TY - JOUR
T1 - 31P magnetic resonance spectroscopy assessment of muscle bioenergetics as a predictor of gait speed in the Baltimore longitudinal study of aging
AU - Choi, Seongjin
AU - Reiter, David A.
AU - Shardell, Michelle
AU - Simonsick, Eleanor M.
AU - Studenski, Stephanie
AU - Spencer, Richard G.
AU - Fishbein, Kenneth W.
AU - Ferrucci, Luigi
N1 - Funding Information:
This work was funded by the Intramural Research Program of the National Institute on Aging, National Institute of Health, Baltimore, MD.
PY - 2016/12
Y1 - 2016/12
N2 - Background: Aerobic fitness and muscle bioenergetic capacity decline with age; whether such declines explain age-related slowing of walking speed is unclear. We hypothesized that muscle energetics and aerobic capacity are independent correlates of walking speed in simple and challenging performance tests and that they account for the observed age-related decline in walking speed in these same tests. Methods: Muscle bioenergetics was assessed as postexercise recovery rate of phosphocreatine (PCR), kPCR, using phosphorus magnetic resonance spectroscopy (31P-MRS) in 126 participants (53 men) of the Baltimore Longitudinal Study of Aging aged 26-91 years (mean = 72 years). Four walking tasks were administered-usual pace over 6 m and 150 seconds and fast pace over 6 m and 400 m. Separately, aerobic fitness was assessed as peak oxygen consumption (peak VO2) using a graded treadmill test. Results: All gait speeds, kPCR, and peak VO2 were lower with older age. Independent of age, sex, height, and weight, both kPCR and peak VO2 were positively and significantly associated with fast pace and long distance walking but only peak VO2 and not kPCR was significantly associated with usual gait speed over 6 m. Both kPCR and peak VO2 substantially attenuated the association between age and gait speed for all but the least stressful walking task of 6 m at usual pace. Conclusion: Muscle bioenergetics assessed using 31P-MRS is highly correlated with walking speed and partially explains age-related poorer performance in fast and long walking tasks.
AB - Background: Aerobic fitness and muscle bioenergetic capacity decline with age; whether such declines explain age-related slowing of walking speed is unclear. We hypothesized that muscle energetics and aerobic capacity are independent correlates of walking speed in simple and challenging performance tests and that they account for the observed age-related decline in walking speed in these same tests. Methods: Muscle bioenergetics was assessed as postexercise recovery rate of phosphocreatine (PCR), kPCR, using phosphorus magnetic resonance spectroscopy (31P-MRS) in 126 participants (53 men) of the Baltimore Longitudinal Study of Aging aged 26-91 years (mean = 72 years). Four walking tasks were administered-usual pace over 6 m and 150 seconds and fast pace over 6 m and 400 m. Separately, aerobic fitness was assessed as peak oxygen consumption (peak VO2) using a graded treadmill test. Results: All gait speeds, kPCR, and peak VO2 were lower with older age. Independent of age, sex, height, and weight, both kPCR and peak VO2 were positively and significantly associated with fast pace and long distance walking but only peak VO2 and not kPCR was significantly associated with usual gait speed over 6 m. Both kPCR and peak VO2 substantially attenuated the association between age and gait speed for all but the least stressful walking task of 6 m at usual pace. Conclusion: Muscle bioenergetics assessed using 31P-MRS is highly correlated with walking speed and partially explains age-related poorer performance in fast and long walking tasks.
KW - Bioenergetics
KW - Lower extremity performance
KW - Magnetic resonance spectroscopy
KW - Muscle
KW - Walking speed
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U2 - 10.1093/gerona/glw059
DO - 10.1093/gerona/glw059
M3 - Article
C2 - 27075894
AN - SCOPUS:85014628997
SN - 1079-5006
VL - 71
SP - 1638
EP - 1645
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
IS - 12
ER -