The prevalence of sarcopenia before and after correction for DXA-derived fat-free adipose tissue

The literature suggests that the estimate of lean mass may be overestimated in the obese using dual-energy X-ray absorptiometry (DXA), as similar to 15% of adipose tissue is composed of fat-free tissue. The purpose of this study was to investigate how the DXA-derived fat-free adipose influences appendicular lean mass and prevalence of sarcopenia across a range of body fat % in both men and women using a national sample (n=1946). The appendicular lean mass/m(2) went from 7.0 kg/m(2) (confidence interval (CI): 6.9, 7.2) to 5.9 kg/m(2) (CI: 5.8, 6.1) following correction in those with >= 35% body fat, whereas it only went from 7.5 kg/m(2) (CI: 7.2, 7.8) to 7.1 kg/m(2) (CI: 6.8, 7.4) following correction in those with < 25% body fat. Fat-free adipose tissue may need to be accounted for when estimating appendicular lean mass and failure to account for fat-free adipose tissue may underestimate the prevalence of sarcopenia.