Suppressed spontaneous secretion of growth hormone in girls after treatment for acute lymphoblastic leukaemia.

The spontaneous secretion of growth hormone during a 24 hour period and the response of growth hormone to growth hormone releasing hormone was studied in 13 girls who had received treatment for acute lymphoblastic leukemia that included cranial irradiation with 20-24 Gy in 12-14 fractions. At the time of investigation the girls were at varying stages of puberty and had normal concentrations of thyroid hormones. The mean interval between the end of treatment and investigation was 4.6 years. The mean age at onset of the disease was 3.2 years and at investigation 10.7 years. The average attained height equalled -0.3 SD at onset, and -1.0 SD at the time of investigation. Secretion of growth hormone was substantially reduced compared with controls and did not increase during puberty. A prompt rise in growth hormone secretion was seen after injection of growth hormone releasing hormone, but the mean maximum growth hormone concentration was, however, only 25 mU/l. There was no correlation between the 24 hour secretion and growth hormone response to growth hormone releasing hormone, or the time since irradiation. These results confirm earlier work that suggested that girls who had received treatment for acute lymphoblastic leukaemia, that included cranial irradiation, have a comparative growth hormone insufficiency characterised by normal prepubertal growth and slow growth during puberty because of an inability to respond to the increased demands for growth hormone at that time

Supplementary Material for: Estradiol and Pubertal Growth in Girls

<b><i>Aim:</i></b> The objective of this study was to determine estradiol levels and assess their relationship to pubertal growth in girls. <b><i>Methods:</i></b> Thirty-seven 24-hour profiles of serum 17β-estradiol were retrospectively analyzed in relation to growth in 27 healthy girls admitted for short/tall stature (n = 20) or recruited as healthy volunteers at Göteborg Pediatric Growth Research Center (GP-GRC). <b><i>Inclusion Criteria:</i></b> Birth weight and length above –2 SDS, gestational age 37–42 weeks, prepubertal height and weight within ±3 SDS and normal growth hormone secretion. Serum estradiol was determined by a validated ultrasensitive extraction radioimmunoassay (detection limit 4 pmol/l). A sixth-grade polynomial was fitted to each girl’s growth data. Growth velocity and age at peak height velocity (PHV) was calculated. <b><i>Results:</i></b> A dose-response model was used to find the morning 17β-estradiol level at which half of the maximal pubertal growth up to PHV had occurred, EC₅₀, which was 20 pmol/l with a 95% confidence interval of 13–31. When 17β-estradiol exceeds early pubertal levels (Tanner breast stage 2, 10–51 pmol/l), less than 25% of the potential pubertal growth velocity up to PHV remains. <b><i>Conclusions:</i></b> Morning 17β-estradiol in the low early pubertal range (13–31 pmol/l) is associated with increasing growth velocity