Combined Evaluation of IGF−1 and IGFBP−3 as an Index of Efficacy and Safety in Growth Hormone Treated Patients

Objective: Measurement of serum insulin−like growth factor−1 (IGF−1) and IGF binding protein−3 (IGFBP−3) levels has been recommended as a useful index for monitoring of growth hormone (GH) therapy in GH deficient children. In this study we aimed to evaluate IGF−1/IGFBP−3 molar ratio during GH treatment as an index of safety and efficacy. Methods: Serum IGF−1 and IGFBP−3 levels and molar ratio of IGF−1/IGFBP−3 were evaluated in 50 GH deficienct children, during 3 years of GH therapy and these parameters were compared with the growth response. Results: All patients completed the first year, 38 the second year and 26 the third year of therapy. Although 15 patients in the first year, 5 patients in the second year, and 5 patients in the third year had high IGF−1 SDS values, height increments were similar in the low IGF−1 group and in the normal or high IGF−1 level groups. Molar ratios were also not statistically different between the groups. Molar ratio of IGF−1/IGFBP−3 seemed to be more reliable in evaluating the efficacy than basal IGF−1 level. Conclusions: Evaluation of the molar ratio of IGF−1/IGFBP−3 may be recommended as a tool to monitor GH treatment and it may be possible to individualize GH treatment accordingly. Conflict of interest:None declared.