Track topics on Twitter Track topics that are important to you
The NOMOTHETICOS study is a unicentric cross-sectional study for a quantitative analysis of feedback-inhibition in the thyrotropic homeostatic control. Structural parameters are obtained in vivo from open-loop analysis in patients with disconnected feedback, i.e. with overt thyroid dysfunction or full dose substitution therapy with levothyroxine.
Control of thyroid hormone homeostasis is essential for function and development of the organism and hence for individual health. It is therefore not surprising that the thyroid's function is controlled by a complex, multi-loop feedback control system.
Today, the central component of the thyrotropic feedback control system is still poorly understood on a physiological level. Therefore, in mathematical models different functional relations describing the feedback-inhibition of thyrotropin incretion by thyroid hormones have been suggested [Danziger and Elmergreen 1956, Roston 1959, Norwich and Reiter 1965, DiStefano and Stear 1968, DiStefano 1969, Saratchandran et al. 1973, Li et al. 1995, Dietrich et al. 2004, Degon et al. 2008, Jonklaas and Soldin 2008, Hörmann et al. 2010]. Most of these models fail in delivering biochemical explanations for the functional interrelations they postulate.
Nevertheless, some clinical applications of these models have been developed, although their diagnostical potential is usually rather limited [Yagi et al. 1997, Pohlenz et al. 1999, Jostel et al. 2009].
Assuming that the pituitary's response to peripheral thyroid hormones is determined by active transmembrane thyroxine transport mechanisms [Dietrich et al. 2008], intracellular deiodination of thyroxine (T4), binding of resulting triiodothyronine (T3) to iodothyronine receptors and, finally, their inhibiting effect on mRNA expression, translation and release of TRH, a novel, physiologically motivated model has been developed that is based on compartment-analytical approaches, Michaelis-Menten kinetics and non competitive divisive inhibition [Dietrich et al 2004]. However, this model has not been sufficiently evaluated in a clinical context.
It is the aim of the NOMOTHETICOS study to deliver new systems-level insights into the pituitary's thyrotropic function. This unicentric cross-sectional study compares different models of feedback-inhibition by means of modern statistical methods like nonlinear regression and Akaike information criterion. Structural parameters are obtained in vivo from open-loop analysis in patients with disconnected feedback in equilibrium.
These parameters can serve as theoretical basis for possible future trials developing advanced diagnostical evaluation methods of thyrotropic pituitary function.
Observational Model: Cohort, Time Perspective: Cross-Sectional
Enrolling by invitation
Ruhr University of Bochum
Published on BioPortfolio: 2014-08-27T03:12:54-0400
Overt hypothyroidism is associated with increased risk for cardiovascular disease (CVD) as indicated by hypertension, hypercholesterolemia, and increased low-density lipoprotein cholestero...
Some people with hypothyroidism have persistent symptoms despite adequate treatment with thyroid hormones. We are testing whether giving calcitonin to such people will improve their qualit...
The aim of this study is to further characterize the treatment related changes in insulin sensitivity, substrate metabolism and intra hepatic- and intramyocellular lipid content in patient...
To investigate the incidence of detected hypothyroidism after iodinated contrast exposure in pediatric patients from birth to 3 years of age (inclusive) in a routine clinical practice sett...
This study evaluates the effectiveness of stimulating the neurological segments c8-th5 in patients with latent hypothyroidism. One half of the participants will receive an osteopathic ma...
Although mild pericardial effusion is a usual finding in patients with hypothyroidism, massive pericardial effusion or pericardial tamponade is rare and customarily related to severe hypothyroidism. T...
The role of subclinical hypothyroidism in the development of depression remains controversial. We examined the prospective association between subclinical hypothyroidism and incident depressive sympto...
Thyroid hormone disease is common among older adults and is associated with cognitive impairment. However, pathologic correlates are not well understood. We studied pathologic and clinical factors ass...
Hyperhomocysteinemia is a known cardiovascular risk factor and a key player in the inflammatory activation of autoimmune diseases. Hashimoto's thyroiditis (HT) is the leading cause of hypothyroidism w...
Similar to overt hypothyroidism, subclinical hypothyroidism (SCH) has been reported to increase the risk of cardiovascular disease. However, the influence of SCH on clinical outcomes following percuta...
A condition in infancy or early childhood due to an in-utero deficiency of THYROID HORMONES that can be caused by genetic or environmental factors, such as thyroid dysgenesis or HYPOTHYROIDISM in infants of mothers treated with THIOURACIL during pregnancy. Endemic cretinism is the result of iodine deficiency. Clinical symptoms include severe MENTAL RETARDATION, impaired skeletal development, short stature, and MYXEDEMA.
Chronic autoimmune thyroiditis, characterized by the presence of high serum thyroid AUTOANTIBODIES; GOITER; and HYPOTHYROIDISM.
A syndrome that results from abnormally low secretion of THYROID HORMONES from the THYROID GLAND, leading to a decrease in BASAL METABOLIC RATE. In its most severe form, there is accumulation of MUCOPOLYSACCHARIDES in the SKIN and EDEMA, known as MYXEDEMA.
Pathological enlargement of the LINGUAL THYROID, ectopic thyroid tissue at the base of the TONGUE. It may cause upper AIRWAY OBSTRUCTION; DYSPHAGIA; or HYPOTHYROIDISM symptoms.
Defective development of the THYROID GLAND. This concept includes thyroid agenesis (aplasia), hypoplasia, or an ectopic gland. Clinical signs usually are those of CONGENITAL HYPOTHYROIDISM.
The thyroid is a butterfly-shaped gland in the neck, just above thecollarbone and is an endocrine gland that make hormones. These Thyroid hormones control the rate of many activities in the body, including how fast the body burns calories and how fast th...
Benign Prostatic Hyperplasia (BPH) Erectile Dysfunction Urology Urology is the branch of medicine concerned with the urinary tract and diseases that affect it. Examples include urethritis, urethrostenosis and incontinence. Urology is a su...
Diabetes Diabetes Endocrine Obesity Oxycontin Renal Disease Thyroid Disorders Endocrinology is the study of the endocrine glands and the hormones that they secrete (Oxford Medical Dictionary). There are several groups of h...