Association of Cardiorespiratory Fitness and Morphological Brain Changes in the Elderly: Results of the Austrian Stroke Prevention Study

Background: Physical activity and cardiorespiratory fitness relate to better cognitive performance. Little is known about the effects of fitness on structural brain abnormalities in the elderly. Objective: Assess the association between maximal oxygen consumption (VO2max), white matter lesion (WML) volume and brain parenchymal fraction (BPF) in a large cohort of community-dwelling elderly individuals. Methods: The study population consisted of 715 participants of the Austrian Stroke Prevention Study who underwent brain MRI with semi-automated measurement of WML volume (cm3) and automated assessment of BPF (%) by the use of SIENAX. A maximal exercise stress test was done on a bicycle ergometer. VO2max was calculated based on maximum and resting heart rate. Results: After adjustment for possible confounders, VO2max was independently associated with WML volume (β = –0.10; p = 0.02); no significant relationship existed with silent cerebral infarcts and BPF. Associations between VO2max and WML load were only significant in men, but not in women. Conclusion: Our findings may have important preventive implications because WMLs are known to be a major determinant of cognitive decline and disability in old age.