Circulating levels of GH predict mortality and complement prognostic scores in critically ill medical patients

Abstract

Circulating levels of GH are increased during critical illness and correlate with outcome in children with meningococcal sepsis. We assessed the prognostic implications of GH on admission and during follow-up in critically ill adult patients admitted to a medical intensive care unit. We measured GH, IGF1 and IGF-binding protein3 (IGFBP-3) plasma concentrations in 103 consecutive critically ill patients and compared it with two clinical severity scores (APACHE II, SAPS II). Median GH levels on admission were similar in septic (n=53) and non-septic (n=50) patients and about 7-fold increased in the 24 non-survivors as compared with survivors (9.50 (interquartile ranges (IQR) 3.53-18.40) vs 1.4 (IQR 0.63-5.04), P<0.0001). GH levels increased with increasing severity of sepsis (sepsis, severe sepsis, and septic shock, P=0.019). By contrast, IGF1 and IGFBP-3 did not correlate with severity of disease or mortality. Logistic regression models showed that GH and both clinical scores were independent predictors of mortality with a similar prognostic accuracy (GH: area under the curve (AUC) 0.81 (95% confidence interval (CI), 0.71-0.92), APACHE II: AUC 0.71 (95% CI, 0.58-0.83), P=0.16, SAPS II: AUC 0.75 (95% CI, 0.63-0.86, P=0.36)). GH improved the prognostic accuracy of the APACHE II score to an AUC of 0.78 (95% CI, 0.66-090, P=0.04) and tended to improve the SAPS II score to an AUC of 0.79 (95% CI, 0.67-0.90, P=0.09). GH plasma concentrations on admission are independent predictors for mortality in adult critically ill patients and may complement existing risk prediction scores, namely the APACHE II and the SAPS II score.