Response of IGF-1 to nutritional support in malnourished hospital patients: a possible indicator of short-term changes in nutritional status.

IGF-1 is a circulating growth factor with hepatic release dependent on nutritional status. To determine if IGF-1 could be a useful nutritional index, 15 malnourished patients were assessed during nutritional support. Patients with protein or protein-calorie malnutrition had lower IGF-1 (39 +/- 7 micrograms/L) than did patients with calorie-only malnutrition (109 +/- 25 micrograms/L, p less than 0.005); transferrin concentrations did not differ between the two groups. Nutritional supplementation produced an increase in IGF-1 (123 +/- 32 micrograms/L, p less than 0.005); the relative increase in IGF-1 (264 +/- 62%, p less than 0.001) exceeded increases in albumin or transferrin (9 +/- 6% and 59 +/- 16%, NS and p less than 0.005, respectively). Reduction or termination of support was followed by a decrease in IGF-1 to 59 +/- 9% of peak values (p less than 0.001) but neither albumin nor transferrin decreased significantly. Changes in IGF-1 were correlated with nitrogen balance (r = 0.45, p less than 0.005). The strong relationship between IGF-1 and nutritional status suggests that IGF-1 determinations may be useful in guiding nutritional therapy in patients whose nitrogen balance is difficult to assess.