Increased Serum Concentration of Free L-Triiodothyronine in Patients Treated with L-Thyroxine

1983 ◽  
Vol 22 (05) ◽  
pp. 251-254
Author(s):  
R. Schmitz ◽  
H. Bongers ◽  
A. Löw ◽  
J. Mahlstedt ◽  
K. Joseph ◽  
...  

This study demonstrates that in spite of measured normal concentrations of carrier proteins one cannot deduce in all cases a normal fT3 from a normal level of TT3 when 1-thyroxine given for diagnostic or therapeutic purposes is present in excess. The displacement of 1-triiodothyronine from its binding sites is shown in 35 patients with non-toxic goitre who received an oral dose of 200 μg 1-thyroxine/die for two weeks. Apart from a significant increase of TT4 (from 7.85 to 14.21 μg/dl ≙ + 81 %) and of fT4 (from 1.58 to 3.7 ng/dl ≙ + 134%) there is only a slight increase in TT3 from 148 to 158 ng/dl (≙ + 10%) after 14 days of treatment. By contrast fT3 rises clearly from 4.97 to 8.07 pg/ml ≙ + 63% (normal range: 2.8-5.6 pg/ml). Compared with the increase of TT3 (+ 10%) the free T3 rises by a factor of 6.3 (63 %/10%). On account of higher affinity of 1-thyroxine to binding proteins the free T4 is influenced to a lesser degree. Compared with the increase of TT4 (+ 81 %) free T4 rises by a factor of 1.6 (134%/81 %). It is supposed that the serum concentration of free T3 can be increased despite a normal concentration of TT3 when 1-thyroxine is present in excess. Therefore, for laboratory work fT3 should be assigned a higher validity than TT3 when patients are treated with comparatively high doses of 1-thyroxine.

Author(s):  
M. Cioffi ◽  
P. Gazzerro ◽  
M.T. Vietri ◽  
R. Magnetta ◽  
A. Durantey ◽  
...  

2017 ◽  
Vol 6 (4) ◽  
pp. 200-205 ◽  
Author(s):  
Jan Calissendorff ◽  
Henrik Falhammar

Background Graves’ disease is a common cause of hyperthyroidism. Three therapies have been used for decades: pharmacologic therapy, surgery and radioiodine. In case of adverse events, especially agranulocytosis or hepatotoxicity, pre-treatment with Lugol’s solution containing iodine/potassium iodide to induce euthyroidism before surgery could be advocated, but this has rarely been reported. Methods All patients hospitalised due to uncontrolled hyperthyroidism at the Karolinska University Hospital 2005–2015 and treated with Lugol’s solution were included. All electronic files were carefully reviewed manually, with focus on the cause of treatment and admission, demographic data, and effects of iodine on thyroid hormone levels and pulse frequency. Results Twenty-seven patients were included. Lugol’s solution had been chosen due to agranulocytosis in 9 (33%), hepatotoxicity in 2 (7%), other side effects in 11 (41%) and poor adherence to medication in 5 (19%). Levels of free T4, free T3 and heart rate decreased significantly after 5–9 days of iodine therapy (free T4 53–20 pmol/L, P = 0.0002; free T3 20–6.5 pmol/L, P = 0.04; heart rate 87–76 beats/min P = 0.0007), whereas TSH remained unchanged. Side effects were noted in 4 (15%) (rash n = 2, rash and vomiting n = 1, swelling of fingers n = 1). Thyroidectomy was performed in 26 patients (96%) and one was treated with radioiodine; all treatments were without serious complications. Conclusion Treatment of uncontrolled hyperthyroidism with Lugol’s solution before definitive treatment is safe and it decreases thyroid hormone levels and heart rate. Side effects were limited. Lugol’s solution could be recommended pre-operatively in Graves’ disease with failed medical treatment, especially if side effects to anti-thyroid drugs have occurred.


1985 ◽  
Vol 8 (6) ◽  
pp. 495-500 ◽  
Author(s):  
Yuh-Shyun Wang ◽  
A. E. Pekary ◽  
M. L. England ◽  
Jerome M. Hershman
Keyword(s):  
Free T4 ◽  

1975 ◽  
Vol 80 (1) ◽  
pp. 42-48 ◽  
Author(s):  
K. W. Wenzel ◽  
H. Meinhold ◽  
H. Schleusener

ABSTRACT Since contradicting results about the existence of T3 or T3 and T4 receptors in pituitary tissue have been reported, the influence of L-triiodothyronine (L-T3) or L-thyroxine (L-T4) on TRH stimulated TSH release was investigated. Oral administration of 50 μg L-T3 caused an increasing inhibition of TSH response to 400 μg TRH from 64 % 2 h after L-T3 intake to 29% after 24 h, while serum T3 peaks up to 5.45 ng/ml occurred between 2 to 4 h after L-T3 ingestion and became normal after 8 to 10 h. This delay in the T3 action on TRH inhibition agrees with the postulate that T3 induces the synthesis of an inhibiting protein which is blocking TSH liberation. Oral administration of 1000 μg L-T4 induced increments of serum T4 up to 221 ng/ml between 6 to 24 h after intake; however, a TRH inhibition of 62 % did not become evident before 48 h. At this time T3 levels had risen to the upper normal range. These results support the theory that T3 is responsible for the regulation of TSH secretion. An intra-pituitary conversion from T4 to T3 seems more likely the cause of the TRH inhibition rather than the peripheral T4-T3 conversion or a direct action by T4 binding sites in the pituitary.


Author(s):  
Claudia Irene Maushart ◽  
Jaël Rut Senn ◽  
Rahel Catherina Loeliger ◽  
Judith Siegenthaler ◽  
Fabienne Bur ◽  
...  

Abstract Context Thyroid hormone is crucial for the adaptation to cold. Objective To evaluate the effect of hyperthyroidism on resting energy expenditure (REE), cold-induced thermogenesis (CIT) and changes in body composition and weight. Design Prospective cohort study. Setting Endocrine outpatient clinic at tertiary referral center. Patients Eighteen patients with overt hyperthyroidism. Main Outcome Measures We measured REE during hyperthyroidism, after restoring euthyroid TH levels and after 3 months of normal thyroid function. In fourteen patients energy expenditure (EE) was measured before and after a mild cold exposure of two hours and CIT was the difference between EEcold and EEwarm. Skin temperatures at eight positions were recorded during the study visits. Body composition was assessed by dual X-ray absorption. Results Free T4 (fT4) and free T3 (fT3) decreased significantly over time (fT4, p=0.0003; fT3, p=0.0001). REE corrected for lean body mass (LBM) decreased from 42 ± 6.7 kcal/24h/kg LBM in the hyperthyroid to 33±4.4 kcal/24h/kg LBM (-21%, p<0.0001 vs hyperthyroid) in the euthyroid state and three months later to 33 ± 5.2 kcal/24h/kg LBM (-21%, p=0.0022 vs. hyperthyroid, overall p<0.0001). Free T4 (p=0.0001) and free T3 (p<0.0001) were predictors of REE. CIT did not change from the hyperthyroid to the euthyroid state (p=0.96). Hyperthyroidism led to increased skin temperature at warm ambient conditions but did not alter core body temperature, nor skin temperature after cold exposure. Weight regain and body composition were not influenced by REE and CIT during the hyperthyroid state. Conclusions CIT is not increased in patients with overt hyperthyroidism.


2021 ◽  
Vol 17 (1) ◽  
pp. 32-37
Author(s):  
A.G. Sazonova ◽  
T.V. Mokhort ◽  
N.V. Karalovich

Background. Chronic kidney disease (CKD) is known to affect the thyroid axis, including thyroid hormone metabolism. It has been established that a decrease in renal function can be combined with changes in thyroid function. Thyroid dysfunction also has implications for renal blood flow, glomerular filtration rate (GFR), tubular transport, electrolyte homeostasis, and glomerular structure. The purpose of the study was to determine the features of thyroid function in patients with type 1 diabetes mellitus (T1DM) and CKD and develop recommendations for hormonal testing of thyroid pathology. Materials and methods. One hundred and twenty-one patients with T1DM with CKD were divided into 3 groups: group 1 — 78 individuals with GFR ≤ 60 ml/min/1.73 m2, group 2 — 20 people receiving renal replacement therapy (RRT), group 3 — 23 patients after renal transplantation (RT) with adequate graft function (the duration of the renal transplant is 3.62 (1.47; 4.28) years). Results. In T1DM and CKD group, the diagnostic value of thyroid-stimulating hormone is reduced due to the absence of differences in its values with a decrease in T4 and T3. Free T3 is the most sensitive marker of thyroid dysfunction in CKD. Thyroid disorders in T1D and CKD patients have a non-immune genesis. T1DM patients on RRT after hemodialysis (HD) procedure have an increase in total and free T4 and free T3, consequently, monitoring of thyroid disorders should be done immediately after the HD session. The restoration of normal values of peripheral conversion index and free T3 occurs within 1–2 years after TR, depending on the duration of RRT receiving. After more than 3 post-transplantation years, there is an increase in peripheral conversion index, which characterizes the imbalance of peripheral thyroid hormones towards a decrease in free T3 with relatively stable free T4. Conclusions. Thyroid dysfunctions are typical for all stages of the pathological process in CKD in patients with type 1 diabetes mellitus, including patients at the terminal stage and after successful kidney transplantation. The changes in thyroid hormones are associated with the RRT experience and can potentially affect the survival of patients.


2020 ◽  
pp. 1-3
Author(s):  
Annapoorani R ◽  
Nagasudha D

Thyroid dysfunction and insulin resistance are important endocrinological causes of spontaneous abortions. This study is resistancewith spontaneous abortions Thyroid dysfunction and Insulin resistance are common endocrinological causes of abortions.The present study is a case control study where 75 patients with spontaneous abortions below 20 weeks were taken as cases and 75 patients with normal on going pregnancy without previous history of miscarriage were taken as controls. Thyroid Function Tests (Free T3 ,Free T4,TSH) ,Oral Glucose Tolerance Test following 75 mg glucose load were done in cases and controls. Fasting glucose and insulin levels were measured and Insulin resistance was calculated using homeostatic model assessment method (HOMA- IR).Free T3 levels were signicantly lower and TSH levels were signicantly higher in study group indicating the presence of hypothyroidism in the abortus group. The HOMA-IR insulin resistance scores were apparently higher in the study group than in the controls, but it was not statistically signicant.


Author(s):  
Nirmal Chandra Sukul ◽  
Tandra Sarkar ◽  
Atheni Konar ◽  
Anirban Sukul

Background: High dilutions of drugs, used in homeopathy, are usually applied by oral route or foliar spray. These dilutions first come in contact with membrane or circulating proteins. Ultra low doses of mercuric chloride, called potencies, promote activity of diastase or ?-amylase in terms of breakdown of starch, a polysaccharide into a disaccharide maltose in a cell-free medium in test tubes. Merc cor or HgCl2 in high doses inhibits the enzyme activity. Aims: To see (i) whether the high and ultra low dose effects of HgCl2 involve different binding sites of the enzyme and (ii) to find an explanation for the low dose effect of HgCl2 in spite of absence of its original molecules. Methodology: Merc cor mother tincture (147 mM HgCl2) in distilled water was used undiluted in this experiment. Merc cor 200c and 1000c were prepared from the mother tincture (MT) by successive dilution with water 1:100 followed by succussion in 200 and 1000 steps, respectively, and finally preserved in 90% EtOH. These potencies and blank 90% ethanol, were diluted with deionized, distilled (DD) water 1:1000 to minimize ethanol content in test solutions. Each test solution or control was mixed with the enzyme 1:10 just before experiment. The control consisted of DD water. An isothermal calorimetry (ITC) instrument was used to measure the interaction between soluble starch and ?-amylase mixed with each potency (200c/1000c) of Merc cor, its mother tincture, ethanol and control. ITC is a thermodynamic technique which helps in measuring directly very small amount of heat evolved during chemical reaction. Soluble starch 90 µM was injected into 300 µl of 15µM ?-amylase at 2 µl / injection. Twenty injections, one every 2 min, were given. The enzyme substrate interaction in terms of heat released (exothermic) or absorbed (endothermic) were monitored by the ITC instrument. All ITC measurements were calculated and analyzed statistically by an in-built software Origin 7. Results and discussion: The data are presented in figures. While Merc cor MT shows endothermic reaction, all its potencies, ethanol and water control show exothermic reactions. There is wide variation in enthalpy (?H), entropy (?S), binding constant (K) and Gibbs free energy change (?G) among the treatments with Merc cor MT, potencies, ethanol and also control. The results indicate that Merc cor MT and its potencies act on different binding sites of the enzyme. The variation in thermodynamic parameters suggest difference in binding interaction between the drug solutions and the enzyme. This in turn influences the enzyme substrate interaction as reported in earlier studies. The potencies are virtually water modified by the starting substance HgCl2. Conclusion: The mother tincture and potencies of mercuric chloride produce different effects on the enzyme substrate interaction. Potencies show wide variation in ?H, ?S, K and ?G values. It appears from the results that the drugs used in homeopathy produce dual action on proteins. At high doses they act on a binding site(s) but at ultra low doses they act on a different binding site(s). Proteins in an organism may serve as targets for initiation of action of homeopathic potencies.


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