Inverse relationship between serum haptoglobin and acute kidney injury in critically Ill patients with sepsis: A retrospective cohort study of the MIMIC-IV 3.0 database.

BACKGROUND

Previous studies have indicated that perioperative serum haptoglobin levels are associated with the risk of Acute Kidney Injury (AKI). However, the relationship between haptoglobin and AKI in sepsis patients remains unclear. This study aimed to investigate the association between serum haptoglobin levels and AKI in critically ill sepsis patients.

METHODS

The authors conducted a retrospective cohort study using data extracted from the Medical Information Mart for the Intensive Care (MIMIC) IV database version 3.0. Multivariable logistic regression analysis was used to control for potential confounders. Curve fitting was performed to assess the linearity of the association, and subgroup analyses were conducted to validate the robustness of the findings.

RESULTS

This study included 1324 participants (mean age 64.7 ± 17.6 years; 53.8 % male). The fully adjusted model showed an inverse association between serum haptoglobin levels and AKI. Each 10 mg/dL increase in haptoglobin decreased AKI odds by 1.4 % (OR = 0.986, 95 % CI 0.973‒0.999, p = 0.037). Patients in the highest haptoglobin group had 34.5 % lower AKI risk versus the lowest group (OR = 0.655, 95 % CI 0.439‒0.976, p = 0.038). The linear relationship (p for non-linearity = 0.152) remained robust in subgroup analyses.

CONCLUSION

The present findings suggest that elevated serum haptoglobin levels may serve as a protective factor against AKI in critically ill sepsis patients. Nevertheless, prospective, randomized, controlled studies are required to confirm the findings presented in this investigation.