Skeletal muscle mass and quality: evolution of modern measurement concepts in the context of sarcopenia

Abstract

Conference on 'Nutrition and age-related muscle loss, sarcopenia and cachexia' The first reports of accurate skeletal muscle mass measurement in human subjects appeared at about the same time as introduction of the sarcopenia concept in the late 1980s. Since then these methods, computed tomography and MRI, have been used to gain insights into older (i.e. anthropometry and urinary markers) and more recently developed and refined methods (ultrasound, bioimpedance analysis and dual-energy X-ray absorptiometry) of quantifying regional and total body skeletal muscle mass. The objective of this review is to describe the evolution of these methods and their continued development in the context of sarcopenia evaluation and treatment. Advances in these technologies are described with a focus on additional quantifiable measures that relate to muscle composition and 'quality'. The integration of these collective evaluations with strength and physical performance indices is highlighted with linkages to evaluation of sarcopenia and the spectrum of related disorders such as sarcopenic obesity, cachexia and frailty. Our findings show that currently available methods and those in development are capable of non-invasively extending measures from solely 'mass' to quality evaluations that promise to close the gaps now recognised between skeletal muscle mass and muscle function, morbidity and mortality. As the largest tissue compartment in most adults, skeletal muscle mass and aspects of muscle composition can now be evaluated by a wide array of technologies that provide important new research and clinical opportunities aligned with the growing interest in the spectrum of conditions associated with sarcopenia.

Developing and Validating an Age-Independent Equation of Multi-Frequency Bioelectrical Impedance Analysis for Estimation of Appendicular Skeletal Muscle Mass and Establishing Sarcopenia Cutoff

“…Theoretically, ALM of DXA reflects whole lean tissues and not perfectly equal to SMM. In addition, muscle quality and muscle composition change with aging [50][51][52][53][54][55][56][57], but the current study does not examine these effect. As another limitation, Prado et al [58] stated that single cutoff may not suitable for all age, and they used large dataset of DXA ALM with 13,236 subjects from 1999-2004 NHANES cohort and LMS curve-fitting procedure to establish age and gender specific cutoffs.…”

Calf circumference: clinical validation for evaluation of muscle mass in the elderly

“…Despite its importance in clinical nursing practice in the care of the elderly, the evaluation of muscle mass is a challenge in the health services, since its determination requires high cost exams such as magnetic resonance imaging and computed tomography (11)(12) . Extensive epidemiological studies (5,(13)(14)(15)(16) used Dual Energy X-Ray Absortometry (DEXA) as a reference method to estimate muscle mass, and this method was recommended by the European Consensus of Sarcopenia (3) and for use in scenarios of clinical practice (12,17) . However, despite its accuracy and accuracy, in developing countries, such as Brazil, its use is expensive both in primary and secondary care services.…”

“…As a result, anthropometric measures are recommended (18) as alternative measures for assessing muscle mass and early identification of sarcopenia in clinical practice and primary health care settings (12,19) , due to the low cost and ease of obtaining. Among them, calf circumference (CC) (19) has been used in recent studies with the objective of measuring muscle mass and estimating the prevalence of sarcopenia (20)(21)(22) , predicting disability (23)(24) , mortality (24)(25) and need for care (26) , as well as for determining cut-off points of decreased muscle mass in the elderly population (27)(28)(29)(30)(31) .…”

Muscle Quality, Strength, and Lower Extremity Physical Performance in the Baltimore Longitudinal Study of Aging

“…Previous studies used the ratio of quadriceps isokinetic peak torque (Quad) via isokinetic dynamometry (ID) to thigh muscle cross-sectional area (TCSA) assessed by computed tomography (CT) to characterize the effect of age and other risk factors on MQ (8, 12, 13, 15). The feasibility of this approach on a large scale is limited because CT and ID are expensive, time consuming to ascertain and difficult to process (10, 16, 17). ID allows for measurement of contractile force at constant velocity; however, it is more expensive than a hand dynamometer (HD) (18) and can be difficult for some older adults to complete due to lower back or leg pain and/or poor strength (13).…”