Geriatric Nutritional Risk Index and Risk of Mortality in Critically Ill Patients With Acute Kidney Injury: A Multicenter Cohort Study

Abstract

Malnutrition is associated with adverse outcomes in acute or chronic diseases. However, the prediction value of the Geriatric Nutritional Risk Index (GNRI) in critically ill patients with acute kidney injury (AKI) has not been well studied. Data was extracted from the Medical Information Mart for Intensive Care III (MIMIC-III) and the electronic intensive care unit database. We used two nutritional indicators, the GNRI and the modified Nutrition Risk in Critically ill (NUTRIC) score, to evaluate the relationship between the nutritional status of patients with AKI and prognosis. The outcome is in-hospital mortality and 90-day mortality. The prediction accuracy of GNRI was compared with the NUTRIC score. A total of 4,575 participants with AKI were enrolled in this study. The median age of 68 (interquartile range, 56-79) years, and 1,142 (25.0%) patients experienced in-hospital mortality, and 1,238 (27.1%) patients experienced 90-day mortality. Kaplan-Meier survival analysis indicated that lower GNRI levels and high NUTRIC score are associated with lower in-hospital and 90-day survival of patients with AKI (P<.001 by log-rank test). After multivariate adjustment, Cox regression analysis demonstrated a 2-fold increased risk of in-hospital (hazard ratio =2.019, 95% confidence interval: 1.699-2.400, P<.001) and 90-day (hazard ratio =2.023, 95% confidence interval: 1.715-2.387, P<.001) mortality in the low GNRI group. Moreover, the multivariate-adjusted Cox model containing GNRI had higher prediction accuracy for the prognosis of patients with AKI than that with NUTRIC score (AUCGNRI model vs. AUCNUTRIC model for in-hospital mortality=0.738 vs. 0.726, AUCGNRI model vs. AUCNUTRIC model for 90-day mortality=0.748 vs. 0.726). In addition, the prediction value of GNRI was validated by the electronic intensive care unit database (7,881 patients with AKI) with satisfying performance (AUCGNRI model=0.680). Our results demonstrated that GNRI is strongly associated with survival in patients in the intensive care unit coexisting with AKI, and the GNRI has a superior predictive value than the NUTRIC score.