Short stature, which is the most frequent reason for consultation in pediatric endocrinology(1), is defined as a height of two or more standard deviations (SD) below the mean for the reference population of the same age and sex(2).

Growth hormone deficiency (GHD) is an important cause of short stature in childhood. Early diagnosis and treatment of GHD have been widely demonstrated to influence correct neurological, metabolic and auxological development(3).

The primary objective of recombinant human growth hormone (rhGH) therapy in these patients is to normalize height during childhood and adolescence and to achieve an adult height (AH) within the normal range and in accordance with their target height (TH)(4).

Several clinical trials have demonstrated the efficacy of treating these children with rhGH to achieve catch-up growth(2). There is, however, individual variability in the response, which results in differences in the degree of benefit patients receive from this treatment(5,6).

In the last two decades, several studies have analyzed factors such as perinatal history, anthropometric data, age at the start of treatment or type of GHD according to the GH peak response to stimuli as predictors of the response to rhGH therapy(7, 8, 9, 10).

Few studies(11, 12, 13), however, have explored other predictors, such as the relationship between serum IGF-I and response to treatment, with the relevance of IGFBP-3 assessment still being a matter of debate. The influence of bone maturation on the final response is another predictor, although the accuracy of AH prediction by BA determination in children with GHD is still unknown(14, 15, 16, 17).

In light of the above, the primary objective of this work is to identify the influence of the analytical parameters serum IGF-I and serum IGFBP-3, and bone maturation ratio (BA/CA), on the response to treatment after one and two years and upon reaching the final height.