Relevant data from studies used to demonstrate the reviews conclusions

First author [ref.] and parameterHVS suspectsControlsp-value
Kinnula [28]n=10n=10
 Resting PaCO2 kPa4.10±0.60ND
 Resting pH7.46±0.06ND
VeqCO2 at 40–50 W exercise41.8±6.0030.0±3.300.01
Jack [29]n=23n=23
 Resting PaCO2 kPa3.87±0.60ND
VeqCO2 at 40 W exercise38.4±5.7028.9±2.50ND
Brat [19]n=29n=29
 Resting arterial PaCO2 kPa4.80 (4.40–4.93)4.80 (4.53–5.07)0.44
 Resting arterial pH7.45 (7.43–7.47)7.44 (7.43–7.45)0.07
 Peak exercise PaCO2 kPa3.87±0.534.67±0.40<0.01
 Peak exercise arterial pH7.47 (7.46–7.50)7.40 (7.37–7.42)<0.01
 Resting d/VT0.21±0.110.22±0.100.77
 Peak exercise d/VT0.18±0.050.13±0.06<0.01
VeqCO2 at rest38.0 (33.0–44.0)37.0 (32.0–40.0)0.31
VeqCO2 at peak exercise38.0 (35.0–43.0)31.0 (27.0–34.0)<0.01
VE/VCO2 slope37.0 (33.0–34.0)27.0 (24.0–30.0)<0.01
Troosters [30]n=24n=20
 NQ scores30.3±9.707.90±5.20<0.001

Data are presented as mean±sd or median (interquartile range), unless otherwise stated. HVS: hyperventilation syndrome; PaCO2: arterial carbon dioxide tension; VeqCO2: ventilatory equivalent for carbon dioxide; d/VT: ratio of dead space volume to tidal volume; ND: not disclosed in study. VE/VCO2 slope: gradient of the VE (abscissa) and VCO2 (ordinate) slope; NQ: Nijmegen Questionnaire.