Oxygen kinetics during 6-minute walk tests in patients with cardiovascular and pulmonary disease

BMC Pulmonary Medicine

Table 1 Characteristics of participants

	Healthy	COPD	Restrictive	PAH	CHF
n	16	84	39	54	27
Sex (females)	8	40	21	36	12
Age (years)	37 ± 12	62 ± 14	63 ± 11	61 ± 14	70 ± 9
BMI (kg/m²)	24 ± 4	26 ± 6	30 ± 7	28 ± 6	31 ± 8
FEV₁(l/s)	3.9 ± 0.9	1.3 ± 0.5	1.8 ± 0.6	1.9 ± 0.7 (n = 53)	2.4 ± 0.8
FVC (l)	5.0 ± 1.3 (n = 15)	2.6 ± 0.8	2.3 ± 0.8	2.8 ± 1.0 (n = 53)	3.3 ± 1.2
FEV₁/FVC	0.8 ± 0.1 (n = 15)	0.5 ± 0.1 (n = 82)	0.8 ± 0.1	0.7 ± 0.2 (n = 53)	0.7 ± 0.1
VO_2SS (ml/min)	2376 ± 630	1031 ± 264	1144 ± 299	961 ± 263	1184 ± 342
VO_2MAX (ml/min)	2377 ± 630	1012 ± 272	1156 ± 289	945 ± 261	1191 ± 331
VO_2MAX (% predicted)	96 ± 15	60 ± 17	66 ± 19	58 ± 18	66 ± 14
HRmax (%predicted)	86 ± 10	69 ± 13	71 ± 12	73 ± 16	70 ± 13
Walking distance (m)	720 ± 83	357 ± 110	381 ± 111	339 ± 120	341 ± 91
Borg	4.1 ± 2.4	4.8 ± 2.4 (n = 80)	4.7 ± 2.1	4.9 ± 2.6	4.5 ± 2.5
Follow-up time (months)	38 ± 6	16 ± 13	21 ± 16	16 ± 14	14 ± 12
Death (n)	0	4	3	10	0
Hospitalizations during follow-up	0	34	17	27	14
MRT (min)	1.13 ± 0.28	1.06 ± 0.28	1.08 ± 0.32	1.07 ± 0.30	0.92 ± 0.34
wMRT (min²/ml)	0.66 × 10^-3 ± 0.13	2.18 × 10^-3 ± 1.68	1.72 × 10^-3 ± 0.81	2.59 × 10^-3 ± 1.18	1.62 × 10^-3 ± 0.55

Data are presented as mean (SD). BMI: body mass index; FEV₁: forced expiratory volume in one second; FVC; forced expiratory vital capacity: FEV₁/ FVC ratio: forced expiratory volume in 1 sec (FEV₁) expressed as % of FVC; VO_2SS = oxygen uptake at steady state; VO_2MAX = maximum oxygen uptake; HRmax: maximum heart rate: MRT: mean response time; wMRT: mean response time corrected for work rate.
The participants are grouped into 5 categories: healthy controls (Healthy); restrictive lung disease (Restrictive); chronic obstructive pulmonary disease (COPD); pulmonary arterial hypertension (PAH); congestive heart failure (CHF).

ISSN: 1471-2466