Summary: Social isolation is directly related to structural changes in brain areas related to memory and cognitive functions. Researchers report that socially isolated people are 26% more likely to develop dementia later in life.
Source: University of Warwick
Social isolation is directly linked to changes in memory-related brain structures, making it a clear risk factor for dementia, scientists have found.
Researchers from the University of Warwick, the University of Cambridge and Fudan University used neuroimaging data from more than 30,000 participants in the UK Biobank dataset to study how social isolation and loneliness are linked to later dementia. Socially isolated individuals have been found to have lower levels of gray matter in brain regions involved in memory and learning.
The results of the study are published online in Neurology.
Based on data from the UK Biobank, an extremely large longitudinal cohort, the researchers used modeling techniques to study the relative associations of social exclusion and loneliness with accidental dementia for all reasons.
After adjusting for various risk factors (including socioeconomic factors, chronic diseases, lifestyle, depression and APOE genotype), socially isolated individuals have a 26% increased chance of developing dementia.
Loneliness is also associated with later dementia, but this relationship is not significant after correcting depression, which explains 75% of the relationship between loneliness and dementia. Therefore, in relation to the subjective feeling of loneliness, objective social isolation is an independent risk factor for later dementia. Additional analysis of the subgroups showed that the effect was noticeable in those over 60 years.
The data show that the socially isolated are 26% more likely to develop dementia later
Professor Edmund Rawls, a neurologist in the Department of Computer Science at the University of Warwick, said: “There is a difference between social isolation, which is an objective state of low social ties, and loneliness, which is subjectively perceived social isolation.
“Both pose health risks, but using the vast set of multimodal datasets from the UK Biobank and working in a multidisciplinary way linking computing and neuroscience, we have been able to show that this is social isolation, not just a sense of , which is an independent risk factor for later dementia. This means that it can be used as a predictor or biomarker for dementia in the UK.
“With the growing prevalence of social exclusion and loneliness in recent decades, this is a serious but underestimated public health problem. Now, in the shadow of the COVID-19 pandemic, there are implications for interventions and care in social relationships – especially among the elderly.
Professor Jianfeng Feng from the Department of Computer Science at the University of Warwick said: “We emphasize the importance of an environmentally friendly method to reduce the risk of dementia in the elderly, ensuring that they are not socially isolated. It is important that people, especially the elderly, do not experience social exclusion during any future pandemic blockade. “
Professor Barbara J. Sahakyan of the University of Cambridge’s Department of Psychiatry said: “Now that we know the risk to brain health and social dementia from social exclusion, it is important for government and communities to take action to ensure that older people communicate and engage with others. . “
For this news study on social isolation and dementia
Author: Sheila Kiggins Source: University of Warwick Contact: Sheila Kiggins – University of Warwick Image: Image is in the public domain
Original research: Closed access. Associations of Social Isolation and Loneliness with Later Dementia by Edmund Rawls et al. Neurology
abstractly
Associations of social isolation and loneliness with later dementia
See also
Objective
To investigate independent associations of social isolation and loneliness with incidental dementia and to investigate potential neurobiological mechanisms.
Methods
We used the UK Biobank cohort to identify Cox’s proportional hazard models with social isolation and loneliness as separate exposures. Demographic (gender, age and ethnicity), socio-economic (education level, household income and Townsend deprivation index), biological (BMI, APOE genotype, diabetes, cancer, cardiovascular disease and other disabilities), cognitive (processing speed and visual memory), behavioral (current smoker, alcohol and physical activity) and psychological (social isolation or loneliness, depressive symptoms and neuroticism) factors measured at baseline were adjusted. Voxel analyzes of the whole brain association were then used to identify gray matter volumes (GMV) associated with social isolation and loneliness. Partial least squares regression was performed to test the spatial correlation of differences in GMV and gene expression using the Allen Human Brain Atlas.
Results
We included 462,619 participants (mean age at baseline 57.0 years [SD 8.1]). At a median follow-up of 11.7 years (SD 1.7), 4998 developed dementia for all reasons. Social isolation is associated with a 1.26-fold increased risk of dementia (95% CI, 1.15-1.37) regardless of various risk factors, including loneliness and depression (ie full adaptation). However, the fully adjusted risk of loneliness-related dementia was 1.04 (95% CI, 0.94-1.16); and 75% of this relationship is due to depressive symptoms. Structural MRI data were obtained from 32,263 participants (mean age 63.5 years) [SD 7.5]). Socially isolated individuals had lower GMVs in the temporal, anterior, and other (e.g., hippocampal) regions. The analysis of mediation showed that the identified GMVs partially mediate the relationship between social isolation at baseline and cognitive function in follow-up. Socially isolated lower GMVs are associated with underexpression of genes that are down-regulated in Alzheimer’s disease and with genes involved in mitochondrial dysfunction and oxidative phosphorylation.
Conclusion
Social isolation is a risk factor for dementia, which is independent of loneliness and many other covariates. Social isolation-related brain structural differences combined with different molecular functions also support the associations of social isolation with cognition and dementia. Therefore, social exclusion may be an early indicator of an increased risk of dementia.
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