Sex Differences in the Influence of Brain and Lifestyle Factors on Neurocognitive Aging

Declines in executive functioning (EF) are a hallmark of neurocognitive aging. Much research has focused on the impact of exercise, brain structure, and brain function on neurocognitive aging, yet their relative predictive weights had not been evaluated. Further, the impact of sex differences on the influence of these factors had not yet been investigated. Fifty-one older adults participated in this study evaluating the outcome of cardiorespiratory fitness (CRF), prefrontal cortex volume, and global efficiency of functional brain networks on EF. A stratified, multiple hierarchical regression was performed to identify the best predictors of EF for each sex. For females, a model containing solely CRF served as the best predictor of EF. A model containing both CRF and network efficiency best predicted EF in males. These results demonstrate that CRF and metrics of structural and functional brain health in older adulthood are independently associated with EF in a sex-dependent manner.