Comprehensive measurements of hydroxylinoleate and hydroxyarachidonate isomers in blood samples from primary open-angle glaucoma patients and controls

Abstract

We previously reported that lower systemic antioxidant capacity is involved in primary open-angle glaucoma (POAG) and exfoliation syndrome pathogeneses as measured by ferric-reducing activity. In the present study, we measured hydroxylinoleate (HODE) and hydroxyarachidonate (HETE) isomer serum levels after sample reduction and saponification to investigate POAG pathogenesis. POAG patients (n\u2009=\u2009198) were recruited and divided into normal- and high-tension glaucoma groups (n\u2009=\u200984 and 114, respectively) depending on intraocular pressure. Total HODE (/linoleic acid) and HETE (/arachidonic acid) serum levels were significantly higher in the POAG group (211.9\u2009±\u2009143.0 and 181.0\u2009±\u2009164.1 µmol/mol, respectively) than in controls (167.1\u2009±\u2009105.2 and 132.5\u2009±\u2009139.7 µmol/mol, p\u2009=\u20090.0025 and 0.0101, respectively). The associations between HODEs/HETEs and glaucoma were further confirmed by multivariate analyses after adjusting for differences in demographic parameters. Among the HODE isomers, the levels of 9- and 13-(Z,E)-HODEs (p\u2009=\u20090.0014) and singlet oxygen-specific products (i.e., 10- and 12-(Z,E)-HODEs, p\u2009=\u20090.0345) were higher in the POAG group than in controls, while free radical-mediated oxidation-specific products (i.e., 9- and 13-(E,E)-HODEs, p\u2009=\u20090.0557) demonstrated a marginal difference. Enzymatic and singlet oxygen-mediated fatty acid oxidation may be major pathways of oxidation process in glaucoma subjects.