Influence of social networks on Alzheimer's disease biomarkers and subjective cognitive decline among elders without dementia: A CABLE study: Prevention (nonpharmacological) / Lifestyle factors (e.g., smoking, etc.).

Background: The social networks has been recommended as a moderator of incident Alzheimer's disease (AD) and aggravated cognitive deficits. Still few data are available about the effect of social networks on cerebrospinal fluid (CSF) AD biomarkers. Method: Participants without dementia were recruited from the Chinese Alzheimer's disease Biomarker and Lifestyle (CABLE) study. Multiple‐adjusted analyses were performed to explore the association of social networks with CSF biomarkers, pre‐AD stage and subjective cognitive decline (SCD). Result: Total eight hundred and twenty‐two individuals without dementia were included in current study. Moderate to high social network scores were significantly associated with CSF low levels of β‐amyloid (Aβ)40 (moderate, β=‐0.198; close, β=‐0.127), Aβ42/Aβ40 (moderate, β=0.227; close, β=0.184) and phosphorylated tau (p‐tau)/Aβ42 (moderate, β=‐0.106; close, β=‐0.1). In addition, moderate and high scores associated with low p‐tau (β=‐0.076) and total‐tau(t‐tau)/Aβ42 (β=‐0.111) respectively. Mostly significant associations of social network scores with biomarkers persisted in advanced age group, males and SCD group after stratified analyses. Moderate to high social network scores decreased risk for A+ (moderate:odds ratio (OR)=0.519, 95% confidence intervals (CI)=0.302‐0.890; high: OR=0.516, 95%CI=0.305‐0.874), A+T+ (moderate: OR=0.208, 95% CI=0.089‐0.488; high: OR=0.228, 95%CI=0.098‐0.528) and A+T+N+ (moderate: OR=0.144, 95% CI=0.055‐0.378; high: OR=0.141, 95%CI=0.054‐0.370)). In addition, close social ties and high social network scores decreased the risk of SCD (p < 0.05). There were no significant associations of moderate social ties and social network scores with SCD (p > 0.05). Conclusion: Social networks weaken the deleterious effect of AD neurodegenerative biomarkers. Furthermore, favorable influences of social networks on early neurobiological alterations of preclinical stage of AD and self‐reported SCD were suggested. [ABSTRACT FROM AUTHOR]