Increase in the Oxidized/Total Coenzyme Q-10 Ratio in the Cerebrospinal Fluid of Alzheimer’s Disease Patients

Background/Aim: The contribution of mitochondrial dysfunction and oxidative stress to the pathogenesis of Alzheimer’s disease (AD) has previously been described. We aimed to investigate whether the balance between the oxidized and reduced forms of coenzyme Q-10 (CoQ-10) is related to the pathogenesis of AD. Materials and Method: Thirty patients with AD (69.0 ± 4.1 years) and 30 healthy control subjects (63.8 ± 16.4 years) were enrolled in this study. Concentrations of oxidized CoQ-10 and reduced CoQ-10 were measured by high-performance liquid chromatography using an electrochemical detector. Results: The percentage of oxidized/total CoQ-10 in the cerebrospinal fluid (%CoQ-10, CSF) was significantly higher in the untreated AD group (78.2 ± 18.8%) than in the control group (41.3 ± 10.4%, p < 0.001), and there was a significant negative correlation between %CoQ-10 and the duration of the illness (r s = –0.93, p < 0.001). Conclusion: These findings in living AD patients suggest a possible role for %CoQ-10 in the pathogenesis of the early stage of AD development.