HealthDay News — Social isolation seems to be an independent risk factor for dementia, according to a study published online June 8 in Neurology.
Chun Shen, Ph.D., from Fudan University in Shanghai, and colleagues examined the independent associations of social isolation and loneliness with incident dementia using the U.K. Biobank cohort. Voxel-wise brain-wide association analyses were used to identify gray matter volumes (GMV) associated with social isolation and loneliness.
Data were included for 462,619 participants; 4,998 developed all-cause dementia during a mean follow-up of 11.7 years. The researchers observed a 1.26-fold increased risk of dementia (95 percent confidence interval, 1.15 to 1.37) in association with social isolation, which was independent of various risk factors, including loneliness and depression. The fully adjusted hazard ratio for dementia associated with loneliness was 1.04 (95 percent confidence interval, 0.94 to 1.16); 75 percent of this relationship was attributed to depressive symptoms. Lower GMVs were seen in temporal, frontal, and other (e.g., hippocampal) regions in socially isolated individuals based on structural magnetic resonance imaging data obtained from 32,263 participants. The identified GMVs partly mediated the association between social isolation at baseline and cognitive function at follow-up.
“People who reported high levels of social isolation had significant differences in brain volume, also associated with cognition and dementia,” a coauthor said in a statement. “Given the findings of this study, social isolation may be an early indicator of an increased risk of dementia.”
One author consults for Cambridge Cognition.