In 107 consecutive septic patients (44 with sepsis, 13 with severe sepsis, and 50 with septic shock), GH, IGF-I, Insulin-like Growth Factor Binding Protein-3 (IGFBP-3), insulin, cortisol, albumin, thyroid hormones, C-reactive protein and interleukin-6 serum levels were measured once within 48 h after onset of a septic episode. Twenty-nine healthy volunteers served as controls.
IGF-I and IGFBP-3 levels were decreased in patients with sepsis and severe sepsis (versus controls), decreasing further in patients with septic shock (versus sepsis). IGF-I levels were positively related to IGFBP-3, albumin, triiodothyronine and thyroxine, and inversely related to cortisol, sepsis severity, C-reactive protein, interleukin-6 and age. In multiple regression analysis, IGF-I levels were independently related to IGFBP-3 and albumin (lower in patients with decreased IGFBP-3 and albumin levels) (p < 0.001 and p = 0.01, respectively), and cortisol (lower in patients with increased cortisol levels) (p = 0.04). IGFBP-3 accounted for most of the variance explained by the model (R2 = 0.519). GH levels were not related to IGF-I levels or mortality. IGF-I and IGFBP-3 levels were not associated with mortality.
The GH/IGF-I axis is severely disrupted in septic patients. IGFBP-3 is the major determinant of IGF-I levels.