Increased plasma levels of phospholipid in Parkinson's disease with mild cognitive impairment

This study aimed to observe the clinical characteristics and changes in plasma phospholipid (PL) concentrations in Parkinson's disease patients with mild cognitive impairment (PD-MCI), and to investigate the association between these changes and cognitive function to provide a basis for early diagnosis and intervention for PD-MCI patients. Oxidative stress plays an important role in the development and progression of Parkinson's disease (PD). PL, important components in cellular membranes, are critical for the maintenance of cell integrity and function. Lipid peroxidation products are significantly increased in the brains of PD patients. In the present study, plasma PL levels were significantly increased in PD-MCI patients or in PD patients with no cognitive impairment (PD-NCI) compared with controls (p < 0.01 and p < 0.05, respectively). PL levels were significantly increased in the PD-MCI group compared with PD-NCI patients (p < 0.01). There was a negative correlation between plasma PL levels and Montreal cognitive assessment scores (r = −0.542; p < 0.001). These findings support the relationship between mild cognitive impairment and membrane injury. The measurement of PL reflects membrane injury in vivo and may be a new useful biomarker for the prognosis of cognitive states in patients with PD.