Age-related changes in human skeletal muscle microstructure and architecture assessed by diffusion-tensor magnetic resonance imaging and their association with muscle strength

• Type of Material: Article
• Authors: Donnie Cameron, University of East Anglia; David A Reiter, Emory University; Fatemeh Adelnia, Vanderbilt University; Ceereena Ubaida-Mohien, National Institutes of Health, Baltimore; Christopher M Bergeron, National Institutes of Health, Baltimore; Seongjin Choi, University of Maryland; Kenneth W Fishbein, National Institutes of Health, Baltimore; Richard G Spencer, National Institutes of Health, Baltimore; Luigi Ferrucci, National Institutes of Health, Baltimore
• Language: English
• Date: 2023-05-10
• Publisher: WILEY
• Publication Version: Final Published Version
• Copyright Statement: © 2023 The Authors.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1111/acel.13851
• Title of Journal or Parent Work: AGING CELL
• Volume: 22
• Issue: 7
• Start Page: e13851
• End Page: e13851
• Keywords: FIBER TYPES; QUANTIFICATION; ULTRASOUND; sarcopenia; skeletal muscle fibers; FEMORIS; Life Sciences & Biomedicine; PARAMETERS; Geriatrics & Gerontology; muscle strength; thigh; Cell Biology; Science & Technology; aging; diffusion tensor imaging; INDEXES; TO-NOISE RATIO; DTI
• Research Categories: Biology, Cell; Biology, Neuroscience; Health Sciences, Radiology; Gerontology

Abstract

Diffusion-tensor magnetic resonance imaging (DT-MRI) offers objective measures of muscle characteristics, providing insights into age-related changes. We used DT-MRI to probe skeletal muscle microstructure and architecture in a large healthy-aging cohort, with the aim of characterizing age-related differences and comparing these to muscle strength. We recruited 94 participants (43 female; median age = 56, range = 22–89 years) and measured microstructure parameters—fractional anisotropy (FA) and mean diffusivity (MD)—in 12 thigh muscles, and architecture parameters—pennation angle, fascicle length, fiber curvature, and physiological cross-sectional area (PCSA)—in the rectus femoris (RF) and biceps femoris longus (BFL). Knee extension and flexion torques were also measured for comparison to architecture measures. FA and MD were associated with age (β = 0.33, p = 0.001, R2 = 0.10; and β = −0.36, p < 0.001, R2 = 0.12), and FA was negatively associated with Type I fiber proportions from the literature (β = −0.70, p = 0.024, and R2 = 0.43). Pennation angle, fiber curvature, fascicle length, and PCSA were associated with age in the RF (β = −0.22, 0.26, −0.23, and −0.31, respectively; p < 0.05), while in the BFL only curvature and fascicle length were associated with age (β = 0.36, and −0.40, respectively; p < 0.001). In the RF, pennation angle and PCSA were associated with strength (β = 0.29, and 0.46, respectively; p < 0.01); in the BFL, only PCSA was associated with strength (β = 0.43; p < 0.001). Our results show skeletal muscle architectural changes with aging and intermuscular differences in the microstructure. DT-MRI may prove useful for elucidating muscle changes in the early stages of sarcopenia and monitoring interventions aimed at preventing age-associated microstructural changes in muscle that lead to functional impairment.