Relationship between lipoprotein concentrations and short-term and 1-year mortality in intensive care unit septic patients: results from the HIGHSEPS study.

BACKGROUND

High-density lipoproteins (HDLs), particles characterized by their reverse cholesterol transport function, display pleiotropic properties, including anti-inflammatory and antioxidant functions. Moreover, all lipoproteins (HDLs but also low-density lipoproteins (LDLs)) neutralize lipopolysaccharides, leading to increased bacterial clearance. These two lipoproteins decrease during sepsis, and an association between low lipoprotein levels and poor outcome was reported. The goals of this study were to characterize the lipid profile of septic patients hospitalized in our intensive care unit (ICU) and to determine the relationship with the outcome.

METHODS

A prospective observational study was conducted in a university hospital ICU. All consecutive patients admitted for septic shock or sepsis were included. Total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride levels were assessed at admission (day 1), at day 3, and at ICU discharge. When available, a prehospitalization lipid profile collected prior to the patient's hospitalization was compiled. Short-term and 1-year prognostic outcomes were prospectively assessed.

RESULTS

A total of 205 patients were included. We found a decrease in HDL-C concentration between previous values and those at admission, followed by an additional decrease at day 3. At ICU discharge, the concentration was higher than that at day 3 but did not reach the concentration measured prior to hospitalization (prior HDL-C = 1.22 (1.04-1.57) mmol/l; day 1 HDL-C = 0.44 (0.29-0.70) mmol/l; day 3 HDL-C = 0.30 (0.25-0.48) mmol/l; and HDL-C at discharge = 0.65 (0.42-0.82) mmol/l). A similar trend was found for LDL-C (prior LDL-C = 2.7 (1.91-3.33) mmol/l; day 1 LDL-C = 1.0 (0.58-1.50) mmol/l; day 3 LDL-C = 1.04 (0.64-1.54) mmol/l; and LDL-C at discharge = 1.69 (1.26-2.21) mmol/l). Mixed models for repeated measures of lipoprotein concentrations showed a significant difference in HDL-C and LDL-C concentrations over time between survivors and nonsurvivors at day 28. An HDL-C concentration at admission of less than 0.4 mmol/l was associated with increased mortality at day 28 (log-rank test, p = 0.034) but not at 1 year (log-rank test, p = 0.24). An LDL-C concentration at admission of less than 0.72 mmol/l was associated with increased mortality at day 28 and at 1 year (log-rank test, p < 0.001 and p = 0.007, respectively). No link was found between prior lipid profile and mortality.

CONCLUSIONS

We showed no relationship between the prehospitalization lipid profile and patient outcome, but low lipoprotein levels in the ICU were strongly associated with short-term mortality.