Association between serum high-density lipoprotein cholesterol concentration and mortality in critically ill patients: A retrospective cohort study

Author(s): Xu Guo, Zhiyu Xu, Hengxing Qu, Ryan Charles Woods, Eunice Njobvu, Zhongyi Zhou, Xiaohong Xie, Jia Tian

Objective: This research aims to explore the association between serum High-Density Lipoprotein Cholesterol (HDL-C) and mortality in critically ill patients.

Design: This was a retrospective cohort study.

Setting: Data were extracted from an online database named ‘Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC III)’.

Patients and participants: 3384 patients were enrolled, including 967 septic patients and 1380 patients with Acute Kidney Injury (AKI).

Interventions: None.

Main variables of interest: Hospital and ICU mortality, ICU Length of Stay (LOS) and hospital LOS.

Results: Serum HDL-C (42.4 ± 18.0 vs. 45.0 ± 15.2, p<0.001) concentration was significantly lower for non-survivors than survivors. A nonlinear relationship between HDL-C and mortality was found. Low HDL-C was associated with increased hospital and ICU mortality, longer ICU LOS and hospital LOS compared with medium HDL-C level (30-60 mg/dL) for all included patients (p<0.01, all). Multivariate logistic regression models showed only low HDL-C (<30 mg/dL) were associated with increased hospital mortality in all three models (model 1 OR: 1.44, 95% CI 1.05 to 1.97, p=0.022; model 2 OR: 1.51, 95% CI 1.01 to 2.27, p=0.044; model 3 OR: 1.69, 95% CI 1.15 to 2.49, p=0.007). In all models, age, mechanical ventilation use, Sequential Organ Failure Assessment (SOFA) score and Elixhauser comorbidity score were positively associated with mortality.

Conclusion: Low HDL-C is associated with increased mortality in patients who are critically ill.