Outcomes of AKI Hospitalization among Patients with Protein-Calorie Malnutrition: A Nationwide Analysis

Background: AKI can lead to malnutrition due to reduced appetite, dietary restrictions and increased protein breakdown. Pre-existing malnutrition can also exacerbate AKI by impairing the body's ability to recover from kidney injury. Our objective is to examine outcomes among patients presenting with both AKI and protein-calorie malnutrition (PCM). Methods: We accessed the National Inpatient Sample from 2017-2020 to identify adult patients with PCM hospitalized due to AKI. The primary outcome was inpatient mortality. The secondary outcomes included cardiac arrest, gastrointestinal bleeding (GIB), intubation, length of stay (LOS), and total hospital charges. We utilized multivariable logistic regression analysis to estimate clinical outcomes, considering a significance threshold of P < 0.05. Results: We identified 19,300,000 hospitalizations with AKI, among which 1,687,445 (8.7%) presented with PCM. Patients with AKI and PCM exhibited higher rates of PVD and anemia, but lower occurrences of obesity, AFIB, DM, PVD, HF, dyslipidemia, CKD and HTN. Clinical outcomes revealed stark differences between PCM and Non-PCM cohorts: in-hospital mortality rates were 13% vs 7.3 % (OR 1.67, CI 1.6-1.7); cardiac arrest rates were not significantly different, GIB rates were 12.2% vs 5.8% (OR 2.1, CI 2.09-2.16), need for intensive care was 13.3% vs 7.8% (OR 1.55, CI 1.52-1.58); LOS was 12.2 days vs 6.9 days (IRR 1.71, CI 1.69-1.172); and hospital charges were $36,910 vs $20,164 (IRR 1.76, CI 1.72-1.78). All data demonstrated a p-value < 0.001 and were adjusted for various factors including age, sex, race, obesity, atrial fibrillation, diabetes mellitus, hypertension, peripheral vascular disease, acute kidney injury, chronic kidney disease, alcohol use, stroke, and inflation during 2017-2020. Conclusion: Despite having lower rates of comorbidities, the PCM group showed significantly worse clinical outcomes, including substantially higher mortality rates, adverse events (GIB), prolonged hospital stays, and increased resource utilization. Clinicians should consider PCM as a negative predictor when managing patients with AKI. Improved patient safety and outcome can be achieved by optimizing inpatient nutrition.