Validation of a multi-frequency bioelectrical impedance analysis device for the assessment of body composition in older adults with type 2 diabetes

Background: Aging and type 2 diabetes (T2DM) increase sarcopenia risk. While DXA is commonly used to assess body composition, direct segmental multi-frequency bioelectrical impedance analysis (DSMF-BIA) offers a practical alternative. This study examined the accuracy of a DSMF-BIA device (InBody-770) versus DXA in older adults with T2DM. Methods: Eighty-four overweight/obese older adults with T2DM (49 women; mean age 71 ± 5 years) from the CEV-65 study who had both DSMF-BIA and DXA at baseline were included. Agreement was evaluated using Bland-Altman plots and intraclass correlation coefficients (ICC). Sub-analyses assessed gender effects and agreement after 10 weeks of interventions (diet, circuit training, empagliflozin). Results: Leg lean mass by DSMF-BIA and DXA was 14.76 ± 3.62 kg and 15.19 ± 3.52 kg, respectively; Bland-Altman indicated no proportional bias (p = 0.353). ASMI did not differ (7.43 vs 7.47 kg/m²; p = 0.84; ICC = 0.965, p < 0.0001; mean difference −0.068, p = 0.595). Gender and interventions did not modify DSMF-BIA accuracy versus DXA. Conclusions: In older adults with T2DM, DSMF-BIA showed high agreement with DXA, supporting its use to measure muscle mass.