Incremental cardiopulmonary exercise testing on a cycle ergometer (peak exercise data) in patients with chronic hypersensitivity pneumonitis (cHP) and healthy subjects

cHPHealthy subjectsp-value
Subjects n2818
Exercise time min7.24±3.027.17±2.050.89
Work rate W66±35138±69<0.001
Work rate % pred53±23104±35<0.001
V′O2 mL·kg−1·min−116.6 (12.3–19.98)25.1 (16.9–32.0)0.003
V′O2 %pred83 (63–97)112 (89–118)<0.001
VE L·min−150 (42–63)71 (45–89)0.05
Breathing reserve % MVV12 (6.4–34.8)41 (32.7–50.8)<0.001
VE/V′CO2 slope37±531±4<0.001
VT L0.91 (0.82–1.25)1.75 (1.29–2.21)<0.001
Respiratory rate breaths·min−152±1140±100.001
ΔPETCO2 mmHg-0.24±2.67-0.11±2.830.88
HR beats·min−1133±20149±260.03
HR % pred84 (75–89)95 (88–99)0.008
V′O2/HR mL·beat−1·min−19.5±2.912.6±5.00.01
V′O2/HR % pred93±19122±29<0.001
SpO2 %81±795±2<0.001
Borg dyspnoea score8 (5–10)4 (1–7)0.004
Borg leg discomfort score8 (4–9)7 (4–9)0.71
ΔIC from rest L-0.01±0.200.11±0.250.08
ΔIC from rest %1.92±124.96±110.43

Data are presented as mean±sd or median (25th–75th percentile), unless otherwise stated. RER: respiratory exchange rate; V′O2: oxygen production; VE: minute ventilation; MVV: maximal voluntary ventilation; V′CO2: carbon dioxide production; VT: tidal volume; IC: inspiratory capacity; PETCO2: end-tidal carbon dioxide tension; HR: heart rate; SpO2: arterial oxygen saturation measured by pulse oximetry.