Increased high‑density lipoprotein‑oxidant index in ischemic stroke patients.

High-density lipoprotein (HDL) is known to have atheroprotective properties which could become dysfunctional under certain disease conditions, particularly during the atherosclerotic progression. The present study sought to assess HDL functionality in acute ischemic stroke (AIS) patients in comparison with controls and the functional alteration among the ischemic stroke subtypes. The HDL functionality was evaluated in 71 statin-naïve, adult patients of South Indian descent, admitted with AIS and were compared with that of 25 age- and sex-matched healthy volunteers. Functional assay of HDL was based on its antioxidant ability to inhibit low-density lipoproteins (LDL) oxidation by air using a dichlorodihydrofluorescein-based fluorescent assay and expressed as HDL oxidant index (HOI). The HOI was higher in ischemic stroke patients as compared with controls (1.07±0.32 vs. 0.51±0.12; P<0.001) indicating high oxidative stress and dysfunctionality in HDL. Regarding the stroke subtypes, HOI was >1 in all stroke subtypes: 1.05±0.301 for Cardioembolic subtype, 1.15±0.41 for large vessel disease, and 1.01±0.25 for small vessel disease when compared with controls. However, no significant difference was noted in HOI values among the three stroke subtypes in the post hoc analysis. It was found that HDL in all ischemic stroke subtypes had less antioxidant capacity, indicating dysfunctional HDL. Functional alteration occurred in HDL of patients even in the presence of normal HDL-cholesterol levels suggesting that dysfunctionality in HDL is unrelated to cholesterol content.