| Autor: |
Sugawara J; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas.; University of Texas Southwestern Medical Center, Dallas, Texas.; Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan., Tarumi T; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas.; University of Texas Southwestern Medical Center, Dallas, Texas.; Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan., Xing C; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas.; University of Texas Southwestern Medical Center, Dallas, Texas.; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, People's Republic of China., Liu J; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas.; University of Texas Southwestern Medical Center, Dallas, Texas., Tomoto T; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas.; University of Texas Southwestern Medical Center, Dallas, Texas., Pasha EP; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas.; University of Texas Southwestern Medical Center, Dallas, Texas., Zhang R; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas.; University of Texas Southwestern Medical Center, Dallas, Texas. |
| Abstrakt: |
Older adults have higher cerebrovascular impedance than young individuals which may contribute to chronic brain hypoperfusion. Besides, middle-aged athletes exhibit lower cerebrovascular impedance than their sedentary peers. We examined whether aerobic exercise training (AET) reduces cerebrovascular impedance in sedentary older adults. We conducted a proof-of-concept trial that randomized 73 older adults to 1 yr of AET ( n = 36) or stretching and toning (SAT, n = 37) interventions. Cerebrovascular impedance was estimated from simultaneous recordings of carotid artery pressure (CAP) via applanation tonometry and cerebral blood flow velocity (CBFV) in the middle cerebral artery via transcranial Doppler using transfer function analysis. Fifty-six participants completed 1-yr interventions, and 41 of those completed cerebrovascular impedance measurements. AET group showed a significant increase in V̇o 2peak after the intervention [estimated marginal mean (95% confidence interval); from 22.8 (21.6 to 24.1) to 24.9 (23.6 to 26.2) mL·kg -1 ·cm -1 , P < 0.001], but not SAT [from 21.7 (20.5 to 22.9) to 22.3 (21.1 to 23.7) mL·kg -1 ·cm -1 , P = 0.114]. Coherence between changes in CBFV and CAP was >0.90 in the frequency range of 0.78-3.12 Hz. The averaged cerebrovascular impedance modulus ( Z ) in this frequency range decreased after 1-yr AET [from 1.05 (0.96 to 1.14) to 0.95 (0.92 to 1.06) mmHg·s·cm -1 , P = 0.023], but not SAT [from 0.96 (0.87 to 1.04) to 1.01 (0.92 to 1.10) mmHg·s·cm -1 , P = 0.138]. Reductions in Z were correlated positively with reductions in carotid pulse pressure ( r = 0.628, P = 0.004) and inversely with mean CBFV ( r = -0.563, P = 0.012) in the AET group. One-year AET reduces cerebrovascular impedance in older adults, which may benefit brain perfusion. NEW & NOTEWORTHY Estimation of cerebrovascular impedance is essential for understanding dynamic cerebral blood flow regulation. This randomized controlled trial demonstrated that aerobic exercise training reduced cerebrovascular impedance in older adults, which may benefit brain perfusion. |
