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Difference in Muscle Quality over the Adult Life Span and Biological Correlates in the Baltimore Longitudinal Study of Aging
Author(s) -
Moore Ann Zenobia,
Caturegli Giorgio,
Metter E. Jeffrey,
Makrogiannis Sokratis,
Resnick Susan M.,
Harris Tamara B.,
Ferrucci Luigi
Publication year - 2014
Publication title -
journal of the american geriatrics society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.992
H-Index - 232
eISSN - 1532-5415
pISSN - 0002-8614
DOI - 10.1111/jgs.12653
Subject(s) - medicine , anthropometry , cross sectional study , quality of life (healthcare) , physical medicine and rehabilitation , physical therapy , cardiology , pathology , nursing
Objectives To examine differences in a proxy measure of muscle quality across the adult life span and explore potential mechanisms of muscle quality change through identification of cross‐sectional correlates of muscle quality. Design Cross‐sectional study. Setting B altimore L ongitudinal S tudy of A ging. Participants Seven hundred eighty‐six individuals with a mean age of 66.3 (range 26–96) (N = 786). A sensitivity analysis was conducted in a subset of participants matched according to sex, muscle mass, and body size. Measurements Muscle quality was operationalized as the ratio of knee‐extension strength (isokinetic dynamometry) to thigh muscle cross‐sectional area (computed tomography). Differences in muscle strength, muscle area, and muscle quality ratio with age were evaluated, and the association between the muscle quality ratio and measures reflecting domains of cognitive function, motor control, peripheral nerve function, adiposity, glucose homeostasis, and inflammation were assessed through multivariate regression analyses. Results A linear relationship between age and muscle quality ratio was observed, suggesting a gradual decline in muscle quality over the adult life course. Associations were observed between muscle quality ratio and measures of adiposity, as well as peroneal nerve motor conduction velocity, finger tapping speed, and memory performance ( P < .01). The association between muscle quality ratio and nerve conduction velocity was maintained after adjustment for anthropometric measurements ( P < .05). Conclusion Muscle quality declines progressively with age over the adult life span and is affected by obesity and neurological factors. Studies are needed to clarify the mechanisms of these associations and their implications for functional outcomes.