A comparison of non-invasive methods of measuring body composition in patients with heart failure: a report from SICA-HF.

Background: Cachexia is common in patients with chronic heart failure and is associated with poor prognosis. How best to measure body composition is not clear.

Methods And Results: We characterized body composition in 120 patients with chronic heart failure: mean (SD) age 70 (10) years, left ventricular ejection fraction 44 (10) %, and median (Q1-Q3) N-terminal pro B-type natriuretic peptide 845 (355-1368) ng/L. We measured body composition using dual-energy X-ray absorptiometry (DEXA) and a multi-frequency bioelectrical impedance analysis (BIA) device (Tanita BIA MC-180MA). Mean (SD) fat mass (FM) was 27.2 (11.7) kg by BIA and 32.3 (12.2) kg by DEXA (mean difference -5.1 kg, 95% limits of agreement: -11.7, 1.5; 4% of values outside limit of agreement); mean (SD) lean mass (LM) was 56.6 (10.9) kg by BIA and 51.1 (9.9) kg by DEXA (mean difference 5.5 kg, 95% limits of agreement: -1.3, 12.3; 6% of values outside limit of agreement); and mean (SD) bone mass (BM) was 3.0 (0.5) kg by BIA and 2.8 (0.6) kg by DEXA (mean difference 0.2 kg, 95% limits of agreement: -0.5, 0.8; 5% of values outside limit of agreement). There was a close correlation between DEXA and BIA for both LM and FM (LM: r = 0.95, P < 0.001; FM: r = 0.96, P < 0.001) but less so for BM (r = 0.84, P < 0.001). Both DEXA and BIA body composition measurements correlated well with other measures of body size (body mass index, hip circumference, and waist circumference).

Conclusions: There are differences in the measurements of FM, LM, and BM between the two techniques, which should not be used interchangeably.