Comparisons between dual-energy X-ray absorptiometry and bioimpedance devices for appendicular lean mass and muscle quality in Hispanic adults.

The purpose of this study was to compare single- and multi-frequency bioimpedance (BIA) devices against dual-energy X-ray absorptiometry (DXA) for appendicular lean mass (ALM) and muscle quality index (MQI) metrics in Hispanic adults. One hundred thirty-one Hispanic adults (18-55 years) participated in this study. ALM was measured with single-frequency bioimpedance analysis (SFBIA), multi-frequency bioimpedance analysis (MFBIA) and DXA. ALM TOTAL (left arm + right arm + left leg + right leg) and ALM ARMS (left arm + right arm) were computed for all three devices. Handgrip strength (HGS) was measured using a dynamometer. The average HGS was used for all MQI models (highest left hand + highest right hand)/2. MQI ARMS was defined as the ratio between HGS and ALM ARMS . MQI TOTAL was established as the ratio between HGS and ALM TOTAL . SFBIA and MFBIA had strong correlations with DXA for all ALM and MQI metrics (Lin's concordance correlation coefficient values ranged from 0·86 (MQI MFBIA-ARMS ) to 0·97 (Arms LM SFBIA ); all P < 0·001). Equivalence testing varied between methods (e.g. SFBIA v . DXA) when examining the different metrics (i.e. ALM TOTAL , ALM ARMS , MQI TOTAL and MQI ARMS ). MQI ARMS was the only metric that did not differ from the line of identity and had no proportional bias when comparing all the devices against each other. The current study findings demonstrate good overall agreement between SFBIA, MFBIA and DXA for ALM TOTAL and ALM ARMS in a Hispanic population. However, SFBIA and MFBIA have better agreement with DXA when used to compute MQI ARMS than MQI TOTAL .