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.