Effect of growth hormone on muscle and protein in critically ill patients

In summary, the effects of protein metabolism of the provision of additional GH are well documented in critically ill patients. Nitrogen balance improves as urea production is diminished. The crucial question is whether this lowers the availability of glutamine for cells dependent on it in critical illness. In parallel, muscle protein synthesis is stimulated by GH and the free glutamine content of muscle is maintained in situations when a depletion of muscle glutamine is otherwise seen. Another consistent finding in most clinical studies is the pronounced interindividual variability in the response to GH. So far, no marker has been identified to predict an individual patient's sensitivity to GH, but the identification of individuals who are likely to benefit from GH treatment during critical illness should be a priority in future clinical research on GH.