Growth hormone treatment before the age of 4 years prevents short stature in young girls with Turner syndrome

Objective: Adult height deficit seen in Turner syndrome (TS) originates, in part, from growth retardation in utero and throughout the first 3 years of life. Earlier diagnosis enables earlier therapeutic intervention, such as with recombinant human GH (r-hGH), which may help to prevent growth retardation. In this open-label, multicentre phase III study, we investigated efficacy and safety in r-hGH treatment in young girls with TS. Subjects and methods: Girls (n = 61) aged < 4 years with TS receiving 0.03 5-0.05 mg/kg per day r-hGH for 4 years were compared with an historical control group (n= 51) comprising untreated, age- and height-matched girls with TS. The main outcome measure was change in height SDS (H-SDS). Other measures included changes in height velocity SDS, IGF1 levels and glucose metabolism. Results: After 4 years, a gain in mean H-SDS of 1.0 SDS (from ―2.33 ± 0.73 to -1.35±0.86 SDS) was observed with r-hGH treatment, in contrast to the decrease in mean H-SDS of 0.3 SDS in the control group (from -2.09 ± 0.81 to ―2.44±0.73 SDS; P < 0.0001). r-hGH treatment was the main predictor of H-SDS gain and accounted for 52% of variability (multivariate analysis). r-hGH was well tolerated. As expected, IGF1 levels rose with treatment. A case of transient glucose intolerance resolved after dietary adaptation. Conclusion: Early treatment with r-hGH helps to prevent natural evolution towards short stature in most girls with TS. IGF1 levels and glucose metabolism should be monitored routinely during r-hGH therapy.