Identification of factors associated with good response to growth hormone therapy in children with short stature: results from the ANSWER Program((R))

Objective: To identify factors associated with growth in children on growth hormone (GH) therapy using data from the American Norditropin Studies: Web-enabled Research (ANSWER) Program (R) registry. Methods: GH-naive children with GH deficiency, multiple pituitary hormone deficiency, idiopathic short stature, Turner syndrome, or a history of small for gestational age were eligible (N = 1,002). Using a longitudinal statistical approach, predictive factors were identified in patients with GHD for change from baseline in height standard deviation score (Delta HSDS) following 2 years of treatment. Results: Gradual increases in Delta HSDS over time were observed for all diagnostic categories. Significant predictive factors of Delta HSDS, ranked by significance were: height velocity (HV) at 4 months > baseline age > baseline HSDS > baseline body mass index (BMI) SDS > baseline insulin-like growth factor I (IGF-I) SDS; gender was not significant. HV at 4 months and baseline BMI SDS were positively correlated, whereas baseline age, HSDS, and IGF-I SDS were negatively correlated with Delta HSDS. Conclusions: These results may help guide GH therapy based on pretreatment characteristics and early growth response.