Malnutrition and short-term mortality in hospitalized general medical patients with acute kidney injury: A prospective observational study.

Background: Acute kidney injury (AKI) is a common condition present at admission to hospital in a proportion of general medical patients and it contributes to mortality. Presence of associated malnutrition could worsen the prognosis. We aimed to study the prevalence of malnutrition in patients with community-acquired AKI requiring hospitalization and its association with short-term (in-hospital and 1-month post-discharge) mortality, admission to the intensive care unit (ICU) and length of hospitalization (LOH).

Materials and methods: We did a prospective observational study including adult general medical patients who had AKI at admission; patients with chronic kidney disease were excluded. We calculated the Charlson Comorbidity Index (CCI) and Sequential Organ Failure Assessment Score (SOFA). Nutritional assessment was done using Subjective Global Assessment (SGA) and also Prognostic Nutritional Index (PNI). Clinical course and vital status at 1 month after discharge was noted. Predictors of mortality were identified using logistic regression.

Results: We recruited 230 patients. The median (interquartile range (IQR)) age was 51 (40 - 64) years; 171 (74.3%) were males. Based on admission creatinine, 60 (26%) were in Kidney Disease Improving Global Outcomes (KDIGO) stage 1, 82 (35.6%) in stage 2, and 88 (38.3%) in stage 3. We found that 132 (57.4%) belonged to SGA category A, 77 (33.5%) to SGA B, and 21 (9.1%) to SGA C. The median (IQR) PNI was 36.3 (30 - 46.6). The short-term mortality was 59 (25.6%). Multivariable analysis showed that male sex (adjusted OR (aOR) (2.75 (1.08 - 6.98); p = 0.033), higher CCI (aOR 1.43 (1.18 - 1.74); p < 0.001), higher SOFA scores (aOR 1.36 (1.19 - 1.55); p < 0.001), and SGA C category (aOR 4.4 (1.39 - 14.03); p = 0.012) to be associated with mortality, while AKI due to underlying infections was associated with survival (aOR 0.38 (0.18 - 0.78); p = 0.008). There was no association of malnutrition with ICU admission or LOH. PNI did not predict mortality.

Conclusion: About 10% of patients with community-acquired AKI had severe malnutrition, and it independently predicts mortality. Male sex, higher CCI, and higher SOFA scores were also associated with mortality. AKI associated with infections has a better prognosis.