Growth, growth hormone and sex steroid secretion in girls with central precocious puberty treated with a gonadotrophin releasing hormone (GnRH) analogue.

We have treated 14 girls with central precocious puberty for a mean period of 2.3 years (range, 0.5-3.9) with intranasal (D-Ser6) GnRH analogue administered in a mean dose of 28 micrograms/kg/day (range, 15-56). With the onset of treatment there was an initial increase in sitting height compared to subischial leg length, but overall there was no significant change in height standard deviation score for bone age. In this respect our results were indistinguishable from untreated children with central precocious puberty. There was a decrease in physiological GH secretion, associated with decreased sex steroid secretion, which probably accounts for the growth deceleration which has been described during GnRH analogue therapy. The effect of this growth deceleration combined with slowing of the rate of epiphyseal maturation may explain the absence of alteration in height prognosis.