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

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.