Endocrine Abstracts

JOINT3759

Introduction: Growth hormone stimulation testing (GHST) is recommended to diagnose growth hormone deficiency (GHD) in children. Sex steroids impact on anterior pituitary function, therefore, the efficacy of GHST in peripubertal children, where endogenous sex steroid levels are low is challenging. Sex steroid priming before GHST has been proposed to improve test efficacy in these children, however clear evidence to support its use in clinical practice is limited.

Methods: A total of 141 children with short stature (height <3rd %) (71boys) (Tanner 1, 43.6%/), mean age 12±2.3years, were evaluated for growth hormone deficiency upon a 2 year period (2020 -2022). Standard GHST with prior steroid priming (n=76, 53.9%, mean age 12.5±2years) were compared to a group without prior steroid priming (n = 65, 46.1%, mean age 11.7±2.4years) (p=NS). For priming, sex steroids were delivered; testosterone enanthate 100mg IM 5-7 days before GHST for boys and estradiol valerate 1-2mg PO 3 days before GHST (glucagon or clonidine) for girls.

Results: Median GH peak max was 7.1ng/ml (IQR: 6.2) without vs. 7.7 (IQR: 8.0) with prior steroid priming (p=NS). Median E2 levels were 40.4 pg/ml (IQR: 77.1) before vs 68.9pg/ml (IQR: 54.3) after priming (P = 0.013); median testosterone levels were 3.2ng/ml (IQR: 5.8) vs 5.7ng/ml (IQR: 6.9) respectively (p=NS). Prepubertal children (Tanner 1) had significantly higher GH response after priming (10.1 vs 8.7 ng/ml, p:0.011) as opposed to pubertal Tanner 2 (9.1 vs 9.3 ng/ml) (p:0.097). Females demonstrated significantly higher median E2 levels after priming (70.6 vs 40.4 pg/ml) (p:0.013) as compared to males with respect to median levels of testosterone (5.7 vs 3.2 ng/ml) (p:0.056).

Conclusion: In our cohort of peripubertal adolescents with short stature sex steroid priming prior to growth hormone stimulation testing failed to reveal statistically significant difference in growth hormone secretion.