Scenario 3

Higher levels of social engagement during midlife are associated with a reduced risk of dementia later in life, according to a study presented at AAIC 2023.

“Strong psychosocial health is believed to have a positive impact on cognition, functional independence, and well-being in ageing adults,” said Dr Renée Groechel from the National Institutes of Health in Bethesda, Maryland, US, who presented the study.

“Associations between late-life psychosocial health and dementia risk have been established in older adults, but it remains less clear how one’s social interactions in midlife [(aged 40–60 years)] may relate to dementia risk in late life,” she noted.

Using data from the ARIC* cohort study, the researchers conducted a prospective study involving 13,216 dementia-free participants at midlife (mean age 57 years, 55 percent female) to assess the association between social engagement (defined as a composite score based on levels of social support and isolation) and dementia incidence. Social support and isolation were evaluated via interviewer-administered questionnaires (visit 2: 1990–1992). Participants were categorized according to the level of their social engagement, which was classified as high, intermediate, or low. [AAIC 2023, abstract 1-07-DEV]

At a median follow-up of 23.7 years, 2,555 participants developed dementia.

After adjusting for potential confounders, individuals with a high level of social engagement at midlife had a 25 percent lower risk of developing dementia in late life than those with a low level of social engagement (hazard ratio [HR], 0.75; p≤0.01).

This effect was also observed among those with intermediate social engagement compared to those with low social engagement (HR, 0.83; p≤0.01), although with a slightly smaller effect, yet still significant.

When the analysis was further stratified by sex, female participants who had high and intermediate levels of midlife social engagement achieved a considerably lower risk of dementia than those with low levels of social engagement (HRs, 0.69 and 0.72, respectively; p≤0.01 for both).

“The effects were very similar to those seen in the whole sample, and that protective association was still significant,” Groechel said.

Male participants with a high social engagement had a lower risk of developing dementia by 18 percent compared with those with low social engagement (HR, 0.82; p≤0.05). However, this correlation was not found in males with intermediate social engagement (HR, 0.97).

“Overall, greater social engagement in midlife might be an important protective factor for dementia in late life … This finding provides further evidence that midlife could be a critical time window for dementia intervention,” said Groechel.

Future longitudinal studies are needed to evaluate the mechanisms by which psychosocial health may modify the likelihood of dementia, she added.