ABSTRACT
Objective:To investigate the relationship between rapid eye movement sleep behavior disorder(RBD)and neurofilament light chain(NfL)levels in patients with Parkinson's disease(PD).Methods:General clinical data of 121 PD patients and 38 healthy controls(HC)who visited the Department of Geriatric Neurology of the First Affiliated Hospital of Kunming Medical University from June 2019 to January 2021 were collected in a prospective study.According to the Rapid Eye Movement Sleep Behavior Disorder Questionnaire(RBDSQ), PD patients were divided into a PD with RBD group(PD-RBD, RBDSQ≥6)and a PD without RBD group(PD-NRBD, RBDSQ<6). General clinical data and plasma NfL levels of patients in the groups were compared.In addition, symptoms during exercise, during non-exercise, and sleep quality in the groups were also compared.Results:Plasma NfL levels were higher in the PD group than in the HC group(19.39 ng/L, 12.58-31.78; 14.85 ng/L, 9.78-22.15; Z=-2.492, P<0.05); plasma NfL levels were significantly higher in the PD-RBD group than in the PD-NRBD group and in the HC group(25.29 ng/L, 19.09-34.75; 17.14 ng/L, 11.70-26.67; 14.85 ng/L, 9.78-22.15; Z=-3.434, P<0.01); there was no significant difference in plasma NfL levels between the HC group and the PD-NRBD group( P>0.05). Receiver operating characteristic(ROC)curve analysis showed that, when the plasma NfL cutoff was set at 17.86 ng/L, PD-RBD and PD-NRBD could be distinguished( AUC=0.70, 95% CI=0.60-0.80, sensitivity 82%, specificity 54%). Binary logistic regression identified NfL level as an independent predictor of PD-RBD( β=0.068, OR=1.103, P=0.003). Conclusions:PD-RBD patients have increased plasma NfL levels, which can potentially serve as a biomarker for PD with RBD.