The relationship between marital and parental status and the risk of dementia

This study examines the association between marital and parental status and their individual and combined effect on risk of dementia diseases in a population-based longitudinal study while controlling for a range of potential confounders, including social networks and exposure to stressful negative life events.

A total of 1,609 participants without dementia, aged 65 years and over, were followed for an average period of 8.6 years (SD = 4.8). During follow-up, 354 participants were diagnosed with dementia. Cox regression was used to investigate the effect of marital and parental status on risk of dementia.

In univariate Cox regression models (adjusted for age as time scale), widowed (hazard ratio (HR) 1.42, 95% confidence interval (CI) = 1.13-1.78), and not having children (HR 1.54, 95% CI = 1.15-2.06) were significantly associated with incident dementia. In multivariate analyses that included simultaneously marital and parental status and covariates that were found to be significant in univariate models (p < 0.10), the HR was 1.30 (95% CI = 1.01-1.66) for widowed, and 1.51 (95% CI = 1.08-2.10) for those not having children. Finally, a group of four combined factors was constructed: married parents (reference), married without children, widowed parents, and widowed without children. The combined effect revealed a 1.3 times higher risk (95% CI = 1.03-1.76) of dementia in widow parents, and a 2.2 times higher risk (95% CI = 1.36-3.60) in widowed persons without children, in relation to married parents. No significant difference was observed for those being married and without children.

Our findings suggest that marital- and parental status are important risk factors for developing dementia, with especially increased risk in those being both widowed and without children.