Growth hormone-insulin-like growth factor-I status and response to growth hormone therapy (0.6 IU/kg/week sc, six times a week for 12 months) were evaluated in 12 girls (chronological age 9.4 +/- 1.6 years) suffering from central precocious puberty with growth velocity less than 4 cm/year and no substantial increase or decrease in predicted adult height during gonadotropin releasing hormone Bn-RH) analogue treatment (D-Trp6-LH-RH, 60 micrograms/kg im/28 days). At baseline, large variations were observed in nocturnal growth hormone (GH) means (pathological values stimulated levodopa GH peaks (pathological values (< 10.0 micrograms/l) 28.6%) and serum insulin-like growth factor-I (IGF-I) levels. Neither GH-nor IGF-I levels were correlated with growth velocity. During recombinant GH therapy, growth velocity increased significantly (baseline 3.0 +/- 0.9 cm/year; 6 months 6.4 +/- 1.9 cm/year, p < 0.001 versus baseline; 12 months 6.0 +/- 1.3 cm/year, p < 0.0001 versus baseline). There was a significant increase in height SDS for bone age (baseline -1.6 +/- 0.5 SDS; 12 months -1.04 +/- 0.6 SDS; p < 0.002) and in predicted adult height (baseline 152.0 +/- 3.6 cm; 12 months 155.9 +/- 3.4 cm; p < 0.002). Our results suggest that combined therapy with Gn-RH analogues and recombinant GH can improve growth velocity and predicted adult height in girls with central precocious puberty and impaired height prognosis during Gn-RH analogue treatment.