Amy Nguyen

While it is observed that females tend to live longer than males, they are at higher risk for many age-related diseases. These disparities may be due to differences in biological, genetic, or lifestyle factors between men and women, but it remains unclear how they contribute to faster biological aging across sexes. In this study, we explore why men and women may experience different aging trajectories by investigating sex differences in biological aging in the Mayo Clinic Study of Aging and examining the extent to which presence of cardiovascular risk factors may be a potential mechanism driving these differences. 

A subsample of 1,668 individuals from the Mayo Clinic Study of Aging (MCSA) was included in this study. Participants were on average 69.9 years old and 53.3% male. Biological aging in this study is measured by the Dunedin Pace of Aging Calculated from Neuroimaging (DunedinPACNI), a previously trained elastic net regression model that estimates an individual's pace of aging from a single MRI brain scan. 

Findings from the primary linear regression model showed that males, on average, had slightly higher PACNI scores than females, indicating faster biological brain aging. A significant age-by-sex interaction further suggested that these differences became more pronounced with increasing age, with male participants experiencing accelerated biological aging compared to females of the same chronological age. In the fully adjusted model, hypertension and diabetes were independently associated with faster biological aging; however, cardiovascular risk factors did not fully account for the observed sex differences in PACNI scores. Overall, these findings highlight the importance of considering men and women separately when studying aging processes. They also suggest that while cardiovascular risk factors appear to explain only part of the observed sex differences in biological aging, they remain important correlates of accelerated biological aging.