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

BACKGROUND: 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. MATERIALS AND METHODS: 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). RESULTS: 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). CONCLUSION: 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.