Resting Brain Perfusion and Selected Vascular Risk Factors in Healthy Elderly Subjects

• Published in: PloS one Vol. 9; no. 5; p. e97363
• Main Authors: Henriksen, Otto M., Jensen, Lars T., Krabbe, Katja, Guldberg, Per, Teerlink, Tom, Rostrup, Egill
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 19.05.2014; Public Library of Science (PLoS)
• Subjects: Aged; Aging; Alzheimer's disease; Alzheimers disease; Arginine - analogs & derivatives; Arginine - blood; Arteriosclerosis; Atherosclerosis; Biology and Life Sciences; Brain; Brain - drug effects; Brain - physiology; Brain mapping; Caffeine; Caffeine - adverse effects; Carotid arteries; Cerebrovascular Circulation - drug effects; Cerebrovascular Circulation - physiology; Dementia; Development and progression; Dyslipidemia; Ethics; Experiments; Female; Geriatrics; Health risks; Hematocrit; Hematocrit - adverse effects; Homocysteine; Homocysteine - physiology; Hormone replacement therapy; Hospitals; Humans; Hypotheses; Influence; Magnetic resonance; Male; Medical research; Medicine and Health Sciences; Metabolism; Middle Aged; Multiple regression models; Nervous system diseases; NMR; Nuclear magnetic resonance; Nuclear medicine; Older people; Perfusion; Phase contrast; Physiology; Regression models; Risk analysis; Risk Factors; Spin labeling; Stroke; Studies; Variability; Veins & arteries; Denmark; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0097363

Both cerebral hypoperfusion and vascular risk factors have been implicated in early aging of the brain and the development of neurodegenerative disease. However, the current knowledge of the importance of cardiovascular health on resting brain perfusion is limited. The aim of the present study was to elucidate the relation between brain perfusion variability and risk factors of endothelial dysfunction and atherosclerosis in healthy aged subjects. Thirty-eight healthy subjects aged 50-75 years old were included. Mean global brain perfusion was measured using magnetic resonance phase contrast mapping and regional brain perfusion by use of arterial spin labeling. Mean global brain perfusion was inversely correlated with caffeine and hematocrit, and positively with end-tidal PCO2. Furthermore, the mean global brain perfusion was inversely correlated with circulating homocysteine, but not with asymmetric dimethylarginine, dyslipidemia or the carotid intima-media thickness. The relative regional brain perfusion was associated with circulating homocysteine, with a relative parietal hypoperfusion and a frontal hyperperfusion. No effect on regional brain perfusion was observed for any of the other risk factors. A multiple regression model including homocysteine, caffeine, hematocrit and end-tidal PCO2, explained nearly half of the observed variability. Both intrinsic and extrinsic factors influenced global cerebral perfusion variation between subjects. Further, the results suggest that the inverse relation between homocysteine and brain perfusion is owing to other mechanisms, than reflected by asymmetric dimethylarginine, and that homocysteine may be a marker of cerebral perfusion in aging brains.