TY - JOUR
T1 - Resistive and elastic work of breathing in older and younger adults during exercise
AU - Smith, Joshua R.
AU - Cross, Troy J.
AU - Van Iterson, Erik H.
AU - Johnson, Bruce D.
AU - Olson, Thomas P.
N1 - Funding Information:
This work was supported by the National Institutes of Health [HL126638 to TPO] and American Heart Association [18POST3990251 to JRS].
Publisher Copyright:
Copyright © 2018 American Physiological Society. All rights reserved.
PY - 2018/7
Y1 - 2018/7
N2 - It is unknown whether the greater total work of breathing (WOB) with aging is due to greater elastic and/or resistive WOB. We hypothesized that older compared with younger adults would exhibit a greater total WOB at matched ventilations (V E) during graded exercise, secondary to greater inspiratory resistive and elastic as well as expiratory resistive WOB. Older (OA: 60 8 yr; n 9) and younger (YA: 38 7 yr; n 9) adults performed an incremental cycling test to volitional fatigue. Esophageal pressure, inspiratory (IRV) and expiratory reserve volumes (ERV), expiratory flow limitation (EFL), and ventilatory variables were measured at matched V E (i.e., 25, 50, and 75 l/min) during exercise. The inspiratory resistive and elastic as well as expiratory resistive WOB were quantified using the Otis method. At V E of 75 l/min, older adults had greater %EFL and larger tidal volumes to inspiratory capacity but smaller relative IRV (P 0.03) than younger adults. Older compared with younger adults had greater total WOB at V E of 50 and 75 l/min (OA: 90 43 vs. YA: 49 21 J/min; P 0.04 for both). At V E of 75 l/min, older adults had greater inspiratory elastic and resistive WOB (OA: 44 27 vs. YA: 24 22 and OA: 23 15 vs. YA: 11 3 J/min, respectively, P 0.03 for both) and expiratory resistive WOB (OA: 23 19 vs. YA: 14 9 J/min, P 0.02) than younger adults. These data demonstrate that aging-induced pulmonary alterations result in greater inspiratory elastic and resistive as well as expiratory resistive WOB, which may have implications for the integrated response during exercise. NEW & NOTEWORTHY Aging-induced changes to the pulmonary system result in increased work of breathing (WOB) during exercise. However, it is not known whether this higher WOB with aging is due to differences in elastic and/or resistive WOB. Herein, we demonstrate that older adults exhibited greater inspiratory elastic and resistive as well as expiratory resistive WOB during exercise.
AB - It is unknown whether the greater total work of breathing (WOB) with aging is due to greater elastic and/or resistive WOB. We hypothesized that older compared with younger adults would exhibit a greater total WOB at matched ventilations (V E) during graded exercise, secondary to greater inspiratory resistive and elastic as well as expiratory resistive WOB. Older (OA: 60 8 yr; n 9) and younger (YA: 38 7 yr; n 9) adults performed an incremental cycling test to volitional fatigue. Esophageal pressure, inspiratory (IRV) and expiratory reserve volumes (ERV), expiratory flow limitation (EFL), and ventilatory variables were measured at matched V E (i.e., 25, 50, and 75 l/min) during exercise. The inspiratory resistive and elastic as well as expiratory resistive WOB were quantified using the Otis method. At V E of 75 l/min, older adults had greater %EFL and larger tidal volumes to inspiratory capacity but smaller relative IRV (P 0.03) than younger adults. Older compared with younger adults had greater total WOB at V E of 50 and 75 l/min (OA: 90 43 vs. YA: 49 21 J/min; P 0.04 for both). At V E of 75 l/min, older adults had greater inspiratory elastic and resistive WOB (OA: 44 27 vs. YA: 24 22 and OA: 23 15 vs. YA: 11 3 J/min, respectively, P 0.03 for both) and expiratory resistive WOB (OA: 23 19 vs. YA: 14 9 J/min, P 0.02) than younger adults. These data demonstrate that aging-induced pulmonary alterations result in greater inspiratory elastic and resistive as well as expiratory resistive WOB, which may have implications for the integrated response during exercise. NEW & NOTEWORTHY Aging-induced changes to the pulmonary system result in increased work of breathing (WOB) during exercise. However, it is not known whether this higher WOB with aging is due to differences in elastic and/or resistive WOB. Herein, we demonstrate that older adults exhibited greater inspiratory elastic and resistive as well as expiratory resistive WOB during exercise.
KW - Aging
KW - Dynamic lung compliance
KW - Mechanical constraints
KW - Operating lung volumes
KW - Work of breathing
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U2 - 10.1152/japplphysiol.01105.2017
DO - 10.1152/japplphysiol.01105.2017
M3 - Article
C2 - 29672228
AN - SCOPUS:85051092782
SN - 8750-7587
VL - 125
SP - 190
EP - 197
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 1
ER -