Comparison of growth hormone releasing hormone therapy and growth hormone therapy in growth hormone deficiency.

Seven children with growth hormone deficiency of hypothalamic origin responded to an i.v. bolus of growth hormone releasing hormone (GHRH) (1-29)-NH2 with a mean serum increase of 10.7 ng/ml growth hormone (GH) (range 2.5-29.3 ng/ml). Continuous s.c. administration of GHRH of 4-6 micrograms/kg twice daily for at least 6 months did not improve the growth rate in five of the patients. One patient increased his growth rate from 1.9 to 3.8 cm/year and another from 3.5 to 8.2 cm/year; however, the growth rate of the latter patient then decreased to 5.4 cm/year. When treatment was changed to recombinant human growth hormone (rhGH) in a dose of 2 U/m2 daily, given s.c. at bedtime, the growth rate improved in all patients to a mean of 8.5 cm/year (range: 6.2 to 14.6). Presently GHRH cannot be recommended for the routine therapy of children with growth hormone deficiency since a single daily dose of rhGH produced catch-up growth which GHRH therapy did not.