Characterization of thyroid function in euthyroid and children with subclinical hypothyroidism using a multivariate homeostatic model

BackgroundSubclinical hypothyroidism (SH) is biochemically defined by increased TSH, and normal thyroid hormones and its management is a matter of debate. Herein, we investigated thyroid function in euthyroid and children with SH using published data from population-based curves and a structure parameter inference approach (SPINA) model. MethodsThe study included 179 children and adolescents with SH and 311 healthy controls. The predicted and calculated secretory capacity of thyroid gland (SPINA-GT) was calculated in all euthyroid children divided into quartiles according to TSH values, and in children with SH, further subcategorized into those with mild SH (TSH: 4.5 - 10 mIU/L) and severe SH (TSH > 10 mIU/L). ResultsCalculated SPINA-GT values decreased significantly (P < 0.001) from the 1st to the 2nd quartile of normal TSH values in euthyroid children. It was also significantly decreased in mild SH compared to euthyroid children with TSH values within the upper 2 quartiles of TSH range and in severe SH compared to mild SH. ConclusionsThe implementation of SPINA model for thyroid function gives a wider perspective of thyroid glands performance within the euthyroid range of TSH, as well as in SH and add to the discussion for the long-term effects of SH and its management.