The product of trunk muscle area and density on the CT image is a good indicator of energy expenditure in patients with or at risk for COPD

Table 5 Bivariate analysis of the CT-derived cross-sectional indices of the erector spinae muscle and clinical parameters

Variable	ESMA		ESMD		ESM product
Variable	r	P	R	P	r	p
Age, year	0.244	0.152	0.005	0,978	0.189	0.270
Height, m	0.429	0.009	0.203	0.236	0.313	0.063
Weight, kg	0.643	< 0.0001	0.185	0.280	0.439	0.007
BMI, kg/m²	0.598	< 0.001	0.182	0.289	0.433	0.008
CAT, n	0.337	0.045	0.081	0.64	0.203	0.235
mMRC score, units	0.196	0.253	0.230	0.178	0.262	0.123
6MWD, m	0.156	0.363	0.190	0.266	0.219	0.199
FEV1, % predicted	0.017	0.923	0.089	0.604	0.066	0.703
FEV1/FVC, %	0.005	0.975	0.140	0.416	0.051	0.768
DLco/V_A, % predicted	0.401	0.015	0.230	0.176	0.330	0.049
LAA%, %	0.344	0.040	0.154	0.371	0.250	0.141
FFM, kg	0.739	< 0.0001	0.315	0.061	0.591	< 0.001
SMM, kg	0.719	< 0.0001	0.287	0.089	0.567	< 0.001
HGS, kg	0.646	< 0.0001	0.496	0.002	0.678	< 0.0001
CC, cm	0.647	< 0.0001	0.292	0.084	0.512	0.001
TEE, kcal/day	0.620	< 0.0001	0.333	0.047	0.534	< 0.001
BMR, kcal/day	0.614	< 0.0001	0.114	0.509	0.397	0.017
PAL	0.323	0.055	0.419	0.011	0.423	0.010
PEmax, cmH₂O	0.348	0.038	0.191	0.265	0.300	0.075
PImax, cmH₂O	0.349	0.037	0.391	0.018	0.429	0.009

BMI body mass index, CAT COPD assessment test, mMRC modified Medical Research Council scale, 6MWD 6-min walking distance, FEV forced expiratory volume, DL_CO/V_A diffusing capacity of carbon monoxide/alveolar volume, LAA% percentage of the lung field occupied by low-attenuation areas, FFM fat-free mass, SMM skeletal-muscle mass, HGS hand-grip strength, CC calf circumference, TEE total energy expenditure; BMR basal metabolic rate, PAL physical activity level, PEmax maximal expiratory pressure, PImax maximal inspiratory pressure, ESMA erector spinae muscle area, ESMD erector spinae muscle density

ISSN: 1465-993X