Peripheral lipid oxidative stress markers are related to vascular risk factors and subcortical small vessel disease

Subcortical white matter hyperintensities (WMH), presumed to indicate small vessel ischemic vascular disease, are found commonly in elderly individuals with and without Alzheimer's disease (AD). Oxidative stress may instigate or accelerate the development of vascular disease, and oxidative stress markers are elevated in AD. Here, we assess independent relationships between three serum lipid peroxidation markers (lipid hydroperoxides [LPH], 8-isoprostane, and 4-hydroxynonenal) and the presence of extensive subcortical WMH and/or AD. Patients were recruited from memory and stroke prevention clinics into four groups: minimal WMH, extensive WMH, AD with minimal WMH, and AD with extensive WMH. Extensive WMH, but not AD, was associated with higher serum concentrations of 8-isoprostane and LPH. Peripheral LPH concentrations mediated the effect of hypertension on deep, but not periventricular, WMH volumes. 4-hydroxynonenal was associated with hyperlipidemia and cerebral microbleeds, but not with extensive WMH or AD. We conclude that lipid peroxidation mediates hypertensive injury to the deep subcortical white matter and that peripheral blood lipid peroxidation markers indicate subcortical small vessel disease regardless of an AD diagnosis.