An Exploratory Cross-Sectional Study on Thyroid Hormone Reference Intervals in Children With Down syndrome

Area of Science:

• Pediatric Endocrinology
• Genetics and Genetic Disorders
• Clinical Biochemistry

Background:

• Accurate thyroid function assessment in children with Down syndrome is hindered by a lack of specific reference intervals.
• Down syndrome is associated with a higher prevalence of thyroid dysfunction, necessitating tailored diagnostic tools.

Purpose of the Study:

• To establish age-specific reference intervals for thyroid-stimulating hormone (TSH) and free thyroxine (FT4) in pediatric Down syndrome population.
• To improve the accuracy of thyroid dysfunction diagnosis in children with Down syndrome.

Main Methods:

• Retrospective cross-sectional study of 301 children with Down syndrome (6 months to 15 years).
• Exclusion of subjects on thyroid-influencing medications or with incomplete thyroid hormone data.
• Nonparametric methods used to calculate serum TSH and FT4 reference intervals.

Main Results:

• Age-specific TSH reference intervals for children with Down syndrome were found to be higher than in the general pediatric population across all age groups (infants, toddlers, school children, adolescents).
• FT4 reference intervals were comparable to the general pediatric population.
• Multivariate regression analysis showed a significant inverse association between age and both TSH and FT4 levels (p < 0.01).

Conclusions:

• This study provides essential age-specific reference intervals for TSH and FT4 in children with Down syndrome.
• These new reference intervals can significantly aid clinicians in the precise evaluation of thyroid hormone status in this population.
• The findings highlight the need for distinct reference ranges to ensure accurate diagnosis and management of thyroid dysfunction in pediatric Down syndrome.