Impaired antioxidative activity of high-density lipoprotein is associated with more severe acute ischemic stroke

Abstract

Background/aims: High-density lipoprotein (HDL) has important anti-atherogenic functions, including antioxidant effects. However, it is unclear whether the antioxidative activity of HDL is associated with the severity and outcome of acute ischemic stroke. We aimed to evaluate this association.

Methods: We prospectively studied 199 consecutive patients admitted with acute ischemic stroke and followed them up until discharge. We measured HDL antioxidant capacity, HDL-associated paraoxonase-1 (PON1) activity and HDL-associated myeloperoxidase (MPO) levels. Severe stroke was defined as National Institutes of Health Stroke Scale (NIHSS) at admission ≥5. Dependency was defined as modified Rankin scale at discharge between 2 and 5.

Results: Patients with severe stroke had lower HDL antioxidant capacity, higher MPO levels and higher MPO/PON1 ratio. Independent risk factors for severe stroke were female gender (RR 2.80, 95% CI 1.37-5.70, p = 0.005), glucose levels (RR 1.01, 95% CI 1.0-1.02, p < 0.01) and HDL antioxidant capacity (RR 1.03, 95% CI 1.01-1.06, p < 0.05). Patients who were dependent at discharge had lower HDL antioxidant capacity, higher MPO levels and higher MPO/PON1 ratio. Independent predictors of dependency at discharge were lack of lipid-lowering treatment (RR 6.86, 95% CI 1.83-25.67, p < 0.005) and NIHSS (RR 1.56, 95% CI 1.29-1.88, p < 0.0001). The HDL antioxidant capacity did not differ between patients who died during hospitalization and those who were discharged. The only independent predictor of in-hospital mortality was NIHSS (RR 1.16, 95% CI 1.06-1.27, p < 0.005).

Conclusions: Impaired antioxidative activity of HDL is associated with more severe acute ischemic stroke and might also predict a worse functional outcome in these patients.

Keywords: Antioxidative activity; High-density lipoprotein; Ischemic stroke; Outcome; Severity.