A Cross-Sectional Study to Correlate Spot Urine Sodium-Potassium Ratio with Renal Function Tests in Cirrhosis Patients
DOI:
https://doi.org/10.61336/jdme.0703.01Keywords:
Liver Cirrhosis,, Renal Insufficiency, , Sodium, Potassium, Urine, CreatinineAbstract
Introduction: Renal dysfunction is a major determinant of outcome in decompensated cirrhosis, but serum creatinine may incompletely reflect kidney function in this population. The spot urinary sodium-to-potassium ratio is an inexpensive index of renal sodium handling. This study examined its association with renal dysfunction in adults with decompensated cirrhosis. Materials and Methods: This hospital-based cross-sectional study included 91 adults with decompensated cirrhosis. Spot urine sodium and potassium and serum creatinine, urea and sodium were measured within 24 hours of admission. Renal function was categorized by serum creatinine as normal (<1.2 mg/dL), mild dysfunction (1.2-1.9 mg/dL), or moderate dysfunction (2.0-2.9 mg/dL). Pearson and Spearman correlations, Kruskal-Wallis testing with Holm-adjusted pairwise comparisons and multivariable linear regression with heteroscedasticity-robust standard errors were used. Results: The mean age was 58.2±8.4 years and 61 participants (67.0%) were men. The mean urinary sodium-to-potassium ratio was 3.23±0.91. It correlated inversely with serum creatinine (Pearson r = -0.776; Spearman ρ = -0.815; both p<0.001) and serum urea (Pearson r = -0.607; p<0.001). Mean ratios decreased progressively from 4.27 in normal renal function to 3.50 in mild and 2.66 in moderate dysfunction (Kruskal-Wallis H = 33.99; p<0.001). All pairwise comparisons remained significant after Holm correction. In adjusted analysis, each 1 mg/dL higher serum creatinine was associated with a 1.18-unit lower ratio (β = -1.175; 95% confidence interval, -1.439 to -0.912; p<0.001). Conclusion: A lower spot urinary sodium-to-potassium ratio was strongly and independently associated with greater renal dysfunction in decompensated cirrhosis. It may serve as a practical adjunct for cross-sectional renal assessment, but longitudinal studies are required before it can be used to predict acute kidney injury or clinical outcomes.
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