Background: Primary care pediatricians use thyroid function tests (TFT) as screening tests in children and adolescents with various health complaints. It is crucial to evaluate the results according to appropriate cut-offs individualized to the child characteristics. Such reference values are missing in the pediatric population.
Objective: To determine normal TSH levels in a large cohort of healthy children.
Methods: Data was collected from the database of Clalit Health Medical Organization ensuring more than 1.3 million children. 75,857 healthy children aged 5 to 18 years in which TFT were evaluated during 2012-2014 were included in the study. Data analyzed included: age, gender, BMI SDS, ethnicity, dispend medications, TSH, FT4 and FT3 levels.
Results: TSH levels were significantly higher in boys compared to girls: median 2.21mIU/L (normal range 0.83- 5.25) vs. 2.1mIU/L (0.89- 5.29), P
Conclusion: Our results in this uniquely large cohort show that the normal range of TSH in children is affected by gender, weight and ethnicity. Reference values should be thus individualized and modified accordingly. Such modifications will improve future clinical decision-making and treatment.
