Measurement Of Thyroid-stimulating Hormone Research Articles

Management of primary hypothyroidism in adults: An analysis of the results of a survey in 546 primary care physicians

ObjectiveTo document current practices in the management of adult patients with hypothyroidism in the setting of primary healthcare. MethodsWe designed a web-based survey to inquire information on real-life practices regarding management of hypothyroidism by primary care physicians in the region of Madrid (Spain). ResultsIn total, 546 out of 3897 (14%) physicians (aged 50.9±8.5 yr, 404 females) completed the survey. More than 90% of respondents requested serum thyrotropin measurement in subjects with symptoms of thyroid hypofunction, family history of thyroid disease and history of autoimmune disease. A thyroid ultrasound was requested to evaluate subclinical and overt hypothyroidism by 27.1% and 69.6% of respondents, respectively. Only 22.1% of respondents stated that they do not treat subclinical hypothyroidism with thyrotropin values less than 10mU/l. Most physicians use brand-name formulations of levothyroxine and advise patients on how to take the tablets. To start treatment, the gradual replacement rate was the option chosen by most of the respondents, even in young patients. The thyrotropin target preferred by most respondents was 0.5–5.0mU/l, especially in older patients. In patients with persistent symptoms, 61.4% search for the causes through complementary investigations. A longer professional practice time was not always accompanied by better adherence to guidelines and expert recommendations. ConclusionOur results reveal a proactive attitude in the diagnosis and of therapy by most of the respondents. However, we observed a tendency to perform unnecessary diagnostic tests and an excessive propensity to treat mild subclinical hypothyroidism.

Macro-TSH - tips and tricks for gynecologists.

Thyroid disorders are one of the most common endocrinopathies in women of reproductive age. Measurement of TSH (thyroid-stimulating hormone) concentration in women planning pregnancy/pregnant is a golden standard of thyroid function assessment. When the laboratory findings do not correspond with the clinical signs, it is reasonable to mark macro-TSH.

Association of serum thyroid hormone levels with positron emission tomography imaging in non-demented older adults.

Although increasing evidence indicates that even variations in normal range thyroid function are associated with Alzheimer's disease (AD), the association between serum thyroid hormone levels within the reference range and AD biomarkers remains unclear. This study examined whether variations in thyroid hormones within the reference range are associated with brain amyloid burden and cortical glucose metabolism in older adults without dementia. One hundred and two non-demented older adults underwent 11 C-Pittsburgh Compound B positron emission tomography (PiB-PET), 18 F-fluorodeoxyglucose (FDG)-PET, and measurement of serum thyroid-stimulating hormone (TSH), free triiodothyronine (T3), and free thyroxine (T4) levels. The discrimination between PiB-negative and PiB-positive subgroup was made on the basis of a subject's cortical uptake value ratio greater than 1.4. The association of serum thyroid hormone levels with global PiB or FDG uptake, and PiB or FDG uptake in each region of interest, including frontal and temporoparietal lobes and posterior cingulate gyrus, was analysed using a multiple regression model with adjustment for covariates, including age, gender, years of education, apolipoprotein E4 status or PiB uptake value. In the PiB-positive subgroup, the serum TSH levels positively associated with the global FDG uptake (β=0.471, P=0.003) and FDG uptake in the frontal and temporoparietal lobes (β=0.466, P=0.003, β=0.394, P=0.012, respectively); the serum-free T3 levels negatively associated with the FDG uptake in the temporoparietal lobe and posterior cingulate region (β=-0.351, P=0.033, β=-0.544, P=0.002, respectively). The PiB-negative subgroup showed no significant associations. The serum thyroid hormone levels did not correlate with the global PiB uptake and PiB uptake in each region. The variations in the thyroid hormones within the reference ranges are associated with glucose metabolism, particularly in the specific regions affected by the neuropathologic changes of AD, in non-demented older adults with brain amyloid burden.

Hashimoto thyroiditis: an evidence-based guide to etiology, diagnosis and treatment.

Hashimoto thyroiditis (HT) is a common autoimmune disorder, affecting women 7–10 times more often than men, that develops because of genetic susceptibility, X chromosome inactivation patterns modulated by environmental factors as well as microbiome composition, and leads to an imbalance in self-tolerance mechanisms. The consequential thyroid infiltration by lymphocytes, potentiated by antibody-mediated autoimmune response through the antibodies against thyroid peroxidase (TPOAbs), leads to a destruction of thyrocytes. The presence of TPOAbs is associated with a 2 to 4-fold increase in the risk of recurrent miscarriages and preterm birth in pregnant women. The clinical presentation of HT includes: (A) thyrotoxicosis, when stored thyroid hormones are released to circulation from destroyed thyroid follicles; (B) euthyroidism, when preserved thyroid tissue compensates for destroyed thyrocytes; and (C) hypothyroidism, when thyroid hormone production by the affected thyroid gland is insufficient. The management of Hashitoxicosis is based on symptoms control usually with β-blockers, euthyroidism requires periodical thyroid stimulating hormone measurements to assess for progression to hypothyroidism, and hypothyroidism is treated with thyroid hormone replacement therapy. The dose of levothyroxine (LT4) used for treatment is based on the degree of preserved thyroid functionality and lean body mass, and usually ranges from 1.4 to 1.8 mcg/kg/day. There is insufficient evidence to recommend for or against therapy with triiodothyronine (T3), apart from in pregnancy when only levothyroxine is indicated, as T3 does not sufficiently cross fetal blood-brain barrier. HT is associated with 1.6 times higher risk of papillary thyroid cancer and 60 times higher risk of thyroid lymphoma than in general the population.

Screening for Thyroid Disorders Among Resistant Hypertension Patients: Are We Doing Enough?

Objective: To perform a quality assurance study assessing if hypo- and hyperthyroidism are appropriately screened for in patients with resistant hypertension.Design: Data was collected from patients diagnosed with resistant hypertension, defined as being on four or more different classes of anti-hypertensive medications. These patients were filtered to determine if thyroid stimulating hormone (TSH) measurement occurred within 90 days of the addition of a fourth medication class.Setting: Two internal medicine residency clinics in Pittsburgh, PA.Participants: Patients were selected who had a diagnosis of hypertension and were seen in clinic between January 1, 2018 and December 23, 2020.Methods: A single center retrospective review was performed.Results: A total of 1,125 patients were identified as having resistant hypertension. Of these, only 74 patients were found to have a TSH measurement taken within 90 days of having a fourth medication class prescribed. Seven TSH values were found to be abnormal with one patient being diagnosed with hyperthyroidism, demonstrating a screening rate of 6.6%. There were statistically significant differences in age, body mass index, and diastolic blood pressure in those screened versus not.Conclusions: Thyroid disease is under-screened as an etiology for resistant hypertension, particularly given the ease of diagnosis and reversibility of these conditions.

Challenges in the Management of Atrial Fibrillation With Subclinical Hyperthyroidism.

Subclinical thyroid disorders have a high prevalence among older individuals and women. Subclinical hypothyroidism is diagnosed by elevated serum levels of thyroid-stimulating hormone (TSH) with thyroxine levels within the reference range, and subclinical hyperthyroidism is diagnosed by low TSH in conjunction with thyroxine and triiodothyronine levels within reference ranges. Atrial fibrillation is the most commonly diagnosed cardiac arrhythmia and has been associated with an increased risk of mortality, heart failure, stroke, and depression. Mechanistic data from animal and human physiology studies as well as observational data in humans support an association of subclinical hyperthyroidism with atrial fibrillation. Guidelines recommend the measurement of TSH in the evaluation of new-onset atrial fibrillation. All patients with overt hyperthyroidism should be treated, and treatment of subclinical hyperthyroidism should be considered in patients older than 65 years with TSH < 0.4 mlU/L, or in younger patients with TSH < 0.1 mlU/L. Guidelines also recommend screening for AF in patients with known hyperthyroidism. Wearable devices that measure the heart electrical activity continuously may be a novel strategy to detect atrial fibrillation in patients at risk. In this review, we explore the interplay between thyroid hormones and atrial fibrillation, management controversies in subclinical hyperthyroidism, and potential strategies to improve the management of atrial fibrillation in patients with subclinical hyperthyroidism.

Low T3 syndrome as a prognostic factor in patients in the intensive care unit: an observational cohort study

ObjectiveTo assess euthyroid sick syndrome as a prognostic factor in patients in the intensive care unit; to detect factors that may affect mortality; and to develop an equation to calculate death probability.MethodsThis was a longitudinal, observational, nonconcurrent cohort study developed in the intensive care unit of Fundação Santa Casa de Misericórdia do Pará. One hundred adults with no prior documented endocrinopathy were submitted to a 20mL blood sample collection for the measurement of thyroid stimulating hormone, free tetraiodothyronine, free triiodothyronine and reverse triiodothyronine.ResultsMost patients were female, aged 20 to 29 years. Most patients who died were older (median age of 48 years), and euthyroid sick syndrome was present in 97.5% of them. Euthyroid sick syndrome was related to death, comorbidities, age and length of stay in the intensive care unit (median of 7.5 days).There was an association between lower thyroid stimulating hormone and death. Patients with free triiodothyronine levels below 2.9pg/mL were more likely to die; reverse triiodothyronine rates were above 0.2ng/mL in those who died. Free triiodothyronine had greater sensitivity and accuracy, and reverse triiodothyronine had greater specificity to predict mortality. Based on the results and cutoff points, a multiple logistic regression formula was developed to calculate the probability of death.ConclusionThe main limitation of this study is the fact that it was conducted in a reference hospital for maternal and child care; therefore, there was a greater number of female patients and, consequently, a sampling bias existed. However, opportune measurement of free and reverse triiodothyronine levels in critical patients and application of the proposed equation are suggested.

Low T3 syndrome as a prognostic factor in patients in the intensive care unit: an observational cohort study.

To assess euthyroid sick syndrome as a prognostic factor in patients in the intensive care unit; to detect factors that may affect mortality; and to develop an equation to calculate death probability. This was a longitudinal, observational, nonconcurrent cohort study developed in the intensive care unit of Fundação Santa Casa de Misericórdia do Pará. One hundred adults with no prior documented endocrinopathy were submitted to a 20mL blood sample collection for the measurement of thyroid stimulating hormone, free tetraiodothyronine, free triiodothyronine and reverse triiodothyronine. Most patients were female, aged 20 to 29 years. Most patients who died were older (median age of 48 years), and euthyroid sick syndrome was present in 97.5% of them. Euthyroid sick syndrome was related to death, comorbidities, age and length of stay in the intensive care unit (median of 7.5 days).There was an association between lower thyroid stimulating hormone and death. Patients with free triiodothyronine levels below 2.9pg/mL were more likely to die; reverse triiodothyronine rates were above 0.2ng/mL in those who died. Free triiodothyronine had greater sensitivity and accuracy, and reverse triiodothyronine had greater specificity to predict mortality. Based on the results and cutoff points, a multiple logistic regression formula was developed to calculate the probability of death. The main limitation of this study is the fact that it was conducted in a reference hospital for maternal and child care; therefore, there was a greater number of female patients and, consequently, a sampling bias existed. However, opportune measurement of free and reverse triiodothyronine levels in critical patients and application of the proposed equation are suggested.

Non-Toxic Multinodular Goiter: From Etiopathogenesis to Treatment.

Goiter term is generally used for defining the enlargement of thyroid gland. Thyroid nodules are very common and some of these nodules may harbor malignancy. Multinodular goiter (MNG) disease without thyroid dysfunction is defined as non-toxic MNG.There are many factors in etiology for development of MNG. They can be classified as iodine dependent and non-iodine dependent factors basically. Beyond this basic classification, the effect of many environmental and acquired factors is also effective on the development of goiter.Many methods have described for diagnosis and treatment for non-toxic MNG. Biochemical tests, imagining methods, invasive and non-invasive methods have been used for diagnosis for many years. Each method has advantages and disadvantages, separately. Although the best method for diagnosis is still debatable, distinguishing malignant nodules from benign nodules is the first and most important step for MNG.Biochemical tests such as serum thyroid stimulating hormone (TSH) measurement, thyroid hormone measurement; and thyroid ultrasonography are used for diagnosis of MNG, traditionally. Nowadays, there are some new techniques were developed like ultrasound-elastography. Furthermore, thyroid scintigraphy may be used if there is abnormal TSH measurement. Fine-needle aspiration biopsy and some cross-sectional imaging methods (computed tomography, magnetic resonance imaging, and positron emission tomography) could be used, too.After a certain diagnosis is made, treatment options should be evaluated. Many treatment methods have been used for goiter from ancient times upon today. From non-invasive methods such as medical follow-up to invasive methods such as lobectomy or thyroidectomy are options for treatment. Patients with compression symptoms due to an enlarged thyroid gland are usually candidates for surgery. In this study, it is aimed to determine the most appropriate treatment for the patient by discussing the advantages and disadvantages of all these methods.The present review discusses definition of goiter term, etiology, epidemiology, pathogenesis, diagnostic methods, and treatment methods for nontoxic MNG.

SERUM CARBOXYMETHYL-LYSINE AND SOLUBLE RECEPTOR FOR ADVANCED GLYCATION END PRODUCTS IN HYPERTHYROID AND HYPOTHYROID PATIENTS.

The formation and accumulation of advanced glycation end products (AGEs) are enhanced with increased oxidative stress and inflammatory conditions. A hyperthyroid and hypothyroid state is associated with oxidative stress. This study aimed to evaluate skin AGE deposition, serum carboxymethyl-lysine (CML), and serum soluble receptor for AGEs (sRAGE) levels in hypothyroid and hyperthyroid patients. A total of 203 subjects were included in this cross-sectional study. After excluding diabetes mellitus, 103 newly diagnosed hypothyroid patients, 50 newly diagnosed hyperthyroid patients, and 50 control (euthyroid) subjects were enrolled. All tests were done before beginning the appropriate treatment. Accumulated AGEs in the skin collagen were measured by skin autofluorescence (SAF) using an AGE Reader. SAF measurements were 1.82 ± 0.04, 1.80 ± 0.40, and 1.63 ± 0.30 arbitrary units for the hypothyroid, hyperthyroid, and euthyroid groups, respectively (p = 0.04). Serum CML levels were 8.2 ± 2.8, 10.2 ± 2.0, and 8.0 ± 3.3 ng/mL for the hypothyroid, hyperthyroid, and euthyroid groups, respectively (p = 0.01). sRAGE levels were similar between the groups. Serum thyroid-stimulating hormone and SAF measurements were positively correlated (r = 0.25, p = 0.02) in the hypothyroid group and negatively correlated in the hyperthyroid group (r = -0.36, p = 0.04). There was no correlation between CML and sRAGE levels. SAF measurements are increased in both hypo- and hyperthyroid normoglycemic patients. Serum CML levels are increased in hyperthyroid patients. Hypo and hyperthyroid states might be associated with acceleration of AGE accumulation and may have a long term effect on metabolic memory.

Sexual Dysfunction in Schizophrenia: A Narrative Review of the Mechanisms and Clinical Considerations

Psychiatric disorders, in general, have a high prevalence of sexual problems, whether from the psychopathology of the disorder itself, pre-existing or co-morbid sexual disorder or from side effects of the treatment for mental disorders. Many patients report an already existing sexual dysfunction at the onset of diagnosis. The risk association for developing sexual dysfunction in patients with schizophrenia includes antipsychotic use and resulting hyperprolactinemia, age, gender, and disease severity. Medication side effects lead to nonadherence, and relapses lead to structural changes in the brain, treatment resistance, and worsening of symptoms. Findings in certain studies propose serum prolactin and thyroid-stimulating hormone measurement as a tool for assessing patients with schizophrenia for sexual dysfunction. Regarding specific symptoms, females especially reported decreased desire at baseline and galactorrhea after treatment. The findings of this review, therefore, suggest that sexual dysfunction may be present in patients with schizophrenia before starting antipsychotic treatment and that patients, especially those who are female, are likely to develop hyperprolactinemia with antipsychotic treatment. Aripiprazole may be an emergent treatment for sexual dysfunction in those who use antipsychotics. It is important for patients to consider sexual dysfunction prior to prescribing antipsychotics. Since sexual dysfunction can impact a patient’s quality of life and affect treatment adherence, it is important for physicians to be aware and monitor patients for symptoms.

Effects of EDTA on chemiluminescent immunoassay measurement of ACTH, cortisol, and thyroid hormones in dogs

When measuring blood hormones, pre-analytical sample handling can impact the quality of the results. Previous studies have shown improved stability of canine cortisol in ethylenediaminetetraacetic acid (EDTA) plasma compared to serum and interchangeability of serum and plasma when cortisol is measured by radioimmunoassay. Additionally, cortisol samples were also interchangeable when measured by chemiluminescent immunoassay if the EDTA concentration was consistent with that of optimally filled tubes, whereas excess EDTA interfered with the measurement of cortisol and serum and EDTA plasma were not interchangeable when measuring total thyroxine (TT4). The main limitation of these studies was that they were performed by spiking pooled serum samples with EDTA or in previously collected blood samples submitted to a clinical pathology laboratory. The purpose of the present study was to evaluate the effect of EDTA on the measurement of adrenocorticotropic hormone (ACTH), cortisol, TT4, free thyroxine (FT4), and thyroid stimulating hormone (TSH) in healthy dogs using the Siemens IMMULITE 1000. Whole blood from forty dogs was aliquoted into three Monoject sample tubes: no additive, completely filled EDTA tube, and 50% filled EDTA tube. Handling and storage conditions were identical, and all samples were analyzed on the same day. Bland-Altman plots and Passing-Bablok regression were used to assess agreement and risks for error, respectively. Proportional errors were found between serum and plasma samples for ACTH, cortisol, TT4, FT4, and TSH; systematic errors were also found for FT4. There was poor agreement and clinically significant differences between the measured concentrations of all hormones in serum and plasma, proving that these sample types are not interchangeable. Incompletely filled EDTA tubes were associated with significantly lower ACTH concentrations compared to completely filled EDTA tubes. When measured by chemiluminescent immunoassays that utilize alkaline phosphatase at the reporter enzyme, serum should be used for cortisol, TT4, FT4, and TSH, while plasma from completely filled EDTA tubes should be used for ACTH.

Risk of over- and under- treatment with levothyroxine in primary care in Copenhagen, Denmark.

A decrease over time in thyroid stimulating hormone (TSH) levels when initiating levothyroxine (L-T4) therapy for hypothyroidism has been reported, where treatment most often is initiated with TSH levels below 10 mIU/L. The primary objective of this study was to investigate whether this lower TSH threshold resulted in an increased number of overtreated patients. Retrospective cohort study comprising inhabitants in Copenhagen had TSH measurements requested by general practitioners which led to a new prescription of L-T4 between 2001 and 2012. Over- and under- treatment were defined as TSH <0.1 mIU/L or above 10 mIU/mL, respectively, in three consecutive measurements. Data were analyzed by Aalen-Johansen estimators and Cox proportional hazards models. In total, 14 533 initiations of L-T4 were included in the study. The cumulative risk of being over- or undertreated was 4.7 and 7.4% after 10 years. The hazard of overtreatment was higher among women, younger adults, and with lower initial TSH levels. The hazard of overtreatment decreased over the time period from 2001 to 2012. Among overtreated individuals, the chance of returning to a normal TSH was about 55% after 10 years. In 18% of the cases, L-T4 therapy was initiated on TSH levels less than 5 mIU/L. Although a still decreasing threshold for initiating L-T4 therapy is known, the risk of overtreatment (and undertreatment) was low and lessened in the period 2001-2012 among Danish primary care patients. Nevertheless, as many as 18% were started on L-T4 with normal TSH levels.

Progression of PTH Resistance in Autosomal Dominant Pseudohypoparathyroidism Type Ib Due to Maternal STX16 Deletions.

Maternally inherited STX16 deletions that cause loss of methylation at GNAS exon A/B and thereby reduce Gsα expression are the most frequent cause of autosomal dominant pseudohypoparathyroidism type Ib (AD-PHP1B). Early identification of these disease-causing variants in the children of affected and unaffected female carriers would prompt treatment with calcium and calcitriol once parathyroid hormone (PTH) levels increase, thereby preventing hypocalcemia and associated complications. This study aimed to determine when PTH and calcium abnormalities develop after birth if a STX16 deletion is inherited maternally. Forty-four children of affected (n = 7) or unaffected (n = 7) females with a STX16 deletion were investigated for the presence of these variants. If a deletion was identified, measurement of PTH, calcium, phosphate, and thyrotropin (TSH) was advised. The STX16 deletion that causes AD-PHP1B was identified in 25 children. Pretreatment laboratory results were available for 19 of those cases. Elevated PTH levels were detected by 2 years of age, and these were progressively higher if laboratory testing was first performed after establishing the genetic defect later in life. Total serum calcium levels remained within normal limits until about 5 years of age. TSH levels showed no consistent rise over time. Establishing whether a STX16 deletion is inherited from a female carrier of a disease-causing variant rapidly establishes the diagnosis of AD-PHP1B. Several years before overt hypocalcemia developed, PTH levels increased, thereby establishing the onset of PTH resistance. Our findings provide diagnostic guidance and when treatment with calcium and calcitriol should be considered in order to prevent hypocalcemia and associated sequelae.

Increased maternal leptin levels may be an indicator of subclinical hypothyroidism in a newborn.

BackgroundSeveral factors may influence newborn thyroid-stimulating hormone (TSH) concentrations and cause subclinical hypothyroidism in a newborn. A sufficient level of leptin signalling is needed for the normal production of TSH and thyroid hormones by the thyroid gland. Our study aimed to investigate the correlation between maternal serum leptin concentration during the third trimester of pregnancy and newborn screening-TSH levels.MethodsThis prospective cross-sectional study was conducted in obstetrics and gynaecology clinics of a state hospital between June and August 2013. Maternal venous blood samples were collected from 270 healthy pregnant women in the third trimester just before delivery. Measurements of maternal fT3, fT4, TSH, anti-thyroid peroxidase (TPO), and anti-thyroglobulin (anti-Tg) antibodies from serum samples were performed by chemiluminescence immunoassay. Maternal serum leptin levels were determined by ELISA. Dried capillary blood spots were used to measure newborn TSH levels.ResultsSubjects were divided into two groups according to the neonatal TSH levels using a cut-point of 5.5 mIU/L. Median maternal serum leptin levels were significantly higher in newborns whose TSH levels were higher than >5.5 mIU/L [13.2 μg/L (1.3 - 46.5) vs 19.7 μg/L (2.4 - 48.5), p<0.05]. Serum leptin levels showed a negative correlation with maternal fT4 (r=0.32, p<0.05), fT3 (r=0.23, p<0.05), and a positive correlation with BMI (r=0.30, p<0.05).ConclusionsOur results suggest that high leptin levels in the third trimester of pregnancy influence maternal thyroid functions and might cause an increase in newborn TSH levels. Detection of high maternal serum leptin levels may be a reason for subclinical hypothyroidism.

Management of primary hypothyroidism in adults: An analysis of the results of a survey in 546 primary care physicians

ObjectiveTo document current practices in the management of adult patients with hypothyroidism in the setting of primary healthcare. MethodsWe designed a web-based survey to inquire information on real-life practices regarding management of hypothyroidism by primary care physicians in the region of Madrid (Spain). ResultsIn total, 546 out of 3897 (14%) physicians (aged 50.9±8.5 yr, 404 females) completed the survey. More than 90% of respondents requested serum thyrotropin measurement in subjects with symptoms of thyroid hypofunction, family history of thyroid disease and history of autoimmune disease. A thyroid ultrasound was requested to evaluate subclinical and overt hypothyroidism by 27.1% and 69.6% of respondents, respectively. Only 22.1% of respondents stated that they do not treat subclinical hypothyroidism with thyrotropin values less than 10mU/l. Most physicians use brand-name formulations of levothyroxine and advise patients on how to take the tablets. To start treatment, the gradual replacement rate was the option chosen by most of the respondents, even in young patients. The thyrotropin target preferred by most respondents was 0.5–5.0mU/l, especially in older patients. In patients with persistent symptoms, 61.4% search for the causes through complementary investigations. A longer professional practice time was not always accompanied by better adherence to guidelines and expert recommendations. ConclusionOur results reveal a proactive attitude in the diagnosis and of therapy by most of the respondents. However, we observed a tendency to perform unnecessary diagnostic tests and an excessive propensity to treat mild subclinical hypothyroidism.

Thyroid dysfunction in cerebral venous thrombosis: a retrospective cohort study

BackgroundCerebral venous thrombosis (CVT) is a multifactorial disease with a variety of related conditions and risk factors. Thyroid dysfunction—especially hyperthyroidism—has been linked to CVT, but this is mainly based on case reports ranging back to 1913, while systematic investigations addressing this issue are lacking. Therefore, we investigated the frequency and clinical characteristics of thyroid dysfunction in a large single-center cohort of CVT patients.MethodsWe retrospectively identified all consecutive patients with aseptic CVT treated at our center between 2006 and 2020. Clinical information was extracted from our electronic medical documentation system. Thyroid-stimulating hormone (TSH) had been routinely measured at admission, free thyroid hormones and thyroid autoantibodies were analyzed whenever available.ResultsOf 120 patients with imaging-confirmed CVT, our main analysis included 107 patients (mean age 42 ± 16 years, 74% female) in whom TSH measurements were available. Nineteen patients (17.8%, 95% confidence interval 10–25%) had thyroid dysfunction. Two had newly diagnosed hyperthyroidism (1.9%, 95% confidence interval 0–4%) caused by Graves’ disease, but without typical symptoms for this condition. Seventeen patients (15.9%, 95% confidence interval 9–23%) had hypothyroidism (12 previously diagnosed with ongoing thyroid hormone replacement therapy; 5 with newly diagnosed subclinical hypothyroidism). Clinical CVT characteristics were similar comparing patients with versus without thyroid dysfunction.ConclusionWe observed a remarkably high prevalence of thyroid dysfunction in CVT patients. Whether this finding reflects a causal relationship warrants further studies. Despite that, the frequent coexistence of both diseases argues for TSH screening in CVT patients.

Comparison between an Emerging Point-of-Care Tool for TSH Evaluation and a Centralized Laboratory-Based Method in a Cohort of Patients from Southern Italy.

Endocrine and metabolic disorders are a common condition in Europe and worldwide, and, among these, thyroid dysfunction still remains a problem. The measurement of thyroid stimulating hormone (TSH) levels represents the first-line assay for the assessment of thyroid function. In the present study, we compared serum concentrations of TSH, measured using a commercially available point-of-care test (POCT) method (FastPack® IP) and an established “conventional” laboratory-based method (Beckmann Access 2) in a cohort of patients from Foggia in Southern Italy. A strong correlation (r = 0.994) was found between both methods and was also confirmed by receiver operating characteristic (ROC) curve analysis (0.82). The within-run coefficient of variation (CV) using FastPack® ranged from 4.03% and 8.57% at the TSH concentrations of 39.49 and 0.70 mIU/L, respectively. The between-run CV was 10.34% and 6.33% at the TSH concentrations of 0.87 and 26.55 mIU/L, respectively. The ratios of within- to between-assay CV were 0.83 and 1.06 at the TSH levels of 0.70 and 52.59 mIU/mL, respectively. In this study, we showed that serum TSH levels can be measured in a few minutes and at low-cost in terms of materials and equipment required. We observed that this approach is user-friendly, accurate, reproducible, and suitable for use in the clinic, while also meeting the criteria for effectiveness, impact, efficiency, and sustainability.

Maternal Perfluoroalkyl Substances, Thyroid Hormones, and DIO Genes: A Spanish Cross-sectional Study.

Results of studies on perfluoroalkyl substances (PFASs) and thyroid hormones (THs) are heterogeneous, and the mechanisms underlying the action of PFASs to target THs have not been fully characterized. We examined the relation between first-trimester maternal PFAS and TH levels and the role played by polymorphisms in the iodothyronine deiodinase 1 (DIO1) and 2 (DIO2) genes in this association. Our sample comprised 919 pregnant Spanish women (recruitment = 2003-2008) with measurements of perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), thyroid-stimulating hormone (TSH), total triiodothyronine (TT3), and free thyroxine (FT4), and we genotyped for single-nucleotide polymorphisms in the DIO1 (rs2235544) and DIO2 (rs12885300) genes. We performed multivariate regression analyses between PFASs and THs and included the interaction term PFAS-genotypes in the models. PFHxS was associated with an increase in TSH (% change in outcome [95% CI] per 2-fold PFAS increase = 6.09 [-0.71, 13.4]), and PFOA and PFNA were associated with a decrease in TT3 (-7.17 [-13.5, -0.39] and -6.28 [-12.3, 0.12], respectively). We found stronger associations between PFOA, PFNA, and TT3 for DIO1-CC and DIO2-CT genotypes, although interaction p-values were not significant. In conclusion, this study found evidence of an inverse association between PFOA and TT3 levels. No clear effect modification by DIO enzyme genes was observed.

Patient-Tailored Levothyroxine Dosage with Pharmacokinetic/Pharmacodynamic Modeling: A Novel Approach After Total Thyroidectomy.

Background: After seven decades of levothyroxine (LT4) replacement therapy, dosage adjustment still takes several months. We have developed a decision aid tool (DAT) that models LT4 pharmacometrics and enables patient-tailored dosage. The aim of this was to speed up dosage adjustments for patients after total thyroidectomy.Methods: The DAT computer program was developed with a group of 46 patients post-thyroidectomy, and it was then applied in a prospective randomized multicenter validation trial in 145 unselected patients admitted for total thyroidectomy for goiter, differentiated thyroid cancer, or thyrotoxicosis. The LT4 dosage was adjusted after only two weeks, with or without application of the DAT, which calculated individual free thyroxine (fT4) targets based on four repeated measurements of fT4 and thyrotropin (TSH) levels. The individual TSH target was either <0.1, 0.1–0.5, or 0.5–2.0 mIU/L, depending on the diagnosis. Initial postoperative LT4 dosage was determined according to clinical routine without using algorithms. A simplified DAT with a population-based fT4 target was used for thyrotoxic patients who often went into surgery after prolonged TSH suppression. Subsequent LT4 adjustments were carried out every six weeks until target TSH was achieved.Results: When clinicians were guided by the DAT, 40% of patients with goiter and 59% of patients with cancer satisfied the narrow TSH targets eight weeks after surgery, as compared with only 0% and 19% of the controls, respectively. The TSH was within the normal range in 80% of DAT/goiter patients eight weeks after surgery as compared with 19% of controls. The DAT shortened the average dosage adjustment period by 58 days in the goiter group and 40 days in the cancer group. For thyrotoxic patients, application of the simplified DAT did not improve the dosage adjustment.Conclusions: Application of the DAT in combination with early postoperative TSH and fT4 monitoring offers a fast approach to LT4 dosage after total thyroidectomy for patients with goiter or differentiated thyroid cancer. Estimation of individual TSH-fT4 dynamics was crucial for the model to work, as removal of this feature in the applied model for thyrotoxic patients also removed the benefit of the DAT.