中老年人群肺功能与认知障碍的关联及抑郁症状和日常活动能力在二者中的中介作用OA

Objective To investigate the association between lung function and the risk of cognitive impair-ment in middle-aged and older adults,and to assess the mediating effects of depressive symptoms and activities of daily living(ADL).Methods Data were drawn from the 2011 China Health and Retirement Longitudinal Study(CHARLS),comprising a sample size of 9 859 participants.Participants were classified into a cognitive impairment group and a non-cognitive impairment group.Simultaneously,participants were divided into four groups according to the quartiles of peak expiratory flow as a percentage of the predicted value(PEF%pred):Q1(PEF%pred≤58.21%),Q2(58.21%<PEF%pred≤78.51%),Q3(78.51%<PEF%pred≤96.48%),and Q4(PEF%pred>96.48%).Baseline characteristics were compared between the cognitive im-pairment and non-cognitive impairment groups,while cognitive status was compared across the PEF%pred quartile groups.Multivariate Logistic regression models were used to examine the association of PEF%pred(as a continuous variable and as quartiles)with the risk of cognitive impairment.Subgroup and interaction an-alyses were further performed to evaluate this relationship in predefined subgroups.Restricted cubic spline(RCS)analysis was employed to explore a potential nonlinear dose-response relationship between PEF%pred and the risk of cognitive impairment.The mediating effects of depressive symptoms and ADL were assessed u-sing the bootstrap method.Results A total of 1 476 participants were assigned to the cognitive impairment group and 8 383 to the non-cognitive impairment group.PEF%pred was significantly lower in the cognitive impairment group than that in the non-cognitive impairment group(P<0.05).In each of the Q1,Q2,and Q3 groups,2 465 participants were enrolled,and 2 464 were enrolled in the Q4 group.The scores of episodic mem-ory,mental status and total cognitive function were significantly lower in the Q1 group than those in the Q2,Q3,and Q4 groups,whereas the incidence of cognitive impairment was significantly higher in the Q1 group than that in the other three groups(all P<0.05).Higher PEF%pred was associated with a reduced risk of cognitive impairment(OR=0.992,95%CI:0.990-0.995,P<0.001).Compared with the Q1 group,the risk of cognitive impairment was reduced by 17.8%in the Q2 group(OR=0.822,95%CI:0.696-0.972,P=0.022),by 30.5%in the Q3 group(OR=0.695,95%CI:0.582-0.831,P<0.001),and by 43.3%in the Q4 group(OR=0.567,95%CI:0.471-0.683,P<0.001).In RCS analysis,a linear association was observed be-tween PEF%pred and the risk of cognitive impairment(Ptotal<0.001),and no nonlinear association was de-tected(Pnon-linearity=0.893).Subgroup analyses showed that the association between PEF%pred and the risk of cognitive impairment remained statistically significant in subgroups stratified by age,sex,residence,retire-ment status,smoking history,alcohol consumption,education level,solid fuel use for cooking or heating,chro-nic lung disease and heart disease(all P<0.05).Significant interactions were observed between PEF%pred and age,residence,alcohol consumption,solid fuel use for cooking or heating,and BMI(all P<0.05).The re-lationship between lung function and cognitive function was significantly mediated by ADL(β=0.034,95%CI:0.023-0.046)and depressive symptoms(β=0.039,95%CI:0.026-0.053),with mediation propor-tions of 6.182%and 7.091%respectively.This relationship was also serially mediated by ADL and depressive symptoms(β=0.016,95%CI:0.012-0.021),accounting for 2.909%of the total effect.Conclusion A high-er PEF%pred is associated with a progressively lower risk of cognitive impairment in middle-aged and older adults.This association exhibits population heterogeneity and is more pronounced among individuals who are middle-aged,reside in urban areas,have no unhealthy lifestyle habits,and have a higher BMI.Maintaining opti-mal lung function may help delay cognitive decline,partially mediated by preserving independence in activities of daily living and alleviating depressive symptoms.