Sibling status and dementia risk in later life

This study examines the associations between sibling status and dementia risk among older adults, with further investigation of gender differences.

Data were drawn from the Health and Retirement Study (2000-2018), with an analytic sample of 17,474 respondents aged 50 and older at baseline. Sibling status was measured by the existence of living siblings, the number of living siblings, and the death of siblings. Both the respondent's gender and the gender composition of siblings were considered. Discrete-time hazard regression models were estimated.

Having living siblings in later life was associated with lower odds of dementia onset, with a stronger effect observed among women than men. Experiencing the loss of two or more siblings was associated with higher odds of dementia onset. However, neither the number of living siblings nor the gender composition of siblings showed a significant association with dementia onset.

This study highlights the importance of siblingship, an important yet underexplored social connection in later life, in relation to cognitive health.