Local fat content and muscle quality measured by a new electrical impedance myography device: correlations with ultrasound variables
S. Longo, Giuseppe Coratella, Susanna Rampichini, Marta Borrelli, Raffaele Scurati, Eloisa Limonta, Emiliano Cè, Fabio Esposito
Abstract
Abstract The present study investigated the relationship between local fat percentage (SK fat ) and muscle quality (MQ) estimated by a new hand‐held electrical impedance myography ( h EIM) device or derived from ultrasound and strength assessments. The right anterior thigh of 90 healthy participants (mean ± SD; age=22.9 ± 2.9 years; 45 men: BMI = 23.9 ± 2.4 kgm −2 ; 45 women: BMI = 21.1 ± 1.9 kgm −2 ) was scanned by h EIM and ultrasound. Correlations between SK fat , local subcutaneous fat (SUB fat ), and echo intensity (EI us ) were explored. Correlations between MQ, EI us , quadriceps femoris anatomical cross‐sectional area (ACSA QF ), knee extensors maximum voluntary isometric torque (T), T/ACSA QF , EI us /SUB fat , and ACSA QF /SUB fat were also assessed. SK fat correlated with SUB fat ( r = 0.88; p < 0.001) and EI us ( r = 0.64; p < 0.001). MQ correlated with EI us ( r = −0.66; p < 0.001), ACSA QF ( r = 0.37; p < 0.001), EI us /SUB fat ( r = 0.37; p < 0.001), and ACSA QF /SUB fat ( r = 0.81; p < 0.001). Multiple regression analysis showed that SUB fat , EI us , and sex explained 86% of SK fat variance, whereas ACSA QF /SUB fat , sex and EI us explained 75% of MQ variance. In conclusion, high h EIM local fat percentage relates to greater subcutaneous fat and intramuscular non‐contractile tissue content. High h EIM muscle quality relates to greater muscle‐size:subcutaneous‐fat ratio and contractile tissue content. Sex influences the prediction of both parameters. This h EIM device seems to be useful to estimate local thigh composition.