Premium
The Effect of Aging on Carotid Artery Wall Dynamics During Acute Maximal Resistance Exercise
Author(s) -
Sherman Sara,
Lefferts Elizabeth,
Lefferts Wesley,
Lima Natalia,
Grigoriadis Georgios,
Fernhall Bo,
Baynard Tracy,
Rosenberg Alexander
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2021.35.s1.04652
Subject(s) - medicine , cardiology , arterial stiffness , photoplethysmogram , blood pressure , heart rate , diastole , common carotid artery , hemodynamics , vascular resistance , carotid arteries , filter (signal processing) , computer science , computer vision
A hypertensive stimulus, such as maximal resistance exercise (RE), places a large stress on the cardiovascular system, evidenced by large increases in pressure and arterial stiffness. Aging also increases central arterial stiffness and therefore results in a greater pressure response to a maximal bout of RE compared to younger adults. Two‐dimensional strain imaging of large arteries, such as the common carotid artery (CCA), provides insight into the elastic properties of the arterial wall that play an integral role in maintaining normal function during a physiologic stress. To date, it is unknown if CCA artery stiffness and strain during an acute bout of maximal RE differ in older adults (OA) compared to younger adults (YA). Purpose To assess the change in CCA stiffness, strain, and systemic hemodynamics during a hypertensive stimulus between young and older adults. Methods Thirty‐one young (YA: 26 ± 5 yrs; 23.8 ± 3.3 kg/m 2 ) and 25 older adults (OA: 60 ± 6 yrs; 30.0 ± 5.5 kg/m 2 ) performed 3 sets of 10 repetitions of maximal isokinetic knee flexion/extension exercise. Measures were completed at rest and during the last 10‐sec of the 3rd exercise set. Circumferential CCA strain, strain rate, strain time to peak (sTPK), and strain rate time to peak (srTPK) parameters were analyzed using 2D speckle tracking software. Heart rate (HR) was measured via three lead ECG. Non‐invasive arterial blood pressure (BP) and cardiac output (CO) measurements were obtained using finger photoplethysmography. Circumferential ‐Stiffness Index (C) was calculated by Ln[Systolic BP/Diastolic BP]/[Strain/100]. Results Older adults had larger increases in mean BP (rest to exercise; OA: 97 ± 10 to 150 ± 26 mmHg, YA: 95 ± 8 to 130 ± 17 mmHg) and greater reductions in sTPK (rest to exercise; OA: 345 ± 39 to 242 ± 52 ms, YA: 308 ± 35 to 247 ± 42 ms) than younger adults during the hypertensive stimulus (Interaction effect, p <0.05). OA's also had a blunted response in HR (rest to exercise; OA: 62 ± 7 to 101 ± 14 bpm, YA: 66 ± 9 to 117 ± 20 bpm) and CO (rest to exercise; OA: 4.6 ± 1.2 to 6.0 ± 1.6 L/min, YA: 5.2 ± 1.0 to 8.7 ± 1.8 L/min) (Interaction effect, p <0.05). Overall group differences suggest older adults have greater C and lower CCA strain rate and strain when compared to young adults (Group effect, p <0.05). Conclusions The greater pressor response experienced by the older adults during maximal RE may be related to their differential arterial wall dynamics, as evidenced by elevated CCA stiffness and reduced CCA strain. Furthermore, the differential CCA wall dynamics may reduce the ability of older adults to accommodate large increases in arterial blood pressure which could potentially contribute to end organ damage distal to the CCA.