The influence of subcutaneous fat on the relationship between body composition and ultrasound-derived muscle quality.

Ultrasound echo intensity (EI) values are a popular assessment of muscle quality. The relationship between EI and total (%fat) and regional (%fat) body composition was examined in 40 men, prior to and after accounting for subcutaneous fat thickness. Uncorrected EI values suggest that muscle quality improves (r = -0.329 to -0.224; P = 0.038-0.165) with greater %fat and %fat. However, corrected EI values indicated that muscle quality decreases (r = 0.711 to 0.798; P < 0.001) with greater %fat and %fat.