Background: Muscle mass declines with age. However, common assessments used to quantify muscle mass are indirect. The D3-creatine (D3Cr) dilution method is a direct assessment of muscle mass; however, longitudinal changes have not been examined in relation to changes in other measures of muscle mass, strength, and performance. Methods: A convenience sample of 40 men from the Osteoporotic Fractures in Men Study (mean age = 83.3 years, standard deviation = 3.9) underwent repeat assessment of D3Cr muscle mass, dual-energy X-ray absorptiometry (DXA) lean mass, grip strength, and walking speed at two time points approximately 1.6 years apart (2014–2016). One-sample t-tests and Pearson correlations were used to examine changes in DXA total body lean mass, DXA appendicular lean mass/height2, DXA appendicular lean mass/weight, D3Cr muscle mass, D3Cr muscle mass/weight, grip strength, walking speed, and weight. Results: D3-creatine muscle mass, D3Cr muscle mass/weight, grip strength, and walking speed all significantly declined (all P < 0.01). The change in DXA measures of lean mass was moderately correlated with changes in D3Cr muscle mass. There was no significant correlation between the change in DXA measures of lean mass and change in walking speed (all P > 0.05). The change in D3Cr muscle mass/weight was moderately correlated with change in walking speed (r = 0.33, P <.05). The change in grip strength was weakly correlated with the change in DXA measures of lean mass and D3Cr muscle mass (r = 0.19–0.32). Conclusions: The results of our study provide new insights regarding the decline in muscle strength and D3Cr muscle mass. The D3Cr method may be a feasible tool to measure declines in muscle mass over time.
Bibliographical noteFunding Information:
The Osteoporotic Fractures in Men Study is supported by National Institutes of Health funding. The following institutes provided support: the National Institute on Aging (NIA), the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the National Center for Advancing Translational Sciences (NCATS), and NIH Roadmap for Medical Research under the following grant numbers: U01 AG027810, U01 AG042124, U01 AG042139, U01 AG042140, U01 AG042143, U01AG042145, U01 AG042168, U01 AR066160, and UL1 TR000128. Funding for the D 3 Cr muscle mass measure was provided by NIAMS (grant number R01 AR065268). GlaxoSmithKline provided in‐kind support by providing the D 3 ‐creatine dose and analysis of urine samples.This research was also supported by the National Institute on Aging of the National Institutes of Health under Award T32‐AG049663.
© 2019 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders
Copyright 2020 Elsevier B.V., All rights reserved.
- Grip strength
- Muscle mass
- Walking speed