Effect of recombinant human growth hormone therapy on idiopathic short stature patients:12 months follow-up

Objective To analyze the effect of GH therapy on idiopathic short stature (ISS) patients and the influential factors.Methods Patients who accepted rhGH therapy and regularly revisited were chosen as rhGH group,and patients who didn't accept rhGH therapy as control group.Growth velocity (GV) and increment in height SDS (ΔHtSDS) were used as outcome variables of growth responses to rhGH therapy.Then the effect and influential factors or the changes on those untreated such as bone age,height age were retrospectively analyzed during the follow-up.Results Thirty-five patients were recruited in rhGH group and 33 patients in control group.The ΔHtSDS and GV of patients in rhGH group during the first 3 months,-6 months,-9 months,-12 months were (0.22±0.13),(0.20±0.10),(0.12±0.14),(0.14±0.15) and (10.78±2.70) cm,(10.52±2.44)cm,(8.31±2.78)cm,(8.50±2.29) cm respectively.The height increments in the first 6 months and 6-12 months were 5.24 cm (0.43 SDS) and 4.24 cm (0.26 SDS),it was 9.54 cm (0.68 SDS) in the first year and 7.00 cm (0.17 SDS) in the second year.According to the simple correlation analysis,it was found that ΔHtSDS in the first year was negatively correlated with patients' age and positively correlated with ΔHtSDS in 3 months after treatment,GV levels in first year were negatively correlated with the peak of GH level and GV in 3 months after treatment.There were significant differences in ΔHtSDS among prepubertal,midpubertal and postpubertal children one year after treatment(P=0.016),ΔHtSDS was significantly higher in prepuberty than midpuberty and postpuberty.But there was no significant difference in GV.Besides,the increment of height age in rhGH group was significantly larger than control group,but there was no significant difference in increment of bone age between two groups.The levels of IGF-1 elevated in rhGH group signigicantly 1 month after treatment and slowed down afterwards.Conclusions For ISS patients,therapy should be started at an earlier age,at least before the puberty in order to achieve better cost-effect ratio.The therapeutic effect in the first 3 months may be a good predictor of one year therapeutic efficacy.While the rhGH therapy didn't significantly accelerate the increment of bone age of patients.