Table 2.
Characteristics of “PA responders” (>1,000 steps/day) vs “nonresponders”
| Participant characteristics | N | “PA responder” | N | “PA nonresponder” | P-value |
|---|---|---|---|---|---|
|
| |||||
| Age | 75 | 64.4±7.3 | 161 | 65.5±8.0 | 0.29 |
| BMI | 75 | 25 [22–28] | 161 | 25 [22–30] | 0.73 |
| FEV1, % predicted | 75 | 50.8±15.9 | 160 | 44.8±17.6 | 0.012 |
| TLC, % predicted | 75 | 112.4±16.9 | 157 | 119.8±22.7 | 0.013 |
| FRC, % predicted | 75 | 150.9±39.1 | 155 | 164.8±41.9 | 0.017 |
| TLCO, % predicted | 74 | 54.8±19.2 | 146 | 52.3±18.0 | 0.35 |
| MRC score | 59 | 3 [2–3] | 126 | 3 [3–4] | 0.024 |
| CRDQtotal | 72 | 87.6±21.4 | 151 | 79.5±18.5 | 0.004 |
| Physical activity, steps/day | 75 | 4,210±2,488 | 161 | 4,222±2,526 | 0.97 |
| 6MWDi group (<350 m/≥350 m), n | 75 | 11/64 | 161 | 56/105 | 0.001 |
| 6MWDi, m | 75 | 444±103 | 161 | 382±115 | <0.001 |
| VO2 peak (mL/kg/min) | 75 | 16.8±3.9 | 160 | 14.8±3.9 | <0.001 |
| Wmax | 75 | 70.7±27.2 | 160 | 58.2±23.6 | <0.001 |
| Quadriceps force, Nm | 71 | 126.1±40.1 | 157 | 111.7±40.1 | 0.012 |
|
| |||||
| Δ FEV1, % predicted | 75 | -0.02±5.94 | 156 | 0.21±5.55 | 0.78 |
| Δ CRDQdyspnea | 72 | 5.7±5.2 | 142 | 4.9±5.1 | 0.27 |
| Δ CRDQtotal | 65 | 15.9±11.5 | 135 | 14.3±11.9 | 0.37 |
| Δ 6MWD, m | 75 | 57.2±67.6 | 156 | 41.4±47.7 | 0.042 |
| 6MWD responders >30 m (n, %) | 75 | 52 (69.3%) | 156 | 98 (62.8%) | 0.33 |
| Δ VO2peak (mL/kg/min) | 74 | 1.13±3.00 | 146 | 1.37±2.75 | 0.55 |
| Δ Quadriceps force (Nm) | 71 | 16.5±23.9 | 153 | 13.5±15.1 | 0.27 |
Notes: Data are median [IQR] or mean ± SD. Bold font denotes statistical significance; Dashed line separates baseline and change (Δ) variables.
Abbreviations: 6MWD, six-minute walk distance; 6MWDi, initial six-minute walk distance; BMI, body mass index; CRDQ, Chronic Respiratory Disease Questionnaire; FEV1, forced expiratory volume in the first second; FRC, functional residual capacity; MRC, Medical Research Council dyspnea scale (score range 1–5); Nm, newton-meters; PA, physical activity; TLC, total lung capacity; TLCO, transfer factor of carbon monoxide.