SAT-106 Growth Hormone Treatment Response in Children

OBJECTIVES: Growth hormone (GH) therapy is an effective treatment in addressing growth failure in children with GH deficiency (GHD). It has also been increasingly used in non-GH deficient (nGHD) conditions. We sought to report the growth response of GHD and nGHD patients who received GH therapy at a tertiary care center. METHODS: Data was collected from health records of patients followed in the endocrinology clinic at Alberta Children’s Hospital, Calgary, Canada, from 2005 to 2019, and used to analyze clinical responses based on indication for GH treatment. RESULTS: A total of 167 patient records (87 males and 80 females) were used for analysis. The average age at the start of GH therapy was 7.3 years (range 0.25 to 16.98 yrs). 74 patients were in the GHD group while 93 were nGHD. Of the patients in the nGHD group, the most common diagnosis were: idiopathic short stature (ISS)(n=45), Turner syndrome (TS)(n=26), and Prader Willi Syndrome (PWS)(n=8). The mean height velocity (HV) in year 1 was highest in the GHD group at 11.68 cm/year (n= 62, sd = 5.93), followed by ISS at 9.41cm/year (n = 52, sd = 4.34). The mean first year HV of those who had received chemotherapy (n= 5, mean = 5.48, sd = 1.92) or had Turner syndrome (n= 24, mean = 7.20, sd = 2.15) was significantly lower than both the GHD and ISS groups. GH peak during a GH stimulation test at baseline was not correlated to the first year height velocity while on GH treatment. However there was a negative linear correlation between baseline IGF1 level and first year height velocity (Spearman’s rho = 0.312216, p-value= 0.01516). Age at GH initiation was negatively correlated with height velocity during GH treatment. Height velocity over time decreased sharply from year 1 to year 3, and became stable for the remaining years of GH therapy. For the entire group, HV for years 1-5 was 9.81 (sd=4.83), 7.40 (sd=2.89), 6.29 (sd=2.38), 5.92 (sd=2.56), 5.66 (sd=2.51). There is no significant correlation between GH dose and height velocity response after adjusting for diagnosis. CONCLUSION: In our population, the response to GH therapy was consistent with those reported in the literature. Response to GH therapy was not associated with GH peak on stimulation but rather to baseline IGF-1 level and age at initiation. Although peak GH to stimulation is required to obtain public funding for GH therapy, these findings demonstrate that GH stimulation test results may not indicate which patients may benefit the most from GH therapy. Follow-up until final adult height will allow us to have a better understanding of the efficacy of GH therapy in patients with both GHD and nGHD conditions.