Slow growth and short stature in children with attention deficit hyperactivity disorder (ADHD): a retrospective study of 493 children who underwent growth hormone provocation testing at one tertiary paediatric endocrine centre.

Objectives: We hypothesised that growth hormone (GH) deficiency (GHD) in children with attention deficit hyperactivity disorder (ADHD) is rare. This study aimed to determine any distinct clinical or biochemical parameters, including GH provocation testing, in children with ADHD on psychostimulants or idiopathic short stature (ISS).

Methods: Retrospective cross-sectional study of children who had GH provocative testing between 1998 and 2013 at one tertiary paediatric endocrine centre. Clinical data included age, sex, anthropometry, pubertal staging, bone age, diagnostic code as per the European Society Paediatric Endocrinology (ESPE), GH provocation test results, thyroid function tests, serum insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) levels.

Results: Four hundred ninety-three subjects underwent GH provocation testing for investigation of short stature to exclude GHD during the study period. Fifty-one children had a diagnosis of ADHD. In the remaining children, the diagnosis was Idiopathic short stature (n=240), GHD +/- hypopituitarism (n=60), and 142 subjects had other causes of short stature. Children with ADHD were older, had higher height and weight SDS and were GH-sufficient. All 51 children with ADHD had a normal serum IGFBP-3, while 20 out of these 51 subjects had a low serum IGF-1.

Conclusions: GHD in children with ADHD on psychostimulant medication is rare. GH testing in children with ADHD may not be necessary, particularly if serum IGFBP-3 is in the normal range. We suggest IGFBP-3 could be used as a surrogate marker of GH sufficiency in children with ADHD. However, this needs to be confirmed with a larger study group.