At the end of a two-year follow-up elevated TSH levels normalize or remain unchanged in most the children with subclinical hypothyroidism.

Data about the natural evolution of subclinical hypothyroidism (SH) in pediatric age are very scanty. Moreover all the available reports in both aged and young patients were based on unselected study populations including also patients with either thyroid disorders or other pathological causes that are well known to be able to affect SH development and evolution. Aim of the study by Wasniewska et al was to prospectively evaluate for the first time the natural course of SH in children and adolescents with no underlying diseases and no risk factors that might interfere with the progression of SH. On the basis of the 2-year follow-up results, the Authors concluded that: a) the natural course of TSH values in a pediatric population with idiopathic SH is characterized by a progressive decrease over time; b) the majority of patients (88%) normalized or maintained unchanged their TSH; and c) TSH changes were not associated with changes of either FT4 values or clinical status or auxological parameters. Study design of this study is very accurate and the results are robust, thus supporting the Authors' conclusions.