TY - JOUR

T1 - Brain energy metabolism and blood flow differences in healthy aging

AU - Aanerud, Joel

AU - Borghammer, Per

AU - Chakravarty, M Mallar

AU - Vang, Kim

AU - Rodell, Anders

AU - Jónsdottir, Kristjana Y

AU - Møller, Peter Arne

AU - Ashkanian, Mahmoud

AU - Seyedi Vafaee, Manouchehr

AU - Iversen, Peter

AU - Johannsen, Peter

AU - Gjedde, Albert

PY - 2012/7

Y1 - 2012/7

N2 - Cerebral metabolic rate of oxygen consumption (CMRO(2)), cerebral blood flow (CBF), and oxygen extraction fraction (OEF) are important indices of healthy aging of the brain. Although a frequent topic of study, changes of CBF and CMRO(2) during normal aging are still controversial, as some authors find decreases of both CBF and CMRO(2) but increased OEF, while others find no change, and yet other find divergent changes. In this reanalysis of previously published results from positron emission tomography of healthy volunteers, we determined CMRO(2) and CBF in 66 healthy volunteers aged 21 to 81 years. The magnitudes of CMRO(2) and CBF declined in large parts of the cerebral cortex, including association areas, but the primary motor and sensory areas were relatively spared. We found significant increases of OEF in frontal and parietal cortices, excluding primary motor and somatosensory regions, and in the temporal cortex. Because of the inverse relation between OEF and capillary oxygen tension, increased OEF can compromise oxygen delivery to neurons, with possible perturbation of energy turnover. The results establish a possible mechanism of progression from healthy to unhealthy brain aging, as the regions most affected by age are the areas that are most vulnerable to neurodegeneration.

AB - Cerebral metabolic rate of oxygen consumption (CMRO(2)), cerebral blood flow (CBF), and oxygen extraction fraction (OEF) are important indices of healthy aging of the brain. Although a frequent topic of study, changes of CBF and CMRO(2) during normal aging are still controversial, as some authors find decreases of both CBF and CMRO(2) but increased OEF, while others find no change, and yet other find divergent changes. In this reanalysis of previously published results from positron emission tomography of healthy volunteers, we determined CMRO(2) and CBF in 66 healthy volunteers aged 21 to 81 years. The magnitudes of CMRO(2) and CBF declined in large parts of the cerebral cortex, including association areas, but the primary motor and sensory areas were relatively spared. We found significant increases of OEF in frontal and parietal cortices, excluding primary motor and somatosensory regions, and in the temporal cortex. Because of the inverse relation between OEF and capillary oxygen tension, increased OEF can compromise oxygen delivery to neurons, with possible perturbation of energy turnover. The results establish a possible mechanism of progression from healthy to unhealthy brain aging, as the regions most affected by age are the areas that are most vulnerable to neurodegeneration.

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Aging

KW - Brain

KW - Cerebrovascular Circulation

KW - Energy Metabolism

KW - Female

KW - Humans

KW - Image Interpretation, Computer-Assisted

KW - Magnetic Resonance Imaging

KW - Male

KW - Middle Aged

KW - Oxygen Consumption

KW - Positron-Emission Tomography

KW - Retrospective Studies

KW - Young Adult

U2 - 10.1038/jcbfm.2012.18

DO - 10.1038/jcbfm.2012.18

M3 - Journal article

C2 - 22373642

VL - 32

SP - 1177

EP - 1187

JO - Journal of Cerebral Blood Flow and Metabolism

JF - Journal of Cerebral Blood Flow and Metabolism

SN - 0271-678X

IS - 7

ER -