Monitoring thyroid function status in elderly patients on amiodarone

Objectives: To evaluate whether elderly patients on amiodarone were having their thyroid function status monitored as recommended in the literature and to identify the frequency and type of thyroid function test abnormalities noted. Methods: Patients on amiodarone were identified by examining the prescription charts and medical files of consecutive admissions into Zammit Clapp Hospital (ZCH) and residents at St Vincent de Paul Residence (SVPR). Data was obtained on whether thyroid function tests had been checked at the start of the medication and every six months; the results of such tests carried out over the previous year; the clinical indication to prescribe the medication; and the course of action followed when results were abnormal. Results: 1334 prescription charts were examined. 69 patients (5.2%) were on amiodarone. The most common clinical indication for the medication was atrial fibrillation (68.1%). As regards thyroid status, 39.1% of subjects had blood tests checked at the start of the medication but only 2.9% every 6 months. Although 75.4% had had their thyroid status checked over the previous year, 8.7% never had any thyroid function tests carried out whilst they were on the medication. In all 27.5% of subjects had thyroid gland dysfunction of which 13% had subclinical hypothyroidism, 11.6% clinical hypothyroidism and 2.9% clinical hyperthyroidism. All patients with abnormal results had been kept on amiodarone even when the arrhythmia had abated. Conclusions: Thyroid dysfunction is a common side effect of amiodarone medication. The regular measurement of thyroid function tests, as recommended, should be adhered to in a stricter manner.peer-reviewe

Thyroid function tests

Thyroid disorders can be difficult to detect clinically, but thyroid function tests can assist in making a diagnosis. Measuring thyroid stimulating hormone is the first step. If it is abnormal, free thyroxine should be measured. A raised concentration of thyroid stimulating hormone with a low concentration of free thyroxine suggests hypothyroidism. A low concentration of thyroid stimulating hormone with a high concentration of free thyroxine suggests hyperthyroidism. Measuring thyroid autoantibodies may help establish the cause of the dysfunction. Different assays can give different results, and tests of thyroid function may be affected by drugs and intercurrent illness

Thyroxine treatment in patients with symptoms of hypothyroidism but thyroid function tests within the reference range: randomised double blind placebo controlled crossover trial

OBJECTIVES: To determine whether thyroxine treatment is effective in patients with symptoms of hypothyroidism but with thyroid function tests within the reference range, and to investigate the effect of thyroxine treatment on psychological and physical wellbeing in healthy participants. DESIGN: Randomised double blind placebo controlled crossover trial. SETTING: Outpatient clinic in a general hospital. Participants: 25 patients with symptoms of hypothyroidism who had thyroid function tests within the reference range, and 19 controls. Methods: Participants were given thyroxine 100 microgram or placebo to take once a day for 12 weeks. Washout period was six weeks. They were then given the other to take once a day for 12 weeks. All participants were assessed physiologically and psychologically at baseline and on completion of each phase. MAIN OUTCOME MEASURES: Thyroid function tests, measures of cognitive function and of psychological and physical wellbeing. RESULTS: 22 patients and 19 healthy controls completed the study. At baseline, patients' scores on 9 out of 15 psychological measures were impaired when compared with controls. Patients showed a significantly greater response to placebo than controls in 3 out of 15 psychological measures. Healthy participants had significantly lower scores for vitality when taking thyroxine compared to placebo (mean (SD) 60 (17) v 73 (16), P<0.01). However, patients' scores from psychological tests when taking thyroxine were no different from those when taking placebo except for a poorer performance on one visual reproduction test when taking thyroxine. Serum concentrations of free thyroxine increased and those of thyroid stimulating hormone decreased in patients and controls while they were taking thyroxine, confirming compliance with treatment. Although serum concentrations of free triiodothyronine increased in patients and controls taking thyroxine, the difference between the response to placebo and to thyroxine was significant only in the controls. CONCLUSIONS: Thyroxine was no more effective than placebo in improving cognitive function and psychological wellbeing in patients with symptoms of hypothyroidism but thyroid function tests within the reference range. Thyroxine did not improve cognitive function and psychological wellbeing in healthy participants

Thyroid stimulating hormone (TSH) ≥2.5mU/l in early pregnancy: prevalence and subsequent outcomes

Objective: There remains controversy over how women with abnormal thyroid function tests in pregnancy should be classified. In this study we assessed the proportion of women with thyroid stimulating hormone (TSH) ≥ 2.5 mU/l in a large obstetric cohort, and examined how many have gone on to develop thyroid disease in the years since their pregnancy. Study design: 4643 women were recruited and samples taken in early pregnancy between 2007 and 2010. Thyroid function tests were analysed in 2014; in women with raised TSH computerised health records and prescription databases were used to identify thyroid disease detected since pregnancy. Results: 58 women (1.5%) had a TSH over 5 mU/l and 396 women (10.3%) had TSH between 2.5 and 5 mU/l. Women with TSH > 5mU/l delivered infants of lower birthweight than those with TSH < 2.5 mU/l; there were no other differences in obstetric outcomes between the groups. Of those who have had thyroid tests since their pregnancy, 78% of those with TSH > 5 mU/l and 19% of those with TSH between 2.5 and 5 mU/l have gone on to be diagnosed with thyroid disease. Conclusions: Using a TSH cut-off of 2.5 mU/l in keeping with European and US guidelines means that over 12% of women in this cohort would be classified as having subclinical hypothyroidism. Treatment and monitoring of these women would have major implications for planning of obstetric services

Postpartum depression and thyroid dysfunction– should pregnant women be screened for thyroid disorders?

The relationship between thyroid dysfunction and postpartum depression has been investigated for quite some time now, but no consensus has been reached regarding the need for screening for thyroid function during pregnancy. This paper aims to investigate whether thyroid hormone screening in pregnancy might contribute to the diagnosis of postpartum depression. Depression was assessed using the Edinburgh Postnatal Depression Scale (EPDS) - one of the most widely used measures in detecting postpartum depression and anxiety. Thyroid function was measured using the commonly recommended thyroid laboratory tests. A structured questionnaire was given to 61 patients closely monitored during their pregnancy and at least one year after giving birth, including for thyroid and depression disorders. The questionnaire was completed anonymously online by the patients and had three sections: one containing the EPDS questions, one assessing thyroid function, and a demographic section. The interdependency between thyroid and depression was analyzed in SPSS using the Pearson chi-square test of independence. The results show no statistically significant relationship between thyroid dysfunction and depression. In other words, women suffering from thyroid dysfunctions have no greater rate of depression compared to women without thyroid dysfunction. As a result, it screening for thyroid disorders during pregnancy may not provide relevant information for detecting postnatal depression

Diagnostic Use of Radionuclides in Diseases of the Thyroid

Since the introduction of radionuclides into clinical medicine, a number of specific tests have been designed to test thyroid function and to diagnose disease of the thyroid gland. These studies can be broadly grouped into in vivo and in vitro studies. Using 131I and 125I , tests have been designed to measure thyroid function at the hypothalamic, pituitary, or thyroid level and at the peripheral level by radioimmunoassay or radioassay of circulating thyroid hormones. The following schema of testing may be used to assess thyroid function

Establishing paediatric reference intervals for thyroid function tests in Croatian population on the Abbott Architect i2000

Evaluation of thyroid function is often requested and therefore defining paediatric reference intervals (RIs) is of vital importance. Currently, there is a distinct lack of paediatric RIs for thyroid function tests in Croatia. Thus, we established RIs for thyroid stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3) and free thyroxine (FT4) in the Croatian paediatric population. Reference intervals were calculated from 397 apparently healthy children, aged from 2 days to 0.3. All thyroid function tests required age partitioning, confirmed by SDR above 0.3. There was no need for sex partitioning, confirmed by SDR below 0.3. Still, FT3 was partitioned due to visually noticeable sex related difference for the oldest group (12 years to < 19 years). This is the first study to establish RIs for thyroid function tests in the Croatian paediatric population. We propose RIs for widely used Abbott platform, thus giving laboratories method- and population-specific paediatric RIs for thyroid function tests that should improve clinical test interpretation

Evaluation of the use of appropriate thyroid function tests

Student Number : 9600048X - MSc (Med) research report - Faculty of Health SciencesDisorders of the thyroid gland are amongst the most common endocrine disorders. The diagnosis of thyroid disease consists of a history and clinical examination, followed by specific confirmatory investigations. These investigations are an important diagnostic component in thyroid disease and are amongst the most common investigations ordered in clinical laboratories. Although these tests are relatively inexpensive individually, they account for a disproportionately large amount of health care expenditure for diagnostic testing. Appropriate laboratory investigation is critical to establish the diagnosis and cause of thyroid disease in the most costeffective way. Discovery Health released a set of evidence-based guidelines in order to educate the clinician with regard to the selection of thyroid function tests. According to these guidelines a TSH (Thyroid Stimulating Hormone) test is the investigation of choice in suspected thyroid disease. This study is a retrospective investigation that compares the difference in ordering patterns of laboratory investigations by clinicians before and after the publication of the guidelines. Two data sets were generated from the data bank of Discovery Health. The first data set (I) was based on records compiled before March 2003 whereas the second data set (II) was based on records compiled from April 2003. Following use of the exclusion and inclusion criteria the sample size totaled 73 850 cases. An analysis was made with regard to the requesting frequency of specific tests. This study will focus solely on the appropriateness of thyroid function tests ordered. It is beyond the scope of this study to attach a specific clinical diagnosis to the results. The thyroid function tests requested before the publication of the evidence-based guidelines were often requested without careful thought and consideration on the part of the clinician. Some of the combination tests ordered (Free T3 and Free T4) are not advocated as an initial investigation in the evaluation of thyroid function and waste funds in this instance. The ordering of inappropriate thyroid function tests often leads to the depletion of funds available to a patient within the financial year. The results revealed that after publication of the guidelines there was an increase in the requesting frequency of TSH as a first line investigation, as well as Free T4 while a decrease in requests for Free T3 was noted. The publication of evidence-based guidelines as a guide to requesting the correct thyroid function tests in order to diagnose suspected thyroid disease appears to have impacted in increasing awareness amongst clinicians with regard to the tests required to diagnose and monitor thyroid disease

Predicting risk of malignancy in patients with indeterminate thyroid nodules

Thyroid cancer is the most prevalent endocrine cancer (1). The prevalence of palpable thyroid nodules in the general adult population is 4% to 7% (2). Ultrasound imaging detects thyroid nodules in 19%-68% of randomly selected individuals (3). The rate of thyroid cancer in nodules found on US is 4% to 15% (4). In order to evaluate thyroid nodules patients undergo thyroid ultrasonography and, if needed, a fine-needle aspiration biopsy. Of all fine-needle aspiration biopsies, 15-30% are indeterminate on cytology (5). While only 3% of these nodules are malignant on average, a much higher percentage of nodules are surgically removed in order to rule out malignancy after indeterminate FNA results. Our goal is to identify clinical and ultrasound predictors of benign results in indeterminate nodules, to assist physicians in selecting nodules for surgical removal versus monitoring with ultrasound imaging. Between October 2010 and November 2017 there were 129 patients with 134 thyroid nodules from Temple University Hospital, Jeanes Hospital, and Fox Chase Cancer Center who had a total or partial thyroidectomy after a cytology report of at least one AUS or FLUS thyroid nodule. These patients were evaluated for age, sex, BMI, TSH, fT4, tT3, nodule size, and ultrasonography features to determine if any features were predictive of a benign or malignant thyroid nodule. Additionally, we looked at whether any of these features were more likely to occur in an AUS nodule or a FLUS nodule. We found that none of the demographic factors, thyroid function tests, or ultrasound features were good predictors of malignancy in AUS or FLUS thyroid nodules. We found that AUS nodules are more likely to be malignant than FLUS nodules, and this held true when we accounted for age, sex, smoking history, and BMI. We concluded that demographic factors and thyroid function tests are unable to predict increased risk of malignancy in Bethesda category III nodules, AUS nodules are more likely to be malignant that FLUS nodules, and nodules with at least one suspicious ultrasound feature are more likely to be AUS nodules than FLUS nodules due to AUS nodules having nuclear atypia and FLUS nodules having architectural atypia