scholarly journals Euthyroid athyroxinemia – a novel endocrine syndrome

2017 ◽  
Vol 2017 ◽  
Author(s):  
Nicholas Woodhouse ◽  
Fatima Bahowairath ◽  
Omayma Elshafie
Keyword(s):  
Thyroid Nodule ◽  
Thyroid Function ◽  
Urinary Iodine ◽  
Free Thyroxine ◽  
List Type ◽  
Thyroid Function Tests ◽  
Thyroxine Level ◽  
Learning Points ◽  
Free Thyroxine Level ◽  
Tsh Levels

Summary A 55-year-old female was referred with abnormal thyroid function tests (TFTs); the free thyroxine level (FT4) was undetectable <3.3 pmol/L (normal: 7.9–14.4), while her FT3, TSH and urinary iodine levels were normal. She was clinically euthyroid with a large soft lobulated goitre that had been present for more than thirty years. She received an injection of recombinant human TSH (rhTSH) following which there was a progressive rise of the FT3 and TSH levels to 23 pmol/L and >100 mIU/L respectively at 24 h, The FT4 however remained undetectable throughout. Being on thyroxine 100 µg/day for one month, her FT4 level increased to 15 pmol/L and TSH fell to 0.08 mIU/L. Four years earlier at another hospital, her FT4 level had been low (6.8 pmol/L) with a normal TSH and a raised Tc-99 uptake of 20% (normal<4%). We checked the TFTs and Tc-99 scans in 3 of her children; one was completely normal and 2 had euthyroid with soft lobulated goitres. Their Tc-99 scan uptakes were raised at 17% and 15%, with normal TFTs apart from a low FT4 7.2 pmol/L in the son with the largest thyroid nodule. This is a previously unreported form of dyshormonogenesis in which, with time, patients gradually lose their ability to synthesize thyroxine (T4) but not triiodothyroxine (T3). Learning points: This is a previously unreported form of dyshormonogenetic goitre. This goitre progressively loses its ability to synthesize T4 but not T3. The inability to synthesize T4 was demonstrated by giving rhTSH.

THE EFFECTS OF PHENYLBUTAZONE ON THYROID FUNCTION

1973 ◽  
Vol 72 (2) ◽  
pp. 257-264 ◽  
Author(s):  
M. O. Abiodun ◽  
R. Bird ◽  
C. W. H. Havard ◽  
N. K. Sood
Keyword(s):  
Thyroid Function ◽  
Significant Rise ◽  
Free Thyroxine ◽  
Continuous Treatment ◽  
Total Serum ◽  
Thyroid Function Tests ◽  
Tsh Secretion ◽  
Total Thyroxine ◽  
Pre Treatment ◽  
Tsh Levels

ABSTRACT It is known that phenylbutazone suppresses the thyroidal uptake of radioactive iodine and the serum level of protein-bound iodine (PBI) during the first week of treatment, with a return to normal values after 2 weeks of continuous treatment. Up till now the initial suppression of thyroid function has been presumed due to inhibition of TSH secretion. In the present study, total serum thyroxine and percentage dialysable thyroxine have been measured and the serum absolute free thyroxine concentration calculated in 12 patients before starting treatment with phenylbutazone orally, after 4 days of treatment and again after 14 days. Serum TSH was assayed in 10 of these patients before, and on the 4th day of treatment. Sera were assayed for TSH after 14 days on the drug in 6 patients. On the 4th day of treatment, the levels of total thyroxine had fallen but the levels of free thyroxine remained unchanged. TSH levels were also unaltered. By the 14th day of treatment, free thyroxine levels had fallen significantly below pre-treatment values but no significant rise in TSH could be demonstrated in the 6 patients studied. At no time was there a fall in TSH levels and we conclude that suppression of some thyroid function tests during the first week of treatment with phenylbutazone is due to direct inhibition of the gland by the drug.

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 Measurement of the Plasma Free Thyroxine Level as a Test of Thyroid Function

BMJ ◽  
1966 ◽  
Vol 2 (5515) ◽  
pp. 668-670 ◽  
Author(s):  
M. Wellby ◽  
M. W. O'Halloran
Keyword(s):  
Thyroid Function ◽  
Free Thyroxine ◽  
Thyroxine Level ◽  
Free Thyroxine Level

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.

scholarly journals Moderate Iodine Deficiency Is Common in Pregnancy but Does Not Alter Maternal and Neonatal Thyroid Function Tests

2020 ◽  
Vol 11 ◽  
Author(s):  
Tal Schiller ◽  
Arnon Agmon ◽  
Viviana Ostrovsky ◽  
Gabi Shefer ◽  
Hilla Knobler ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Content ◽  
First Trimester ◽  
Thyroid Function Tests ◽  
Neonatal Thyroid Function ◽  
Iodine Deficiency In Pregnancy ◽  
In Pregnancy

IntroductionAn Israeli national survey found that 85% of pregnant women had urinary iodine content (UIC) levels below the adequacy range (&lt;150 µg/L). Widespread desalinated water usage and no national fortification plan are possible causes. Studies assessing relationships between iodine status and maternal and neonatal thyroid function provided varying results. Our aims were to determine whether iodine deficiency was associated with altered maternal or neonatal thyroid function and the factors leading to iodine deficiency.MethodsA cross-sectional study including 100 healthy women without prior thyroid disease, in their first trimester of a singleton pregnancy were recruited from an HMO clinic in central Israel. The women were followed from their first trimester. All women completed a 24-h dietary recall and life habits questionnaires. We tested for UIC, maternal and neonatal thyroid function, maternal autoantibodies, and neonatal outcomes.ResultsMedian UIC in our cohort was 49 µg/L [25%–75% interquartile range (IQR) 16-91.5 µg/L], with 84% below adequacy range. No correlation was found between iodine deficiency and maternal or neonatal thyroid function which remained within normal ranges. Antibody status did not differ, but thyroglobulin levels were significantly higher in iodine insufficient subjects. UIC was higher in women consuming an iodine containing supplement. There was no association between UIC and dietary iodine content or water source.ConclusionsModerate iodine deficiency is common in our healthy pregnant women population. Our data imply that moderate iodine deficiency in pregnancy seem sufficient to maintain normal maternal and neonatal thyroid function.

scholarly journals Transient cold nodule of the thyroid due to localized postpartum thyroiditis

1998 ◽  
pp. 562-564 ◽  
Author(s):  
R Luboshitzky ◽  
G Qupti ◽  
A Ishai ◽  
M Dharan
Keyword(s):  
Thyroid Nodule ◽  
Thyroid Function ◽  
Needle Aspiration ◽  
Thyroid Function Tests ◽  
Thyroid Scintigraphy ◽  
Postpartum Thyroiditis ◽  
Normal Thyroid Function ◽  
Function Tests ◽  
Needle Aspiration Cytology ◽  
Cold Nodule

A 27-year-old woman with no previous personal or family history of thyroid disease was referred to us for the evaluation of thyroid nodule, five months postpartum. Thyroid scintigraphy demonstrated a left cold nodule. Fine needle aspiration cytology of the nodule showed a mixture of colloid, follicular cells and lymphocytes, suggesting lymphocytic thyroiditis. Thyroid function tests were normal and thyroid autoantibodies were negative. After two months the thyroid nodule was not palpated and thyroid scintigraphy returned to normal. Thyroid function tests remained normal twelve months after delivery. These findings suggest that postpartum thyroiditis may present as a localized transient form and should be considered in the differential diagnosis of painless solitary nodule that appears postpartum.

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