The significance of measuring serum IGF_1,IGFBP_3 and OST for the judgement of abnormal skeletal development and therapeutic monitoring in precocious children

Objective To study the value of measuring serum insulin-like growth factor Ⅰ (IGF 1),insulin-like growth factor binding protein Ⅲ (IGFBP 3) and osteocalcin (OST) for evaluating acceleration of skeletal growth and skeletal maturity,and its value for therapeutic monitoring in precocious children. Methods Serum IGF 1 and IGFBP 3 were measured with immunoradiometric assay,serum OST was measured with radioimmunoassay in 117 girls with idiopathic precocious puberty. The girls were grouped according to age,and various parameters collected from them were compared with normal values of matched girls. Furthermore,the girls were grouped according to Tanner's staging (the extent of precocious puberty),the analysis of correlativity between various parameters to the extent of precocious puberty was performed,and the analysis of correlativity between the level of serum IGF 1 and advancing of bone age was performed. Various parameters were measured once more in 38 of the study girls after six months of the treatment,and the parameters were compared with that before treatment. Results ①The levels of serum IGF 1 and OST in the girls with precocious puberty were elevated obviously than that in matched normal girls,but the level of serum IGFBP 3 was reduced obviously than that in matched normal girls. It was demonstrated that typical elevation of serum IGF 1 and OST occurred in normal adolescence appeared ahead of time in the girls with precocious puberty. ②The extent of precocious puberty correlated closely with the level of serum IGF 1 ( r=0.489,P 0.05),and the advancing of bone age correlated closely with the level of serum IGF 1 ( r=0.411,P 0.05). It was demonstrated that the more serious the acceleration of skeletal growth and advancing of skeletal maturity were,the more obvious the elevation of serum IGF 1 was. ③After the treatment,the concentration of serum IGF 1 reduced from (455.52±119.45) μg/L to (284.55±99.52) μg/L ( P 0.001),and the concentration of serum OST reduced from (29.82±10.62) μg/L to (14.07±4.71) μg/L ( P 0.001). It was demonstrated that as the illness relieved,the levels of serum IGF 1 and OST reduced obviously. Conclusions Serum IGF 1 and OST could act as quantitative parameters for evaluating acceleration of skeletal growth and advancing of skeletal maturity in girls with idiopathic true precocious puberty. It could act as a parameter for therapeutic monitoring on delaying skeletal maturity and ameliorating skeletal development that to re-examine the change of serum IGF 1 and OST at regular intervals during treatment course.