Diagnosis Of Thyroid Disorders Research Articles

Simultaneous Identification of Major Thyroid Hormones by a Nickel Immobilized Biological Nanopore.

Thyroid hormones (THs) are a variety of iodine-containing hormones that demonstrate critical physiological impacts on cellular activities. The assessment of thyroid function and the diagnosis of thyroid disorders require accurate measurement of TH levels. However, largely due to their structural similarities, the simultaneous discrimination of different THs is challenging. Nanopores, single-molecule sensors with a high resolution, are suitable for this task. In this paper, a hetero-octameric Mycobacterium smegmatis porin A (MspA) nanopore containing a single nickel ion immobilized to the pore constriction has enabled simultaneous identification of five representative THs including l-thyroxine (T4), 3,3',5-triiodo-l-thyronine (T3), 3,3',5'-triiodo-l-thyronine (rT3), 3,5-diiodo-l-thyronine (3,5-T2) and 3,3'-diiodo-l-thyronine (3,3'-T2). To automate event classification and avoid human bias, a machine learning algorithm was also developed, reporting an accuracy of 99.0%. This sensing strategy is also applied in the analysis of TH in a real human serum environment, suggesting its potential use in a clinical diagnosis.

Assessing the incidence and prevalence of thyroid disorders along with the indications of thyroid surgeries in Indian subjects

Background: Most common endocrine disorders seen globally are Thyroid disorders which pose a high burden on the health care sector globally including in India. Assessing these disorders definitively is a challenging condition for treating physicians as no single definitive test exists for confirmatory diagnosis of thyroid disorders. However, various clinical, FNAC (Fine needle aspiration cytology), and histopathologic tests can be done to diagnose these disorders. Histopathology remains the gold standard for confirmatory diagnosis of thyroid nodules. Aims: The present retrospective clinical study was conducted to assess the incidence and prevalence of thyroid disorders along with the indications of Thyroid surgeries in Indian subjects. Materials and Methods: In 50 subjects with thyroid nodules who underwent thyroidectomy, clinical data were retrospectively collected and assessed concerning clinical and histopathologic parameters of the thyroid nodule. The collected data were assessed to form results and were expressed as mean, number, and percentage. Results: Most common finding was movement with deglutition seen in 98% (n=49) subjects followed by laryngeal crepitus in 84% (n=42) subjects, mobility in 78% (n=39) subjects, tenderness in 20% (n=10) subjects, and pressure effect and neck nodes in 2% (n=1) subject each.

Analysis of HLA Variants and Graves' Disease and Its Comorbidities Using a High Resolution Imputation System to Examine Electronic Medical Health Records.

Hyperthyroidism is a prevalent endocrine disorder, and genetics play a major role in the development of thyroid-associated diseases. In particular, the inheritance of HLA has been demonstrated to induce the highest susceptibility to Graves’ disease (GD). However, thus far, no studies have reported the contribution of HLA to the development of GD and the complications that follow. Thus, in the present study, to the best of our knowledge, for the first time, a powerful imputation method, HIBAG, was used to predict the HLA subtypes among populations with available genome-wide SNP array data from the China Medical University Hospital (CMUH). The disease status was extracted from the CMUH electronic medical records; a total of 2,998 subjects with GD were identified as the cases to be tested and 29,083 subjects without any diagnosis of thyroid disorders were randomly selected as the controls. A total of 12 HLA class I genotypes (HLA-A*02:07-*11:01, HLA-B*40:01-*46:01 and *46:01-*46:01, and HLA-C*01:02-*01:02, *01:02-*03:04, and *01:02-*07:02) and 17 HLA class II genotypes (HLA-DPA1*02:02-*02:02, HLA-DPB1*02:01-*05:01, *02:02-*05:01, and *04:01-*05:01, HLA-DQA1*03:02, HLA-DRB1*09:01-*15:01, and *09:01-*09:01) were found to be associated with GD in the Taiwanese population. Moreover, the HLA subtypes HLA-A*11:01, HLA-B*46:01, HLA-DPA1*01:03, and HLA-DPB1*05:01 were found to be associated with heart disease, stroke, diabetes, and hypertension among subjects with GD. Our data suggest that several HLA alleles are markedly associated with GD and its comorbidities, including heart disease, hypertension, and diabetes.

Measurement of paraoxonase-1, visfatin levels in Iraqi diabetic and diabetic with hypothyroidism

Introduction and Aim: This study is to evaluate the levels of paraoxonase-1 and visfatin in diabetic and diabetic with hypothyroidism patients and to discover the relationship of paraoxonase-1 and visfatin levels in these patients. Materials and Methods: The study included 35 subjects in control group (G1), 35 with diabetes (G2), and 35 diabetes with hypothyroidism (G3), aged ranging 25-50 years for all the study groups and BMI with (20.5-25.4) Kg/m2. Serum and whole blood were used for estimating F.B.S., HbA1c%, lipid profile, T4, TSH, paraoxonase-1 and visfatin. Results: The results revealed a significant elevation in F.B.S., HbA1c%, TC, TG, VLDL and LDL in G2 and G3 compared to G1. The HDL levels showed a significant decrease in G2, G3 compared to G1. Also, showed significant reduction in T4 in G3 compared to G2 and G1. A significant elevation in TSH in G3 compared to G2 and G1 and a significant decrease in paraoxonase-1 but increase in visfatin for G3 more than G2 when compared to G1 were observed. Conclusion: The study concluded that paraoxonase -1 and visfatin are suggestive reliable markers for the diagnosis of thyroid disorder in diabetics with hypothyroidism depending on their relation with T4 and TSH.

Approaching the diagnosis of thyroid disorders in preterm infants.

Approaching the diagnosis of thyroid disorders in preterm infants.

Association of Bleeding Patterns with Thyroid Dysfunction in Patients with Abnormal Uterine Bleeding: A Prospective Cross-sectional Study

Introduction: Excessive menstruation outside the normal parameters is one of the most common manifestations of hypothyroidism affecting the females. Thyroid disorders, such as hypothyroidism and hyperthyroidism are associated with late onset puberty, anovulatory cycles and abnormally high incidence of foetal morbidity and mortality. Aim: To study the association of bleeding pattern with thyroid dysfunction among patients with abnormal uterine bleeding. Materials and Methods: This was a prospective cross-sectional study carried out in the Department of Obstetrics and Gynaecology at Shri BM Patil Medical College, Hospital and Research Center, Vijayapura, Karnataka, India, from October 2012 to June 2014, among 140 female with a provisional diagnosis of abnormal uterine bleeding were subjected to testing for serum Triiodothyronine (T3), Thyroxine (T4), Thyroid Stimulating Hormone (TSH) and Thyroid Peroxidase (TPO) antibodies estimation in their serum. Data was analysed using Chi-square test and the p-value<0.05 was considered significant. Results: Total of 140 patients, with maximum number of patients in the study belonged to the age group 31-40 years (57,40.71%) and 46 (32.8%) patients were para 2. Among different bleeding patterns observed, most common was menorrhagia 62 (44.28%). The prevalence of subclinical hypothyroidism was 10 (7.14%), there were five hypothyroid cases (3.5%), and two hyperthyroid cases (1.4%) among 140 cases. The total thyroid disorders associated were 17 (12.14%). Conclusion: In this study association of thyroid dysfunction with AUB has been noted. With early diagnosis of thyroid disorders in AUB patients followed by appropriate treatment, the menstrual irregularities can be resolved and major surgical procedures can be avoided.

Incidence of hypocalcaemia among post-thyroidectomy patients at a tertiary care hospital at Trivandrum, Kerala, South India

Background: Hypocalcemia is one of the most common complications of thyroid surgery. It is usually temporary, but it may rarely take several months to resolve. The aim of this study was to determine the incidence of hypocalcaemia after total thyroidectomy and assess the biochemical factors that may be predictive of hypocalcemia.Methods: An observational study was conducted in 98 patients at the general surgery department of a tertiary care medical college hospital for a period of one year. Convenient method of sampling was done. All the patients undergoing total thyroidectomy were included in this study. The serum calcium level was evaluated at different times in the post-operative period as a part of the routine post-operative care at the hospital. During the postoperative period patients were carefully watched for clinical symptoms and signs of hypocalcemia.Results: In the study group, 19 (19.4%) had hypocalcemia. In the study group, 14 (14.3%) had symptomatic hypocalcemia and 5 patients (5.1%) had asymptomatic hypocalcemia. 18 patients (18.4%) had temporary hypocalcemia and 1 patient (1%) had permanent hypocalcemia. Among the patients with hypocalcemia, 18 (95%) were females and 1 (5%) patient was male. 13 (68%) patients were euthyroid, 5 (26%) patients were hyperthyroid and 1 (5%) patient was hypothyroid. Significant association was seen between diagnosis of thyroid disorders and hypocalcemia, thyroid function and hypocalcemia and between operating time and hypocalcemia.Conclusions: Incidence of hypocalcemia in patients who had undergone total thyroidectomy was found to be less. Majority of them had temporary hypocalcemia and permanent hypocalcemia was seen only in one patient.

Anatomical variations of the thyroid gland: An experimental cadaveric study

IntroductionThe thyroid gland displays numerous variations in its anatomy. Understanding the variations that occur can benefit diagnosis of thyroid disorders and improve management. The aim of this study was to investigate how factors such as age and sex may influence variations in the thyroid. MethodsTwenty cadavers (10 males & 10 females) with a mean age of 78 were dissected. Variations in anatomy and vasculature were examined. Correlation between age and thyroid size was tested for significance using GraphPad prism 7. ResultsMost cadavers, 65%, had the superior thyroid artery originating from the external carotid artery, while 25% were from the bifurcation and 10% from the common carotid. The average weight for thyroids was 19.9 g in males and 13.9 g in females. A significant negative correlation was found between age and thyroid size. DiscussionThyroid gland variations, such as pyramidal lobes which affected 30% of cadavers, could impact medical interventions. Evidence from this study has confirmed the high incidence of such variations emphasising the requirement for preoperative imaging.

A study of thyroid dysfunction among elderly in a tertiary care hospital

Introduction and Aim: The prevalence of thyroid disorders all over the world is on the rise. However, the diagnosis is complicated among the elderlies due to factors such as non-specific clinical manifestations and interacting medications. The aim of the study is to estimate the prevalence and type of thyroid dysfunction among the elderly.
 Materials and Methods: The cross-sectional study was undertaken in the Department of General Medicine of a tertiary care teachinghospital. The study included 100 subjects aged above 60 years, of both genders. Data for clinical examination and biochemical tests such as T3, T4, TSH and lipid profile were collected. Reports of USG/FNAC, performed in cases of thyroid nodule, were also checked.Results:The prevalence of thyroid disorders was 22% of the study population. Overt and subclinical hypothyroidism were observed among 4% and 17% respectively, with 1% having hyperthyroidism. Subclinical hypothyroidism was more common among women. No specific trend was observed with increasing age.TPO antibodies were positive among 73% of the cases. Patients with thyroid dysfunction had higher values of triglycerides, total cholesterol and LDL. The proportion of dyslipidemia was significantly higher among elderly with thyroid dysfunction as compared to people with no thyroid dysfunction (90.90% Vs 24.35%, P value < 0.001).
 Conclusion: Thyroid dysfunction in the elderly is common. Strong clinical suspicion of thyroid diseases in elderly patients presenting with non-specific symptoms is needed. This would aid in the diagnosis of thyroid disorders among the elderly.

Performance Evaluation of SVM and Random Forest for the Diagnosis of Thyroid Disorder

Performance Evaluation of SVM and Random Forest for the Diagnosis of Thyroid Disorder

Adolescent Thyroid Disorders and Risk for Type 2 Diabetes in Young Adulthood.

Thyroid hormones play a key role in systemic metabolism, yet the relationship between thyroid dysfunction and risk for type 2 diabetes is unclear. To assess type 2 diabetes risk in adulthood among adolescents with thyroid disorders. A nationwide, population-based study of Israeli adolescents who were examined before military recruitment during 1988 to 2007 and were followed until December 31, 2016. 1 382 560 adolescents (mean age 17.3 years). The diagnosis of thyroid disorders was based on recent thyroid function tests. Data were linked to the Israeli National Diabetes Registry. Cox proportional hazard models were applied. Type 2 diabetes incidence. During a mean follow-up of 18.5 years, 1.12% (69 of 6,152) of adolescents with thyroid disorders were diagnosed with type 2 diabetes vs 0.77% of adolescents without thyroid disorders. The hazard ratio (HR) for type 2 diabetes was 2.3 (95% CI, 1.8-2.9) among those with thyroid disorders, after adjustment for sex, birth-year, body mass index, and sociodemographic confounders. The increased diabetes risk was observed in both men and women, with the presence or absence of obesity, and in the absence of other health conditions and was associated with different types of thyroid disorders. It was also similar when the outcome was defined as type 2 diabetes diagnosed at or before the age of 30 years (HR 2.3, 95% CI, 1.5-3.5). Thyroid disorders diagnosed in adolescence are a risk factor for early-onset type 2 diabetes in both men and women.

European Biological Variation Study (EuBIVAS): within- and between-subject biological variation estimates for serum thyroid biomarkers based on weekly samplings from 91 healthy participants.

Thyroid biomarkers are fundamental for the diagnosis of thyroid disorders and for the monitoring and treatment of patients with these diseases. The knowledge of biological variation (BV) is important to define analytical performance specifications (APS) and reference change values (RCV). The aim of this study was to deliver BV estimates for thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), thyroglobulin (TG), and calcitonin (CT). Analyses were performed on serum samples obtained from the European Biological Variation Study population (91 healthy individuals from six European laboratories; 21-69 years) on the Roche Cobas e801 at the San Raffaele Hospital (Milan, Italy). All samples from each individual were evaluated in duplicate within a single run. The BV estimates with 95% CIs were obtained by CV-ANOVA, after analysis of variance homogeneity and outliers. The within-subject (CV I ) BV estimates were for TSH 17.7%, FT3 5.0%, FT4 4.8%, TG 10.3, and CT 13.0%, all significantly lower than those reported in the literature. No significant differences were observed for BV estimates between men and women. The availability of updated, in the case of CT not previously published, BV estimates for thyroid markers based on the large scale EuBIVAS study allows for refined APS and associated RCV applicable in the diagnosis and management of thyroid and related diseases.

Thyroid nodules segmentation methods in clinical ultrasound images: A review

Thyroid is an extremely essential butterfly shaped organ which is positioned in front of neck. For finding thyroid disease, ultrasound imaging is considered a best for identification of thyroid nodules because of its inexpensive and trouble-free nature. For diagnosis of thyroid disorder, it is very important to separate thyroid nodules from thyroid gland. For the same in biomedical image processing, image segmentation and classification followed by image preprocessing is very imperative steps. The key goal of this work is to categorized of thyroid nodules, thyroid gland segmentation methods. This paper explained different segmentation methods like counter and shaped based, region based and machine learning and deep learning strategies for thyroid gland and thyroid nodules. In addition, grouping of thyroid knobs is classified by traditional and convolution neural network for different feature extraction methods. All these methods are evaluated and compared by different quality metrics. After careful assessment of plenty of paper we did comparative and comprehensive analysis of segmentation methods with deep learning. Segmentation by deep learning approach gives better performance but it required more marked data base. In thyroid nodules segmentation region-based methods and contour and shape-based methods gives better performance. This paper concludes segmentation methods and their performance which is based on image attributes applications etc. The performance is assets by accuracy, selectivity and specificity and mean overlap parameters. Moreover, we concentrate on several advantages and disadvantages of current thyroid nodules ultrasound image segmentation of thyroid nodules and thyroid gland methods for 2Dimentionsl Ultrasound image, which would be useful for future studies such as identification of specific thyroid disease.

English

BACKGROUND Malnourishment is a major public health challenge in India. The prevalence of thyroid disorders is about 15 – 25 % in different parts of the country. As Thyroid hormone is essential for normal erythropoiesis, anaemia often accompanies thyroid disorders. It is also observed that iron deficiency anaemia state negatively influences the thyroid hormone function. So, the relationship between anaemia and thyroid disorders is complex and both have to be addressed. Keeping this in view, we tried to study the haematological parameters of inpatients with thyroid disorders in our hospital. METHODS A retrospective hospital based observational study was conducted in Gayatri Vidya Parishad Institute of Healthcare and Medical Technology, Visakhapatnam. All adults (> 18 yrs. of age), non-pregnant patients admitted during the period November 2017 to November 2018 with a diagnosis of thyroid disorder at discharge were included in the study. Fasting thyroid profile (using Siemens advanced fully automated analyser) and haematological parameters (using automated haematology analyser - LABLIFE NOBLE III) were obtained. Data analysis was done using Microsoft Excel 2013 and SPSS version 26. RESULTS 107 patients were included in the study. Mean age of the patients was 33.20 (± 12.45) years with majority being female (91.6 %) and of the age group 18 – 40 years (80.3 %). Hypothyroidism (73.83 %) was the most common thyroid disorder observed followed by subclinical hypothyroidism (19.63 %) & hyperthyroidism (6.54 %). About 79.6 % of female patients and all male patients had anaemia of varying degree. Majority of the patients had moderate degree of anaemia [haemoglobin of 8 - 11.9 gm / dL (females) / 8 - 12.9 gm / dL (males)]. Both microcytic hypochromic anaemia (53.8 %) and normocytic normochromic anaemia (46.2 %) were almost equally prevalent in female patients. Statistically significant positive correlation was observed between TSH (Thyroid Stimulating Hormone) and mean corpuscular volume. (Pearson’s correlation = 0.324, significant correlation at the level 0.01.). CONCLUSIONS Our study highlighted the association between anaemia and thyroid dysfunction. As anaemia is common in our country and the occurrence of hypothyroidism and other thyroid disorders is on the rise, it is essential for clinicians to understand the interrelation between both the disorders and make appropriate therapeutic decisions for simultaneous treatment of anaemia as well as thyroid dysfunction as one may be the cause of the other. KEYWORDS Anaemia, Thyroid Dysfunction, Hypothyroidism

Low Yield of Thyroid-Function Tests in Adult Hospitalized Patients - A Retrospective Analysis.

BackgroundIn the US, serum thyroid-stimulating hormone (TSH) and thyroxine measurements are the fourth- and tenth-commonest laboratory tests ordered, respectively. Diagnosis of thyroid disorder requires clinical suspicion supported by laboratory values. However, in the setting of acute illness, both the clinical and laboratory pictures can be confounded.ObjectiveTo study clinical outcomes and derangement patterns of inpatient thyroid-function tests.DesignThis retrospective study was conducted at an academic center on admissions aged ≥18 years and TSH tests performed over a 1-year period. Admissions with active pregnancy and/or prior thyroid-related diagnosis were excluded.Main OutcomesClinical outcomes were divided based on new diagnosis of thyroid-related disorder, newly prescribed thyroxine replacement, or antithyroid drugs/ endocrinology referrals, or both. In order to analyze the derangement patterns of abnormal TSH, only the results of the first test ordered were considered (as some admissions had multiple TSH tests ordered).ResultsA total of 7,204 admissions aged ≥18 years had TSH tests done. Of these, 1,912 were excluded. Of the 5,292 admissions with no prior thyroid disorder or active pregnancy, 183 (3.46%) were assigned a new diagnosis of thyroid-related disorder, 54 (1.02%) received treatment/referral, and 46 (0.87%) received both a new diagnosis and treatment/referral. Based on the TSH results (reference range 0.42–4.0 mIU/L) of the 5,292 admissions, 4,312 (81.5%) and 980 (18.5%) admissions were flagged normal and abnormal, respectively. Of the 980 admissions with one or more abnormal TSH results, 21 (2.14%) had first ordered TSH <0.05 mIU/L, 855 (87.25%) admissions had first TSH result between 0.05–10 mIU/L, and lastly 104 (10.61%) were >10 mIU/L.ConclusionThere is low value in testing inpatients for thyroid disorders, and testing comes at significant expense to the health-care system.

Clinico-histopathological Assessment of Patients Undergoing Thyroidectomy

Objective: To determine the clinical presentation and histopathological evaluation of patients undergoing thyroidectomies at tertiary care Hospital.&#x0D; Methodology: This cross-sectional study was done at department of general surgery of LUMHS/Jamshoro. Duration of the study was 1 year from October 2017 to September 2018. All the cases with a diagnosis of thyroid disorder and underwent thyroidectomy were selected and above 25 years of the age were included. All the surgeries were carried out by senior surgeons along with the cooperation of the ENT surgeons. After surgeries specimens of all the cases were sent to the diagnostic laboratory for the histological assessment. Data was collected via self-made proforma.&#x0D; Results: Of 58 patients majority i.e. 43.10% were found with age group of 35-44 years. Females found in the majority 63.80%. The swelling was noted among all of the cases, followed by pain, difficulty in swallowing, difficulty in breathing and&#x0D; others 8.62%, 10.34%, 20.68% and 25.68% respectively. Adenomatous goiter was the most common histopathological finding in 82.75% cases, papillary carcinoma was found 8.62%, follicular carcinoma was only in one case and anaplastic carcinoma was also in 1 case.&#x0D; Conclusion: Swelling, difficulty in swallowing and difficulty in breathing were the most common clinical features. Adenomatous goiter was the most common histological finding and papillary carcinoma was the commonest malignancy.

Thyroid Disease Classification Using Decision Tree and SVM

Thyroid is one of the disease that can be increasing day by day due to their lifestyle. Thyroid disease is avery common disease among humans. A Thyroid disorders are the conditions that affects the thyroid glandand also the butterfly-shaped gland at the front of the neck. The thyroid gland is located on the below ofAdam’s apple that wrapped around the trachea. The Hydroxide is also known as T4 and it is the primaryhormone produced by the gland. Thyroid hormone that regulates the body numerous metabolic mechanismsthroughout the body. When compare to male, female is more affected than male due to the thyroid disease.In thyroid, there are two types of diseases, They are Hyperthyroidism and Hypothyroidism. Hypothyroidismthat produces a lots of thyroid hormone in the blood and in Hypothyroidism that produces less thyroidhormone in the blood. This is controlled by the pituitary gland and hypothalamus. The disorders of thesetissues can also be affecting a thyroid function and it causes the thyroid problems. There are the Specifictypes of thyroid glands are includes: Hypothyroidism, Hyperthyroidism, Goiter, Thyroid nodules andThyroid cancer. This paper describes about the diagnosis of thyroid disorders using decision tree attributesplitting rules. The proposed method, classifies the thyroid nodules accurately and efficiently. In this study,the comparative thyroid disease diagnosis were performed by using the Machine learning techniques thatcan be a method which is Support Vector Machine (SVM), Naïve Bayes and Decision Trees. The accuracyof this classification is to be 99.89%. This result is very efficient when compared to our previous work thatused the Decision tree.

Tiroid Ultrason Görüntülerinde Fraktal Analiz Uygulaması

The concept of fractals is used for complex and irregular objects or structures in systems. The complexity of medical images allows us to use Fractal geometry rather then Euclidian geometry for their characterization. In this paper, we have discussed the analysis of thyroid ultrasound images to calculate fractal dimension. Fractal analysis software was used for the calculation of fractal dimension and correlation coefficient values. In the fractal analysis on the thyroid ultrasound images, the determination of the dimensions of the lesions, nodules or cysts in the region by using fractal concepts can be predicted and used as an assistive system for physicians in the treatment and early diagnosis of thyroid disorders.

Chitotriosidase-1 levels in Iraqi Type 2 Diabetic Patients with Thyroid Disorders

Study aimed to determination of chitotriosidase-1 levels in Iraqi diabetic and diabetic patients with thyroid disorder. Also, study aimed to found relation correlation for chitotriosidase-1 with FSG, T3, T4 and TSH. Ninety subjects were including in this study. First group consisted of (30) healthy individuals who have no history of any thyroid disorders or diabetes mellitus as control group. Second group (G2) (n=30) patients with diabetic and hyperthyroidism as association disease, and third group (G3) (n=30) include patients with diabetic and hypothyroidism as association disease. Serum used in (FSG, T3, T4, TSH, and Chitotriosidase-1) determination. Results showed a significant elevation in patients’ groups (G2, G3) comparing to control group in FSG. In addition to a significant elevation in G3 compared to G2. Results, also, revealed a significant elevation in T3 and T4 levels in G2 when comparing with G1 and G3. While there is significant decrease in these parameters in G3 compared to G1 and G2. Results revealed a significant decrease in G2 in TSH levels comparing to G1and G3. While there is significant increase in TSH level in G3 compared to G1 and G2. Results revealed a significant increased in Chitotriosidase-1 levels in G2 comparing to G1and G3. Results, also, showed a significant decrease in G3 comparing to G2 and a significant increase was found in G3 comparing to G1. Conclusion could be drowning from this study that chitotriosidase-1 may be helpful in monitoring and early diagnosis of thyroid disorder in these patients.

Age and Assay Related Changes of Laboratory Thyroid Function Tests in the Reference Female Population.

SummaryBackgroundLaboratory thyroid function tests play a central role in the diagnosis of thyroid disorders. The aim of our cross-sectional study was to determine reference values for thyroid tests in a rigorously selected group of Montenegrin females, investigate the impact of possible age-related changes and the influence of the interassay bias between three frequently used immunoassays.MethodsFemale subjects were randomly selected, aged between 20 and 69 and 946 of them met the selection criteria. TSH, fT3, fT4, thyroid peroxidase and thyroglobulin antibodies were measured. Eighty samples were further analyzed on two other immunochemistry platforms.ResultsMedian TSH progressively increased with age, there was no difference in fT3, while fT4 was significantly higher in the two oldest groups compared to the others. When using the age-related 97.5 percentile of TSH the percentage of reclassification was highest in the 20–29 years of age group (5.2%, p<0.05). In the oldest band, 7.7% had TSH values above cohort-specific and below the age-related upper reference limit. Bland-Altman bias plots revealed the highest interassay absolute mean difference between compared TSH assays of 24.5% and for fT4 assays of 13.8%.ConclusionsThe correlation coefficients between fT3 assays from different manufacturers were low. Serum TSH and fT4 concentrations increased with age and the implementation of age-specific TSH reference intervals would be of interest. The bias between the three commercial immunoassays indicated that the standardization of thyroid function tests is a task of great importance.