IGF-I concentration and changes in critically ill patients

Insulin-like growth factor 1 (IGF-I) is an anabolic growth factor that affects nitrogen balance and its changing trend is not clearly understood in critically ill patients. This study was carried out to evaluate the association between serum IGF-I levels and its changing trend in critically ill patients. In this nested case-control study, all consecutive patients admitted to the medical ICU of Rasoul-e-Akram and Firuzgar hospital (Tehran, Iran) from January through October 2008 were included. IGF1 concentration was measured within the first 24h of ICU admission and the fourth, seventh and tenth day since admission. Patients were followed until discharge from ICU or expiration. The study population consisted of 90 patients (mean age: 58.01 ± 22.56), 31 (34.4%) of who died and 59 (65.6%) were discharged. On admission, 43 patients (47.7%) had low IGF-I levels, whereas 47 (52.3%) had normal or high levels. The concentration of IGF-I was not significantly different in every 4 measurements between expired and discharged patients. Significant decrease was seen between first to fourth day IGF-I concentration (p = 0.005). Changing trend was not statistically different in two groups of patients. There was no relation between low IGF-I concentration on admission day and increased adverse outcome, but overall these patients had lower IGF1. No clear association was found between changing trend of IGF1 and mortality. Stress on admission time may cause decreasing pattern of IGF-I in the first 4 days of admission.