SECRETION OF GROWTH-HORMONE RELEASING HORMONE IN OBESE CHILDREN

We have evaluated baseline and I-dopa-stimulated peripheral growth hormone releasing hormone (pGHRH) secretion in 6 obese prepubertal children and in 7 age-matched controls. Baseline pGHRH levels were no different between obese (36.6+/-9.8 pg/ml, mean+/-SE) and control children (40.6+/-10.1 pg/ml). Administration of I-dopa (500 mg po) caused a significant increase of pGHRH levels in both the obese (65.3+/-19.8 pg/ml, p<0.05) and the control children (84.1+/-10.0 pg/ml, p<0.003). Mean peak pGHRH levels after 1-dopa were not significantly different between the two groups, whereas mean peak GH levels were significantly lower (p<0.05) in the obese (7.9+/-1.9 ng/ml) than in the control children (20.5+/-4.9 ng/ml). We conclude that despite reduced GH secretion, obese children have normal baseline and 1-dopa stimulated pGHRH levels.