Reference values for fasting serum concentrations of thyroid-stimulating hormone and thyroid hormones in healthy Danish/North-European white children and adolescents

Abstract

Thyroid-stimulating hormone (TSH) and thyroid hormones influence the functions of many organ systems, as well as child development and growth. Several studies have reported an association between ethnicity and thyroid hormones.

This study aims to explore pediatric serum concentrations of TSH, free triiodothyronine (fT3), and free thyroxine (fT4) and their relation to age and sex and subsequently to present pediatric reference intervals from healthy Danish/North-European white children.

A population-based cohort in Denmark of 2411 (1435 girls) healthy school children and adolescents aged 6.0–18.9 years were included. Fasting concentrations of serum TSH, fT3, and fT4 were determined from venous blood samples using immunologic chemiluminescent assays. Age- and sex-dependent percentiles were generated using the GAMLSS function.

Median values of fT3 and fT4, but not TSH, were lower in the older age group compared with the youngest age group for both sexes (all p < .05). A significant difference for fT3 was found between the sexes for all age groups (all p < .001). fT4 was negatively correlated with body mass index standard deviation scores in boys.

In conclusion, serum concentrations of thyroid hormones vary during childhood and adolescence and differ with age and sex.

Keywords:

• Adolescent
• child
• humans
• reference values
• thyroid hormones
• thyrotropin

Acknowledgements

This study is part of the research activities in TARGET (The Impact of our Genomes on Individual Treatment Response in Obese Children, www.target.ku.dk), and BIOCHILD (Genetics and Systems Biology of Childhood Obesity in India and Denmark, www.biochild.ku.dk). The study is part of The Danish Childhood Obesity Biobank; ClinicalTrials.gov ID-no.: NCT00928473. The Novo Nordisk Foundation Center for Basic Metabolic Research is an independent Research Center at the University of Copenhagen partially funded by an unrestricted donation from the Novo Nordisk Foundation (www.metabol.ku.dk). The authors wish to thank Mrs. Oda Troest and Mrs. Birgitte Holløse for their invaluable assistance.

Disclosure statement

The authors have no conflicts of interest or financial relationships relevant to this article to disclose.

Additional information

Funding

This work was supported by The Innovation Fund Denmark; under Grant 0603-00484B (TARGET) and Grant 0603-00457B (BIOCHILD); The Novo Nordisk Foundation under Grant NNF15OC0016544; and The Region Zealand Health Scientific Research Foundation.