PLASMA-LEVELS OF INSULIN-LIKE GROWTH-FACTOR BINDING PROTEIN-3 IN ACUTE TRAUMA PATIENTS

Insulin-like growth factors (IGFs) are a family of polypeptides that r egulate cell growth. Their action and bioavailability are modified by binding proteins such as IGF binding protein-3 (IGFBP-3), Plasma IGFBP -3 level was found to be growth hormone (GH)-dependent, which makes de tection of IGFBP-3 useful in the evaluation of GH secretion. In the ea rly catabolic flow phase of severe injury, when plasma levels of GH an d IGF-1 are low versus uninjured levels, the role of IGFBP-3 has not b een investigated. We have measured basal levels of these polypeptide h ormones in 16 adult(13 men and three women aged 47 +/- 7 years) severe ly injured (Injury Severity Score, 32 +/- 2), hypermetabolic resting e nergy expenditure [REE] to basal energy expenditure [BEE] ratio, 1.30 +/- 0.05), ventilator-dependent, multiple-trauma patients within 48 to 60 hours of injury when the patients were receiving maintenance fluid s without calories or nitrogen. These basal values were compared with those of 16 age-matched postabsorptive normals. In the catabolic flow phase of injury, plasma levels of GH, IGF-1, and IGFBP-3 were signific antly reduced by 50%, 46%, and 45%, respectively. There was a signific ant linear inverse relationship between IGFBP-3 and age and also a pos itive correlation between IGFBP-3 and IGF-1 in both control and injure d subjects. The ratio of IGFBP-3 to IGF-1 was not changed in trauma vi ctims. Measurement of plasma IGFBP-3 levels has potential as a marker for monitoring GH therapeutic efficacy. Copyright (C) 1995 by W.B. Sau nders Company