Changes in DXA-derived lean mass and MRI-derived cross-sectional area of the thigh are modestly associated

Dallin Tavoian,Kwasi Ampomah,Shinichi Amano,Brian C. Clark,Timothy D. Law

doi:10.1038/s41598-019-46428-w

Dallin Tavoian, Kwasi Ampomah + Show 3 more

Open Access

https://doi.org/10.1038/s41598-019-46428-w

Copy DOI

Abstract

Dual-energy X-ray absorptiometry (DXA) derived measures of lean mass demonstrate strong associations with magnetic resonance imaging (MRI) derived measures of muscle volume (MV) in cross-sectional studies, however, few studies have compared changes in response to an intervention. The purpose of this study was to determine the accuracy of DXA at detecting changes in lean mass, using MRI-derived MV as a reference standard. 10 male and 16 female subjects (29.2 ± 9.5 years) underwent DXA and MRI scans before and after a 10-week resistance training intervention. DXA thigh lean mass was compared to MRI mid-thigh MV, and percent change in size was compared between MRI and DXA. There was a strong correlation between measures cross-sectionally (r = 0.89) in agreement with previous investigations. However, there was a modest correlation of percentage change over time between methods (r = 0.49). Bland-Altman plots revealed that the amount of random error increased as the magnitude of the change from baseline increased. DXA measures of change in lean mass were modestly associated with MRI measures of change in MV. While there are several advantages to using DXA for the measurement of lean mass, the inability to accurately detect changes over time calls into question its use in clinical trials.

Highlights

Skeletal muscle plays a critical role in health as it permits the performance of exercise, as well as the activities of daily living
The purpose of this study was to examine the relationship between magnetic resonance imaging (MRI)- and dual-energy X-ray absorptiometry (DXA)-derived measures of thigh skeletal muscle size/ mass in a cross-sectional analysis as well as a longitudinal analysis where resistance exercise served as a stimulus for skeletal muscle adaptation
Examination of individual cases demonstrated that only 46% of scans agreed within 3%. For those differing in their estimate by >3%, we noted that in 43% of cases the MRI resulted in higher estimate of percent change, whereas in 57% of cases the DXA resulted in a higher estimate of percent change

Summary

Introduction

Skeletal muscle plays a critical role in health as it permits the performance of exercise, as well as the activities of daily living. In one study it was reported that 3-months of resistance exercise training in adolescents resulted in a significant increase in appendicular skeletal muscle size when MRI was used as the quantification method, but no significant difference in lean mass with DXA20 Another study, this time in older adults, reported increases in thigh muscle size after a 1-year resistance training protocol when measured with CT, but not DXA22. The data were discrepant, with the DXA-derived estimate indicating no significant increase, whereas the MRI-derived estimate demonstrated an increase While these measures are not always directly comparable, results of this nature highlight the need to better understand how DXA- and MRI-derived measures of change in skeletal muscle mass and size compare, as this knowledge has implications for interpreting findings as well as the design of clinical trials. The purpose of this study was to examine the relationship between MRI- and DXA-derived measures of thigh skeletal muscle size/ mass in a cross-sectional analysis as well as a longitudinal analysis where resistance exercise served as a stimulus for skeletal muscle adaptation

Objectives

Methods

Results

Discussion

Conclusion