Prevalence and Prognostic Significance of Malnutrition in Critically Ill Patients With Acute Kidney Injury.

Objective(s): Malnutrition is a significant factor associated with adverse outcomes in various diseases. However, the prevalence of malnutrition among critically ill patients with acute kidney injury (AKI) and its impact on outcomes have not been thoroughly investigated. The purpose of this study was to investigate the prevalence and prognostic significance of malnutrition in critically ill patients with AKI.

Methods: Critically ill patients with AKI were selected from the Medical Information Mart for Intensive Care IV through a retrospective cohort study. The nutritional status of these patients was assessed using the Prognostic Nutritional Index (PNI), Geriatric Nutritional Risk Index (GNRI), and Controlling Nutritional Status (CONUT). Cox proportional hazard model, Kaplan-Meier analysis, and limited cubic spline were used to evaluate the association between malnutrition risk and 28-day mortality. In addition, logistic regression, Cox regression, and linear regression were used to assess the correlation between malnutrition risk and in-hospital mortality, 90-day mortality, and hospital length of stay, respectively.

Results: Of the 1,129 patients enrolled, 49.6%, 80.0%, and 57.7% were found to have moderate to severe malnutrition based on PNI, GNRI, and CONUT scores, respectively. Higher risk of malnutrition was associated with lower hemoglobin, lymphocytes, serum albumin, total cholesterol, higher creatinine, blood urea nitrogen, sepsis organ failure assessment score, simplified acute physiology score II, higher mortality, and longer hospital stay. Among the patients, 215 (19.04%) died within 28 days of intensive care unit admission. Malnutrition was significantly associated with 28-day mortality risk compared with good nutrition (adjusted hazard ratio for severe malnutrition: PNI:HR 1.57, 95% confidence interval [CI] 1.15-2.14; GNRI:HR 1.62, 95% CI 1.01-2.55; CONUT:HR 2.51, 95% CI 1.31-4.80). These nutritional measures further enhanced the predictive accuracy of 28-day mortality, with the CONUT score demonstrating the strongest association. Furthermore, logistic regression, Cox regression, and linear regression models, respectively, revealed that malnutrition risk was significantly associated with in-hospital mortality, 90-day mortality, and hospital length of stay.

Conclusions: Malnutrition is prevalent among critically ill patients with AKI and significantly correlates with 28-day mortality, in-hospital mortality, 90-day mortality, and hospital length of stay. Further research is necessary to evaluate the impact of malnutrition screening and nutritional interventions on improving adverse outcomes.