High-density lipoprotein-cholesterol and triglyceride levels and their prognosis in critically ill septic patients

Abstract

BACKGROUND

Lipoproteins, particularly high-density lipoproteins (HDLs), have the ability to bind to lipopolysaccharides, the primary component of the extracellular membrane of gram-negative bacteria, as well as to lipoteichoic acid, an immunostimulant derived from gram-positive bacteria. Triglyceride (TG) levels are also indicators of acute inflammation. Altered levels of both are prevalent in sepsis, rendering them potential biomarkers that are cost-effective and readily applicable in clinical practice for monitoring these patients. It is crucial to compare the levels of these molecules with those of more traditional and costly biomarkers.

AIM

To evaluate the association between HDL and TG levels in the diagnosis of sepsis (HDL/TG day 1), as well as the association between the ratio of HDL and TG levels on days 3 and day 1 (HDL/TG ratio) and 28-day mortality in patients with sepsis. We also compared the serum levels of HDL and TG levels with traditional inflammatory markers used in the prognostic assessment of sepsis: Interleukin (IL)-1β, IL-6, and IL-10, measured serially in patients with sepsis.

METHODS

This was a prospective cohort study. Adult patients (> 18 years of age) admitted to the intensive care unit with sepsis and receiving vasopressors were included. We recorded the epidemiological and clinical characteristics, as well as the severity scores, at the time of sepsis diagnosis and on day 3 of sepsis management. We measured HDL 1, TG 1, IL-1β, IL-6, IL-10, and C-reactive protein (CRP) levels upon the diagnosis of sepsis and on day 3 and calculated the HDL and TG ratios. The main outcome was 28-days mortality.

RESULTS

Seventy-five patients had measurements on day 1 (male:female ratio 58%:42%), and 50 patients had measurements on day 3. Patients who died had lower HDL 1 [9 mg/dL (5-17) vs 18.5 mg/dL (8-31), P = 0.02] but did not have lower TG levels on day 1 [142 mg/dL (83-224) vs 148 mg/dL (97-196), P = 0.97]. Additionally, patients who succumbed exhibited a non-statistically significant increase in the HDL ratio [1.26 (1-1.79) vs 1.16 (1.01-1.39), P = 0.29] and a non-statistically significant increase in the TG ratio [1.16 (0.85-1.36) vs 1.02 (0.67-1.36), P = 0.69]. HDL levels on day 1 were negatively associated with IL-10 on day 1 (Pearson’s r = -0.37; P < 0.01) and with CRP on day 1 (Pearson’s r = -0.52; P < 0.01), but not with IL-6 (P = 0.19) or IL-1β (P = 0.62). TG 1 was positively associated with CRP on day 1 (Pearson’s r = 0.57, P < 0.01) but not with IL-6 (P = 0.21), IL-10 (P = 0.12), or IL-1β (P = 0.09).

CONCLUSION

HDL levels are a promising biomarker for the evaluation of patients with sepsis, and their levels correlate with traditional biomarkers in this field, such as CRP and IL-10. Further multicenter studies with larger cohorts should be conducted to confirm or refute this hypothesis.

Keywords: Sepsis; High-density lipoprotein; Triglycerides; Immunologic response; Sequential organ failure assessment; Interleukins; Mitochondrial metabolism

Core Tip: High-density lipoprotein (HDL) and triglyceride (TG) should be considered inflammatory biomarkers in sepsis, yet they exhibit distinct characteristics in the early response to the condition. TG levels correlate with patient severity upon intensive care unit admission, while lower HDL levels at the time of sepsis diagnosis are slightly linked to higher mortality. However, an early improvement in HDL does not correlate with better outcomes. Nonetheless, both biomarkers are associated with levels of significant inflammatory markers in sepsis, such as interleukin-10 and C-reactive protein.