Midlife Work-Related Stress is Associated with Late-Life Gray Matter Volume Atrophy

Abstract

Background: Work-related stress has been associated with an increased dementia risk. However, less is known about the mechanisms that underlie these associations. Objective: The goal is to examine associations between midlife work-related stress and late-life structural brain alterations. Methods: The Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) study participants were randomly selected from independent population-based surveys (mean age 50) in Finland. MRI measurements included gray matter (GM) volume, white matter lesions (WML) and medial temporal atrophy (MTA) (1st re-examination, n = 102); and GM volume, hippocampal volume, WML volume, cortical thickness, and MTA (2nd re-examination, n = 64). Work-related stress comprised a score from two questions administered in midlife. Results: Higher levels of midlife work-related stress were associated with lower GM volume (β =-0.077, p = 0.033) at the first re-examination, even after adjusting for several confounders. No significant associations were found with MTA, WML, or MRI measurements at the second re-examination. Conclusion: Previously shown associations of midlife work-related stress with dementia risk may be at least partly explained by associations with lower GM volume in late-life. The lack of associations at the second re-examination may indicate a critical time window for the effects of midlife work-related stress, and/or selective survival/participation.