Clinical characteristics at baseline and follow-up
| Baseline | Follow-up | Change | 95% CI# | p-value | |||
| No follow-up (n=30) | Returning (n=31) | at 3 years (n=31) | Baseline to follow-up | Per year | |||
| Demographics | |||||||
| Age years | 65 (9) | 67 (8) | 70 (8) | – | – | – | – |
| Male % | 77.3 | 61.3 | 61.3 | – | – | – | – |
| Current smoker % | 10.0 | 12.9 | 6.5 | – | – | – | – |
| Smoking history pack years | 40 (20) | 52 (40) | 52 (40) | – | – | – | – |
| BMI kg·m–2 | 22.6 (4.7)¶ | 26.7 (5.1) | 26.7 (6.0) | −0.01 (1.66) | 0.00 | −0.62 to 0.60 | 0.1 |
| MRC dyspnoea score (out of 5) | 3 (1.4) | 3 (1.1) | 3 (1.3) | −0.16 (1.24) | −0.05 | −0.55 to 0.28 | 0.5 |
| Respiratory measurements | |||||||
| FEV1% predicted | 38.3 (17.5) | 47.0 (20.2) | 42.8 (21.5) | −5.56 (15.0) | −1.62 | −5.81 to −0.54 | 0.02 |
| FEV1/FVC | 0.34 (0.14) | 0.38 (0.16) | 0.40 (0.16) | 0.01 (0.16) | 0.00 | −0.01 to 0.07 | 0.1 |
| Exacerbations per year | 2.1 (2.4) | 1.8 (2.0) | 2.1(2.2) | 0.26 (2.85) | 0.07 | −0.82 to 1.35 | 0.6 |
| Muscle indices | |||||||
| 6MWD min | 408 (116) | 399 (132) | 325 (172) | −71.7 (162) | −16.8 | −119 to −27.4 | 0.003 |
| SPPB total score (out of 12) | 10 (1.9) | 11 (1.4) | 9 (3.0) | −1.42 (2.99) | −0.45 | −2.70 to −0.40 | 0.01 |
| Balance score (out of 4) | 4.0 (0.4) | 4.0 (0.2) | 3.7 (1.0) | −0.39 (1.21) | −0.1 | −0.84 to 0.06 | 0.09 |
| Gait speed score (out of 4) | 3.8 (0.4) | 3.8 (0.5) | 3.4 (1.1) | −0.39 (1.09) | −0.1 | −0.79 to 0.01 | 0.06 |
| 4 m gait speed time s | 4.2 (0.8) | 4.2 (0.9) | 4.3 (1.5) | −0.03 (1.59) | −0.1 | −0.64 to 0.45 | 0.7 |
| Chair-stand score (out of 4) | 2.6 (1.4)¶ | 3.1 (1.0) | 2.3 (1.3) | −0.87 (1.31) | −0.3 | −1.35 to −0.39 | 0.0009 |
| Chair-stand time s | 16.1 (13.3)¶ | 13.8 (9.4) | 19.3 (14.7) | 5.46 (15.8) | 1.6 | 0.47 to 13.1 | 0.05 |
| FFM kg | 46.8 (9.1)¶ | 52.1 (9.8) | 50.3 (11.4) | −1.80 (3.47) | −0.58 | −3.08 to −0.53 | <0.01 |
| FFMI | 14.3 (3.4) | 16.3 (2.2) | 16.3 (3.2) | 0.06 (1.66) | 0.02 | −0.54 to 0.67 | 0.8 |
| QMVC kg | 28.8 (9.5) | 32.6 (8.0) | 27.2 (9.0) | −5.20 (11.2) | −1.48 | −7.19 to −2.90 | <0.0001 |
| QMVC % predicted | 68.8 (29.7) | 72.7 (16.7) | 64.8 (18.8) | −7.39 (12.9) | −2.20 | −12.3 to −2.50 | <0.01 |
| RFCSA mm2 | 516 (184) | 603 (136) | 449 (126) | −154 (245) | −42.2 | −181 to −99.8 | <0.0001 |
| SNIP | 56.0 (19.2) | 53.7 (24.2) | 60.6 (19.2) | 4.6 (20.1) | 1.94 | −2.760 to 11.99 | 0.2 |
| Cardiovascular indices | |||||||
| Systolic BP mmHg | 132 (14.2) | 140 (16.3) | 136 (16.3) | −3.97 (19.3) | −1.39 | −11.1 to 3.12 | 0.7 |
| aPWV m·s−1 | 10.6 (3.5) | 10.7 (2.7) | 10.3 (2.7) | −2.35 (5.63) | −0.66 | −1.44 to 0.96 | 0.7 |
| Inflammatory markers | |||||||
| Fibrinogen g·dL−1 | 3.8 (0.9) | 3.4 (0.7) | 3.8 (0.8) | 0.35 (0.51) | 0.11 | 0.16 to 0.54 | <0.001 |
| WCC ×109·L−1 | 7.2 (1.7) | 8.0 (2.9) | 7.9 (2.3) | −0.10 (2.62) | 0.02 | −10.5 to 4.66 | 0.4 |
| hsCRP mg·L−1 | 9.8 (16.3) | 11.4 (22.5) | 8.1 (19.6) | −13.1(22.1) | −4.02 | −0.86 to 1.06 | 0.8 |
Baseline, follow-up and change data are expressed as mean (standard deviation) unless otherwise stated. BMI: body mass index; MRC: Medical Research Council; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; 6MWD: 6-min walk distance; SPPB: short physical performance battery; FFM: fat-free mass; FFMI: fat-free mass index; QMVC: quadriceps maximal voluntary contraction; RFCSA: rectus femoris (cross-sectional area); SNIP: maximal sniff nasal inspiratory pressure; BP: blood pressure; aPWV: aortic pulse wave velocity; WCC: white cell count; hsCRP: high-sensitivity C-reactive protein. #: confidence interval based on change from baseline to follow-up; ¶: baseline measure differed significantly between the returning cohort and the non-follow-up cohort.