Objective To observe the efficacy of different dosages of growth hormone combined with gonadotropin-releasing hormone analogue (GnRHa) in the treatment of girls with idiopathic central precocious puberty (ICPP).

Methods A total of 84 girls with ICPP were selected as research subjects and were divided into high-dose group and low-dose group according to the random number table method, with 42 cases in each group. Patients of both groups were given subcutaneous injection of GnRHa, and the low-dose group was given 0.15 U/(kg·d) dose injection of growth hormone, and the high-dose group was treated with 0.20 U/(kg·d) dose injection of growth hormone. The developmental indicators, sex hormones luteinizing hormone (LH), estradiol (E₂), follicle-stimulating hormone (FSH), uterine and ovarian volumes and serum levels of insulin-like growth factor 1 (IGF-1) and insulin growth factor binding protein-3 (IGFBP-3) were compared between the two groups before and after treatment, and the occurrence of adverse reactions in the two groups were recorded.

Results At 6 months of treatment, the bone age maturation speed, levels of LH, E₂ and FSH, and levels of serum IGF-1 and IGFBP-3 were decreased in both groups, uterine, left and right ovarian volumes were decreased, and the growth rate and predicted adult height were increased compared with the treatment before(P < 0.05), but there were no statistical between-group differences in above indicators(P>0.05). The total incidence rate of adverse reactions was 2.38% in low-dose group and 11.90% in high-dose group (P>0.05).

Conclusion Both 0.15 U/(kg·d) and 0.20 U/(kg·d) doses of growth hormone combined with GnRHa can effectively promote the growth and development of girls with ICPP, regulate the levels of sex hormones and reduce the uterine and ovarian volumes, but 0.15 U/(kg·d) dose of growth hormone has fewer adverse reactions, thus low-dose growth hormone therapy is preferred for the same benefit.