Background The mortality rate of sepsis-associated acute kidney injury (S-AKI) is high, yet there is a lack of authoritative prognostic criteria for its outcome. The lactate-to-albumin ratio (LAR) has been associated with mortality in conditions such as sepsis, heart failure, and respiratory failure. However, there is limited research on the relationship between LAR and S-AKI. This study aimed to investigate the association between LAR and the mortality rate of S-AKI. Methods In our study, we performed a retrospective cohort analysis using the Medical Information Mart for Intensive Care (MIMIC)-IV database. Our primary focus was on determining the occurrence of 30-day, 60-day, and in-hospital mortality as the primary outcomes. To validate the association between LAR and these outcomes, we employed multivariable logistic Cox regression models to calculate hazard ratios. Results This study included a total of 4793 participants, with a mean age of 63.3 years and a median LAR (log2) of -0.90. After accounting for confounding variables, it was found that patients in the highest LAR (log2) quartile had a higher risk of mortality compared to those in the lowest LAR (log2) quartile. The adjusted hazard ratios for mortality were 1.44 (95% confidence interval [CI]: 1.36~1.53), 1.38 (95% CI: 1.32~1.46), and 1.47 (95% CI: 1.39~1.56) for the highest LAR (log2) quartile, respectively. Moreover, the adjusted hazard ratios for mortality at 30-day, 90-day, and in-hospital intervals were 1.28 (95% CI: 1.23~1.33), 1.26 (95% CI: 1.21~1.31), and 1.27 (95% CI: 1.22~1.32) for each 1 unit increase in LAR, respectively. Conclusion This study indicates that in septic AKI patients, a higher LAR is associated with an increased risk of all-cause mortality within 30-day, 90-day and in-hospital mortality. This suggests that LAR may serve as an independent risk factor for adverse outcomes in septic AKI patients. Keywords Septic AKI, Lactate-to-albumin ratio, MIMIC IV

The authors have declared no competing interest.

ID: 52390976

This study did not receive any funding

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The datasets generated and analyzed during the current study are available in the Medical Information Mart for Intensive Care IV (https://mimic.physionet. org/).

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