Thyroid Function Tests In Children Research Articles

Thyroid Function Tests in Children and Adolescents With Trisomy 21: Definition of Syndrome-Specific Reference Ranges.

The lack of syndrome-specific reference ranges for thyroid function tests (TFT) among pediatric patients with Down syndrome (DS) results in an overestimation of the occurrence of hypothyroidism in this population. To (a) outline the age-dependent distribution of TFT among pediatric patients with DS; (b) describe the intraindividual variability of TFT over time; and (c) assess the role of elevated thyrotropin (TSH) in predicting the future onset of overt hypothyroidism. In this retrospective, monocentric, observational analysis, we included 548 patients with DS (0-18 years) longitudinally assessed between 1992 and 2022. Exclusion criteria were abnormal thyroid anatomy, treatments affecting TFT, and positive thyroid autoantibodies. We determined the age-dependent distribution of TSH, FT3, and FT4 and outlined the relative nomograms for children with DS. Compared with non-syndromic patients, median TSH levels were statistically greater at any age (P < .001). Median FT3 and FT4 levels were statistically lower than controls (P < .001) only in specific age classes (0-11 for FT3, 11-18 years for FT4). TSH levels showed a remarkable fluctuation over time, with a poor (23%-53%) agreement between the TSH centile classes at 2 sequential assessments. Finally, the 75th centile was the threshold above which TSH values predicted future evolution into overt hypothyroidism with the best statistical accuracy, with a satisfactory negative predictive value (0.91), but poor positive predictive value (0.15). By longitudinally assessing TFT in a wide pediatric DS population, we outlined the syndrome-specific reference nomograms for TSH, FT3, and FT4 and demonstrated a persistent upward shift of TSH compared to non-syndromic children.

Interpretation, differential diagnosis, and clinical implications of abnormal thyroid function tests in children

In children, abnormal thyroid function tests (TFTs) can present diagnostic difficulty due to the variety of clinical manifestations that may accompany them. Pediatric patients with abnormal TFTs are discussed in this article, along with their differential diagnoses and approaches to management. The most prevalent causes of pediatric hypothyroidism and hyperthyroidism, including Hashimoto’s thyroiditis and Graves’ disease, are thoroughly reviewed. Additionally, we explore other potential etiologies of abnormal TFTs in children: congenital hypothyroidism, resistance to thyroid hormone, nonthyroidal illness syndrome, medication use, iodine deficiency, and interferences with thyroid function immunoassays. In the setting of the pediatric population, diagnostic assessment and analysis of TFTs involving thyroid-stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3) are addressed.

Abnormal Calcium, Calcinosis, and Creatinine in Down's syndrome

The hypercalcaemia in association with trisomy 21 (Down's syndrome) is often not recognised and therefore underdiagnosed. Patients present with the tetrad of hypercalcaemia, Down’s syndrome, renal impairment, and nephrocalcinosis. 1-3 A 30-month old child with Down’s syndrome had a long history of nonspecific symptoms, constipation and feeding difficulties. He was on excessive bottle feeds, taking 14 bottles daily, each with six ounces of milk. He presented with a cardiac arrest having been unwell with an acute illness. Blood tests showed hypercalcemia, raised urea and creatinine which were not explained by any other aetiologies. Post-mortem analysis showed acute pyelonephritis and nephrocalcinosis. In children with Down’s syndrome, early detection of hypercalcaemia and introduction of low calcium feeds may prevent morbidity and mortality. Awareness and monitoring of serum calcium levels along with routine thyroid function tests in children with Down syndrome, would be important to prevent such occurrences.

Association Between Thyroid Parenchymal Echogenicity and Thyroid Function in Pediatric Population

Background: The association between the thyroid echo pattern and thyroid function has an important impact on the diagnosis and treatment of thyroid diseases in children. Objectives: The present study aimed to compare thyroid parenchymal echogenicity with thyroid function tests and evaluate the value of a thyroid ultrasound (US) in predicting thyroid function parameters in the pediatric population. Methods: A total of 434 children (age range: 5 - 18 years; mean age: 13.18 ± 3.42 years) were categorized into two groups based on the thyroid parenchymal appearance on the US as subjects with homogeneous (group 1) and heterogeneous (group 2) echo patterns. Thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), thyroglobulin antibody (Tg-Ab), and thyroperoxidase antibody (TPO-Ab) levels were evaluated and compared between the two groups. Results: The levels of TSH, fT3, fT4, Tg-Ab, and TPO-Ab were significantly different between the two groups (P &lt; 0.0001). All thyroid function tests were within normal ranges in 73.4% (168/229) and 14.6% (30/205) of children with homogeneous and heterogeneous echo patterns, respectively. The homogeneous thyroid gland on the US had 73.8% sensitivity in predicting normal TSH and 100% sensitivity in predicting normal fT3 and fT4. The sensitivity for predicting negative Tg-Ab and TPO-Ab were 78.7 and 85.3%, respectively. Conclusions: The current study compared the homogeneous and heterogeneous thyroid echo patterns with the thyroid function tests in children. The obtained results confirmed the value of the thyroid US in predicting thyroid function in the pediatric population.

Interpretation of abnormal thyroid function tests in children and adolescents

Interpretation of abnormal thyroid function tests in children and adolescents

A comparative study of thyroid function tests in children with and without birth asphyxia

A comparative study of thyroid function tests in children with and without birth asphyxia

Evaluation of the thyroid disorders in children with familial Mediterranean fever.

Although it is well-known that autoimmune thyroid diseases are more common in most of the autoimmune connective tissue diseases, the relationship between autoinflammatory diseases and autoimmune thyroid diseases has not well-evaluated yet and still remains unclear. The aim of this study was to investigate the frequency of autoimmune diseases of the thyroid gland and to evaluate thyroid function tests in children with familial Mediterranean fever. Thyroxine, thyroid-stimulating hormone, and thyroid autoimmune markers such as thyroid peroxidase and thyroglobulin antibodies, and thyroid ultrasound findings of 133 patients with familial Mediterranean fever and 70 healthy controls were evaluated. Serum levels of thyroid-stimulating hormone, free thyroxine, and thyroid autoimmunity markers were similar in patients with familial Mediterranean fever compared with healthy controls. There was no relationship between the duration of the disease and thyroid-stimulating hormone, free thyroxine, anti-thyroid peroxidase, and anti-thyroglobulin levels. This study revealed that incidence of thyroid dysfunction and autoimmunity is not increased in patients with familial Mediterranean fever. In conclusion, routine screening of serum thyroid function tests and thyroid antibody levels is not required in patients with familial Mediterranean fever in the absence of clinical symptoms or family history. Key Points • It is well-known that autoimmune thyroid diseases are common in autoimmune diseases. • The relationship between autoimmune thyroid diseases and autoinflammatory diseases like familial Mediterranean fever is still unclear. • In this study, we report the similar frequency of the autoinflammatory thyroid diseases in patients with familial Mediterranean fever and healthy controls. • A routine screening of serum thyroid function tests and thyroid antibody levels may not be required in patients with familial Mediterranean fever in the absence of clinical symptoms or family history.

Determinants of deranged thyroid function parameters in children admitted for management of diabetic ketoacidosis/diabetic ketosis

BackgroundEuthyroid sick syndrome (ESS) frequently arises in children admitted with diabetic ketoacidosis/diabetic ketosis (DKA/DK). This study evaluates the interplay of various metabolic factors with occurrence of deranged thyroid function tests in children suffering from DKA/DK.Methods98 DKA and 96 DK pediatric patients were selected from hospital records. Those on thyroxine replacement, with overt hypothyroidism, or with positive anti-thyroperoxidase (TPO) antibody were excluded. Tests for liver function, renal function, lipid profile, serum osmolarity, thyroid function, c-peptide levels, and glycosylated hemoglobin were done on all patients. Children were divided into euthyroid (n = 88) and ESS groups (n = 106).ResultsThe ESS group had a higher level of white blood cell count (WBC), plasma glucose (PG), beta-hydroxybutyric acid (β-HB), triglyceride (TG), anion gap (AG), glycosylated hemoglobin (HbA1c) and a lower level of HCO3−, prealbumin (PA), and albumin (ALB) compared with the euthyroid group (P < 0.05). Free T3 (FT3) levels were significantly correlated to β-HB, HCO3−, AG, PA, and HbA1c (r = − 0.642, 0.681, − 0.377, 0.581, − 0.309, respectively; P < 0.01). Free T4 (FT4) levels were significantly correlated to β-HB, HCO3−, and ALB levels (r = − 0.489, 0.338, 0.529, respectively; P < 0.01). TSH levels were significantly affected by HCO3− only (r = − 0.28; P < 0.01). HCO3− level was the most important factor deciding euthyroid or ESS on logistic regression analysis (OR = 0.844, P = 0.004, 95%CI = 0.751–0.948).ConclusionsLower levels of free thyroid hormones and occurrence of ESS were associated with a higher degree of acidosis in children with DKA/DK.

Evaluation of Thyroid Function Tests in Children with Chronic Liver Diseases

Objective:Studies examining changes in thyroid function in the course of chronic liver disease have mostly been conducted in adults. The aim of this study was to investigate thyroid dysfunction in children with chronic liver diseases.Methods:Between 2005 and 2018, patients aged up to 18 years of age, diagnosed with chronic liver disease and had thyroid function test results available were included. Anthropometric characteristics, liver and thyroid function results were collected and analyzed.Results:The study included 107 (53 female; 49.5%) patients aged between one month and 18 years-old. Of the 107 patients, 96 (89.7%) had normal thyroid function results, seven (6.5%) had subclinical hypothyroidism (SH) and four (3.7%) had euthyroid sick syndrome. Of the patients with SH, one (14.2%) had glycogen storage diasease, one (14.2%) had biliary atresia, one (14.2%) had undiagnosed cholestatic liver disease, one (14.2%) had Alagille syndrome, one (14.2%) had idiopatic hepatitis, one (14.2%) had progressive familial intra-hepatic cholestasis and one (14.2%) had congenital hepatic fibrosis. Spearman correlation analysis showed a negative correlation between free tri-iodothyronine and direct bilirubin (r=-0.329, p=0.027).Conclusion:In conclusion, euthyroid sick syndrome or SH may affect up to 10% of children with chronic liver diseases. It is suggested that thyroid function should be evaluated in cases of pediatric chronic liver disease at diagnosis and during follow-up. Moreover, this study is the first to show a negative correlation between free T3 levels and direct bilirubin, suggesting a possible association between liver disease severity and thyroid function.

The Influence of Gonadotropin-Releasing Hormone Agonist Treatment on Thyroid Function Tests in Children with Central Idiopathic Precocious Puberty.

Introduction:In recent years, the treatment of idiopathic central precocious puberty using gonadotropin-releasing hormone agonist (GnRH) agonist has been considered as a common treatment. To date, there is not much information about the effect of GnRH agonist treatment on pediatric thyroid function.Aim:The aim of this study was to evaluate the influence of GnRH treatment on thyroid function tests in children with central idiopathic precocious puberty.Material and Methods:This cross-sectional study investigated 50 children with idiopathic precocious puberty treated with GnRH agonist, who were referred to Bahrami pediatric hospital, Tehran, Iran. Patients` height, weight, and symptoms of hypothyroidism were evaluated every two months. Thyroid function tests, T4 and thyroid-stimulating hormone (TSH), were reviewed every 6 months. Data were analyzed using SPSS Statistics, Version 18.Results:The majority of the children who participate in this study were female. 72% of children with central idiopathic precocious puberty had a significant increase in TSH level (P=0.002). In this group of patients, 66% and 6% had subclinical and clinical increases in thyroid function tests, respectively. The estimated time to thyroid dysfunction was 12.37 months. It is found that only 2% of patients showed thyroid dysfunction during the first 6 months of the treatment.Conclusion:The results of this study showed that more than 70% of children who were undergoing GnRH agonist treatment for central precocious puberty had impaired thyroid function (especially subclinical hypothyroidism). Therefore, evaluating thyroid function in children with precocious puberty who are under treating with GnRH agonist, would be reasonable; especially one year after initiating the treatment.

The Effect of Educational Intervention on Body Mass Index and Thyroid Function Tests in Children and Adolescents with Obesity and Overweight

Background Studies declare the possibility of thyroid abnormalities in the obese patients and return of normal thyroid activities after weight loss. Therefore in this study, the effect of educational intervention on body mass index (BMI) and thyroid function tests in obese children has been evaluated. Materials and Methods: The current randomized clinical trial research included 126 overweight or obese children and adolescents with an age range of 7 to 18 years, form Birjand city (Iran), who were divided into two control and intervention groups for 6 months between 2015 and 2016. The educational intervention consisted of 1 session per month (each session was 60 minutes), which was done by the researcher. BMI, thyroid stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) in both groups were measured and compared before and after the intervention, and data were analyzed using SPSS software version 19.0. Results: In the intervention group, the average of TSH and FT4 after 6 months of intervention showedboth significant decreases and increases, respectively (p=0.003 and p< 0.001). In the control group, both THS and BMI average had a significant increase (p<0.001), and FT3 and FT4 significant decrease (p=0.009 and p=0.001, respectively). After 6 months, BMI and TSH average in the intervention group compare to the control group had significant decrease (p = 0.02 and p<0.001, respectively), and average of FT4 and FT3 was significantly increased (p Conclusion: Educational intervention was effective in reducing BMI and improving thyroid tests; hence, is highly recommended for the modification of BMI and the improvement of thyroid tests in obese children and adolescents.

Is It Necessary to Measure Thyroid Hormone Levels in Children Receiving Antiepileptic Drugs?

Purpose This article evaluates the effect of antiepileptic drugs (AEDs) on thyroid function tests in children with epilepsy. Methodology One hundred twenty children were studied, with 40 patients taking older generation AEDs Na valproate (N = 20) and carbamazepine (N = 20), 40 patients taking newer generation AEDs levetiracetam (N = 20) and oxcarbazepine (N = 20), and 40 healthy children as controls. Serum T3, T4, FT4, and thyroid-stimulating hormone (TSH) were measured. Results Patients taking Na valproate had lower T3, T4, and a higher TSH level than controls. Patients taking carbamazepine had the lowest T3, T4, and FT4 serum levels among patients receiving AEDs. Conclusion The thyroid function tests were affected by the use of Na valproate and carbamazepine compared to both the control group and the group taking newer AEDs oxcarbazepine and levetiracetam. In addition, there was no effect of levetiracetam on thyroid function test results.

Korean pediatric reference intervals for FT4, TSH, and TPO Ab and the prevalence of thyroid dysfunction: A population-based study

BackgroundThe appropriate age-related reference intervals for thyroid-stimulating hormone (TSH) and free thyroxine (FT4) are important in interpreting the results of thyroid function tests in children and adolescents. However, these reference intervals are scanty. This study aimed to establish the reference intervals for FT4, TSH, and thyroid peroxidase antibody (TPO Ab), and identify the epidemiological prevalence of thyroid dysfunction in a Korean pediatric population. MethodsThe data from a sample of 2042 children and adolescents aged 10–18years who underwent a nationwide Korean representative sampling and cross-sectional survey with blood collection for a thyroid function test using an electrochemiluminescence immunoassay were evaluated. ResultsBased on the National Academy of Clinical Biochemistry (NACB) criteria, the median and range (2.5th – 97.5th percentile) for FT4 and TSH in total were 16.47pmol/L (12.61–21.49pmol/L) and 2.48mIU/L (0.63–7.03mIU/L), respectively. Positive TPO Ab (3.1%) by NACB was >19.16kIU/L (boys) and >29.30kIU/L (girls) for adolescents aged 10–18years. FT4 and TSH were associated with increasing and decreasing age, respectively. Boys' FT4 and girls' TPO Ab levels were greater than for the other sex, respectively. Using the new reference interval, overt hypothyroidism, subclinical hypothyroidism, subclinical hyperthyroidism, and overt hyperthyroidism were found in 0.5%, 2.1%, 1.3%, and 1.2%, respectively, of Korean children and adolescents. ConclusionsThis study provides evidence-based age- and sex-specific reference intervals for thyroid hormones and autoantibodies, and identifies the current prevalence of thyroid dysfunction in a Korean pediatric group.

Kistik Fibrosisli Çocuklarda Tiroid Fonksiyon Testleri: Tiroid Disfonksiyonu Bu Hastalarda Tahmin Edilenden Daha mı Fazla?

Kistik Fibrosisli Çocuklarda Tiroid Fonksiyon Testleri: Tiroid Disfonksiyonu Bu Hastalarda Tahmin Edilenden Daha mı Fazla?

Abnormal thyroid function tests in children on ethionamide treatment [Short communication

Ethionamide (ETH) treatment may cause hypothyroidism. Clinical data, serum thyroid stimulating hormone (TSH) and free thyroxine (fT4) levels were retrospectively assessed in 137 children receiving anti-tuberculosis treatment including ETH. Abnormal thyroid function tests (TFTs) were recorded in 79 (58%) children: elevated serum TSH and suppressed fT4 (n = 30), isolated elevated serum TSH (n = 20), isolated low serum fT4 (n = 28) and isolated low TSH (n = 1). The risk for biochemical hypothyroidism was higher for children on regimens including para-aminosalicylic acid and in human immunodeficiency virus infected children. TFT abnormalities are frequent in children on ETH and are mainly due to primary hypothyroidism or euthyroid sick syndrome.

CHANGING IN THYROID FUNCTION TEST IN CHILDREN UNDERWENT ANTIEPILEPTIC THERAPY

Objective To determine the changes in thyroid function tests in children who underwent antiepileptic therapy in Shahid Beheshti Hospital, Kashan, in 2008. Materials & Methods This analytical-observational study was carried out in a cohort fashion without an external control group (self controlled) on 45 children with new onset epilepsy who had not been previously treated with antiepileptic medications. Three subjects were excluded from the study because of presenting clinical symptoms of hypothyroidism. Plasma levels of TSH, T3, FT3, T4 and FT4 hormones were measured and compared at baseline and 3 and 6 months after treatment. Results The results of Mann-Whitney statistical analysis suggested that the increase in the plasma level of TSH was significant only in the Sodium Valproate group. The plasma level of T3 significantly decreased 3 and 6 months after treatment in the Phenobarbital group while the plasma level of FT3 significantly decreased only in the Sodium Valproate group. The decrease in T4 plasma level was significant in all groups (Carbamazepine group, Sodium Valproate group and Phenobarbital group) 3 and 6 months after the onset of treatment but the decreasing in FT4 plasma level was only significant in the Carbamazepine group 6 months after the commencement of treatment. Conclusion Phenobarbital had the least effect on thyroid hormones. Considering the effect of such medications on thyroid function tests, it seems necessary to check the plasma levels of hormones periodically after beginning the treatment.

Natural History of Thyroid-Stimulating Hormone in Children

Few population-based data on thyroid function tests in children are available. Investigators in Israel determined the natural history of thyroid-stimulating hormone (TSH) using data from a health insurance administrative database. Of 1 million enrolled children (age range, 6 months to 16 years), 121,000 (12%) with no …

Reference intervals for TSH and thyroid hormones are mainly affected by age, body mass index and number of blood leucocytes, but hardly by gender and thyroid autoantibodies during the first decades of life

Objectives The purpose of our study was to establish reference intervals for thyroid function tests in children and adolescents and to identify factors that may influence the limits of these intervals. Methods TSH, FT3, FT4, T3, T4, t-uptake, TPO-antibody (TPO-Ab) and TG-antibody (TG-Ab) levels were determined in blood of 1004 infants, children and adolescents by the Elecsys system (Roche). Results A distinct overall age-dependent decrease of analyte levels was found for all parameters investigated. Puberty was accompanied by an increase of TSH, FT3 and T3 levels. Results of T4 and t-uptake were significantly higher in girls compared to boys. The exclusion of children with increased TPO-Ab and TG-Ab had no significant effect on the limits of the reference interval. We found that besides age, BMI-SDS but also white blood cells count and gender played a role in the prediction of analyte variation. Conclusions Covariates like BMI-SDS and white blood cell count should be taken into consideration when interpreting TSH and thyroid hormone measurements as well whereas gender and TPO-Ab or TG-Ab play a minor role.

Reference range of thyroid hormones in normal Indian school‐age children

There is an ongoing debate on narrowing the TSH reference range in adults. In view of the scarce data on normal values of thyroid function tests in children from India, we planned to establish a reference range for thyroid hormones in school-age children. All children (N = 9527; 6-19 years) from six schools representing various zones of Delhi were evaluated for clinical evidence of goitre, thyroid ultrasound, serum free T3 (FT3), free T4 (FT4) and TSH and anti-thyroid peroxidase (anti-TPO) antibodies. From this sample, a reference population (N = 5122) was obtained by excluding those with a personal or family history of thyroid disease, use of thyroid medications, goitre, hypoechogenicity/nodularity on ultrasound or serum anti-TPO antibodies. Thyroid hormone (FT3, FT4 and TSH) reference ranges were established for each year of life for the total and reference populations. In the reference population, mean serum FT3 was in the range 4.19-4.84 pm/l for boys and 4.03-4.47 pm/l for girls, mean serum FT4 14.69-17.36 pm/l for boys and 14.32-15.88 pm/l for girls, and mean serum TSH 2.57-3.6 mIU/l for boys and 1.83-3.58 mIU/l for girls. For TSH, the 97th percentile was in the range 6.01-8.4 mIU/l for boys and 5.28-8.04 mIU/l for girls, suggesting that at least in children there may not be a need to reduce the upper limit of normal for serum TSH. This study provides mean reference intervals for FT3, FT4 and TSH for each year of life for both the sexes separately using strict exclusion criteria.

Height, Weight, IGF-I, IGFBP-3 and Thyroid Functions in Prepubertal Children with Attention Deficit Hyperactivity Disorder: Effect of Methylphenidate Treatment

Objective: To investigate if there are any disease-related or methylphenidate-induced aberrations in growth parameters, growth hormone insulin-like growth factor (IGF)-I, IGFBP-3 axis and the thyroid function tests in children with attention deficit hyperactivity disorder (ADHD). Methods: Newly diagnosed and untreated prepubertal children with ADHD were longitudinally followed before and approximately every 4 months after methylphenidate treatment for up to 16 months. Height SDS, weight SDS, BMI SDS, serum GH, IGF-I, IGFBP-3, T₄, free T₄, T₃, and TSH were measured at each visit. Results: All of the examined parameters were within normal limits for age before treatment. Methylphenidate treatment did not significantly affect SDS of height, weight, BMI, IGF-I and IGFBP-3 in the long run. Serum T₄ and free T₄ levels showed modest reductions within normal limits in a time-dependent manner. Conclusions: Prepubertal children with ADHD had normal height, weight, BMI, serum IGF-I and IGFBP-3 and thyroid functions. Methylphenidate treatment had no sustained effects on growth parameters, IGF-I and IGFBP-3 during the follow-up period of this study. However, it caused a mild decrease in total and free T₄ which may warrant further monitoring.