老年人偏颇体质在久坐行为与认知衰弱间的中介效应研究

背景　久坐与老年人轻度认知功能损害和衰弱有关，但其关联机制尚不明确，而中医体质学说可为此提供新的理论来源。目的　探讨老年人偏颇体质在久坐行为与认知衰弱间的中介效应。方法　采用分层整群抽样法，于2019年12月从济南市随机选取6个社区、10个行政村的1 130例老年人为调查对象。采用一般资料调查表、国际体力活动问卷（IPAQ）短卷（评估久坐行为）、中医体质量表（CCMQ）（测定中医体质类型）、简易精神状态量表（MMSE）（评估认知功能）、中文版Tilburg衰弱量表（评估衰弱状况）进行问卷调查。若研究对象同时存在认知功能障碍和衰弱症状则将其判定为认知衰弱。采用多因素Logistic回归分析探究久坐行为、偏颇体质与认知衰弱的关联。结果　本研究共发放问卷1 130份，回收有效问卷1 091份，有效回收率为96.55%。1 091例老年人中有久坐行为358例（32.8%），无久坐行为733例（67.2%）；平和质448例（41.1%），偏颇体质643例（58.9%）；认知衰弱89例（8.2%），非认知衰弱1 002例（91.8%）。不同年龄、婚姻状况、受教育程度、至少患1种慢性病情况、久坐行为、中医体质类型老年人认知衰弱患病率比较，差异有统计学意义（P<0.05）。多因素Logistic回归分析结果显示，久坐行为〔是：OR=1.914，95%CI（1.193，3.072）〕和中医体质类型〔偏颇体质：OR=6.501，95%CI（3.035，13.923）〕是老年人发生认知衰弱的影响因素（P<0.05）；久坐行为〔是：OR=1.463，95%CI（1.111，1.927）〕是老年人中医体质类型的影响因素（P<0.05）。中介作用分析结果显示，老年人偏颇体质在久坐行为与认知衰弱间存在中介效应（Z=2.323，P<0.05），中介效应占总效应的11.22%。结论　久坐行为不仅能够直接影响老年人认知衰弱的发生情况，还可能通过偏颇体质间接对其产生作用，今后应进一步凸显“辨体、调体”在认知衰弱预防与干预中的地位。

Mediating Effect of Abnormal TCM-based Constitution on the Association between Sedentary Behavior and Cognitive Frailty in Elderly People

Background　Sedentary behavior is associated with mild cognitive impairment and frailty in elderly people，but the mechanism of association is still unclear.TCM-based constitution theory may provide a new theoretical source for this.Objective　To investigate the mediating effect of abnormal TCM-based constitution on the association between sedentary behavior and cognitive frailty among elderly people.Methods　In December 2019，by use of random stratified sampling，six communities and 10 administrative villages in Jinan City，China were selected，from which a cluster sample of eligible 1 130 elderly individuals were enrolled，and were invited to attend a questionnaire survey using the General Demographic Questionnaire，the International Physical Activity Questionnaire-Short Form （used to assess sedentary behavior），Constitution in Chinese Medicine Questionnaire（used to assess TCM-based constitution），Mini-mental State Examination（used to assess cognitive function） and the Chinese version of Tilburg Frailty Indicator（used to assess frailty）.Cognitive frailty was defined as the presence of both cognitive impairment and frailty.Multivariate Logistic regression analysis was performed to investigate the association of sedentary behavior and abnormal TCM-based constitution with cognitive frailty.Results　In all，1 091 cases（96.55%） who returned responsive questionnaires were included for final analysis.Among the respondents，358（32.8%）had sedentary behavior and other 733（ 67.2%）did not；448 （41.1%） had balanced TCM-based constitution while 643 （58.9%） had abnormal；89（8.2%）were found with cognitive frailty and other 1 002（91.8%） without.The prevalence of cognitive frailty was varied according to age，marital status，education level，and prevalence of at least one chronic disease，sedentary behavior，and TCM-based constitution（P<0.05）.Multivariate Logistic regression analysis showed that sedentary behavior〔OR=1.914，95%CI（1.193，3.072）〕and abnormal TCM-based constitution 〔OR=6.501，95%CI（3.035，13.923）〕were associated with the onset of cognitive frailty （P<0.05）.Sedentary behavior was associated with TCM-based constitution 〔OR=1.463，95%CI（1.111，1.927）〕（P<0.05）.Mediation analysis found that there was mediating effect of abnormal TCM-based constitution on the association between sedentary behavior and cognitive frailty（Z=2.323，P<0.05），accounting for 11.22% of the total effect.Conclusion　Sedentary behavior may not only directly affect cognitive frailty，but also indirectly impact it through abnormal TCM-based constitution.In view of this，we should further highlight the role of differentiation and regulation of TCM-based constitution in the prevention and intervention of cognitive frailty.