Linear modulation of serum thyrotrophin by thyroid hormone treatment in hypothyroidism

1980 ◽  
Vol 95 (4) ◽  
pp. 472-478 ◽  
Author(s):  
A. Eugene Pekary ◽  
Jerome M. Hershman ◽  
Clark T. Sawin
Keyword(s):  
Thyroid Hormone ◽  
Hormone Replacement ◽  
Hormone Treatment ◽  
Significant Negative Correlation ◽  
Thyroid Hormone Replacement ◽  
Basal Serum ◽  
Thyroid Hormone Levels ◽  
Peak Versus ◽  
Hypothyroid Patients ◽  
Serum Tsh

Abstract. Basal serum TSH and the peak TSH response to a 500 μg TRH bolus were measured in 57 euthyroid and in 29 hypothyroid subjects either receiving graded thyroid hormone replacement or acutely removed from full replacement therapy. Serum TSH, total T4 and T3 were determined by sensitive radioimmunoassay methods. The peak versus basal TSH data for hypothyroid patients were linear within individuals. The regression slope of the peak versus basal TSH data for all hypothyroid subjects did not differ significantly from the corresponding slope for all euthyroid subjects. Basal and peak TSH versus T3 and T4 data for hypothyroid patients were also linear within each individual. Moreover, the regression of the basal TSH values averaged over the non-replacement to full replacement state against the TSH versus T3 slope had a significant negative correlation. This trend leads to an array of regression lines which average to the familiar hyperbolic relationship between thyrotrophin and thyroid hormone levels in man.

scholarly journals Combination Treatment with T4 and T3: Toward Personalized Replacement Therapy in Hypothyroidism?

2012 ◽  
Vol 97 (7) ◽  
pp. 2256-2271 ◽  
Author(s):  
Bernadette Biondi ◽  
Leonard Wartofsky
Keyword(s):  
Quality Of Life ◽  
Thyroid Hormone ◽  
Replacement Therapy ◽  
Hormone Replacement ◽  
Hormone Action ◽  
Thyroid Hormone Replacement ◽  
Thyroid Hormone Action ◽  
Thyroid Hormone Replacement Therapy ◽  
Hypothyroid Patients

Abstract Context: Levothyroxine therapy is the traditional lifelong replacement therapy for hypothyroid patients. Over the last several years, new evidence has led clinicians to evaluate the option of combined T3 and T4 treatment to improve the quality of life, cognition, and peripheral parameters of thyroid hormone action in hypothyroidism. The aim of this review is to assess the physiological basis and the results of current studies on this topic. Evidence Acquisition: We searched Medline for reports published with the following search terms: hypothyroidism, levothyroxine, triiodothyronine, thyroid, guidelines, treatment, deiodinases, clinical symptoms, quality of life, cognition, mood, depression, body weight, heart rate, cholesterol, bone markers, SHBG, and patient preference for combined therapy. The search was restricted to reports published in English since 1970, but some reports published before 1970 were also incorporated. We supplemented the search with records from personal files and references of relevant articles and textbooks. Parameters analyzed included the rationale for combination treatment, the type of patients to be selected, the optimal T4/T3 ratio, and the potential benefits of this therapy on symptoms of hypothyroidism, quality of life, mood, cognition, and peripheral parameters of thyroid hormone action. Evidence Synthesis: The outcome of our analysis suggests that it may be time to consider a personalized regimen of thyroid hormone replacement therapy in hypothyroid patients. Conclusions: Further prospective randomized controlled studies are needed to clarify this important issue. Innovative formulations of the thyroid hormones will be required to mimic a more perfect thyroid hormone replacement therapy than is currently available.

Prospective Study of the Impact of Thyroid Hormone Replacement on Nasal Functions in Hypothyroid Patients

2013 ◽  
Vol 149 (2_suppl) ◽  
pp. P134-P134
Author(s):  
Elnur Akbarov ◽  
Hakan Birkent ◽  
Ozgur Karacalioglu ◽  
Omer Karakoc ◽  
Murat T. Akcam ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Prospective Study ◽  
Hormone Replacement ◽  
Thyroid Hormone Replacement ◽  
The Impact ◽  
Hypothyroid Patients

Plasma homocysteine is decreased in the hypothyroid rat

2000 ◽  
Vol 78 (7) ◽  
pp. 565-570 ◽  
Author(s):  
René L Jacobs ◽  
Lori M Stead ◽  
Margaret E Brosnan ◽  
John T Brosnan
Keyword(s):  
Cardiovascular Disease ◽  
Thyroid Hormone ◽  
Independent Risk Factor ◽  
Hormone Replacement ◽  
Plasma Homocysteine ◽  
Total Plasma ◽  
Thyroid Hormone Replacement ◽  
Cystathionine Beta Synthase ◽  
Osmotic Pumps ◽  
Hypothyroid Patients

Recent clinical studies have indicated that plasma homocysteine was significantly increased in hypothyroid patients. Since hyperhomocysteinemia is an independent risk factor for cardiovascular disease we investigated homocysteine metabolism in hypothyroid rats. Hypothyroidism was induced in one study by addition of propylthiouracil (PTU) to the drinking water for 2 weeks. In a second study, thyroidectomized and sham-operated rats were used with thyroid hormone replacement via mini-osmotic pumps. Unlike the human hypothyroid patients, both groups of hypothyroid rats exhibited decreased total plasma homocysteine (30% in PTU rats, 50% in thyroidectomized rats) versus their respective controls. Thyroid replacement normalised homocysteine levels in the thyroidectomized rat. Increased activities of the hepatic trans-sulfuration enzymes were found in both models of hypothyroidism. These results provide a possible explanation for the decreased plasma homocysteine concentrations. The hypothyroid rat cannot be used as a model to study homocysteine metabolism in hypothyroid patients.Key words: homocysteine, cystathionine beta-synthase, cystathionine gamma-lyase, thyroid hormone.

scholarly journals Permissive effects of thyroid hormones on rat anterior pituitary mitotic activity

2004 ◽  
Vol 180 (1) ◽  
pp. 35-43 ◽  
Author(s):  
LA Nolan ◽  
CK Thomas ◽  
A Levy
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Mitotic Activity ◽  
Anterior Pituitary ◽  
Hormone Replacement ◽  
Male Rats ◽  
Thyroid Hormone Replacement ◽  
Thyroid Hormone Levels ◽  
Apoptotic Activity ◽  
Intact Rats

The anterior pituitary is active mitotically and apoptotically under basal conditions and in response to a variety of physiological and pathophysiological stimuli. Hypothyroidism in man is associated with a modest but very occasionally dramatic increase in overall pituitary size. The mechanisms underlying this reversible phenomenon remain obscure. In the present study we have examined young adult rat anterior pituitary following surgical thyroidectomy and subsequent thyroid hormone treatment and withdrawal using an extremely accurate system for quantifying directly identified mitotic and apoptotic events. Despite the expected increase in the number and/or proportion of immunohistochemically identifiable thyrotrophs three weeks after thyroidectomy, mitotic and apoptotic activity remained unchanged, as did pituitary wet weight, in comparison with sham-operated and intact controls. In contrast, mitotic but not apoptotic activity was enhanced by treatment of thyroidectomized animals with thyroid hormones (triiodothyronine (T3) and thyroxine (T4) 1.8 microg and 3.6 microg/100 g body weight per day respectively), and once again declined to levels seen in intact animals within 72 h of subsequent thyroid hormone withdrawal. Thyroid hormone-induced enhancement of mitotic activity was also seen in intact rats treated with similar doses of thyroid hormones for 7 days and in thyroidectomized rats treated for a similar period with very low dose thyroid hormone replacement at a level that had no effect on raised hypothalamic TRH- or pituitary TSHbeta-transcript prevalence (0.018 microg T3 plus 0.036 microg T4/100 g body weight per day). Thus changes in mitotic and apoptotic activity are unlikely to be the principle mechanism for the apparent increase in thyrotrophs up to 4 weeks after thyroidectomy. In contrast, the data indicate that thyroid hormones have a permissive effect on anterior pituitary mitotic activity in thyroidectomized male rats. Thyroid hormone-induced enhancement of mitotic activity in intact rats further suggests that in euthyroid rats, ambient thyroid hormone levels are a limiting factor for anterior pituitary mitotic activity. In summary, this time course study of young, male rats has shown for the first time that thyroidectomy, thyroid hormone replacement and subsequent withdrawal has no significant effect on anterior pituitary apoptotic activity. Secondly, it has shown that the anterior pituitary mitotic response to thyroidectomy is blocked by complete thyroid hormone deprivation, but can be restored by very low level thyroid hormone replacement, and thirdly that in intact animals thyroid hormone levels significantly limit anterior pituitary mitotic activity.

Effect of vitamin D3 loading and thyroid hormone replacement therapy on the decreased serum 25-hydroxyvitamin D level in patients with hypothyroidism

1986 ◽  
Vol 113 (3) ◽  
pp. 329-334 ◽  
Author(s):  
Julia Bársony ◽  
P. Lakatos ◽  
J. Földes ◽  
T. Fehér
Keyword(s):  
Vitamin D ◽  
Thyroid Hormone ◽  
Hormone Replacement ◽  
Substitution Therapy ◽  
Thyroid Hormone Replacement ◽  
Hormone Synthesis ◽  
Hydroxyvitamin D ◽  
Thyroid Hormone Replacement Therapy ◽  
25 Hydroxyvitamin D ◽  
Hypothyroid Patients

Abstract. Twelve hypothyroid subjects, 13 healthy and 12 healthy women with a slight deficiency of vitamin D were studied to distinguish seasonal changes from the thyroxine-dependent ones. Serum 25-hydroxyvitamin D levels of hypothyroid patients were lower than those of healthy individuals when the sera were obtained in the autumn. In hypothyroid patients a single oral dose of 100 000 IU vitamin D3 resulted in a smaller increase in 25-hydroxyvitamin D concentration than in controls having subclinical exogenous vitamin D deficiency. Substitution therapy with thyroid hormone, started in our study always in autumn, increased the 25-hydroxyvitamin D concentration in hypothyroid patients, which was opposite to the autumn-to-spring variation of this hormone observed in healthy controls. The increase of 25-hydroxyvitamin D, dehydroepiandrosterone and its sulphate values following substitution therapy in the hypothyroid patients may indicate that thyroid hormone(s) is (are) involved in the regulation of steroid hormone synthesis.

scholarly journals Risk factors for thyroid hormone replacement therapy after hemithyroidectomy and development of a predictive nomogram

2021 ◽  
Author(s):  
Zhen Cao ◽  
Rui Liu ◽  
Mengwei Wu ◽  
Xiequn Xu ◽  
Ziwen Liu
Keyword(s):  
Risk Factors ◽  
Thyroid Hormone ◽  
Regression Model ◽  
Thyroid Nodule ◽  
Goodness Of Fit ◽  
Hormone Replacement ◽  
Goodness Of Fit Test ◽  
Thyroid Hormone Replacement ◽  
Preoperative Serum ◽  
Serum Tsh

Abstract Purpose Hemithyroidectomy is a valid operation to retain functional contralateral thyroid lobe that is indicated for a variety of thyroid diseases. This study aimed at determination of the risk factors for thyroid hormone replacement following hemithyroidectomy and to develop a predictive nomogram. Methods Data of patients treated by hemithyroidectomy for benign thyroid disease between January 2015 and January 2020 were retrospectively analyzed. Baseline characteristics, surgery-related variables, and preoperative and postoperative thyroid function of patients were collected from the case records and compared between patients with postoperative euthyroidism and patients with postoperative hypothyroidism. Postoperative euthyroidism patients without thyroid hormone replacement were compared to those who developed postoperative hypothyroidism with thyroid hormone replacement. The factors associated with thyroid hormone replacement were used to construct a binomial logistic-regression model and visualized as a predictive nomogram to evaluate the risk of thyroid hormone replacement following hemithyroidectomy. Results Of the 378 patients (74% female) included in the study, 110 (29.1%) developed postoperative hypothyroidism. Preoperative serum thyroid-stimulating hormone (TSH) > 2.172 µIU/mL was identified as an independent risk factor for postoperative hypothyroidism (odds ratio [OR] = 8.02; 95% confidence interval [CI]: 4.87-13.20; P < 0.001). Of 110 patients with postoperative hypothyroidism, 56 (50.9%) received thyroid hormone replacement. Unilateral thyroid nodule and preoperative serum TSH > 2.172 µIU/mL were independent predictors of postoperative thyroid hormone replacement (P = 0.01, and P < 0.001, respectively). Temporary subclinical hypothyroidism occurred in 12 patients; all 12 reverted to euthyroid state without thyroid hormone replacement. The discriminative effect of the binomial regression model was proved reliable by the Hosmer–Lemeshow goodness-of-fit test (P = 0.856), and predictive ability of the nomogram was satisfactory with a C-index of 0.85. Conclusion Hypothyroidism is common after hemithyroidectomy, and almost half of the patients will need thyroid hormone replacement. Elevated preoperative serum TSH level and unilateral thyroid nodule were independent predictors of thyroid hormone replacement following hemithyroidectomy. The predictive nomogram could be a useful tool for clinical practice.

Sign in / Sign up

Export Citation Format

Share Document