HUMAN GROWTH-HORMONE PREVENTS THE PROTEIN CATABOLIC SIDE-EFFECTS OF PREDNISONE IN HUMANS

Prednisone treatment causes protein wasting and adds additional risks to a patient, whereas human growth hormone (hGH) treatment causes positive nitrogen balance. To determine whether concomitant administration of hGH prevents the protein catabolic effects of prednisone, four groups of eight healthy volunteers each were studied using isotope dilution and nitrogen balance techniques after 7 d of placebo, hGH alone (0.1 mg·kg-1·d-1), prednisone alone (0.8 mg·kg-1·d-1), or prednisone plus hGH (n = 8 in each group). Whether protein balance was calculated from the leucine kinetic data or nitrogen balance values, prednisone alone induced protein wasting (P < 0.001), whereas hGH alone resulted in positive (P < 0.001) protein balance, when compared to the placebo-treated subjects. When hGH was added to prednisone therapy, the glucocorticoid-induced protein catabolism was preventjed. Using leucine kinetic data, negative protein balance during prednisone was due to increased (P < 0.05) proteolysis, whereas hGH had no effect on proteolysis and increased (P < 0.01) whole body protein synthesis. During combined treatment, estimates of proteolysis and protein synthesis were similar to those observed in the placebo treated control group. In conclusion, human growth hormone may have a distinct role in preventing the protein losses associated with the administration of pharmacologic doses of glucocortisteroids in humans.