Combination of DXA and BIS body composition measurements is highly correlated with physical function-an approach to improve muscle mass assessment

Adam J Kuchnia; Yosuke Yamada; Levi Teigen; Diane Krueger; Neil Binkley; Dale Schoeller

doi:10.1007/s11657-018-0508-7

Combination of DXA and BIS body composition measurements is highly correlated with physical function-an approach to improve muscle mass assessment

Arch Osteoporos. 2018 Sep 14;13(1):97. doi: 10.1007/s11657-018-0508-7.

Authors

Adam J Kuchnia¹, Yosuke Yamada², Levi Teigen³, Diane Krueger⁴, Neil Binkley⁴, Dale Schoeller^{5

6}

Affiliations

¹ Department of Nutritional Sciences, University of Wisconsin-Madison, Nutritional Sciences Building, 1415 Linden Drive Suite 266, Madison, WI, 53706, USA. kuchnia@wisc.edu.
² Section of Healthy Longevity Researches, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, Tokyo, Japan.
³ Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Saint Paul, MN, USA.
⁴ University of Wisconsin Osteoporosis Clinical Research Program, Madison, WI, USA.
⁵ Department of Nutritional Sciences, University of Wisconsin-Madison, Nutritional Sciences Building, 1415 Linden Drive Suite 266, Madison, WI, 53706, USA.
⁶ Biotechnology Center, University of Wisconsin-Madison, Madison, WI, USA.

PMID: 30218261
DOI: 10.1007/s11657-018-0508-7

Abstract

Rationale: Fluid volume estimates may help predict functional status and thereby improve sarcopenia diagnosis.

Main result: Bioimpedance-derived fluid volume, combined with DXA, improves identification of jump power over traditional measures.

Significance: DXA-measured lean mass should be corrected for fluid distribution in older populations; this may be a surrogate of muscle quality.

Purpose: Sarcopenia, the age-related loss of muscle mass and function, negatively impacts functional status, quality of life, and mortality. We aimed to determine if bioimpedance spectroscopy (BIS)-derived estimates of body water compartments can be used in conjunction with dual-energy X-ray absorptiometry (DXA) measures to aid in the prediction of functional status and thereby, ultimately, improve the diagnosis of sarcopenia.

Methods: Participants (≥ 70 years) had physical and muscle function tests, DXA, and BIS performed. Using a BMI correction method, intracellular water (ICW_c), extracellular water (ECW_c), and ECW_c to ICW_c (E/I_c) ratio was estimated from standard BIS measures. Jump power was assessed using jump mechanography.

Results: The traditional measure used to diagnose sarcopenia, DXA-derived appendicular lean mass (ALM) corrected for height (ALM/ht²), was the least predictive measure explaining jump power variability (r² = 0.31, p < 0.0001). The best measure for explaining jump power was a novel variable combining DXA ALM and BIS-derived E/I_c ratio (ALM/(E/I_c); r² = 0.70, p < 0.0001). ALM/(E/I_c) and ICW_c had the highest correlation with jump power and grip strength, specifically jump power (r = 0.84 and r = 0.80, respectively; p < 0.0001).

Conclusions: The creation of a novel variable (ALM/(E/I_c)) improved the ability of DXA to predict jump power in an older population. ALM/(E/I_c) substantially outperformed traditional lean mass measures of sarcopenia and could well be an improved diagnostic approach to predict functional status. DXA-measured ALM should be corrected for fluid distribution, i.e., ALM/(E/I_c); this correction may be considered a surrogate of muscle quality.

Keywords: Bioimpedance spectroscopy; Extracellular water; Intracellular water; Muscle function; Muscle quality; Sarcopenia.

MeSH terms

Absorptiometry, Photon / methods*
Aged
Body Composition
Dielectric Spectroscopy / methods*
Female
Geriatric Assessment / methods*
Humans
Male
Middle Aged
Muscle, Skeletal / diagnostic imaging*
Predictive Value of Tests
Sarcopenia / diagnosis*