Growth hormone secretion in Turner's syndrome and influence of oxandrolone and ethinyl oestradiol.

We investigated 24 hour growth hormone secretion by intermittent 20 minute blood sampling in 34 prepubertal patients with Turner's syndrome, aged 4.3-12.4 years. Growth hormone profiles were analysed by the PULSAR programme and results expressed as the sum of growth hormone pulse amplitudes. Six patients had abnormal growth hormone pulse frequencies. In the remaining 28, growth hormone pulse amplitudes declined significantly with increasing age, but there was no correlation between growth hormone pulse amplitudes and growth rates. Concentrations of insulin like growth factor-1 (IGF-1) rose with age but did not correlate with either growth rates or growth hormone secretion. Fifteen patients were given oxandrolone and 11 low dose ethinyl oestradiol. Both agents increased height velocity without increasing growth hormone secretion. We conclude that the relation between growth hormone secretion and growth in Turner's syndrome is less certain than in normal children. End organ resistance is probably due to a skeletal dysplasia. Both oxandrolone and low dose ethinyl oestradiol improve the growth of girls with Turner's syndrome, but their mechanism of action remains uncertain.