Social isolation links to amyloid pathology and lower cognition

In a cross-sectional study of 957 non-demented adults from the Chinese Alzheimer's Biomarker and LifestyLE study, researchers examined how social isolation relates to cognition and Alzheimer's disease biomarkers. Participants had a mean age of 64.19 years, and 46% were male. After adjusting for age, gender, education, and APOE ε4 status, social isolation was significantly associated with lower MMSE (β = -0.09) and MoCA scores (β = -0.11). Social isolation was also linked to decreased cerebrospinal fluid Aβ42 and Aβ40 levels. Specifically, smaller social networks correlated with poorer cognition and decreased Aβ42 and Aβ40. Being without a spouse was associated with decreased Aβ42 and Aβ40 alongside increased P-tau/Aβ42 and T-tau/Aβ42 ratios. Subgroup analyses showed that these associations were primarily observed in males and APOE ε4 non-carriers.