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 (VO(2)max), 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 (cm(3)) and automated assessment of BPF (%) by the use of SIENAX. A maximal exercise stress test was done on a bicycle ergometer. VO(2)max was calculated based on maximum and resting heart rate. RESULTS: After adjustment for possible confounders, VO(2)max was independently associated with WML volume (β = -0.10; p = 0.02); no significant relationship existed with silent cerebral infarcts and BPF. Associations between VO(2)max 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.