Background
Methods
Patients and study design
Pulmonary function testing
CT scan acquisition and analysis
Measurement of BMR and TEE
Measurement of BMR
Measurement of TEE by the DLW method
Statistical analysis
Results
Patient characteristics
Variable | Data (range) |
---|---|
Total number of patients | 36 |
Sex, M/F | 36/0 |
Age, year | 70.3 ± 5.8 (52–78) |
Height, m | 1.65 ± 0.1 (1.53–1.77) |
Weight, kg | 60.2 ± 10.1 (39.8–81.0) |
BMI, kg/m2 | 21.9 ± 3.2 (15.2–30.1) |
Smoking history, pack-years | 56.5 ± 23.3 (25–120) |
GOLD 0/1/2/3/4 | 8/6/14/6/2 |
FEV1, L | 1.89 ± 0.7 (0.7–3.3) |
FEV1, %predicted | 69.4 ± 24.4 (27.1–110.3) |
FEV1/FVC, % | 55.4 ± 17.4 (27.0–94.1) |
DLco/VA, %predicted | 74.0 ± 27.4 (28.9–127.0) |
LAA% less than -950 HU, % | 13.9 ± 13.6 (0.1–52.0) |
mMRC dyspnea scale score, 0/1/2/3/4 | 14/13/6/3/0 |
6MWD, m | 434.9 ± 94.6 (275–750) |
CAT score, n | 10.1 ± 6.1 (1–29) |
FFM, kg | 45.5 ± 7.4 (30.0–59.2) |
SMM, kg | 24.9 ± 3.4 (18.2–30.2) |
HGS, kg | 33.9 ± 7.0 (22.1–46.9) |
CC, cm | 33.3 ± 3.1 (26.9–38.8) |
PEmax, cmH2O | 75.4 ± 22.6 (36.1–143.2) |
PImax, cmH2O | 63.6 ± 21.2 (27.3–110.3) |
TEE, kcal/day | 2273 ± 445.4 (1265–3453) |
BMR, kcal/day | 1262 ± 179.9 (863.0–1694) |
PAL | 1.80 ± 0.20 (1.36–2.16) |
PMA, cm2 | 30.8 ± 5.8 (18.5–46.5) |
PMD, HU | 32.6 ± 7.0 (14.6–43.5) |
RAMA, cm2 | 8.7 ± 1.7 (5.5–12.8) |
RAMD, HU | 26.5 ± 6.8 (12.5–39.0) |
ESMA, cm2 | 26.2 ± 5.0 (12.6–36.6) |
ESMD, HU | 36.4 ± 9.7 (-3.2–54.1) |
Distribution of the three muscle areas and densities
GOLD 0 | GOLD 1 | GOLD 2 | GOLD 3, 4 | |
---|---|---|---|---|
N | 8 | 6 | 14 | 8 |
Age, years | 70.3 ± 7.1 | 68.8 ± 8.9 | 71.36 ± 4.4 | 69.6 ± 4.5 |
Height, m | 1.65 ± 0.08 | 1.65 ± 0.06 | 1.65 ± 0.05 | 1.66 ± 0.05 |
Weight, kg | 59.1 ± 13.0 | 60.8 ± 6.6 | 63.6 ± 9.6 | 54.8 ± 9.2 |
BMI, kg/m2 | 21.2 ± 3.7 | 21.8 ± 1.3 | 23.5 ± 3.0※ | 19.7 ± 3.2 |
CAT score, n | 9.6 ± 4.0 | 10.0 ± 7.0 | 7.8 ± 5.6 | 14.6 ± 6.7 |
LAA% | 9.4 ± 8.6# | 8.3 ± 5.6# | 9.2 ± 8.2# | 30.7 ± 17.0 |
PMA | 30.2 ± 6.8 | 30.1 ± 3.0 | 32.7 ± 6.3 | 28.6 ± 5.1 |
PMD | 32.9 ± 8.6 | 34.1 ± 6.5 | 33.9 ± 6.7 | 28.9 ± 5.8 |
PM product | 1030.2 ± 425.7 | 1035.4 ± 274.8 | 1133.1 ± 391.3 | 838.8 ± 245.5 |
RAMA | 8.5 ± 2.1 | 8.7 ± 1.0 | 9.1 ± 1.6 | 8.1 ± 1.7 |
RAMD | 25.5 ± 6.0 | 29.5 ± 7.7 | 27.5 ± 7.2 | 23.7 ± 6.1 |
RAM product | 222.7 ± 98.0 | 260.0 ± 81.8 | 257.5 ± 93.1 | 198.9 ± 85.6 |
ESMA | 25.3 ± 5.4 | 26.5 ± 6.1 | 27.6 ± 4.9 | 24.3 ± 3.9 |
ESMD | 34.9 ± 8.6 | 39.8 ± 2.6 | 37.2 ± 12.5 | 33.9 ± 8.9 |
ESM product | 894.6 ± 344.0 | 1056.5 ± 280.0 | 1077.0 ± 361.8 | 843.9 ± 346.3 |
PMA /Ht2 | 11.0 ± 2.3 | 11.0 ± 0.8 | 12.1 ± 2.4 | 10.4 ± 1.8 |
RAMA /Ht2 | 3.1 ± 0.8 | 3.2 ± 0.2 | 3.4 ± 0.5 | 3.0 ± 0.7 |
ESMA /Ht2 | 9.3 ± 1.8 | 9.7 ± 2.0 | 10.2 ± 1.7 | 8.8 ± 1.3 |
Bivariate correlation analysis
Relationship between muscle areas and density in each muscle
Relationship between clinical traits and muscle area, density, and area–density products
Variable | PMA | PMD | PM product | |||
---|---|---|---|---|---|---|
r | P | r | p | r | p | |
Age, years | 0.226 | 0.186 | 0.134 | 0.435 | 0.193 | 0.260 |
Height, m | 0.228 | 0.181 | 0.405 | 0.014 | 0.329 | 0.050 |
Weight, kg | 0.569 | < 0.001 | 0.497 | 0.002 | 0.557 | < 0.001 |
BMI, kg/m2 | 0.566 | < 0.001 | 0.414 | 0.012 | 0.507 | 0.002 |
CAT, n | 0.374 | 0.025 | 0.490 | 0.779 | 0.212 | 0.215 |
mMRC score, units | 0.058 | 0.736 | 0.260 | 0.126 | 0.191 | 0.265 |
6MWD, m | 0.246 | 0.148 | 0.268 | 0.114 | 0.306 | 0.069 |
FEV1, % predicted | 0.076 | 0.659 | 0.289 | 0.088 | 0.225 | 0.186 |
FEV1/FVC, % | 0.019 | 0.915 | 0.197 | 0.249 | 0.194 | 0.384 |
DLco/VA, % predicted | 0.395 | 0.017 | 0.465 | 0.004 | 0.512 | 0.001 |
LAA%, % | 0.350 | 0.036 | 0.336 | 0.045 | 0.385 | 0.020 |
FFM, kg | 0.660 | < 0.0001 | 0.572 | < 0.001 | 0.659 | < 0.0001 |
SMM, kg | 0.573 | < 0.001 | 0.598 | < 0.001 | 0.628 | < 0.0001 |
HGS, kg | 0.491 | 0.002 | 0.473 | 0.004 | 0.521 | 0.001 |
CC, cm | 0.595 | < 0.001 | 0.497 | 0.002 | 0.572 | < 0.001 |
TEE, kcal/day | 0.630 | < 0.0001 | 0.646 | < 0.0001 | 0.680 | < 0.0001 |
BMR, kcal/day | 0.506 | 0.002 | 0.467 | 0.004 | 0.504 | 0.002 |
PAL | 0.483 | 0.003 | 0.551 | < 0.001 | 0.555 | < 0.001 |
PEmax, cmH2O | 0.313 | 0.063 | 0.416 | 0.012 | 0.373 | 0.025 |
PImax, cmH2O | 0.096 | 0.577 | 0.486 | 0.003 | 0.324 | 0.054 |
Variable | RAMA | RAMD | RAM product | |||
---|---|---|---|---|---|---|
r | P | r | p | r | p | |
Age, year | 0.150 | 0.382 | 0.292 | 0.084 | 0.261 | 0.124 |
Height, m | 0.279 | 0.100 | 0.251 | 0.140 | 0.277 | 0.103 |
Weight, kg | 0.569 | < 0.001 | 0.418 | 0.011 | 0.518 | 0.001 |
BMI, kg/m2 | 0.571 | < 0.001 | 0.380 | 0.022 | 0.488 | 0.003 |
CAT, n | 0.247 | 0.146 | 0.127 | 0.459 | 0.199 | 0.246 |
mMRC score, units | 0.037 | 0.831 | 0.260 | 0.881 | 0.012 | 0.947 |
6MWD, m | 0.241 | 0.157 | 0.262 | 0.123 | 0.296 | 0.079 |
FEV1, % predicted | 0.059 | 0.731 | 0.278 | 0.100 | 0.201 | 0.240 |
FEV1/FVC, % | 0.023 | 0.893 | 0.182 | 0.288 | 0.104 | 0.545 |
DLco/VA, % predicted | 0.238 | 0.163 | 0.338 | 0.044 | 0.339 | 0.043 |
LAA%, % | 0.384 | 0.021 | 0.296 | 0.079 | 0.359 | 0.031 |
FFM, kg | 0.624 | < 0.0001 | 0.510 | 0.002 | 0.612 | < 0.0001 |
SMM, kg | 0.542 | < 0.001 | 0.513 | 0.001 | 0.575 | < 0.001 |
HGS, kg | 0.519 | 0.001 | 0.395 | 0.017 | 0.503 | 0.002 |
CC, cm | 0.594 | < 0.001 | 0.507 | 0.002 | 0.587 | < 0.001 |
TEE, kcal/day | 0.663 | < 0.0001 | 0.679 | < 0.0001 | 0.732 | < 0.0001 |
BMR, kcal/day | 0.517 | 0.001 | 0.498 | 0.002 | 0.538 | < 0.001 |
PAL | 0.494 | 0.002 | 0.542 | < 0.001 | 0.578 | < 0.001 |
PEmax, cmH2O | 0.361 | 0.031 | 0.361 | 0.031 | 0.392 | 0.018 |
PImax, cmH2O | 0.005 | 0.975 | 0.133 | 0.438 | 0.060 | 0.726 |
Variable | ESMA | ESMD | ESM product | |||
---|---|---|---|---|---|---|
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/VA, % 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 |
Relationships between energy expenditure and muscle area, density, and area–density products
Variable | TEE | PAL | VIF | ||
---|---|---|---|---|---|
β | p | β | p | ||
PMA | 0.522 | < 0.001 | 0.442 | 0.008 | 1.076 |
PMD | 0.508 | < 0.001 | 0.501 | 0.004 | 1.201 |
PM product | 0.548 | < 0.0001 | 0.504 | 0.002 | 1.124 |
RAMA | 0.545 | < 0.0001 | 0.437 | 0.009 | 1.085 |
RAMD | 0.572 | < 0.0001 | 0.517 | 0.002 | 1.114 |
RAM product | 0.620 | < 0.0001 | 0.545 | 0.001 | 1.111 |
ESMA | 0.456 | 0.002 | 0.226 | 0.221 | 1.230 |
ESMD | 0.242 | 0.097 | 0.370 | 0.026 | 1.053 |
ESM product | 0.390 | 0.007 | 0.357 | 0.037 | 1.112 |
Variable | TEE | PAL | ||
---|---|---|---|---|
r | p | r | p | |
PMA | 0.559 | 0.002 | 0.344 | 0.073 |
PMD | 0.575 | 0.001 | 0.507 | 0.006 |
PM product | 0.600 | 0.001 | 0.455 | 0.015 |
RAMA | 0.643 | < 0.001 | 0.362 | 0.059 |
RAMD | 0.672 | < 0.0001 | 0.497 | 0.007 |
RAM product | 0.713 | < 0.0001 | 0.492 | 0.008 |
ESMA | 0.556 | 0.002 | 0.223 | 0.253 |
ESMD | 0.425 | 0.024 | 0.431 | 0.022 |
ESM product | 0.538 | 0.003 | 0.365 | 0.056 |