|Reeds, Peter - Peter|
Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2003
Publication Date: 3/14/2003
Citation: Shi, J.R., Sekhar, R.V., Balasubramanyam, A., Ellis, K., Reeds, P.J., Jahoor, F., Sharma, M.D. 2003. Short-and long-term effects of growth hormone replacement therapy on protein metabolism in growth hormone deficient adults. Journal of Federation of American Societies for Experimental Biology. 17:A810. Interpretive Summary:
Technical Abstract: To investigate the effect of GH replacement therapy on protein kinetics and body composition in hypopituitary patients with growth hormone deficiency (GHD). Splanchnic and whole body protein kinetics were measured in 8 adults with GHD and 8 matched healthy controls in the fasted and fed states using intravenous (2H3-) and oral (13C-) leucine infusions. Measurements were repeated in the GHD subjects after 2 weeks and 6 months of GH treatment. Body composition (fat free mass, FFM and fat mass) were measured by DEXA before and after 6 months of GH. There was no significant difference in leucine kinetics (µmol/kg FFM/h) between GHD subjects and controls. After 2 weeks of GH, leucine oxidation decreased (fasted: 41±5 vs. 30±6, P < 0.05; fed: 49±3 vs. 41±3.6, P < 0.05) and leucine balance improved (fasted: -14±4 vs. -3.5±3, P < 0.05; fed: 65±13 vs. 72±7, P = 0.07), because of increased protein synthesis. After 6 months of GH, these changes were maintained in the fasted but not in the fed state. Splanchnic leucine uptake was not affected by GH therapy. GH caused a modest but not significant increase in FFM. GH replacement in GHD patients causes an acute improvement in protein balance due to an increase in synthesis and a decrease in catabolism. This effect is lost after 6 months of treatment, as protein kinetics return to pre-treatment homeostasis.