Growth hormone therapy in children with idiopathic short stature – the effect on appetite and appetite-regulating hormones: a pilot study

<p><b>Aim</b>: To investigate the effect of growth hormone (GH) therapy on appetite-regulating hormones and to examine the association between these hormones and the response to GH, body composition, and resting energy expenditure (REE).</p> <p><b>Methods</b>: Nine pre-pubertal children with idiopathic short stature underwent a standard meal test before and 4 months following initiation of GH treatment. Ghrelin, GLP-1, leptin, and insulin levels were measured; area under the curve (AUC) was calculated. Height, weight, body composition, REE, and insulin-like growth factor levels were recorded at baseline and after 4 and 12 months.</p> <p><b>Results</b>: Following 4 months of GH therapy, food intake increased, with increased height-standard deviation score (SDS), weight-SDS, and REE (<i>p </i>< .05). Significant changes in appetite-regulating hormones included a decrease in postprandial AUC ghrelin levels (<i>p </i>= .045) and fasting GLP-1 (<i>p </i>= .038), and an increase in fasting insulin (<i>p </i>= .043). Ghrelin levels before GH treatment were positively correlated with the changes in weight-SDS (fasting: <i>r</i> = .667, <i>p </i>= .05; AUC: <i>r</i> = .788, <i>p </i>= .012) and REE (fasting: <i>r</i> = .866, <i>p </i>= .005; AUC: <i>r</i> = .847, <i>p </i>= .008) following 4 months of GH therapy. Ghrelin AUC at 4 months was positively correlated with the changes in height-SDS (<i>r</i> = .741, <i>p </i>= .022) and fat-free-mass (<i>r</i> = .890, <i>p </i>= .001) at 12 months of GH treatment.</p> <p><b>Conclusions</b>: The reduction in ghrelin and GLP-1 following GH treatment suggests a role for GH in appetite regulation. Fasting and meal-AUC ghrelin levels may serve as biomarkers for predicting short-term (4 months) changes in weight and longer term (12 months) changes in height following GH treatment. The mechanisms linking GH with changes in appetite-regulating hormones remain to be elucidated.</p> <p><b>Abbreviations:</b> SDS: standard deviation score; REE: resting energy expenditure; SMT: standard meal test; AUC: area under the curve; ISS: idiopathic short stature; SGA: small for gestational age; FFM: fat-free-mass; FM: fat mass; EER: estimated energy requirements; DRI: dietary reference intakes; IQR: inter-quartile range