidism. In identifying low levels of thyroid-stimulating hormone it is necessary to investigate the level of free thyroxine, free or bound triiodothyronine. Patients with primary sub-normal levels of thyroid-stimulating hormone with concentration of thyroid hormones in the upper limit or in normal range should be evaluated within 2-3 months. It is recommended to perform scintigraphy and possible 24-hour test the absorption of radioactive iodine if in patient with 2nd degree endogenous subclinical hyperthyroidism there is nodular goiter to determine treatment strategy. Ultrasonography with color Doppler can be informative for patients with endogenous subclinical hyperthyroidism and nodular goiter. Determining the level of antibodies to thyroid-stimulating hormone receptors can confirm the etiology of autoimmune-induced hyperthyroidism.

scholarly journals Misleading results from immunoassays of serum free thyroxine in the presence of rheumatoid factor

1997 ◽  
Vol 43 (6) ◽  
pp. 957-962 ◽  
Author(s):  
Anthony G W Norden ◽  
Rodwin A Jackson ◽  
Lorraine E Norden ◽  
A Jane Griffin ◽  
Margaret A Barnes ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Rheumatoid Factor ◽  
Equilibrium Dialysis ◽  
Thyroid Stimulating Hormone ◽  
Normal Serum ◽  
Free Thyroxine ◽  
Free Triiodothyronine ◽  
Serum Free ◽  
Serum Free Thyroxine ◽  
Stimulating Hormone

Abstract A novel interference with measurements of serum free thyroxine (FT4) caused by rheumatoid factor (RhF) is described. We found misleading, sometimes gross, increases of FT4 results in 5 clinically euthyroid elderly female patients with high RhF concentrations. All 5 patients had high FT4 on Abbott AxSYM® or IMx® analyzers. “NETRIA” immunoassays gave misleading results in 4 of the 5 patients; Amerlex-MAB® in 2 of 4 patients; AutoDELFIA®in 2 of the 5; and Corning ACS-180® and Bayer Diagnostics Immuno 1® in 1 of the 5. BM-ES700® system results for FT4 in these women remained within the reference range. Results for serum T4, thyroid-stimulating hormone, free triiodothyronine, thyroid-hormone-binding globulin, and FT4 measured by equilibrium dialysis were normal in all 5 patients. Drugs, albumin-binding variants, and anti-thyroid-hormone antibodies were excluded as interferences. Addition to normal serum of the RhF isolated from each of the 5 patients increased the apparent FT4 (Abbott AxSYM). Screening of 83 unselected patients demonstrated a highly significant positive correlation between FT4 (Abbott AxSYM) and RhF concentrations. Discrepant, apparently increased FT4 with a normal result for thyroid-stimulating hormone should lead to measurement of the patient’s RhF concentration.

An Endobronchial Mass Developing 17 Years After Total Thyroidectomy Due To Follicular Thyroid Cancer

2010 ◽  
Author(s):  
Jin Woo Kim ◽  
Ji Young Kang ◽  
Chan Kwon Park ◽  
Sang Haak Lee ◽  
Soon Seog Kwon ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Total Thyroidectomy ◽  
Follicular Thyroid Cancer

scholarly journals Association between Thyroid-Stimulating Hormone Level after Total Thyroidectomy and Hypercholesterolemia in Female Patients with Differentiated Thyroid Cancer: A Retrospective Study

2019 ◽  
Vol 8 (8) ◽  
pp. 1106 ◽  
Author(s):  
Young Ki Lee ◽  
Hokyou Lee ◽  
Seunghee Han ◽  
Hyein Jung ◽  
Dong Yeob Shin ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Total Thyroidectomy ◽  
Differentiated Thyroid Cancer ◽  
Ldl Cholesterol ◽  
Density Lipoprotein ◽  
Recurrence Risk ◽  
Thyroid Stimulating Hormone ◽  
Metabolic Derangement ◽  
Tsh Suppression ◽  
Tsh Levels

Less-intense TSH suppression strategies can be used for differentiated thyroid cancer (DTC) patients with a low recurrence risk, but their metabolic outcomes are not well known. We aimed to evaluate changes in the serum cholesterol levels and the risk of hypercholesterolemia according to postoperative TSH levels in 1092 female DTC patients receiving levothyroxine after total thyroidectomy. The preoperative-to-follow-up change in total cholesterol (TC) levels in the TSH level <0.03, 0.03–0.3, 0.3–2, and 2–5 mIU/L groups was −3.69 mg/dL (p = 0.006), +0.13 mg/dL (p = 0.926), +12.46 mg/dL (p < 0.001), and +16.46 mg/dL (p < 0.001), respectively. When compared with TSH levels of 0.03–0.3 mIU/L, those of 0.3–2 mIU/L were found to be associated with hypercholesterolemia (adjusted odds ratio (AOR) = 1.86 and 5.08 for TC 200–240 and ≥240 vs. <200 mg/dL) and hyper-low-density lipoprotein (LDL)-cholesterolemia (AOR = 2.76 for LDL-cholesterol ≥160 vs. <130 mg/dL). Additionally, TSH levels of 2–5 mIU/dL were associated with hypercholesterolemia (AOR = 2.85 and 6.95 for TC 200–240 and ≥240 vs. <200 mg/dL) and hyper-LDL-cholesterolemia (AOR = 2.08 and 4.17 for LDL-cholesterol 130–159 and ≥160 mg/dL vs. <130 mg/dL). In patients with normal TSH level maintenance following thyroidectomy, TC levels markedly increased, resulting in an increased hypercholesterolemia prevalence. Metabolic derangement risk due to insufficient levothyroxine replacement should be considered in the adoption of less-intense TSH suppression strategies, postoperatively, in DTC patients.

Gallstone formation due to rapid weight loss through hyperthyroidism

2019 ◽  
Vol 32 (12) ◽  
pp. 1395-1398
Author(s):  
Satoshi Nakano ◽  
Mitsuyoshi Suzuki ◽  
Hidenori Haruna ◽  
Atsuyuki Yamataka ◽  
Toshiaki Shimizu
Keyword(s):  
Weight Loss ◽  
Cholesterol Metabolism ◽  
Gallstone Formation ◽  
Final Diagnosis ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Function Tests ◽  
Rapid Weight Loss ◽  
Free Triiodothyronine ◽  
Thyrotropin Receptor Antibody ◽  
Loss Of Appetite

Abstract Background Cholesterol metabolism has dramatically changed under hyperthyroid status. However, a combination of hyperthyroidism and cholecystolithiasis is very rare. Case presentation We report a case of cholelithiasis accompanied by hyperthyroidism in a 13-year-old girl who had recently lost 13 kg of weight (from 53 to 40 kg) in 1 month without loss of appetite. Ultrasonography showed multiple hyperechoic areas with acoustic shadowing in the gallbladder. Thyroid function tests showed that her serum free triiodothyronine (T3) and thyroxine (T4) levels were elevated and the thyroid-stimulating hormone level was decreased. In addition, serum thyrotropin receptor antibody and thyroid-stimulating antibody were detected. The final diagnosis was cholelithiasis with Graves’ disease. Thiamazole ingestion was started immediately after the diagnosis, and laparoscopic cholecystectomy was performed 33 days after hospitalization. Conclusions Massive and sudden weight loss could be a risk factor for gallstone formation in children. In addition, hyperthyroidism has the potential to promote cholelithiasis via cholesterol metabolism.

scholarly journals In primary care, is measuring free-thyroxine plus thyroid-stimulating hormone to detect hypopituitarism cost-effective? A cost utility analysis using Markov chain models

BMJ Open ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. e029369 ◽  
Author(s):  
Brian Shine ◽  
Tim James ◽  
Amanda Adler
Keyword(s):  
Primary Care ◽  
Model Simulation ◽  
Cost Effective ◽  
Cost Utility ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Life Years ◽  
Secondary Hypothyroidism ◽  
Stimulating Hormone

ObjectiveWe examined whether it is cost-effective to measure free thyroxine (FT4) in addition to thyrotropin (thyroid-stimulating hormone (TSH)) on all requests for thyroid function tests from primary care on adult patients.BackgroundHypopituitarism occurs in about 4 people per 100 000 per year. Loss of thyrotropin (TSH) secretion may lead to secondary hypothyroidism with a low TSH and low FT4, and this pattern may help to diagnose hypopituitarism that might otherwise be missed.DesignMarkov model simulation.Primary outcome measureIncremental cost-effectiveness ratio (ICER), the ratio of cost in pounds to benefit in quality-adjusted life years of this strategy.ResultsThe ICER for this strategy was £71 437. Factors with a large influence on the ICER were the utilities of the treated hypopituitary state, the likelihood of going to the general practitioner (GP) and of the GP recognising a hypopituitary patient. The ICER would be below £20 000 at a cost to the user of an FT4 measurement of £0.61.ConclusionWith FT4 measurements at their present cost to the user, routine inclusion of FT4 in a thyroid hormone profile is not cost-effective.

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