Growth hormone (GH) provocation testing in the assessment of children with disorders of growth-a 16 year experience from one tertiary centre

Abstract

Introduction: The diagnosis of growth hormone deficiency (GHD) in children and adolescents with short stature and poor growth involves obtaining a relevant clinical history, examination and if indicated pituitary imaging. Confirmation of biochemical GHD is a complex process involving GH provocation testing. Aim: To describe the clinical and biochemical characteristics of patients undergoing GH testing in the last 16 years at one tertiary paediatric endocrine unit. Methods: A retrospective chart review of all the subjects who had undergone GH testing between 1998 to 2013 was performed. Five hundred and ninety-one subjects undertook GH testing; 97 subjects were excluded as their clinical data was unavailable, Data collected included age, height, weight, body mass index, clinical diagnosis as per ESPE diagnostic code, bone age, growth hormone provocation test results (combined arginine-glucagon test), thyroid function, FBC, ESR, coeliac serology, Karyotype, ELFT. Results: The mean ± SD age of subjects was 9.6 ± 4.2 year (age 0.23-19.35); 34.7% were females and 65.3% were males. Within the total group 75.8% of subjects were prepubertal with no statistical significant difference in pubertal status between the GHD and non- GHD groups. 428 subjects (86.6%) had a peak GH response >10 mU/l on GH testing so were classified as non-GHD, The majority of these subjects (48.7%) had idiopathic short stature. 13.4% of them had GHD defined as peak GH level <10 mU/l during both tests. GHD subjects had significantly higher weight and BMI SDS than the ISS non-GHD group (p < 0.0001 by ANOVA between the groups). Summary and conclusion: Only 14% of children were diagnosed with GHD, while 86% of subjects were GH sufficient. Overall these results suggest that the clinical criteria that prompts GH testing has low specificity and sensitivity for diagnosing GHD, so an improved clinical algorithm for ordering GH testing to diagnose GHD in a child with short stature or growth failure appears warranted.L720733772015-11-20 <br />