文摘
Reference ranges for thyrotropin, free thyroxin (FT4) and free triidothyronine (FT3) are well known for healthy adults but may not be applicable to younger subjects. The aim of the investigation was to establish our reference intervals for thyrotropin, FT4 and FT3 in healthy children using radioisotopic assay techniques and therefore to test for significant differences between the age groups. The samples for thyrotropin, FT4 and FT3 were obtained from 242 healthy children (115 females, 127 males) in the age range 1 year to 19 years. Newborns were excluded from the study. The age groups were determined in children completing puberty staging : before and after 12 years for males; and before and after 14 years for females. An overall significant difference was observed between girls and boys for the FT4 concentration but not for FT3 and thyrotropin. We found higher FT4 and FT3 median values in younger age groups than in older, according to the literature.