Serum free thyroid hormones in different degrees of hypothyroidism and in euthyroid autoimmune thyroiditis

1987 ◽  
Vol 114 (4) ◽  
pp. 559-564 ◽  
Author(s):  
C. Ferrari ◽  
A. Paracchi ◽  
E. Parisio ◽  
F. Codecasa ◽  
M. Mucci ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Thyroid Function ◽  
Autoimmune Thyroiditis ◽  
Subclinical Hypothyroidism ◽  
Healthy Subjects ◽  
Direct Determination ◽  
Serum Free ◽  
Free Thyroid Hormones ◽  
Hypothyroid Patients

Abstract. Serum total and free T4 and T3, thyroxinebinding globulin (TBG) and TSH, basal and 20, 30 and 60 min after TRH (200 μg, iv), were evaluated in 125 hypothyroid patients (38 with severe, 23 with mild, and 64 with subclinical hypothyroidism), in 35 euthyroid subjects with autoimmune thyroiditis, and in 51 healthy controls. T4/TBG and T3/TBG ratios were also calculated. A significant decrease in all indices of thyroid function except for T3 occurred simultaneously with a significant increase in basal and TRH-stimulated TSH levels from healthy subjects to subclinical hypothyroids, from subclinical to mild and from mild to severe hypothyroids; euthyroid patients with autoimmune thyroiditis did not differ from healthy subjects. All severe hypothyroid patients had low T4 as well as free T4 (FT4), free T3 (FT3), T4/TBG and T3/TBG ratios, but among mild and subclinical hypothyroids direct determination of FT4 and FT3 proved to be a better index of thyroid function than determination of T4 and T3 even after correction for TBG levels. FT4 was the most commonly abnormal index (19 of 23 subjects with mild and 14 of 64 with subclinical disease). Regression analysis showed that FT4, T4/TBG ratio, T4, and FT3 had a significant inverse correlation with TSH in hypothyroid patients. Discriminant analysis showed that among the thyroid parameters, FT4 is the variable which discriminates best between control subjects and the 3 groups of hypothyroid patients. These data extend previous reports and in a large series of patients confirm the biological meaning and the clinical value of direct measurement of serum free thyroid hormones in hypothyroidism. Nevertheless, the finding that both FT4 and FT3 are in the normal range in some patients with mild and in most with subclinical hypothyroidism indicates that increased TSH secretion remains the most sensitive index of thyroid failure.

THYROID FUNCTION AND PLASMA CYCLIC AMP RESPONSE TO INTRAVENOUS GLUCAGON

1977 ◽  
Vol 85 (4) ◽  
pp. 760-768 ◽  
Author(s):  
S. Nistrup Madsen
Keyword(s):  
Cyclic Amp ◽  
Thyroid Hormones ◽  
Thyroid Function ◽  
Healthy Subjects ◽  
Blood Levels ◽  
Sensitive Test ◽  
Normal Response ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients

ABSTRACT The glucagon stimulated increase in plasma cyclic AMP has been studied in 17 healthy subjects, in 13 hyperthyroid and in 14 hypothyroid patients. Six hyperthyroid and 2 hypothyroid patients were re-investigated after at least 15 months of treatment. The results show: 1) The glucagon stimulated cyclic AMP response is significantly increased in hyperthyroid patients considered as a group, and is reduced in patients with hypothyroidism. 2) Three hyperthyroid and 4 hypothyroid patients showed a normal response to iv glucagon, indicating that the plasma cyclic AMP response to iv glucagon is not a sensitive test for the evaluation of peripheral thyroid states. This suggests that the effects of thyroid hormones in the liver does not necessarily follow the effects in other tissues. 3) Re-investigation of treated patients showed that the cyclic AMP response can be normalized by treatment, both in hyperthyroidism and in hypothyroidism. However, in patients treated for hyperthyroidism a hyper-response to glucagon can continue after blood levels of thyroid hormones are reduced to normal. This suggests an inertia in the loss of the hyper-response to glucagon, once a hyperfunction has been induced. A similar inertia in the loss of glucagon sensitivity in hypothyroidism could explain the large number of normal tests in hypothyroid patients.

Serum free thyroid hormones in subclinical hypothyroidism

1986 ◽  
Vol 9 (4) ◽  
pp. 315-319 ◽  
Author(s):  
A. Pacchiarotti ◽  
Enio Martino ◽  
L. Bartalena ◽  
F. Aghini-Lombardi ◽  
L. Grasso ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Subclinical Hypothyroidism ◽  
Serum Free ◽  
Free Thyroid Hormones

The influence of free fatty acids on the free fraction of thyroid hormones in serum as estimated by ultrafiltration

1987 ◽  
Vol 116 (1) ◽  
pp. 102-107 ◽  
Author(s):  
C. Bregengåard ◽  
C. Kirkegaard ◽  
J. Faber ◽  
S. Poulsen ◽  
K. Siersbæk-Nielsen ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Thyroid Hormones ◽  
Healthy Subjects ◽  
Binding Proteins ◽  
Free Fraction ◽  
Nonthyroidal Illness ◽  
Serum Free ◽  
Free Thyroid Hormones ◽  
Serum Pool ◽  
Somatic Illness

Abstract. Thyroid hormones are displaced from their binding proteins in serum during nonthyroidal somatic illness, and FFA have been claimed to contribute. It seems mandatory to evaluate this effect using techniques for the measurements of serum free thyroid hormones in which serum remains undiluted. We measured the effect of 7 common human FFA on the free fraction of T4, T3 and rT3 in serum from healthy subjects using an ultrafiltration technique by which serum is diluted only minimally. In addition we measured the effect of oleic acid on the free fractions of the iodothyronines in pooled serum from healthy subjects and in pooled serum from patients with nonthyroidal illness. All FFA tested were able to displace both T4, T3 and rT3, but to a varying degree, arachidonic and linoleic acid being the most potent ones. A 20% increase in the free fractions of T4, T3 and rT3, respectively, was obtained by adding between 1.7–3.3 mmol/l, 1.3–4.6 mmol/l and 1.0–2.4 mmol/l of the different FFA. A serum pool obtained from patients with nonthyroidal somatic illness was more sensitive to oleic acid than a serum pool obtained from healthy subjects, since 2–3 times less oleic acid was necessary to induce a 20% increase in the free fractions of thyroid hormones. It is concluded that FFA are able to displace both T4, T3 and rT3 from their serum binding proteins in healthy subjects as well as in patients with nonthyroidal illness. However, serum from patients with nonthyroidal illness was more sensitive to the displacing activity of oleic acid than serum from healthy subjects. This was possibly due to reduced affinity of the serum binding proteins to thyroid hormones, and it could be argued that a factor different from FFA seemed responsible.

scholarly journals Neonates Born to Mothers with Graves’ Disease: 15 Year Experience of a Pediatric Endocrinology Department

2020 ◽  
Vol 33 (7-8) ◽  
pp. 483
Author(s):  
Inês Romão Luz ◽  
João Rio Martins ◽  
Mónica Jerónimo ◽  
Joana Serra Caetano ◽  
Rita Cardoso ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Cord Blood ◽  
Thyroid Function ◽  
Case Series ◽  
Function Evaluation ◽  
Graves Disease ◽  
Thyrotropin Receptor ◽  
Second Trimester ◽  
Pediatric Endocrinology ◽  
Free Thyroid Hormones

Introduction: Graves disease is characterized by the existence of autoantibodies directed to the thyrotropin receptor, which can have a stimulatory/inhibitory action, in women with the condition, their fetus or neonate. Our aim was to review the case series of these neonates in order to establish neonatal thyroid function predictors.Material and Methods: Retrospective cohort study of the database of the Department of Pediatric Endocrinology, including patients born to mothers with Graves’ disease, between 2002 and 2017. Clinical and biochemical data were collected from mothers and offspring.Results: Fifty newborns, from 46 women with a median of 3.5 years after diagnosis, were included. During all trimesters of pregnancy, more than half of women had positive autoantibodies directed to the thyrotropin receptor. Not every woman had a complete thyroid function evaluation every trimester. In 32 newborns, cord blood screening was done. During the neonatal period, there were three cases of hypothyroidism and two of hyperthyroidism. The mothers of these five newborns had higher levels of free thyroid hormones during the second trimester (p = 0.03). The level of antibodies directed to the thyrotropin receptor was significantly higher in the cord blood (p = 0.03) and in the first neonatal test (p = 0.03) of these dysthyroid newborns.Discussion: Our results reinforce the need for every pregnant woman with Graves’ disease to be subject to thyroid function and autoantibodies evaluation during every trimester, as well as the importance of evaluating these antibodies in cord blood.Conclusion: High levels of free thyroid hormones during the second trimester of pregnancy and antibodies directed to the thyrotropin receptor value in cord blood are predictors of dysthyroidism in neonates born from women with Grave’s disease.

Pharmacokinetics of thyrotrophin-releasing hormone in patients in different thyroid states

1991 ◽  
Vol 128 (1) ◽  
pp. 153-159 ◽  
Author(s):  
E. Iversen
Keyword(s):  
Thyroid Hormones ◽  
Half Life ◽  
Thyrotrophin Releasing Hormone ◽  
Tissue Degradation ◽  
The Central Nervous System ◽  
Membrane Bound ◽  
Hormone Control ◽  
Hypothyroid Patients

ABSTRACT In view of recent reports suggesting that thyroid hormone control of TRH degradation occurs outside the central nervous system in animals, the effect of thyroid status on serum and tissue degradation of TRH in man was investigated. In six patients with hyperthyroidism and six patients with hypothyroidism, constant TRH infusions were carried out for determination of plasma clearance rate (PCR) and half-life of disappearance (t½) of TRH, with simultaneous determination of half-life of disappearance in serum in vitro (t½p). Using a kinetic model, this enabled the calculation of the half-life of disappearance in the extravascular tissue compartment (t½t). All patients were reinvestigated after they had become euthyroid. PCR, t½ and t½p were 22·1 ±3·4 ml/kg per min, 6·8±1·1 min and 17·3±6·7 min (means ± s.d.) respectively in the euthyroid patients. The t½p was slightly but significantly prolonged during hyperthyroidism. The t½ was 5·6 min in the hyperthyroid patients compared with 9·4 min in the hypothyroid patients. The calculated t½t was 6·5 min in the euthyroid patients. In the patients with untreated hyperthyroidism, t½t was significantly reduced (22·7±10·7%; mean ± s.d.), while it was considerably prolonged (41·1±24·6%) in patients with untreated hypothyroidism. The percentage reduction or prolongation of t½t was negatively correlated with the logarithm of the serum concentrations of thyroxine (r = 0·92) and tri-iodothyronine (r= 0·91) in the untreated patients. Thus, thyroid hormones induce alterations in the pharmacokinetics of TRH. This may partly be due to induction by thyroid hormones of membrane-bound pyroglutamyl aminopeptidase. Journal of Endocrinology (1991) 128, 153–159

scholarly journals Performance evaluation of the Vitros®3600 immunodiagnostic system for the determination of free thyroid hormones

2011 ◽  
Vol 49 (8) ◽  
Author(s):  
Giorgia Querci ◽  
Giulia Galli ◽  
Paolo Piaggi ◽  
Veronica Rosellini ◽  
Monica Giannetti ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Thyroid Hormones ◽  
Free Thyroid Hormones

scholarly journals Variation in thyroid function in subclinical hypothyroidism: importance of clinical follow-up and therapy

2011 ◽  
Vol 164 (3) ◽  
pp. 317-323 ◽  
Author(s):  
Jesper Karmisholt ◽  
Stig Andersen ◽  
Peter Laurberg
Keyword(s):  
Thyroid Function ◽  
Subclinical Hypothyroidism ◽  
Repeated Measurements ◽  
Thyroid Peroxidase ◽  
Biochemical Tests ◽  
Free Triiodothyronine ◽  
Significant Difference ◽  
Hypothyroid Patients ◽  
Symptoms And Signs

Subclinical hypothyroidism (SCH) is a common condition that is often observed without therapy. However, no evidence-based recommendation exists with regards to how patients with untreated SCH should be monitored.Monitoring involves regular assessment of symptoms and signs of hypothyroidism (HYPO) and biochemical tests of thyroid function. An important question when repeated tests of thyroid function are performed is how large a difference in test results is needed to be confident that the change is real and not just due to chance variation.Recent data show that the least significant difference between two tests in SCH is 40% for TSH and 15% for free thyroxine and free triiodothyronine, with 90% confidence. Furthermore, monitoring has to be based on biochemical function testing because serial evaluation of symptoms and signs related to HYPO is rather insensitive in detecting worsening of thyroid insufficiency.When the presence of thyroid peroxidase auto-antibodies (TPO-Ab) in serum has been demonstrated, repeated measurements do not add much useful information in the monitoring of individual subclinical hypothyroid patients, as levels of TPO-Ab vary in parallel with TSH in these patients.Lastly, we discuss how differences in the monitoring procedure influence the diagnostic outcome, and we suggest a follow-up approach for untreated subclinical hypothyroid patients.

scholarly journals Relationship of TSH with BMI in subclinical hypothyroid patients

2019 ◽  
Vol 9 (4) ◽  
pp. 4193-4198
Keyword(s):  
Thyroid Hormones ◽  
Negative Correlation ◽  
Subclinical Hypothyroidism ◽  
Inverse Correlation ◽  
Feedback Mechanism ◽  
Negative Feedback Mechanism ◽  
Body Development ◽  
Relationship Of ◽  
The Relationship ◽  
Hypothyroid Patients

Thyroid hormones (T3 and T4) synthesized by thyroid gland and play an essential role in normal body development and tissue metabolism. Iodine is an essential factor that is required for the synthesis of thyroid hormones. The secretion of thyroid hormones is regulated by Negative feedback mechanism. After reached in blood circulation the majority of T4 and T3 bound with carrier proteins called thyroxine binding proteins (TBG) which shows higher affinity for T4. The common diseases related to thyroid hormones include Hypothyroidism, hyperthyroidism, thyroiditis, goiter, nodes, and tumors of thyroid glands (benign and malignant). Subclinical hypothyroidism also called mild thyroid failure is defined as normal thyroid hormones but mildly elevated TSH (5 – 10 uIU/ml) with no or mild sign and symptoms. The thyroid disorders are more prevalent in females than males. Hypothyroidism is associated with obesity and various studies conducted to find out the relationship between TSH and BMI observed different finding in the particular study. In the present study, a poor positive correlation between TSH and BMI was observed in the total euthyroid subjects. A poor negative association between TSH and BMI in euthyroid males and poor positive (r value – 0.21) relationship was observed in euthyroid females. In Subclinical hypothyroid patients (total, male and female), Poor negative correlation was observed between TSH and BMI. The conclusion of this study is, as TSH increased the BMI will also increase in (mostly females) euthyroid subjects. The Inverse or poor negative correlation was observed within TSH and BMI among euthyroid males and an inverse correlation was noticed in patients with subclinical hypothyroidism.

Sign in / Sign up

Export Citation Format

Share Document