Evolution of GH secretion in urine during an in-patient slimming course in obese children

OBJECTIVE: To estimate the change in GH excretion in urine (GH-U) during a slimming course, and if increased, to assess the components of the course related to the increase in obese children. DESIGN: Observational follow-up study of patients admitted for primary obesity to an in-patient slimming course lasting at least 10 weeks. SUBJECTS: 48 complete observations out of 54 consecutive pre-pubertal patients admitted to a paediatric centre for treatment of primary obesity (BMI greater than the 90th percentile of the national reference curves). MEASUREMENTS: GH excretion in urine by immunoradiometric assay, at entry and after 10 weeks, various anthropometric measurements, nutritional intake and departure from the prescribed diet, time spent in physical activity, sleep duration. RESULTS: A mean decrease of 0.90 standard deviations for BMI was accompanied by a 34% increase of GH-U. Time spent in physical activity was the only component of the course found to be related to the magnitude of GH-U increase. CONCLUSION: The results of this observational study confirm that GH-U is increased after a slimming course in children, and suggest that physical activity is a major contributor to the restoration of normal GH-U levels.