Changes in the IGF-IGFBP axis in critical illness.

Abstract

In critical illness, serum concentrations of the growth hormone-dependent complexes containing insulin-like growth factors I and II are decreased. This is initially due to a transient growth hormone resistance, but in the longer term, the less pulsatile pattern of growth hormone secretion may be a major factor since only pulsatile growth hormone increases the levels of insulin-like growth factor-I and the acid-labile subunit. Other factors contributing to a low insulin-like growth factor level are nutritional deficiency and the direct effects of inflammatory cytokines. The growth hormone-independent proteins IGFBP-2, IGFBP-4 and IGFBP-6 increase in critical illness, suggesting a redistribution of insulin-like growth factors from growth hormone-dependent ternary complexes with IGFBP-3 and IGFBP-5 to binary complexes with these binding proteins, which might facilitate transport to the tissues. IGFBP-1, which is acutely regulated by metabolic status, is elevated on admission to intensive care but may fall in response to nutritional support. Initial evidence suggests that the level of IGFBP-1 may be predictive of outcome in critically ill patients, suggesting a possible prognostic role for this protein.

• Authors: R C Baxter
• Journal: Best practice & research. Clinical endocrinology & metabolism (Best Pract Res Clin Endocrinol Metab) Vol. 15 Issue 4 Pg. 421-34 (Dec 2001) ISSN: 1521-690X [Print] Netherlands
• PMID: 11800515 (Publication Type: Journal Article, Review)
• Copyright: Copyright 2001 Harcourt Publishers Ltd.

Chemical References

• Biomarkers
• Insulin-Like Growth Factor Binding Proteins
• Somatomedins
• Human Growth Hormone

Topics

• Biomarkers
• Critical Illness
• Human Growth Hormone (metabolism)
• Humans
• Insulin-Like Growth Factor Binding Proteins (metabolism)
• Nutritional Physiological Phenomena
• Somatomedins (metabolism)