MATTERS OF THE HEART AND MIND: CARDIOVASCULAR AND PSYCHOSOCIAL RISK FACTORS FOR COGNITIVE IMPAIRMENT AND DEMENTIA AMONG OLDER ADULTS IN THE U.S.

Cognitive function decline has been associated with cardiovascular and
psychosocial factors. The resulting cognitive impairment and dementia (CID), including
Alzheimer’s disease and other related dementia, impose a significant burden among older
adults (aged 65 or older) which is expected to increase by 55% or more. CID affected
20% of older adults in the US, and the risk of CID doubles every five years after age 65.
This study examined the impact of heart diseases or stroke, depressive symptoms in
middle-age, and loneliness on the risk of CID among older adults in the US. We
conducted a longitudinal study using the Health and Retirement Study (HRS) data from
1998–2020. HRS participants aged 50 years or older with information regarding heart
disease or stroke, depression, and loneliness were included in the study. There were over
12,000 participants in study 1 and study 2, while study 3 included 8,569 participants.
Fine-Gray competing risk analysis was used to assess the associations.
We found that the occurrence and timing of heart disease or stroke were
significantly associated with CID. Additionally, most of the participants were female
(58%) with a median age of 59 years at baseline and an average follow-up of nearly 15
years. There was a 21% increased risk CID among those with heart disease and the effect
was more evident among older females with a 28% increased risk. The occurrence of
stroke was associated with twice increased risk of CID, and this pattern persisted for both
males and females. We found in the study of depression and CID that depressive
symptoms in middle-age (especially impairment in executive functions) were associated
with a 47% increased risk of CID in later life. Furthermore, specific individual depressive
symptoms such as “felt depressed”, “everything is an effort”, and “could not get going”
were significantly associated with the risk of CID. In our study of loneliness and CID,
we found that loneliness (especially social isolation) was also significantly associated
with a 40% increased risk of CID. The impact of loneliness was significant among both
males (52% increased risk of CID), and females (34% increased risk of CID), and more
significant among White participants who had 38% increased risk of CID compared to
other racial/ethnic groups. However, social connectedness was not strongly associated
with the risk of CID.
Our findings suggest that interventions should target different cardiovascular and
psychosocial factors to prevent or reduce the risk of CID.