Demographic and baseline clinical characteristics
| Placebo BRJ (n=65) | Nitrate-rich BRJ (n=57) | P value | |
| Gender, n (% female) | 26 (41) | 27 (42) | 1 |
| Age (years) | 68 (62, 74) | 70 (64, 78) | 0.3 |
| Smoking (pack-years) | 45 (29, 60) | 45 (26, 60) | 0.6 |
| BMI (kg/m2) | 26 (23, 31) | 27 (24, 32) | 0.6 |
| FEV1 (L) | 1.1 (0.8, 1.4) | 1.2 (1.0, 1.6) | 0.4 |
| FEV1 (% predicted) | 48 (33, 63) | 53 (37, 65) | 0.3 |
| GOLD stage | |||
| 2, n (%) | 27 (42) | 31 (54) | 0.4 |
| 3, n (%) | 24 (37) | 20 (35) | 1.0 |
| 4, n (%) | 14 (21) | 6 (11) | 1.0 |
| FFM (kg) | 48.4 (41.7, 57.4) | 48.9 (43.2, 55.5) | 0.8 |
| FFMI (kg/m2) | 17.1 (15.5, 19.8) | 17.5 (15.9, 19.2) | 0.8 |
| Baseline ISWT (m) | 280 (210, 395) | 270 (190, 360) | 0.7 |
| Inhalers | |||
| LABA, n (%) | 2 (3) | 0 (0) | 0.2 |
| LAMA, n (%) | 50 (77) | 50 (88) | 0.4 |
| LABA-ICS, n (%) | 39 (60) | 38 (67) | 0.1 |
| LABA-LAMA, n (%) | 7 (11) | 2 (4) | 0.1 |
| MRC dyspnoea score | 3 (3, 3) | 3 (3, 3) | 0.7 |
| CAT score | 19 (13, 23) | 20 (13, 24) | 0.9 |
| HADS-A | 6 (3, 10) | 7 (3, 10) | 1.0 |
| HADS-D | 5 (3, 9) | 5 (3, 8) | 1.0 |
| Baseline systolic BP (mm Hg) | 130 (120, 145) | 135 (124, 152) | 0.2 |
| Baseline diastolic BP (mm Hg) | 80 (74, 87) | 82 (75, 88) | 0.5 |
| Baseline MAP (mm Hg) | 96 (90, 106) | 100 (95, 107) | 0.1 |
| Baseline PAL | 3.0 (2.6, 3.8) | 3.0 (2.4, 4.3) | 0.9 |
| Baseline step count (per day) | 3791 (2271, 6885) | 3507 (1605, 5314) | 0.3 |
| Baseline time >3 METs (min) | 43 (13, 94) | 17 (8, 36) | 0.03 |
Data shown are median (IQR) or number (%). P values are for Mann-Whitney U test between groups.
BMI, body mass index; BP, blood pressure; BRJ, beetroot juice; CAT, COPD Assessment Test; FFM, fat-free mass; FFMI, fat-free mass index; GOLD, Global Initiative for Chronic Obstructive Lung Disease; HADS-A, Hospital Anxiety and Depression Scale-Anxiety; HADS-D, Hospital Anxiety and Depression Scale-Depression; ICS, inhaled corticosteroids; ISWT, incremental shuttle walk test; LABA, long-acting beta agonist; LAMA, long-acting muscarinic agonist; MAP, mean arterial pressure; METs, metabolic equivalents of task; MRC, Medical Research Council; PAL, physical activity level.