Multidomain interventions based on a life-course model to prevent dementia in at-risk Chinese older adults: A randomized controlled trial

BACKGROUND

Due to the time-dependent effect of specific risk factors for dementia, multidomain interventions based on a life-course model might achieve optimal preventive effects against dementia.

OBJECTIVE

The purpose of this study was to investigate the effectiveness of multidomain interventions based on a life-course model of modifiable risk factors for dementia in at-risk Chinese older adults.

DESIGN

This was a two-arm, proof-of-concept, randomized controlled trial.

SETTING AND PARTICIPANTS

We randomly assigned 96 community-dwelling at-risk adults aged 60 years or older in a 1:1 ratio to either the 6-month multidomain intervention group (dementia literacy, physical activity, cognitive training, social activity and optional modules) or the control group (health education).

METHODS

The primary outcomes were the dementia risk score and cognitive composite Z score. The secondary outcomes included the individual components of the dementia risk score (protective and risk factors) and cognitive composite Z score (global cognition, memory, executive function and language), social isolation (loneliness, social contact, and social participation), dementia literacy and prevention belief. Linear mixed models with maximum likelihood estimation were used to calculate the outcomes between the groups over time.

RESULTS

The primary analyses showed that the dementia risk score was significantly lower (p < 0.001) and that the cognitive composite Z score was significantly higher (p = 0.013) in the multidomain intervention group than in the control group. Baseline characteristics did not modify the effects of the multidomain interventions (p value for interaction > 0.05). For secondary outcomes, statistically significant group × time interactions were observed for the protective (p = 0.001) and risk factors (p = 0.049), as well as in executive function (p = 0.020), loneliness (p = 0.029), dementia literacy (p < 0.001) and prevention belief (p < 0.001).

CONCLUSIONS

Multidomain interventions based on a life-course model are feasible and have the potential to reduce dementia risk and improve cognitive function in at-risk Chinese older adults.

REGISTRATION

The trial was registered at the Chinese Clinical Trials Registry (ChiCTR2100053417).

Childhood Friendship Experiences and Cognitive Functioning in Later Life: The Mediating Roles of Adult Social Disconnectedness and Adult Loneliness

BACKGROUND AND OBJECTIVES

This study investigated the relationship between childhood friendships and cognitive functioning, as assessed with cognitive status and decline among adults aged 45 and older in China. We also examined the mediating effect of adult social disconnectedness and adult loneliness for this relationship.

RESEARCH DESIGN AND METHODS

This study was based on 3 waves of data from the China Health and Retirement Longitudinal Study (CHARLS; 2011, 2013, 2015; N = 13,959). Cognitive functioning was assessed with episodic memory. Childhood friendship measures were taken from the 2014 life history module of the CHARLS. Two dimensions of adult social isolation, loneliness and social disconnectedness, were included as mediators. Latent growth curve modeling was utilized to test the associations between childhood friendships, adult social isolation, and cognitive functioning.

RESULTS

Adverse childhood friendship experiences were found to be significantly associated with both lower initial cognitive status and the rate of decline in cognitive functioning. Our findings indicated that adult loneliness and social disconnectedness partly mediated the link between childhood friendship experiences and the initial level of cognitive functioning, but not cognitive decline later in life.

DISCUSSION AND IMPLICATIONS

The findings emphasized the enduring importance of childhood friendships for cognitive functioning later in life. Interventions that focus on improving social participation through fostering friendships in childhood may have long-term benefits for cognition later in life.