Background and Objectives: Acute kidney injury (AKI) is a frequent and life-threatening complication in patients with liver cirrhosis (LC). Nephrotic-range proteinuria may reflect underlying structural renal vulnerability; however, its association with AKI severity in cirrhosis remains unclear. Materials and Methods: We conducted a retrospective cohort study of 408 adults with LC admitted to a tertiary referral hospital between January 2016 and December 2025. Nephrotic-range proteinuria was defined as a urine protein-to-creatinine ratio (UPCR) ≥3.5 g/g measured within 7 days before or at admission. AKI was staged using serum creatinine-based Kidney Disease: Improving Global Outcomes criteria. Baseline creatinine was defined as the lowest value within 7 days before admission; if unavailable, the lowest stable value within the preceding 3 months was used. Severe AKI was defined as KDIGO stage 2–3. Multivariable logistic regression was performed to evaluate the association between nephrotic-range proteinuria and severe AKI after adjustment for age, sex, diabetes mellitus, hypertension, chronic kidney disease (CKD), sepsis, ICU admission, and Child–Pugh class. Results: Of the 408 patients, 56 (13.7%) had nephrotic-range proteinuria. Severe AKI occurred more frequently in patients with nephrotic-range proteinuria than in those without (39.3% vs. 21.9%), corresponding to an absolute risk difference of 17.4 percentage points (p = 0.008). In the adjusted model, nephrotic-range proteinuria was associated with a higher likelihood of severe AKI (adjusted odds ratio OR, 2.27; 95% confidence interval CI, 1.17–4.41; p = 0.015). CKD (adjusted OR, 2.26; 95% CI, 1.33–3.81; p = 0.002), ICU admission (adjusted OR, 2.03; 95% CI, 1.22–3.39; p = 0.007), and Child–Pugh class C versus A (adjusted OR, 3.50; 95% CI, 1.37–8.93; p = 0.009) were also significantly associated with severe AKI. Conclusions: Among hospitalized patients with LC, nephrotic-range proteinuria was associated with a higher likelihood of severe AKI. Quantitative proteinuria assessment may help identify patients at increased risk of advanced renal dysfunction, although causal inference is limited by the retrospective observational design.
Kim et al. (Tue,) studied this question.