The variability of responses to growth hormone therapy in children with short stature

Abstract

Growth hormone (GH) is widely prescribed for children with short stature across a range of growth disorders. We describe the variability of responses seen in conditions approved for GH therapy. Although responses in different growth disorders are satisfactory, evidence is increasing for an unacceptably high rate of poor or unsatisfactory response (i.e., not leading to significant catch-up growth) in terms of change in height standard deviation score and height velocity. Consequently, there is a need to define a poor response and to prevent or correct it by optimizing treatment regimens. This review discusses the optimal investigation of the child who is a candidate for GH therapy so that a diagnosis-based guide to therapy and dosage can be made. The relevant parameters in the evaluation of growth response are described together with the definitions of a poor response.

Keywords: Growth; growth hormone therapy; growth response; height; recombinant human insulin-like growth-factor-1 therapy; short stature.

Figure 1

Algorithm for management of poor response to growth harmone.^*Height velocity < mean –1.0 standard deviation equals an increase in height standard deviation score of 0.4 for severe idiopathic growth hormone deficiency (IGHD) and 0.3 for other diagnoses. Use reference for severe IGHD according to Ranke[10] for any diagnosis or if other diagnosis-specific references are used then consider using a more strict cut-off.^**Consider that GH stimulation tests were falsely low which is the case in the majority of ‘IGHD’ patients without magnetic resonance imaging abnormalities. CGH array: Comparative genomic hybridization array, SHOX deficiency: Short stature homeobox-containing deficiency, SDS: Standard deviation score, SGA: Small for gestational age, SPIGFD: Severe primary insulin-like growth factor deficiency