Re-evaluation of exercise as a screening test for ruling out human growth hormone deficiency

Human growth hormone (HGH) response to exercise was studied in 27 normal children and 152 children with a chief complaint of short stature and in 9 patients with HGH deficiency. Of the 152 children 107 could be ruled out of HGH deficiency since HGH level increased to more than 5 ng/ml during exercise, and of the remaining 45 children of non-responders to exercise, 22 were ruled out of HGH deficiency since bone age to chronological age ratio was more than 0.9 and/or height increment for the past 3 years was more than 15 cm. Seventeen patients were hospitalized for further examinations, which resulted in finding normal HGH secretion in response to insulin-induced hypoglycemia, arginine infusion and/or propranolol-glucagon test in 12 children and also in finding no HGH deficiency in children higher than -2.0 S.D., but 5 HGH-deficient children in those lower than -2.0 S.D. Exercise can be used as a screening test for ruling out HGH deficiency when HGH secretion in response to exericse is evaluated by height, bone age and height increment of the patients.