scholarly journals Subclinical Hyperthyroidism: Diagnostic Criteria and Principles of Treatment

2016 ◽  
pp. 92-96
Author(s):  
Vita Galytska

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 subnormal 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 thyroid1stimulating hormone is 0,1–0,39 mIU/l; stage 2 – the level of thyroid1stimulating 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 thyroid1stimulating hormone it is necessary to investigate the level of free thyroxine, free or bound triiodothyronine. Patients with primary subnormal 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.

2016 ◽  
pp. 75-79
Author(s):  
Vita Galitskaya

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.


2016 ◽  
pp. 114-118
Author(s):  
V.V. Galitskaya ◽  

This article presents the European Thyroid Association guidelines for diagnosis and treatment of subclinical hyperthyroidism, 2015. Determination of thyroid-stimulating hormone levels can help to diagnose a variety of pathological conditions: disorders of sexual development, amenorrhea (primary or secondary), infertility, miscarriage, 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: Class 1 – the level of thyroid-stimulating hormone is 0.1–0.39 mIU/l; class 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. 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 and 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 in 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. Key words: thyroid, thyroid stimulating hormone, hyperthyroidism, thyrotoxicosis, subclinical hyperthyroidism, Graves’ disease, toxic multinodular goiter.


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 ◽  
...  

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.


2020 ◽  
Author(s):  
Cheng Huang ◽  
Ying Wu ◽  
Linong Chen ◽  
Zhiya Yuan ◽  
Shuzhe Yang ◽  
...  

Abstract Background: The reference intervals of thyroid hormone will change at different stages of pregnancy because of physiological alterations. On the other hand, the reference intervals of hyroid hormone will also change in different detection systems due to manufacturer’s methodology as well as different race. The objective in this study was to establish the assay method- and trimester-specific reference intervals for thyroid stimulating hormone, free thyroxine, and free triiodothyronine for pregnant women in the Chengdu.Methods: A prospective, population-based cohort study involved 23701 reference samples of pregnant women during the three trimesters and 8646 non-pregnant women with pre-pregnancy clinical and laboratory tests. The 2.5th and 97.5th percentiles were calculated as the reference intervals for thyroid stimulating hormone, free thyroxine, and free triiodothyronine at each trimester of pregnant women according to ATA Guidelines.Results: The reference interval of thyroid stimulating hormone in the 2.5th and 97.5th percentiles has a significant increasing trend from first trimester, to second trimester, and to third trimester, which was 0.08-3.79 mIU/L for first trimester, and 0.12-3.95 mIU/L for second trimester, and 0.38-4.18 mIU/L for third trimester, respectively (P < 0.001). However, the reference intervals of free thyroxine and free triiodothyronine in the 2.5th and 97.5th percentiles have significant decreasing trends from first trimester, to second trimester, and to third trimester, which were 11.87-18.83 pmol/L and 3.77-5.50 pmol/L for first trimester, and 11.22-18.19 pmol/L and 3.60-5.41 pmol/L for second trimester, and 10.19-17.42 pmol/L and 3.37-4.79 pmol/L for third trimester, respectively (both P < 0.001).Conclusion: It is necessary to establish assay method- and trimester-specific reference intervals for thyroid stimulating hormone, free thyroxine, and free triiodothyronine because the reference intervals of these thyroid hormones are significantly different at different stages of pregnancy.


2019 ◽  
Vol 57 (7) ◽  
pp. 1044-1052 ◽  
Author(s):  
Danchen Wang ◽  
Songlin Yu ◽  
Chaochao Ma ◽  
Honglei Li ◽  
Ling Qiu ◽  
...  

Abstract Background Thyroid hormone levels are essential for diagnosing and monitoring thyroid diseases. However, their reference intervals (RIs) in elderly Chinese individuals remain unclear. We aimed to identify factors affecting thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels using clinical “big data” to establish hormone level RIs for elderly Chinese individuals. Methods We examined 6781, 6772, and 6524 subjects aged ≥65 years who underwent FT3, FT4, and TSH tests, respectively, at the Peking Union Medical College Hospital between September 1, 2013, and August 31, 2016. Hormones were measured using an automated immunoassay analyzer (ADVIA Centaur XP). RIs were established using the Clinical Laboratory Standards Institute document C28-A3 guidelines. Results The median TSH was significantly higher in women than in men; the opposite was true for median FT3 and FT4 levels. No differences were observed in TSH or FT4 by age in either sex or overall; FT3 levels significantly decreased with age. Seasonal differences were observed in TSH and FT3 levels but not FT4 levels; the median TSH was the highest in winter and lowest in summer, whereas the median FT3 was the lowest in summer (albeit not significantly). RIs for TSH were 0.53–5.24 and 0.335–5.73 mIU/L for men and women, respectively; those for FT3 were 3.76–5.71, 3.60–5.42, and 3.36–5.27 pmol/L in 64- to 74-, 75- to 84-, and 85- to 96-year-old subjects, respectively. The RI for FT4 was 11.70–20.28 pmol/L. Conclusions RIs for TSH in elderly individuals were sex specific, whereas those for FT3 were age specific.


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