989 resultados para THYROID-STIMULATING HORMONE
Resumo:
Subclinical hypothyroidism, defined as an elevated thyroid stimulating hormone and normal thyroxine level, is common with aging, particularly after 65 years old. This condition is potentially associated with important consequences, such as cardiovascular diseases and cognitive disorders. So far, indications for screening and thyroxine replacement therapy are still controversial. In this review, we examine the data on those risks and the potential benefits of the treatment. We also present a large European randomized clinical trial that should clarify this controversy, in order to improve clinical care of patients with subclinical hypothyroidism and to give reliable data on maintaining good health among the elderly.
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AIM: To evaluate intellectual outcome, motor skills and anthropometric data of children with congenital hypothyroidism (CH). METHODS: Children with permanent CH who were born in 1999 in Bavaria were eligible for this prospective, population-based study. Cognitive performance was evaluated by the Kaufman Assessment Battery for Children and motor skills were assessed by the motor test, Motoriktest für vier-bis sechsjahrige Kinder (MOT) 4-6. RESULTS: Eighteen of 21 eligible children participated (86%). Median age of the children was 5.5 years (range 4.9-5.8). Treatment with levothyroxine was started after a median of 7.2 days (range 4-15) with a median dose of 12.0 microg/kg (range 7.2-17.0). Mean intelligence quotient (IQ) of the children was 100.4 (standard deviation [SD] 10.1): no children had IQ values below the normal range. Reactivity and speed of movement were significantly reduced in children with CH. Children with an initial thyroid-stimulating hormone (TSH) value of >200 mU/L performed significantly worse than children with TSH value of
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Galactorrhea is a relatively common condition, but has rarely been seen following breast reduction surgery. To date there are only seven cases reported in the literature, all in premenopausal women. Postsurgical galactorrhea is a diagnosis of exclusion and differential diagnosis is extensive. Common causes should be excluded first. We present the case of a 56-year-old postmenopausal woman who underwent bilateral breast reduction and developed galactorrhea 2 months postoperatively. MRI scan of the skull as well as Thyroid-Stimulating Hormone (TSH), prolactin levels were normal. She was on long-term hormonal replacement therapy. Because of suspected nerve-related pain in her right breast she was commenced on amitriptyline. We hypothesise that galactorrhea may have been caused by underlying neuroma or irritation of the anterior branch of the T4 intercostal nerve or hormonal replacement therapy or a combination of both.
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Small peptide hormones produced in the lower part of the brain (hypothalamus) regulate episodic and basal secretion of hormones from the anterior pituitary gland that affect metabolism and growth in cattle. This study focused on long-term growth in young calves subjected to hypophysectomy (HYPOX), hypophyseal stalk transection (HST), and sham operation control (SOC). Crossbred (Hereford x Aberdeen Angus) and Hereford, and Aberdeen Angus calves were HYPOX (n = 5), HST (n = 5), or SOC (n = 8) at 146 days of age, whereas another group was HST (n = 5) or SOC (n = 7) at 273 days of age. Body weight was determined every 21 days from birth to 1008 days of age. From day 146-1008, growth was arrested (P < 0.001) in HYPOX (0.06 kg/day) compared with SOC (0.50 kg/day) calves. Growth continued but at a significantly lower rate (P < 0.05) in calves HST at 146 days (0.32 kg/day) and 273 days (0.32 kg/day) compared with SOC (0.50 kg/day). Although episodic growth hormone (GH) secretion was abolished and peripheral blood serum GH concentration remained consistently lower in HST calves (2.4 ng/ml) than in the SOC (5.5 ng/ml; P < 0.01), the calves continued to grow throughout 1008 days. Peripheral serum thyroid stimulating hormone (TSH) concentration was less (P < 0.05) in HST compared with SOC calves. There was an abrupt decrease (P < 0.001) in serum thyroxine (T4) (4-fold) and triiodothyronine (T3) (3-fold) concentration after surgery that remained to 360 days in HST compared with SOC calves. At sacrifice, pituitary gland weight was markedly reduced (P < 0.001) in HST (0.18 g/100 kg body weight) compared with SOC (0.55 g/100 kg body weight) calves. Histological examination of pituitary glands from HST calves indicated the persistence of secretory GH and TSH cells in the same areas of the anterior pituitary gland as SOC calves. Coronal sections of the gland revealed GH and TSH secreting cells in HST calves that were similar to the controls. These results indicate that long-term growth continues, but at a slower rate, after hypophyseal stalk transection of immature calves in spite of complete abolition of episodic GH secretion and consistently decreased basal secretion of GH, TSH, T4, and T3 compared with sham-operated animals. Growth was abolished after hypophysectomy of immature calves in which circulating GH and TSH was undetectable.
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BACKGROUND: Follow-up of abnormal outpatient laboratory test results is a major patient safety concern. Electronic medical records can potentially address this concern through automated notification. We examined whether automated notifications of abnormal laboratory results (alerts) in an integrated electronic medical record resulted in timely follow-up actions. METHODS: We studied 4 alerts: hemoglobin A1c > or =15%, positive hepatitis C antibody, prostate-specific antigen > or =15 ng/mL, and thyroid-stimulating hormone > or =15 mIU/L. An alert tracking system determined whether the alert was acknowledged (ie, provider clicked on and opened the message) within 2 weeks of transmission; acknowledged alerts were considered read. Within 30 days of result transmission, record review and provider contact determined follow-up actions (eg, patient contact, treatment). Multivariable logistic regression models analyzed predictors for lack of timely follow-up. RESULTS: Between May and December 2008, 78,158 tests (hemoglobin A1c, hepatitis C antibody, thyroid-stimulating hormone, and prostate-specific antigen) were performed, of which 1163 (1.48%) were transmitted as alerts; 10.2% of these (119/1163) were unacknowledged. Timely follow-up was lacking in 79 (6.8%), and was statistically not different for acknowledged and unacknowledged alerts (6.4% vs 10.1%; P =.13). Of 1163 alerts, 202 (17.4%) arose from unnecessarily ordered (redundant) tests. Alerts for a new versus known diagnosis were more likely to lack timely follow-up (odds ratio 7.35; 95% confidence interval, 4.16-12.97), whereas alerts related to redundant tests were less likely to lack timely follow-up (odds ratio 0.24; 95% confidence interval, 0.07-0.84). CONCLUSIONS: Safety concerns related to timely patient follow-up remain despite automated notification of non-life-threatening abnormal laboratory results in the outpatient setting.
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Background: There is limited evidence about the impact of treatment for subclinical hypothyroidism, especially among older people. Aim: To investigate the variation in GP treatment strategies for older patients with subclinical hypothyroidism depending on country and patient characteristics. Design and setting: Case-based survey of GPs in the Netherlands, Germany, England, Ireland, Switzerland, and New Zealand. Method: The treatment strategy of GPs (treatment yes/no, starting-dose thyroxine) was assessed for eight cases presenting a woman with subclinical hypothyroidism. The cases differed in the patient characteristics of age (70 versus 85 years), vitality status (vital versus vulnerable), and thyroid-stimulating hormone (TSH) concentration (6 versus 15 mU/L). Results: A total of 526 GPs participated (the Netherlands n = 129, Germany n = 61, England n = 22, Ireland n = 21, Switzerland n = 262, New Zealand n = 31; overall response 19%). Across countries, differences in treatment strategy were observed. GPs from the Netherlands (mean treatment percentage 34%), England (40%), and New Zealand (39%) were less inclined to start treatment than GPs in Germany (73%), Ireland (62%), and Switzerland (52%) (P = 0.05). Overall, GPs were less inclined to start treatment in 85-year-old than in 70-year-old females (pooled odds ratio [OR] 0.74 [95% confidence interval [CI] = 0.63 to 0.87]). Females with a TSH of 15 mU/L were more likely to get treated than those with a TSH of 6 mU/L (pooled OR 9.49 [95% CI = 5.81 to 15.5]). Conclusion: GP treatment strategies of older people with subclinical hypothyroidism vary largely by country and patient characteristics. This variation underlines the need for a new generation of international guidelines based on the outcomes of randomised clinical trials set within primary care
Resumo:
Subclinical hypothyroidism, which is defined as elevated thyroid-stimulating hormone (TSH) levels with free thyroxine concentrations within the reference range, is a common disorder that increases with age and affects up to 18% of the elderly, with a higher prevalence in women compared to men. Prospective data have shown an increased risk of coronary heart disease events, heart failure, and cardiovascular mortality among affected adults. Conflicting results have been found on the association between subclinical hypothyroidism and cognitive impairment, depression and the risk of fractures. Management strategies including screening and treatment of subclinical hypothyroidism are still controversial, while the ongoing European randomised controlled trial "TRUST" targets to solve these uncertainties. This narrative review aims to assess current evidence on the clinical aspects, as well as screening and treatment recommendations in adults with subclinical hypothyroidism.
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QUESTIONS UNDER STUDY As the best management of subclinical hypothyroidism is controversial, we aimed to assess variations in treatment strategies depending on different Swiss regions, physician and patient characteristics. METHODS We performed a case-based survey among general practitioners (GPs) in different Swiss regions, which consisted of eight hypothetical cases presenting a female patient with subclinical hypothyroidism and nonspecific complaints differing by age, vitality status and thyroid-stimulating hormone (TSH) concentration. RESULTS A total of 262 GPs participated in the survey. There was considerable variation in the levothyroxine starting dose chosen by GPs, ranging from 25 µg to 100 µg. Across the Swiss regions, GPs in the Bern region were significantly more inclined to treat, with a higher probability of initiating treatment (60%, p = 0.01) and higher mean starting doses (45 µg, p <0.01) compared with the French-speaking region (44%, 36 µg); the Zurich region had intermediate values (52%, 39 µg). We found no association between treatment rate and other physician characteristics. GPs were more reluctant to initiate treatment in 85-year-old than in 70-year-old women (odds ratio [OR] 0.77, 95% confidence interval [CI] 0.63-0.94), and more likely to treat women with a TSH of 15 mU/l than those with a TSH of 6mU/l (OR 8.71, 95% CI 6.21-12.20). CONCLUSIONS There are strong variations in treatment strategies for elderly patients with subclinical hypothyroidism across different Swiss regions, including use of higher starting doses than the recommended 25 µg in the Swiss guidelines, which recommend a starting dose of 25 µg. These variations likely reflect the current uncertainty about the benefits of treatment, which arise from the current lack of evidence from adequately powered clinical trials.
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The ratio of cystatin C (cysC) to creatinine (crea) is regarded as a marker of glomerular filtration quality associated with cardiovascular morbidities. We sought to determine reference intervals for serum cysC-crea ratio in seniors. Furthermore, we sought to determine whether other low-molecular weight molecules exhibit a similar behavior in individuals with altered glomerular filtration quality. Finally, we investigated associations with adverse outcomes. A total of 1382 subjectively healthy Swiss volunteers aged 60 years or older were enrolled in the study. Reference intervals were calculated according to Clinical & Laboratory Standards Institute (CLSI) guideline EP28-A3c. After a baseline exam, a 4-year follow-up survey recorded information about overall morbidity and mortality. The cysC-crea ratio (mean 0.0124 ± 0.0026 mg/μmol) was significantly higher in women and increased progressively with age. Other associated factors were hemoglobin A1c, mean arterial pressure, and C-reactive protein (P < 0.05 for all). Participants exhibiting shrunken pore syndrome had significantly higher ratios of 3.5-66.5 kDa molecules (brain natriuretic peptide, parathyroid hormone, β2-microglobulin, cystatin C, retinol-binding protein, thyroid-stimulating hormone, α1-acid glycoprotein, lipase, amylase, prealbumin, and albumin) and creatinine. There was no such difference in the ratios of very low-molecular weight molecules (urea, uric acid) to creatinine or in the ratios of molecules larger than 66.5 kDa (transferrin, haptoglobin) to creatinine. The cysC-crea ratio was significantly predictive of mortality and subjective overall morbidity at follow-up in logistic regression models adjusting for several factors. The cysC-crea ratio exhibits age- and sex-specific reference intervals in seniors. In conclusion, the cysC-crea ratio may indicate the relative retention of biologically active low-molecular weight compounds and can independently predict the risk for overall mortality and morbidity in the elderly.
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Background. This study was planned at a time when important questions were being raised about the adequacy of using one hormone to treat hypothyroidism instead of two. Specifically, this trial aimed to replicate prior findings which suggested that substituting 12.5 μg of liothyronine for 50 μg of levothyroxine might improve mood, cognition, and physical symptoms. Additionally, this trial aimed to extend findings to fatigue. ^ Methods. A randomized, double-blind, two-period, crossover design was used. Hypothyroid patients stabilized on levothyroxine were invited to participate. Thirty subjects were recruited and randomized. Sequence one received their standard levothyroxine dose in one capsule and placebo in another during the first six weeks. Sequence two received their usual levothyroxine dose minus 50 μg in one capsule and 10 μg of liothyronine in another. At the end of the first six week period, subjects were crossed over. T tests were used to assess carry-over and treatment effects. ^ Results. Twenty-seven subjects completed the trial. The majority of completers had an autoimmune etiology. Mean baseline levothyroxine dose was 121 μg/d (±26.0). Subjects reported small increases in fatigue as measured by the Piper Fatigue Scale (0.9, p = 0.09) and in symptoms of depression measured by the Beck Depression Inventory-II (2.3, p = 0.16) as well as the General Health Questionnaire-30 (4.7, p = 0.14) while treated with substitution treatment. However, none of these differences was statistically significant. Measures of working memory were essentially unchanged between treatments. Thyroid stimulating hormone was about twice as high during substitution treatment (p = 0.16). Free thyroxine index was reduced by 0.7 (p < 0.001), and total serum thyroxine was reduced by 3.0 (p < 0.001) while serum triiodothyronine was increased by 20.5 (p < 0.001) on substitution treatment. ^ Conclusions. Substituting an equivalent amount of liothyronine for a portion of levothyroxine in patients with hypothyroidism does not decrease fatigue, symptoms of depression, or improve working memory. However, due to changes in serum hormone levels and small increments in fatigue and depression symptoms on substitution treatment, a question was raised about the role of T3 in the serum. ^
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Pituitary cell types arise in a temporally and spatially specific fashion, in response to combinatorial actions of transcription factors induced by transient signaling gradients. The critical transcriptional determinants of the two pituitary cell types that express the pro-opiomelanocortin (POMC) gene, the anterior lobe corticotropes, producing adrenocorticotropin, and the intermediate lobe melanotropes, producing melanocyte-stimulating hormone (MSHα), have remained unknown. Here, we report that a member of the T-box gene family, Tbx19, which is expressed only in the rostral ventral diencephalon and pituitary gland, commencing on e11.5, marks pituitary cells that will subsequently express the POMC gene and is capable of altering progression of ventral cell types and inducing adrenocorticotropin in rostral tip cells. It is suggested that Tbx19, depending on the presence of synergizing transcription factors, can activate POMC gene expression and repress the α glycoprotein subunit and thyroid-stimulating hormone β promoters.
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The recombinant human thyroid stimulating hormone (rhTSH) containing oligosaccharides terminated with NeuAc(alpha 2-3)Gal(beta 1-4)GlcNAc beta 1 showed higher in vivo activity and lower metabolic clearance rate (MCR) than pituitary human TSH (phTSH), which contains oligosaccharides terminating predominantly in SO(4)4GalNAc(beta 1-4)GlcNAc beta 1. To elucidate the relative contribution of the sulfated and sialylated carbohydrate chains of each subunit in the MCR and bioactivity of the hormone, the alpha and beta subunits of phTSH, rhTSH, and enzymatically desialylated rhTSH (asialo-rhTSH; asrhTSH) were isolated, their oligosaccharides were analyzed, and the respective subunits were dimerized in various combinations. The hybrids containing alpha subunit from phTSH or asrhTSH showed higher in vitro activity than those with alpha subunit from rhTSH, indicating that sialylation of alpha but not beta subunit attenuates the intrinsic activity of TSH. In contrast, hybrids with beta subunit from rhTSH displayed lower MCR compared to those with beta subunit from phTSH. The phTSH alpha-rhTSH beta hybrid had the highest in vivo bioactivity followed by rhTSH alpha-rhTSH beta, rhTSH alpha-phTSH beta, phTSH alpha-phTSH beta, and asrhTSH dimers. These differences indicated that hybrids with beta subunit from rhTSH displayed the highest in vivo activity and relatively low MCR, probably due to higher sialylation, more multiantennary structure, and/or the unique location of the beta-subunit oligosaccharide chain in the molecule. Thus, the N-linked oligosaccharides of the beta subunit of glycoprotein hormones have a more pronounced role than those from the alpha subunit in the metabolic clearance and thereby in the in vivo bioactivity. In contrast, the terminal residues of alpha-subunit oligosaccharides have a major impact on TSH intrinsic potency.
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A 9-year-old girl presented with a 6-month history of inflamed tender nodules in the pretibial area. These eventually healed leaving depressed areas of atrophy and loss of subcutaneous tissue. Histology showed a predominantly lymphocytic lobular panniculitis, consistent with connective tissue panniculitis. Investigations revealed an elevated thyroid stimulating hormone, elevated thyroid antiperoxidase antibody and a weakly positive antinuclear antibody (titre 1 in 40). She was commenced on hydroxychloroquine 300 mg daily, which resulted in resolution of the pannictulitis. She developed focal Vitiligo oil the thighs. This gradually improved with 0.1% mometasone furoate ointment. The hydroxychloroquine dose was tapered to 200 mg daily after 12 months, then to 100 mg daily after 18 months therapy. Her thyroid autoantibody levels continued to rise and the hydroxychloroquine was increased again to 300 mg daily. She became borderline hyothyroid. Hashimoto's thyroiditis was diagnosed. Thyroxine was instituted with a resultant improvement in her thyroid blood tests. The lipoatrophy has not developed further during 2-year follow up.
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Transgenic BALB/c mice that express intrathyroidal human thyroid stimulating hormone receptor (TSHR) A-subunit, unlike wild-type (WT) littermates, develop thyroid lymphocytic infiltration and spreading to other thyroid autoantigens after T regulatory cell (Treg) depletion and immunization with human thyrotropin receptor (hTSHR) adenovirus. To determine if this process involves intramolecular epitope spreading, we studied antibody and T cell recognition of TSHR ectodomain peptides (A–Z). In transgenic and WT mice, regardless of Treg depletion, TSHR antibodies bound predominantly to N-terminal peptide A and much less to a few downstream peptides. After Treg depletion, splenocytes from WT mice responded to peptides C, D and J (all in the A-subunit), but transgenic splenocytes recognized only peptide D. Because CD4+ T cells are critical for thyroid lymphocytic infiltration, amino acid sequences of these peptides were examined for in silico binding to BALB/c major histocompatibility complex class II (IA–d). High affinity subsequences (inhibitory concentration of 50% < 50 nm) are present in peptides C and D (not J) of the hTSHR and mouse TSHR equivalents. These data probably explain why transgenic splenocytes do not recognize peptide J. Mouse TSHR mRNA levels are comparable in transgenic and WT thyroids, but only transgenics have human A-subunit mRNA. Transgenic mice can present mouse TSHR and human A-subunit-derived peptides. However, WT mice can present only mouse TSHR, and two to four amino acid species differences may preclude recognition by CD4+ T cells activated by hTSHR-adenovirus. Overall, thyroid lymphocytic infiltration in the transgenic mice is unrelated to epitopic spreading but involves human A-subunit peptides for recognition by T cells activated using the hTSHR.
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Objectives: We report the unusual case of a patient with a thyrotropinoma, discovered after a hemithyroidectomy for a suspicious thyroid nodule, and its therapeutic challenges. Materials and methods: In a patient who underwent hemithyroidectomy for cold thyroid nodule, hyperthyroid symptoms persisted, despite stopping levothyroxine treatment. Further investigation was carried out through the following laboratory tests: thyroid-stimulating hormone (TSH) test; free thyroxine (fT4) test; and the thyrotropin releasing hormone (TRH) test. A pituitary magnetic resonance imaging (MRI) scan and genetic analysis was also carried out. The test results confirmed the diagnosis of a thyrotropinoma. Results: Treatment with long-acting somatostatin analogues normalised thyroid hormones and symptoms of hyperthyroidism. Conclusion: The diagnostic approach to the thyroid nodule should include a detailed clinical and biochemical examination. Initial biochemical evaluation by TSH alone does not allow detecting inappropriate TSH secretion that may increase the risk of thyroid malignancy. In case of a thyrotropinoma, the ideal treatment consists of combined care of central and peripheral thyroid disease.