Clinical correlates of decreased plasma coenzyme Q10 levels in patients with multiple system atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative disease. Recent studies revealed decreased coenzyme Q10 (COQ10) levels in the cerebellum and blood samples of MSA patients. But few studies focused on the associations of COQ10 with the clinical symptoms of MSA. In this study, we aimed to quantify plasma COQ10 and characterize its association with clinical features.

We recruited 40 patients with MSA, 30 patients with Parkinson's disease (PD), and 30 healthy participants. Plasma COQ10 was quantified by UPLC-MS. The basic demographic data, motor symptoms, and non-motor symptoms were also assessed.

Plasma COQ10 levels were significantly different in MSA, PD, and controls (P = 0.001). Post-hoc analysis revealed plasma COQ10 levels in MSA patients were lower than that in controls after adjusting for age, gender, and total cholesterol (P = 0.001). COQ10 levels differentiated MSA patients from controls with modest accuracy (P = 0.001). A sensitivity of 40% and a specificity of 97.5% was calculated with the receiver operating characteristic curve. However, COQ 10 levels did not discriminate between the MSA and PD groups (P = 0.07). Plasma COQ10 levels were correlated with the severity of motor symptoms only in MSA-C patients (b = -0.025, P = 0.009).

The association between decreased COQ10 levels and the severity of motor symptoms in MSA-C patients promotes further research. Plasma COQ10 levels alone may not be a reliable MSA diagnostic biomarker, and cannot be considered a useful biomarker in the differential diagnosis of MSA vs PD.