Blood Lipid Biomarkers in Early Parkinson’s Disease and Parkinson’s Disease with Mild Cognitive Impairment

Background: Lipid biomarkers have potential neuroprotective effects in Parkinson’s disease (PD) and there is limited evidence in the field. Objective: This study aims to investigate the association between comprehensive blood lipid biomarkers and PD. Methods: A total of 205 PD patients and 102 non-PD subjects were included from Early Parkinson’s disease Longitudinal Singapore (PALS) cohort. We investigated 6 serum lipid biomarkers including total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (Apo A1), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (Apo B). PD patients were further classified into mild cognitive impairment (MCI) and normal cognition (NC) subgroups. We conducted a cross-sectionals study to examine the association between lipids and PD and further explored the relationship between lipids and PD-MCI. Results: PD patients had significantly lower level of lipid panel including TC, TG, HDL-C, Apo A1, LDL-C, and Apo B (all p < 0.05). TC, TG, Apo A1, and Apo B levels were independent protective factors (p < 0.05) for PD in the logistic regression model. PD-MCI group had significantly higher mean TC, TG, and Apo A1 levels compared to PD-NC group. Higher TC, TG, and Apo A1 levels were independent risk factors (p < 0.05) for PD-MCI. Conclusion: We demonstrated that PD patients had significantly lower levels of lipid biomarkers while PD-MCI patients had higher levels of TC, TG, and Apo A1. TC, TG, and Apo A1 may be useful biomarkers for PD-MCI.