Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “thyroid dysfunction”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,369 records · Page 76Linked to original sources
PubMed2000

Amiodarone-induced thyroid disorders: a clinical review.

Although amiodarone is regarded as a highly effective anti-arrhythmic agent, its use may lead to alterations in thyroid gland function and/or thyroid hormone metabolism, partly because of its rich iodine content. Patients treated with amiodarone may manifest altered thyroid hormone profile without thyroid dysfunction, or they may present with clinically significant amiodarone-induced hypothyroidism or amiodarone-induced thyrotoxicosis. The former results from the inability of the thyroid to escape from the Wolff-Chaikoff effect. It prevails in areas with high dietary iodine intake, and it is readily managed by discontinuation of amiodarone or thyroid hormone replacement. Amiodarone-induced thyrotoxicosis occurs more frequently in areas with low iodine intake; it may arise from iodine-induced excessive thyroid hormone synthesis (type I) or destructive thyroiditis with release of preformed hormones (type II). Type I should be treated with thionamides alone or in combination with potassium perchlorate, whereas type II benefits from treatment with glucocorticoids. Surgery may be a feasible option for patients who require long-term amiodarone treatment.

Amiodarone↗
PubMed1997

Inhibition of TSH-induced hydrogen peroxide production by TNF-alpha through a sphingomyelinase signaling pathway.

Tumor necrosis factor-alpha (TNF-alpha) has been suggested to be related to the pathogenesis of autoimmune thyroid diseases, nonthyroid illness, and other thyroid dysfunctions induced by infectious diseases. In relation to these, in vitro studies demonstrated that TNF-alpha influences growth and/or differentiated functions mediated by thyroid-stimulating hormone (TSH), including 125I organification. In the present study, we found that TNF-alpha inhibits TSH-induced H2O2 production, which is an inevitable process for iodide organification, and hence thyroid hormone synthesis, in FRTL-5 thyroid cells. In the cells, TNF-alpha induced ceramide production and the addition of exogenous ceramide or sphingomyelinase treatment of the cells simulated TNF-alpha actions. Although TSH stimulation of H2O2 production is mediated by the phospholipase C (PLC)-Ca2+ pathway, TNF-alpha and exogenous and endogenous ceramide affected neither TSH-dependent PLC activation and Ca2+ mobilization nor TSH-induced cAMP accumulation but attenuated Ca(2+)-induced H2O2 production. We conclude that TNF-alpha, through a sphingomyelinase-ceramide pathway, regulates TSH-induced H2O2 production at steps beyond the Ca2+ mobilization step in the PLC-Ca2+ signaling pathway coupled to TSH. This suggests participation of TNF-alpha in thyroid disorder in hormone synthesis induced by thyroid disease associated with the activation of immune systems.

Animals↗
PubMed2006

The association of polymorphisms in the type 1 and 2 deiodinase genes with circulating thyroid hormone parameters and atrophy of the medial temporal lobe.

CONTEXT: Thyroid function has been related to Alzheimer disease (AD) and neuroimaging markers thereof. Whether thyroid dysfunction contributes to or results from developing AD remains unclear. Variations in the deiodinase type 1 (DIO1) and type 2 (DIO2) genes that potentially alter thyroid hormone bioactivity may help in elucidating the role of thyroid function in AD. OBJECTIVE: We investigated the association of recently identified polymorphisms in the DIO1 (D1a-C/T, D1b-A/G) and DIO2 (D2-ORFa-Gly3Asp, D2-Thr92Ala) genes with circulating thyroid parameters and early neuroimaging markers of AD. DESIGN AND PARTICIPANTS: The Rotterdam Scan Study is a population-based cohort study among 1,077 elderly individuals aged 60-90 yr. MAIN OUTCOME MEASURES: DIO1 and DIO2 polymorphisms and serum TSH, free T4, T3, and reverse T3 (rT3) levels were determined in 995 nondemented elderly, including 473 persons with assessments of hippocampal and amygdalar volume on brain magnetic resonance imaging. RESULTS: Carriers of the D1a-T allele had higher serum free T4 and rT3, lower T3, and lower T3/rT3. The D1b-G allele was associated with higher serum T3 and T3/rT3. The DIO2 variants were not associated with serum thyroid parameters. No associations were found with hippocampal or amygdalar volume. CONCLUSION: This is the first study to report an association of D1a-C/T and D1b-A/G polymorphisms with iodothyronine levels in the elderly. Polymorphisms in the DIO1 and DIO2 genes are not associated with early magnetic resonance imaging markers of AD. This suggests that the previously reported association between iodothyronine levels and brain atrophy reflects comorbidity or nonthyroidal illness rather than thyroid hormones being involved in developing AD.

Aged↗
PubMed1997

Manifestation of primary hyperthyroidism after pituitary adenomectomy: a case report.

We report a 47-year-old Japanese man who presented with visual disturbance due to a pituitary tumor with suprasellar extension. The patient had mild secondary hypothyroidism preoperatively, and was started on administration of levothyroxine sodium immediately before transsphenoidal surgery. After the operation, levothyroxine sodium was continued for several months. Pathological examination of the surgical specimen, together with endocrinological investigation revealed that the suprasellar tumor was a FSH-producing pituitary adenoma. Since 3 months after the operation, he has developed muscle weakness and finger tremor. He was found to be thyrotoxicosis, and levothyroxine sodium was discontinued. Seven weeks after levothyroxine sodium was discontinued, thyrotoxicosis continued, with a positive thyrotropin binding inhibitory immunoglobulin (TBII) and a high diffuse 123I-uptake by the thyroid. He was started on thiamazole 30 mg/day. Although his thyroid dysfunction improved within 2 months, hyperthyroidism worsened repeatedly on attempts to discontinue thiamazole, and he required continuous treatment at 2.5 mg/day. Patients with occult autoimmune thyroiditis rarely progress to thyrotoxicosis after operations on other endocrine organs such as the adrenal or parathyroid gland. In patients with pituitary adenoma, thyroid function and thyroid-associated autoantibodies should be investigated pre- and post-operatively.

Adenoma↗
PubMed2005

Pro-A-type and N-terminal pro-B-type natriuretic peptides in different thyroid function states.

QUESTIONS UNDER STUDY: Natriuretic peptides are produced predominantly in the heart and secreted in response to volume expansion and pressure overload. A wide spectrum of cardiac changes is observed in thyroid dysfunctions. This study investigates mid regional pro A-type (proANP) and N-terminal pro-B-type natriuretic peptide (NTproBNP) levels in different thyroid states and evaluates the effect of L-thyroxine treatment on natriuretic peptides in patients with subclinical hypothyroidism. METHODS: Case-control and double-blind, placebo-controlled trial. Sera from 161 female patients (35 with overt, 63 with subclinical hypothyroidism; 10 with overt, 14 with subclinical hyperthyroidism; 40 euthyroid controls) were analysed. ProANP and NT-proBNP were measured at baseline and 48 weeks after L-thyroxine treatment in subclinical hypothyroidism. RESULTS: Circulating proANP and NT-proBNP levels were higher in hyperthyroid patients than in hypothyroid and euthyroid patients (p <0.001). Plasma proANP levels tended to be lower in overt hypothyroidism than in subclinical hypothyroidism. ProANP and NT-proBNP levels correlated weakly to thyroid stimulating hormone (TSH) (r = -0.3 and -0.2, respectively). The natriuretic peptide levels of subclinical and overt hypothyroid subjects showed no difference with those of euthyroid subjects. L-thyroxine treatment had no effect on natriuretic peptide levels in subclinical hypothyroidism. CONCLUSION: Natriuretic peptide levels are altered in different thyroid states with a more pronounced effect in hyperthyroidism than in hypothyroidism. Hyperthyroidism should be considered in patients presenting with unclear symptoms and mildly elevated natriuretic peptide levels, as overt hyperthyroidism results in increased serum A- and B-type natriurectic peptide levels, typically seen in mild heart failure.

Atrial Natriuretic Factor↗
PubMed1993

Usefulness of antimicrosomal antibody titers in the diagnosis and treatment of postpartum thyroiditis.

BACKGROUND: Postpartum thyroiditis is a common but frequently unrecognized disorder, affecting approximately 5% of women during the first 12 months after delivery. We investigated whether the antimicrosomal antibody titer could be used to determine which women with positive titers postpartum (1) might develop symptomatic or biochemical abnormalities within the first postpartum year (early disease), (2) might require therapy with thyroid hormone, and (3) might have persistent abnormalities (late disease). METHODS: Women (n = 55) who had positive antimicrosomal antibody titers at delivery were prospectively followed for 11 to 45 months. Titers were evaluated again at 6 to 10 weeks postpartum and approximately every 8 weeks for the first year. RESULTS: Early disease occurred in 40 of 55 (73%) women, late disease occurred in 29 of 55 (53%) women, and treatment was required by 21 of 55 (38%) women. The occurrence of early disease was associated with the occurrence of late disease (P < .05). The chances of developing early disease were 6 to 1 (P = .01) when serum titers of antimicrosomal antibodies were > or = 400 at delivery, and 5 to 1 (P = .02) when titers were > or = 1600 at 6 to 10 weeks postpartum. The chances of being given thyroid hormone therapy were 23 to 1 (P = .006) when titers at delivery were > or = 6400, and 6 to 1 when titers at 6 to 10 weeks postpartum were > or = 6400 (P = .004). Titers were not useful in estimating who would have late disease. CONCLUSIONS: Screening for postpartum thyroid dysfunction after delivery using antimicrosomal antibody titers is highly useful. The titer value can help guide the physician in the care of patients with postpartum thyroiditis whose disease may not be self-limiting and who will probably require thyroid hormone therapy.

Autoantibodies↗
PubMed1989

Thyroid function tests. Guidelines for interpretation in common clinical disorders.

While a wide variety of thyroid function tests are currently available, all are sometimes abnormal in patients without thyroid disease. To interpret test results properly, the clinician needs to be aware of factors altering thyroid function tests. In every instance, the clinician needs to begin by asking whether the patient is thyrotoxic or hypothyroid and then should order a test to substantiate or exclude the diagnosis. In this way, accurate and early diagnosis of thyroid dysfunction can be routinely established.

Algorithms↗
PubMed1995

[Clinical screening after thyroid gland diseases: contribution of orienting ultrasound examination].

AIM: Of this study was to define the significance of approximate ultrasound explorations of the thyroid gland for the clinical screening for thyroid diseases. METHOD: 918 patients in the medical service of a general hospital were screened for thyroid diseases by means of clinical, functional and sonomorphological methods. A sonographic screening scan with a 5 MHz probe provided data concerning structure and dimension of thyroid gland. Maximal sagittal diameter (SDm, normal range < 18 mm) was taken as a measure for thyroid size. RESULTS: Echogenicity has no essential meaning for thyroid dysfunction screening, but is indispensable for the detection of circumscript or general echo deficiency. SDm has proved to be a simple and well reproducible measure for thyroid size. Among 41 patients with thyrotoxicosis 40 had enlarged SDm, which means a sensitivity of 97.6%. However, a high rate of false positives makes TSH-screening of all enlarged thyroid glands obligatory. Moreover, SDm allows the estimation of a lack of thyroid mass as the most common cause of hypothyroidism. CONCLUSION: We recommend that an approximate ultrasound exploration of the thyroid gland including measuring of SDm should be part of every diagnostic procedure for thyroid disease, as it is precise and not time consuming.

Adult↗
PubMed1996

The effects of hypothyroidism and replacement therapy on cholesteryl ester transfer.

To characterize further the impact of thyroid dysfunction on the transport of cholesterol in plasma, we studied plasma lipids and cholesteryl ester transfer (CET) in 10 hypothyroid women before and 3 months after thyroid replacement therapy. CET, estimated as the net mass transfer of CE from HDL to the apolipoprotein B-containing lipoproteins (very low density and low density lipoproteins) was significantly decreased at 4 h (P < 0.05) and 6 h (P < 0.001) when the patients were hypothyroid (T4, 2.01 +/- 1.4; TSH, 55.5 +/- 39.9 microIU/mL) and increased to normal levels after hormone replacement and restoration of eumetabolism. Plasma lipid levels in the hypothyroid state closely resembled those in a female reference group, although total plasma cholesterol fell significantly [pretreatment, 218 +/- 36 vs. posttreatment, 192 +/- 49 (P < 0.025); control, 218 +/- 28 mg/dL (mean +/- SD)] after treatment. Concentrations of cholesteryl ester transfer protein (CETP) were unchanged (pretreatment, 2.35 +/- 0.83 vs. posttreatment, 2.30 +/- 1.19 mg/dL). The results of recombination studies using different lipoprotein fractions suggest that decreases in CET during hypothyroidism may be secondary to acceptor lipoprotein (low density and very low density lipoprotein) changes in the hypothyroid state and not to changes in the concentration of CETP itself.

Adult↗
PubMed2006

Effects of hyperthyroidism induced by L-thyroxin administration on lipid peroxidation in various rat tissues.

Thyroid dysfunctions are associated with many pathological signs in the body. One of these is lipid peroxidation that develops due to over- or under-secretion of thyroid hormones. The present study was conducted to determine lipid peroxidation that develops in different tissues including the brain, liver and heart of rats in experimental hyperthyroidism induced by L-thyroxin. The study was carried out on 30 male Sprague-Dawley rats. They were divided into three groups as control, sham hyperthyroidism and hyperthyroidism. Malondialdehyde (MDA) and glutathione (GSH) levels in rat tissues were determined at the end of a 3-weeks period of L-thyroxin administration. It was observed that MDA levels in the hyperthyroidism group were significantly higher in the cerebral cortex, liver and ventriculer tissue of heart (p < 0.001) than in the control and in sham hyperthyroidism groups. GSH levels were higher in the hyperthyroidism group than in control and sham hyperthyroidism groups in all tissues (p < 0.001). Results demonstrate that hyperthyroidism induced by L-thyroxin activates both oxidant and antioxidant systems in cerebral, hepatic and cardiac tissues. However, the increase in antioxidant activity cannot adequately prevent oxidative damage.

Animals↗
PubMed1976

[The systolic time intervals in functional disorders of the thyroid: a simple and fast screening test].

The systolic time intervals (LVET, PEP, and ratio LVET/PEP) were determined in 53 patients presenting with signs or symptoms of thyroid dysfunction. Patients with clinical evidence of congestive heart failure, with arterial hypertension or old myocardial infarction, and patients receiving cardioactive drugs, were excluded from the study. Thyroid function was evaluated by means of T3-RIA, serum thyroxin and TRH stimulation test.

Adult↗
PubMedDate not supplied

[Pregnancy complicated by diabetes mellitus].

Interdisciplinary team work and recommendations of diabetologist and obstetrician is the condition of success of antenatal care and consequently perinatal outcome in pregnancy complicated by diabetes. Careful insight into the metabolic, haemodynamic and vascular disturbances is the basic of contemporary surveillance in diabetic pregnancy. The authors emphasise that a diabetic pregnant woman must not only pay attention to adequate nutrition and balanced exercise, but also be aware of and cope with characteristic, momentary swings in glycemia in order to overcome them by appropriate insulin therapy. Continuous supervision for several other complications associated with diabetic pregnancy, viz. hypertension, retinopathy, thyroid dysfunction, nephropathy and the threat of in utero foetal death is justified. Briefly, rigorous measures to sustain normoglycemia and normal blood pressure, examination of the retina, thyroid and renal functions as well as foetal status evaluation are paramount in appropriate management of major common diabetic complications in pregnancy.

Adult↗
PubMedDate not supplied

Association between chronic urticaria and thyroid autoimmunity.

The association between chronic idiopathic urticaria (CIU) and thyroid autoimmunity has most often been suggested in studies investigating thyroid microsomal antibodies, which are less sensitive and specific than anti-thyroperoxidase antibodies, moreover these studies were not case-control studies in large series. By comparing a large patient series presenting with CIU with a large numbered control group we aimed to learn the extent of autoimmune thyroid disease. We compared the frequency of thyroid autoantibodies in 140 patients with CIU with 181 age-and sex-matched volunteers. Thyroid function tests and thyroid autoantibodies were measured by chemiluminescent immunometric assay in study groups. The frequency of thyroid autoantibodies was significantly higher in patients with CIU than that in healthy controls (29.28 %/5.52%; p < 0.001). Of 41 patients, 10 had thyroid dysfunction and the other cases were euthyroid. The higher frequency of these antibodies in our patients shows that there was a strong association between CIU and thyroid autoimmunity.

Adolescent↗
PubMed1994

Endocrine effects of cytokines.

Recent trends in antineoplastic therapy include the increasing use of cytokine-containing regimens. These widely distributed, naturally occurring substances play a pivotal role in the physiology of the neuroendocrine/immune system. It is not known to what extent the chronic administration of pharmacologic doses of exogenous cytokines may create hormonal and metabolic derangements that may, in themselves, complicate their therapeutic efficacy. This article reviews the endocrine functions of a variety of cytokines. The interferons, for example, induce insulin resistance and impaired glucose tolerance, are associated with thyroid dysfunction, and can stimulate the ACTH/cortisol axis and growth hormone. The hormonal/metabolic actions of the interleukins are being intensively studied, especially by bone metabolism, reproductive, and thyroid physiologists. Tumor necrosis factor has a profound impact on bone metabolism and remodeling, decreases lipoprotein lipase, and can affect thyroid function.

Antineoplastic Agents↗
PubMed1988

Gallium uptake in the thyroid gland in amiodarone-induced hyperthyroidism.

Amiodarone is an iodinated antiarrhythmic agent that is effective in the treatment of atrial and ventricular arrhythmias. A number of side effects are seen, including pulmonary toxicity and thyroid dysfunction. A patient with both amiodarone-induced pneumonitis and hyperthyroidism who exhibited abnormal gallium activity in the lungs, as well as diffuse gallium uptake in the thyroid gland is presented. The latter has not been previously reported and supports the concept of iodide-induced "thyroiditis" with gallium uptake reflecting the inflammatory response.

Amiodarone↗
PubMed2006

Immunogenetic association and thyroid autoantibodies in juvenile autoimmune thyroiditis in North India.

OBJECTIVES: Autoimmune thyroid diseases (AITD) encompass a number of conditions that have in common cellular and humoral responses targeting the thyroid gland. Interactions between susceptibility genes and environmental triggers are thought to initiate an autoimmune response to thyroid antigens leading to disease manifestation. Commencement of the disease in childhood leads to the presumption that genetics may have an important role in the causation of the disease. DESIGN: The present study was aimed at evaluating the human leucocyte antigen (HLA) encoded susceptibility to develop juvenile autoimmune thyroiditis (JAT) in patients from North India. PATIENTS: We studied 48 consecutive patients of JAT along with 176 first-degree relatives for their thyroid function (FT4, TSH) and anti-thyroid peroxidase antibody status (AbTPO). MEASUREMENTS: HLA studies were carried out using serology for HLA-class I antigens and DNA analysis of HLA-class II alleles. The data were compared with a cohort of 308 ethnically matched healthy individuals. RESULTS: We observed overt hypothyroidism in 50% and AbTPO positivity in 70.8% of the index cases. Among the first-degree relatives, goitre was observed in 51.7%, thyroid dysfunction in 28.4% and AbTPO in 29.5% of individuals. Of the 37 relatives who underwent fine-needle aspiration cytology (FNAC), 60% had evidence of chronic lymphocytic thyroiditis (CLT). A strong positive association of HLA-DRB1*1404 was observed with the JAT (35.4%vs. 10.4%, chi2 = 19.8, Pc = 0.0001). We also observed a higher (72%, P = 0.03) paternal transmission of HLA-DRB1*1404 to affected offspring in comparison to unaffected offspring. HLA-DRB1*03 was also increased among JAT patients but did not reach statistical significance. CONCLUSION: These studies point towards an important role of immune modifying genes, such as HLA, in influencing susceptibility to juvenile-onset AITD.

Adolescent↗
PubMed2006

[Use of lithium carbonate for the treatment of amiodarone-induced thyrotoxicosis].

Among the amiodarone-induced thyroid dysfunctions, thyrotoxicosis is the most troublesome and with the highest rate of morbidity and mortality. Treatment consists in the use of a high dose of anti-thyroid drugs and steroids in an isolated form or in combination. Association of several other drugs have been proposed for the treatment of refractory cases. In this study we report the case of a 40 y.o. patient, with a history of idiopatic dilated miocardiopathy, who developed severe amioradone-induced thyrotoxicosis after heart transplantation. Since the patient did not respond to an initial treatment consisting of a high dose of anti-thyroid drugs combined with steroids, a low dose of lithium carbonate was added for a short period of time, which resulted in normalization of the thyroid function. In this case, the addition of lithium carbonate to the two other drugs resulted in a successful and safety therapy in controlling amiodarone-induced thyrotoxicosis.

Adult↗
PubMed1986

Thyroid function tests in acutely ill patients. Comparison of analogue based free thyroid hormone assays with free thyroxine index.

A prospective study of 100 acutely ill patients was carried out to assess the value of the free thyroxine (FT4) assay as a replacement screening procedure for the free thyroxine index (FTI). We found that the FT4 assay was significantly influenced by the albumin concentration, so that the number of follow-up tests required increased markedly. This was especially true at the low end of the FT4 range where the need for thyrotropin assays increased by 162%. The free triiodothyronine (FT3) assay was also shown to be albumin dependent. It is not useful to replace one set of difficulties due to protein binding with another, and overall it was concluded that it is not cost-effective to screen hospital patients for thyroid dysfunction using free hormone assays based on labelled analogue techniques.

Humans↗