The growth hormone response to growth hormone-releasing hormone stimulation in infantile protein-calorie malnutrition

Growth hormone kinetics in infantile malnutrition are characterized by high basal values and decreased responses to various provocative stimuli. The mechanism of this alteration has not been explained. To determine whether altered sensitivity to growth hormone releasing hormone (GHRH) plays a role in this phenomenon, we perfomed GHRH testing in 19 infants with primary malnutrition of grades II and III before and after 6 weeks of nutritional rehabilitation. GHRH (1-44) NH2 was administered intravenously by bolus injection at a dose of 1 mcg/kg. Mean baseline GH maximum elevation above baseline (ΔGH), and area under the Gh response curve (Σ GH) were measured. The injections stimulated a rapid rise in GH which reached a maximum at 15-30 mins after GHRH. There were no significant differences in the magnitude or time couse of the responses between infants in the malnourished and recovering states (Δ GH 29±7 vs. 34±5 ng ml:Σ GH 3379±571 vs. 3459±397 ng. min/ml respectively), and responses were similar to thoses of normal prepuberal children. We conclude that altered sensitivity of pituitary to GHRH appears not to underlie the alterations of growth hormone dynamics observed in malnutrion.