Cardiorespiratory fitness mediates the effects of aging on cerebral blood flow.
The brain's vasculature is likely to be subjected to the same age-related physiological and anatomical changes affecting the rest of the cardiovascular system. Since aerobic fitness is known to alleviate both cognitive and volumetric losses in the brain, it is important to investigate some of the possible mechanisms underlying these beneficial changes. Here we investigated the role that estimated cardiorespiratory fitness (eCRF) plays in determining the relationship between aging and cerebral blood flow (CBF) in a group of older adults (ages 55-85). Using arterial spin labeling to quantify CBF, we found that blood flow in the gray matter was positively correlated with eCRF and negatively correlated with age. Subsequent analyses revealed that eCRF fully mediated the effects of age on CBF in the gray matter, but not in the white matter. Additionally, regional measures of CBF were related to regional measures of brain volume. These findings provide evidence that age-related effects on cerebrovascular health and perfusion in older adults are largely influenced by their eCRF levels.
Neuroscience Program, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Benjamin
B
Zimmerman
Department of Bioengineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Bradley P
BP
Sutton
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Kathy A
KA
Low
Neuroscience Program, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Mark A
MA
Fletcher
Department of Psychology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Chin Hong
CH
Tan
Department of Psychology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Nils
N
Schneider-Garces
Department of Bioengineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Yanfen
Y
Li
Department of Bioengineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Cheng
C
Ouyang
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Edward L
EL
Maclin
Department of Psychology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Gabriele
G
Gratton
Department of Psychology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Monica
M
Fabiani
aging; arterial spin labeling; cardiorespiratory fitness; cerebral blood flow; perfusion; vascular health