TY - JOUR
T1 - Brain energy metabolism and blood flow differences in healthy aging
AU - Aanerud, Joel
AU - Borghammer, Per
AU - Mallar Chakravarty, M.
AU - Vang, Kim
AU - Rodell, Anders B.
AU - Jónsdottir, Kristjana Y.
AU - Møller, Arne
AU - Ashkanian, Mahmoud
AU - Vafaee, Manouchehr S.
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 - Aging
KW - energy metabolism
KW - neurovascular coupling
KW - positron emission tomography
UR - http://www.scopus.com/inward/record.url?scp=84863470066&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84863470066&partnerID=8YFLogxK
U2 - 10.1038/jcbfm.2012.18
DO - 10.1038/jcbfm.2012.18
M3 - Review article
C2 - 22373642
AN - SCOPUS:84863470066
SN - 0271-678X
VL - 32
SP - 1177
EP - 1187
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 7
ER -