Baseline clinical characteristics expressed as n/%, mean (SD) and median (25th and 75th centiles)
| No sarcopenia (n=220) | Low SMI only (n=27) | Low function only (n=285) | Sarcopenia (n=90) | p Value | |
|---|---|---|---|---|---|
| Age (years) | 66 (10) | 69 (7) | 73 (9)* | 73 (8)* | <0.001 |
| Sex (M:F) | 147:73 | 14:13 | 136:149* | 57:33 | <0.001 |
| MRC | 3 (1) | 3 (1) | 4 (1)* | 4 (1)* | <0.001 |
| FEV1 (% predicted) | 46.3 (18.6) | 37.9 (16.6) | 45.6 (17.7) | 40.5 (19.6) | 0.013 |
| LTOT (n/%) | 12/5 | 1/4 | 19/7 | 4/9 | 0.811 |
| Use of walking aid (n/%) | 5/2 | 0/0 | 54/19* | 15/17* | <0.001 |
| BMI (kg/m) | 28.8 (5.7) | 21.1 (3.0)* | 29.2 (6.2) | 21.4 (4.0)* | <0.001 |
| SMM (kg) | 26.6 (6.9) | 18.8 (5.0)* | 22.9 (6.5) | 18.9 (5.1)* | <0.001 |
| SMI (kg/m2) | 9.2 (1.8) | 6.8 (1.4)* | 8.6 (1.8)* | 6.9 (1.3)* | <0.001 |
| Handgrip (kg) | 33.9 (8.6) | 29.6 (7.5) | 22.6 (8.4)* | 21·5 (7.3)* | <0.001 |
| Peak QMVC (kg) | 32.2 (10.5) | 23.0 (7.6)* | 23.3 (8.2)* | 19.8 (7.6)* | <0.001 |
| QMVC % predicted | 70.1 (17.0) | 63.1 (14.4) | 56.3 (14.3)* | 54.9 (16.3)* | <0.001 |
| 4MGS (m/s) | 1.07 (0.16) | 1.00 (0.16) | 0.77 (0.21)* | 0.77 (0.22)* | <0.001 |
| 5STS (s) | 12.4 (10.4, 14.8) | 14.1 (11.4, 13.9) | 16.1 (12.8, 26.7)* | 19.6 (12.9, 60.0)* | <0.001 |
| SPPB | 11 (1) | 11 (1) | 8 (3)* | 8 (3)* | <0.001 |
| ISWT (m) | 309 (153) | 257 (99) | 152 (106)* | 157 (118)* | <0.001 |
| CAT | 19 (7) | 22 (7) | 23 (8)* | 24 (9) * | <0.001 |
| SGRQ total | 47.3 (16.1) | 51.0 (14.0) | 55.9 (17.1)* | 57.1 (17.5) * | <0.001 |
| Smoking status (current:former:never) | 43:170:7 | 6:19:2 | 49:216:20 | 16:67:7 | 0.561 |
| Charlson Index | 1 (1, 2) | 1 (1, 3) | 1 (1, 3) | 1 (1, 2) | 0.151 |
| Hospital inpatient days previous 12 months | 0 (0, 2) | 0 (0, 2) | 0 (0, 5) | 0 (0, 4) | 0.791 |
| Number of exacerbations previous 12 months | 2 (1, 3) | 2 (1, 5) | 2 (1, 4) | 2 (1, 4) | 0.128 |
| Self-report physical activity | |||||
| Energy expenditure (kcal/week) | 780.3 (388.1, 1567.5) | 695.6 (288.8, 1506.3) | 380.0 (89.1, 868.1)* | 376.3 (56.9, 734.4)* | <0.001 |
| Time in moderate activity (min/week) | 224.0 (108·8, 450.6) | 193.1 (82.5, 432.5) | 110.3 (27.3, 241.9)* | 107.5 (22.5, 207.5)* | <0.001 |
| Objective physical activity (n=129) | |||||
| Daily step count | 5127 (2475, 6815) | 3916 (1679, 5411) | 2697 (1129, 4995) | 1482 (1205, 3301) | <0.001 |
| Physical activity level (METS/day) | 1.45 (0.22) | 1.60 (0.21) | 1.38 (0.85) | 1.36 (0.12) | 0.034 |
| Time in moderate intensity activity ≥3 METS (min/day) | 47 (20, 106) | 108 (63, 223) | 30 (8, 69) | 35 (5, 82) | 0.018 |
| Active energy expenditure (kcal/day) | 246 (106, 473) | 466 (219, 847) | 134 (42, 329) | 105 (25, 276) | 0.006 |
*Significant difference to ‘no sarcopenia’ reference group.
4MGS, 4-metre gait speed; 5STS, five-repetition sit-to-stand test; BMI, body mass index; CAT, COPD Assessment Test; iBODE, body mass index, obstruction, dyspnoea, exercise capacity Index; ISWT, incremental shuttle walk test; kcal, kilocalorie; LTOT, long-term oxygen therapy; METS, metabolic equivalents; MRC, Medical Research Council; SGRQ, St George's Respiratory Disease Questionnaire; SMI, Skeletal Muscle mass Index; SMM, skeletal muscle mass; SPPB, short physical performance battery; QMVC, quadriceps maximum voluntary contraction.