TY - JOUR
T1 - Older age and male sex are associated with higher cerebrovascular impedance
AU - Sugawara, Jun
AU - Tarumi Ph.D., Takashi
AU - Xing, Changyang
AU - Liu, Jie
AU - Tomoto, Tsubasa
AU - Pasha, Evan P.
AU - Zhang, Rong
N1 - Funding Information:
This study was supported in part by the National Institutes of Health Grant R01HL102457 (to R. Zhang) and Japan Society for the Promotion of Science Grant 16KK0011 (to J. Sugawara).
Publisher Copyright:
© 2021 the American Physiological Society
PY - 2021/1
Y1 - 2021/1
N2 - Cerebral blood flow (CBF) becomes pulsatile in response to the pulsatile change in perfusion pressure that is regulated by cerebrovascular impedance. In this study, we aimed to characterize age-related differences in cerebrovascular impedance across the adult lifespan. Carotid artery pressure [(CAP), via applanation tonometry] and CBF velocity (CBFV) in the middle cerebral artery (via transcranial Doppler) were measured in 148 healthy adults (21-79 yr, 62% women). Cerebrovascular impedance was quantified using transfer function analysis. Coherence between changes in CBFV and CAP was >0.90 in the frequency range of 0.78-2.73 Hz, suggesting a linear dynamic relationship between these two variables. Impedance modulus at the first harmonics (0.78-1.56 Hz) of CBFV and CAP oscillations (Z1), reflecting mainly heart rate frequency, was 20% higher in the old (>64 yr, P = 0.002) and 13% higher in the middle-aged (45-64 yr, P = 0.08) than in young individuals (<45 yr). In addition, Z1 was 24% higher in men than in women (P < 0.001). Multiple linear regression analysis revealed that Z1 is negatively associated with systolic (b = -0.470), diastolic (b = -0.418), pulsatile (b = -0.374), and mean CBFV (b = -0.473; P < 0.001 for all) after adjustment for age, sex, and body mass index (BMI). These results suggest that older age and male sex are associated with higher cerebrovascular impedance than young individuals, which may contribute to brain hypoperfusion.
AB - Cerebral blood flow (CBF) becomes pulsatile in response to the pulsatile change in perfusion pressure that is regulated by cerebrovascular impedance. In this study, we aimed to characterize age-related differences in cerebrovascular impedance across the adult lifespan. Carotid artery pressure [(CAP), via applanation tonometry] and CBF velocity (CBFV) in the middle cerebral artery (via transcranial Doppler) were measured in 148 healthy adults (21-79 yr, 62% women). Cerebrovascular impedance was quantified using transfer function analysis. Coherence between changes in CBFV and CAP was >0.90 in the frequency range of 0.78-2.73 Hz, suggesting a linear dynamic relationship between these two variables. Impedance modulus at the first harmonics (0.78-1.56 Hz) of CBFV and CAP oscillations (Z1), reflecting mainly heart rate frequency, was 20% higher in the old (>64 yr, P = 0.002) and 13% higher in the middle-aged (45-64 yr, P = 0.08) than in young individuals (<45 yr). In addition, Z1 was 24% higher in men than in women (P < 0.001). Multiple linear regression analysis revealed that Z1 is negatively associated with systolic (b = -0.470), diastolic (b = -0.418), pulsatile (b = -0.374), and mean CBFV (b = -0.473; P < 0.001 for all) after adjustment for age, sex, and body mass index (BMI). These results suggest that older age and male sex are associated with higher cerebrovascular impedance than young individuals, which may contribute to brain hypoperfusion.
KW - Aging
KW - Cerebral blood flow
KW - Fourier analysis
KW - Sex-difference
KW - Transcranial doppler
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U2 - 10.1152/JAPPLPHYSIOL.00396.2020
DO - 10.1152/JAPPLPHYSIOL.00396.2020
M3 - Article
C2 - 33151779
AN - SCOPUS:85100279721
SN - 8750-7587
VL - 130
SP - 172
EP - 181
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 1
ER -