Elevated atherogenic index of plasma is associated with severe acute kidney injury in critically ill patients with cardiovascular disease - a MIMIC-IV analysis with external validation in the eICU-CRD database.
Elevated atherogenic index of plasma is associated with increased risk of severe acute kidney injury and renal replacement therapy in critically ill patients, but further prospective studies are needed to confirm these findings.
Where it sits
this study against the rest of the lypressin corpusSummary and findings
This study measured the association between the atherogenic index of plasma (AIP) and severe acute kidney injury (AKI) in critically ill patients with cardiovascular disease. The analysis included 5,872 patients from the MIMIC-IV database and an external validation in the eICU-CRD database. The study found that elevated AIP was associated with increased incidence of stage 3 AKI and renal replacement therapy (RRT).
Abstract
The atherogenic index of plasma (AIP) is a lipid-based marker of cardiovascular risk, yet its prognostic value for severe acute kidney injury (AKI) in critically ill patients with cardiovascular disease (CVD) remains uncertain. This retrospective study analyzed 5,872 patients from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, with external validation in the eICU Collaborative Research Database (eICU-CRD). The primary outcome was stage 3 AKI, and secondary outcomes included renal replacement therapy (RRT) and length of stay. Stage 3 AKI was observed in 20.7% of patients, with the incidence increasing across AIP quartiles (Q1-Q4: 15.9-26.8%), and 5.3% of patients requiring RRT (Q1-Q4: 2.6-10.9%). High AIP was associated with stage 3 AKI (adjusted OR = 1.35; 95% CI: 1.11-1.64), RRT (OR = 1.95; 95% CI: 1.33-2.87), longer hospital LOS (β = 3.58; <i>p</i> < 0.001) and ICU LOS (β = 1.14; <i>p</i> < 0.001). Restricted cubic splines revealed linear associations between AIP and both renal outcomes (stage 3 AKI and RRT). Mediation analysis indicated that stage 3 AKI mediated 12.6% of the association between the AIP and in-hospital mortality. The predictive models achieved AUCs of 0.916 for RRT and 0.727 for stage 3 AKI. These associations with renal outcomes were robust, as confirmed by entropy balancing and external validation in the eICU-CRD. Elevated AIP is a robust, externally validated predictor of stage 3 AKI and RRT, with substantial predictive accuracy for RRT. Furthermore, it appears to influence in-hospital mortality partially through renal injury, warranting confirmation in future prospective studies.
Background
The study investigates the prognostic value of the atherogenic index of plasma (AIP) as a marker for severe acute kidney injury (AKI) in critically ill patients with cardiovascular disease (CVD). Previous research has established AIP as a lipid-based marker of cardiovascular risk, but its specific relationship with AKI outcomes remains unclear. This study aims to clarify this association and its potential implications for patient management.
Methods
This retrospective analysis utilized data from 5,872 patients in the MIMIC-IV database, with external validation from the eICU Collaborative Research Database (eICU-CRD). The primary outcome was stage 3 AKI, while secondary outcomes included renal replacement therapy (RRT) and length of hospital stay. The study employed logistic regression to assess the association between AIP and outcomes, adjusting for confounding variables.
Results
The primary finding indicated that stage 3 AKI occurred in 20.7% of patients, with a significant increase in incidence across AIP quartiles (Q1: 15.9%, Q2: 18.9%, Q3: 23.5%, Q4: 26.8%). The adjusted odds ratio for high AIP predicting stage 3 AKI was 1.35 (95% CI: 1.11-1.64), and for RRT, it was 1.95 (95% CI: 1.33-2.87). Additionally, AIP was associated with longer lengths of stay in both the hospital (β = 3.58, p < 0.001) and ICU (β = 1.14, p < 0.001).
Interpretation
These findings suggest that elevated AIP is statistically significantly associated with increased risk of stage 3 AKI and RRT in critically ill patients. However, while the odds ratios indicate a relationship, the clinical significance of these findings may be limited by the small effect sizes and the retrospective nature of the study. Potential confounding factors inherent in observational studies may also affect the robustness of these conclusions.
Key findings
- 20.7% of patients experienced stage 3 AKI, with incidence increasing across AIP quartiles (Q1-Q4: 15.9-26.8%)
- 5.3% of patients required RRT, with incidence across AIP quartiles (Q1-Q4: 2.6-10.9%)
- Adjusted OR for high AIP associated with stage 3 AKI was 1.35 (95% CI: 1.11-1.64)
- Adjusted OR for high AIP associated with RRT was 1.95 (95% CI: 1.33-2.87)
- Predictive model for RRT achieved AUC of 0.916
- Predictive model for stage 3 AKI achieved AUC of 0.727
Limitations
- Retrospective study design
- Observational data may introduce confounding factors
- External validation required for confirmation
- Single-site analysis may limit generalizability
- Short follow-up period for assessing long-term outcomes