Abstract: Background　Previous studies have showed that the rapid eye movement sleep behavior disorder（RBD） and autonomic dysfunction are associated with the severity of the Parkinson's disease（PD），but there is a lack of studies on whether autonomic dysfunction plays a role in the relationship between RBD and PD severity. Objective　To examine whether autonomic dysfunction plays an intermediary role in the relationship between RBD and PD severity，and whether the role is influenced by age. Methods　A total of 669 PD patients meeting the inclusion criteria were selected from the Parkinson's Progression Markers Initiative database from January to December 2018. General socio-demographics，RBD prevalence（assessed by the REM Sleep Behaviour Disorder Screening Questionnaire），autonomic dysfunction prevalence（assessed by the Scales for Outcomes in Parkinson's Disease-Autonomic questionnaire），and PD severity 〔assessed by the modified Hoehn and Hahr （H-Y） staging〕 were collected. Using the RBD as the independent variable，severity of PD as the dependent variable，the autonomic dysfunction as the intermediate variable，and age as the subgroup variable（less than 56 years，56-65 years and greater than 65 years），a model for investigating the intermediating effect size of autonomic dysfunction between RBD and PD severity was constructed. Results　Those aged above 65 years had a higher mean modified H-Y staging than those aged less than 56 or 56-65 years（P<0.05）. Pearson correlation analysis showed that the severity of PD was positively correlated with RBD and autonomic dysfunction（r=0.200，0.299，P<0.01），and RBD was positively correlated with autonomic dysfunction（r=0.384，P<0.01）. In all participants，autonomic dysfunction partially played an intermediary role between RBD and PD severity，with an effect size of 0.031 with Bootstrap 95%CI（0.022，0.041），accounting for 50.00% （0.031/0.062） of the total effect.For those aged less than 56 years，autonomic dysfunction fully played an intermediary role between RBD and PD severity，with an effect size of 0.034 with Bootstrap 95%CI（0.016，0.056）. For those aged between 56-65 years，autonomic dysfunction partially played an intermediary role between RBD and PD severity，with an effect size of 0.028 with Bootstrap 95%CI（0.014，0.046），accounting for 39.43% （0.028/0.071） of the total effect. For those older than 65 years，autonomic dysfunction fully played an intermediary role between RBD and PD severity，with an effect size of 0.027 with Bootstrap 95%CI（0.012，0.046）. Conclusion　Autonomic dysfunction may produce intermediating effect on the relationship between RBD and PD severity，and the effect size may be impacted by age.

Key words: Parkinson disease, Rapid eye movement sleep behavior disorder, Autonomic dysfunction, Severity of illness, Mediating effect

摘要： 背景　既往研究发现快速眼动睡眠行为障碍（RBD）、自主神经功能障碍与帕金森病（PD）病情严重程度有相关关系，但关于自主神经功能障碍是否影响RBD与PD病情严重程度关系的研究相当缺乏。目的　探讨自主神经功能障碍在RBD与PD病情严重程度间的中介效应，并分析年龄对中介效应的影响。方法　选取2018年1—12月帕金森进展标志物计划（PPMI）数据库中符合纳入标准的PD患者669例为研究对象。分析患者的一般资料、RBD情况〔以快速眼动睡眠行为障碍量表（RBDSQ）进行评价〕、自主神经症状〔以自主神经症状量表（SCOPA-AUT）进行评价〕、PD病情严重程度〔以修订后Hoehn and Hahr（H-Y）分期进行评价〕。以RBD为自变量、PD病情严重程度为因变量，自主神经功能障碍为中介变量，年龄为亚组变量（<56岁、56~65岁、>65岁），构建中介效应模型。结果　<56岁、56~65岁PD病情修订后H-Y分期低于>65岁患者（P<0.05）。Pearson相关分析结果显示，PD患者病情严重程度与RBD、自主神经功能障碍均呈正相关（r值分别为0.200、0.299，P<0.01），RBD与自主神经功能障碍呈正相关（r=0.384，P<0.01）。自主神经功能障碍在RBD与PD病情严重程度之间存在部分中介效应，中介效应值为0.031，Bootstrap法95%CI（0.022，0.041），占总效应比值为50.00%（0.031/0.062）。年龄亚组分析：对于年龄<56岁的PD患者，自主神经功能障碍在RBD与PD病情严重程度之间起完全中介效应，中介效应值为0.034，Bootstrap法95%CI（0.016，0.056）；对于年龄56~65岁的PD患者，自主神经功能障碍在RBD与PD病情严重程度之间起部分中介效应，中介效应值为0.028，Bootstrap法95%CI（0.014，0.046），占总效应比值为39.43%（0.028/0.071）；对于年龄>56岁的PD患者，自主神经功能障碍在RBD与PD病情严重程度之间起完全中介效应，中介效应值为0.027，Bootstrap法95%CI（0.012，0.046）。结论　自主神经功能障碍是RBD影响PD病情严重程度路径上的中介变量，不同的年龄亚组间中介效应机制存在差异。

关键词: 帕金森病, 快速眼动睡眠行为障碍, 自主神经功能障碍, 疾病严重程度, 中介效应