Radioimmunoassay of free thyroxine in serum: comparison with clinical findings and results of conventional thyroid-function tests.

1980 ◽  
Vol 26 (8) ◽  
pp. 1186-1192 ◽  
Author(s):  
M F Bayer ◽  
I R McDougall
Keyword(s):  
Thyroid Function ◽  
Clinical Status ◽  
Diagnostic Value ◽  
Clinical Findings ◽  
Free Thyroxine ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Healthy Individuals ◽  
Function Tests ◽  
The Mean

Abstract We have evaluated a radioimmunoassay for free thyroxine (FT4) involving antibody-coated tubes (GammaCoat 125I Free T4RIA; Clinical Assays, Div. of Travenol Labs, Inc.). The coefficient of correlation between FT4 and the FT4 index was 0.98 for all patients with various thyroid disorders, 0.77 for hospitalized patients with miscellaneous diseases, and 0.74 for healthy individuals. FT4 values also agreed well with triiodothyronine or thyrotropin concentrations in these patients and were consistent with each patient's clinical status. Patients with severe nonthyroidal illnesses and abnormal thyroid-function tests, despite clinical euthyroidism, had normal FT4 values. In this group, the mean FT4 was almost identical to that in the controls, although mean thyroxine, triiodothyronine, and FT4 index differed significantly and the correlation between FT4 and FT4 index was poorer (r = 0.66). For most patients, the diagnostic value of FT4 measurements is comparable to that of the FT4 index, and it may be superior in patients with severe nonthyroidal illnesses. The test costs less and saves time as compared to the FT4 index computation, and it can be used routinely with thyrotropin assay for the diagnosis of hypothyroidism or with triiodothyronine assay for the diagnosis of hyperthyroidism.

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).

Pictorial reporting of multiple thyroid function results.

1976 ◽  
Vol 22 (10) ◽  
pp. 1562-1566
Author(s):  
R W Pain ◽  
B M Duncan
Keyword(s):  
Thyroid Function ◽  
Reporting System ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Testing Procedures ◽  
Function Tests ◽  
Free Thyroxine Index ◽  
Total Thyroxine ◽  
Experience Difficulty

Abstract Clinicians experience difficulty in correctly interpreting the results of in vitro thyroid function tests in the presence of abnormalities of thyrobinding proteins or when results are borderline. This difficulty has been largely resolved in our laboratory by three innovations. First, the borderline areas for each of three routine tests of thyroid function (total thyroxine, thyrobinding index, and free thyroxine index) were accurately determined. Second, the results from this routine profile of three tests were displayed pictorially so as to produce patterns characteristic of various diagnostic situations, including euthyroidism in the presence of abnormalities of thyrobinding proteins. Third, interpretive comments and, in the case of borderline patterns, suggested further testing procedures were added to the report. Clinicians find the reporting system helpful and respond when additional tests are suggested. The system, operated manually at first, was later computerized.

Free thyroid hormone index, thyroid hormone/thyroxin-binding globulin ratio, triiodothyronine uptake, and thyroxin-binding globulin compared for diagnostic value regarding thyroid function.

1983 ◽  
Vol 29 (1) ◽  
pp. 74-79 ◽  
Author(s):  
T J Wilke
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Function ◽  
Diagnostic Value ◽  
Clinical Findings ◽  
Thyroid Function Tests ◽  
Free Thyroid Hormone ◽  
Age Related ◽  
Age Dependent ◽  
Uptake Test ◽  
The Relationship

Abstract The thyroid hormone/thyroxin-binding globulin (TBG) ratio and the free thyroid hormone index (FTI) were compared in 372 subjects classified according to age, sex, and biochemical and clinical findings. Age-related variations in thyroid function tests were investigated, as was the relationship between triiodothyronine uptake and TBG. Men, but not women, showed significant age-dependent changes in concentrations of thyroid hormones. FTI was as good as the thyroid hormone/TBG ratio in hyperthyroidism and was a better index of thyroid status in pregnancy, TBG deficiency, and hypothyroidism. In addition, the triiodothyronine uptake correlated extremely well with TBG (r = -0.95, p less than 0.001) and was very efficient in detecting decreased and significantly increased concentrations of TBG. I conclude that FTI is a better discriminator of functional status of the thyroid over a wider range of TBG values than is the thyroid hormone/TBG ratio. Further, the triiodothyronine uptake test produced diagnostic information equivalent to that of TBG estimation and thus should not be replaced in routine use.

scholarly journals Report of the IFCC Working Group for Standardization of Thyroid Function Tests; Part 2: Free Thyroxine and Free Triiodothyronine

2010 ◽  
Vol 56 (6) ◽  
pp. 912-920 ◽  
Author(s):  
L. M. Thienpont ◽  
K. Van Uytfanghe ◽  
G. Beastall ◽  
J. D. Faix ◽  
T. Ieiri ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Working Group ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Free Triiodothyronine ◽  
Function Tests

scholarly journals Association of Thyroid Function With Suicide Ideation/Attempt -A Systematic Review and Meta-analysis

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A824-A825
Author(s):  
Freddy Jean Karlo Toloza Bonilla ◽  
Yuanjie Mao ◽  
Lakshmi P Menon ◽  
Gemy Maria George ◽  
Madhura Borikar ◽  
...  
Keyword(s):  
Suicidal Ideation ◽  
Thyroid Function ◽  
Suicide Ideation ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Control Group ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Inclusion Criteria ◽  
The Mean

Abstract Background: Thyroid disorders are very prevalent and could affect virtually the entire human body, including cognitive and psychiatric domains. However, the relationship between thyroid dysfunction and suicide is still controversial. Material and Methods: A systematic review and meta-analysis was conducted to describe the association of thyroid function with suicide ideation/attempt in adults. A comprehensive search from databases’ inception (MEDLINE, EMBASE, Cochrane, PsycINFO, PsycArticles, PSYNDEX and Scopus) to July 20, 2018 was conducted with no language restrictions. We included studies that reported mean values and standard deviation (SD) of thyroid hormone levels [Thyroid-stimulant hormone (TSH), free T4 (FT4), free T3 (FT3), total T4 (TT4), and total T3 (TT3)] in patients with suicide ideation/attempt compared with controls. Four reviewers worked independently and in duplicate for assessment of inclusion criteria, data extraction, and assessment of risk of bias. The mean value and SD of the thyroid function tests were used to calculate the mean difference for each subgroup. Random-effects models for meta-analyses were applied. Results: Overall, 2278 articles were identified, and 13 observational studies met the inclusion criteria. These studies involved 2651 participants, including 817 participants diagnosed with suicidal ideation/attempt. Group sizes of patients with suicide ideation/attempt ranged from 7 to 122 participants with mean age ranging from 23 to 49 years. Control group sizes ranged from 8 to 464 participants with mean age ranging from 24 to 50 years. Two studies included only women, two studies included only men, and 9 studies included both (% female range: 29 to 78%). Patients with suicide ideation/attempt had lower levels of FT3 (-0.19 pg/mL; P=0.04) and TT4 (-0.23 µg/dL; P=0.05) compared to controls. There were no differences in TSH, TT3 or FT4 levels between groups. In a subgroup analysis comparing current suicidal ideation vs current suicidal attempt vs history of suicidal ideation/attempt with the control group, there were no differences in any of the thyroid function tests. None of the included studies compared rates of overt/subclinical thyroid disease among groups. The overall risk of bias of the included studies was low-to-moderate. Conclusions: There is scarce evidence regarding the association of thyroid disorders and suicide. We found statistically significant lower thyroid hormone levels in patients with suicidal ideation/attempt. The clinical implications of this finding remain unknown and further research is needed to evaluate the association of thyroid disorders with suicide.

scholarly journals Clinical study of thyroid swellings

2021 ◽  
Vol 7 (3) ◽  
pp. 448
Author(s):  
Ashwini S. Rathod ◽  
Girija A. Ghate ◽  
Ammu Korah ◽  
Lakshmi Krishnan ◽  
Ruchir R. Dashora
Keyword(s):  
Thyroid Function ◽  
Clinical Signs ◽  
Neck Region ◽  
Signs And Symptoms ◽  
Thyroid Function Test ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Simple Cyst ◽  
Etiological Factors ◽  
Function Tests

<p><strong>Background:</strong> Thyroid swellings are very frequently encountered in ENT practice, ranging from a simple cyst to a malignant tumour. Disorder of structure of thyroid gland, due to various etiological factors, will give rise to swelling in the neck region. Clinical signs and symptoms are inadequate to diagnose thyroid disorders as similar presentations are seen in various thyroid disorders. So, this study of thyroid swellings was done to know different clinical presentations, age and sex distribution, correlation between thyroid swellings and thyroid function tests, analyse various thyroid swellings and etiological factors based on pathological reports.</p><p class="abstract"><strong>Methods:</strong> A prospective study with 50 patients of thyroid swellings was conducted over 2 years, after taking consent from each patient. Patients were clinically examined by inspection, palpation, percussion, auscultation and underwent thyroid function tests. Ultrasonography (USG) and fine needle aspiration cytology (FNAC) was done in all patients.  </p><p class="abstract"><strong>Results:</strong> Total 50 patients of thyroid swellings were studied. Mean age of the patients was 38.92 years with female preponderance (74%). Thyroid swellings were commonly present bilaterally (54%). 82% cases showed euthyroid state. USG revealed that most of the patients had colloid nodule (46%), followed by MNG (26%). Majority of lesions were benign on both USG and FNAC reports. MNG (44%) was reported frequently in the provisional diagnosis, followed by colloid nodule (24%).</p><p class="abstract"><strong>Conclusions:</strong> In all cases of thyroid swellings, detailed clinical history, thorough clinical examination is required. Thyroid function test, USG and FNAC reports help to reach the definitive diagnosis. Histopathological report confirms and gives final diagnosis.</p><p> </p>

scholarly journals L-T4 Therapy in the Presence of Pharmacological Interferents

2020 ◽  
Vol 11 ◽  
Author(s):  
Salvatore Benvenga
Keyword(s):  
Thyroid Function ◽  
Cardiovascular Complications ◽  
Primary Hypothyroidism ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Central Hypothyroidism ◽  
Serum Free ◽  
Function Tests ◽  
Frequent Monitoring ◽  
Serum Free Thyroxine

Pharmacological interference on L-thyroxine (L-T4) therapy can be exerted at several levels, namely from the hypothalamus/pituitary through the intestine, where the absorption of exogenous L-T4 takes place. A number of medications interfere with L-T4 therapy, some of them also being the cause of hypothyroidism. The clinician should be aware that some medications simply affect thyroid function tests with no need of modifying the dose of L-T4 that the patient was taking prior to their prescription. Usually, the topic of pharmacological interference on L-T4 therapy addresses the patient with primary hypothyroidism, in whom periodic measurement of serum thyrotropin (TSH) is the biochemical target. However, this minireview also addresses the patient with central hypothyroidism, in whom the biochemical target is serum free thyroxine (FT4). This minireview also addresses two additional topics. One is the costs associated with frequent monitoring of the biochemical target when L-T4 is taken simultaneously with the interfering drug. The second topic is the issue of metabolic/cardiovascular complications associated with undertreated hypothyroidism.

scholarly journals HYPOTHYROIDISM AND GOITER IN A YOUNG MALE WITH SUSPECTED DIETARY IODINE DEFICIENCY FOLLOWED BY THYROTOXICOSIS AFTER IODINE SUPPLEMENTATION

2020 ◽  
Vol 6 (1) ◽  
pp. e19-e22
Author(s):  
Itivrita Goyal ◽  
Manu Raj Pandey ◽  
Rajeev Sharma
Keyword(s):  
Thyroid Gland ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Young Male ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Normal Range ◽  
Iodine Supplementation ◽  
Function Tests

Objective: Iodine deficiency disorders (IDDs) remain a major public health concern in most parts of the world but are extremely rare in North America. We describe a case of goiter in a young male with dietary history and findings suggestive of IDD. Methods: Laboratory and imaging procedures including thyroid function tests, autoantibodies, urine iodine, thyroid ultrasound, and radioactive iodine (RAI) uptake scan were performed. Results: On initial presentation, thyroid-stimulating hormone (TSH) was 24.4 mIU/L (normal range is 0.4 to 5.0 mIU/L), free thyroxine was <0.4 ng/dL (normal range is 0.8 to 1.8 ng/dL), and thyroid peroxidase antibody was positive at 43 IU/mL (normal range is <35 IU/mL). He reported consuming strawberries and peanut butter sandwiches with no intake of dairy or seafood due to gastrointestinal issues (abdominal pain, bloating, and nausea). Physical exam revealed a diffusely enlarged, palpable thyroid gland (grade II goiter). Ultrasound of the neck showed an enlarged thyroid gland with no nodules. RAI uptake scan showed diffuse increased uptake (91%). Given his poor diet, a 24-hour urinary iodine excretion test was ordered which was suggestive of very low iodine intake. He was started on multivitamins with 150 μg of iodine daily. On follow up, clinical exam showed grade I goiter and TSH had normalized to 0.7 mIU/L and free thyroxine was 1.2 ng/dL. He continued on iodine supplementation and tolerated iodine-rich foods. Six months later, thyroid function tests showed hyperthyroidism with TSH of <0.002 ng/dL and free thyroxine was elevated to 2.8 ng/dL. Iodine supplements were stopped. Conclusion: Hypothyroidism and goiter due to IDD should be suspected in the setting of poor dietary intake. IDDs can be rapidly diagnosed in a patient on a restricted diet with multiple urinary iodine determinations and RAI study. Regular thyroid labs should be done to monitor for hyperthyroidism that can develop after iodine supplementation.

scholarly journals THYROID FUNCTION IN PREGNANCY: MATERNAL AND FETAL OUTCOMES WITH HYPOTHYROIDISM AND SUBCLINICAL THYROID DYSFUNCTION

2011 ◽  
Vol 22 (3) ◽  
pp. 169-187
Author(s):  
NEIL K VANES ◽  
JOHN H LAZARUS ◽  
SHIAO-Y CHAN
Keyword(s):  
Thyroid Hormones ◽  
Pregnant Women ◽  
Thyroid Function ◽  
Thyroid Dysfunction ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Fetal Outcomes ◽  
Function Tests ◽  
Maternal Wellbeing ◽  
In Pregnancy

Thyroid hormones are important in the development of the fetus and the placenta as well as in maintaining maternal wellbeing. Thyroid disorders are common in the population as a whole, particularly in women, and therefore are common during pregnancy and the puerperium. Biochemical derangement of thyroid function tests are present in approximately 2.5–5% of pregnant women.

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