Aging
Widowhood, Immunosenescence, and Mortality in Older American: Evidence from the Health and Retirement Study Youngjoon Bae* Youngjoon Bae Yuan Zhang Jaydon Jun Yu Chin Grace A. Noppert Rebecca Stebbins Daniel W. Belsky Allison E. Aiello
Widowhood is linked to an increased risk of mortality, particularly among men. Studies examining biomarkers related to the loss of a loved one have identified changes in the immune system as a potential mechanism behind this risk. However, most research has focused on general indicators of inflammation. Another immune pathway related to the stress of widowhood is immunosenescence, which refers to the gradual decline of the immune system associated with aging.
We analyzed data derived from flow cytometry analysis of blood samples from 8,136 US adults aged 50 and older, participants in the Health and Retirement Study (HRS). We first explored the associations between widowhood and measures of immunosenescence through linear regression models. Specifically, Immunosenescence was assessed using three log-transformed T-cell aging markers, including the CD4+:CD8+ T-cell ratio, EMRA CD4+: Naïve CD4+ Ratio, and EMRA CD8+: Naïve CD8+ Ratio. Next, we examined whether widowhood was linked to increased mortality rates by employing Cox proportional hazard models, taking immunosenescence into account. In both analyses, we adjusted for age, race, ethnicity, education, depression, and recent spousal loss (<= 5 years).
We observed that widowhood was associated with significantly higher levels of T-cell aging markers in men but not women, in fully adjusted models (see Figure 1 for details). The survival analysis results indicated that elevated levels of T-cell aging markers were risk factors for mortality in both men and women—however, the small impact of these T-cell markers on the relationship between widowhood and mortality was found only in men. These findings suggest that widowers have a more aged immune profile than married men, and the relationship between widowhood and mortality among men may be partially explained by immunosenescence. Men may be at greater risk for poor health outcomes and mortality upon widowhood suggesting the need for early intervention and prevention.
