Interobserver variability of ventilatory anaerobic threshold in asymptomatic volunteers

Table 1 Descriptive Statistics of the Study Population (N = 1,056)

Parameter	Missing data, n	n (%)	Median (interquartile range)
Men		515 (48.8%)
Age, years			60 (49–69)
Weight, kg			79 (69–90)
Height, cm			169 (162–176)
BMI, kg/m²			27.3 (24.6–30.6)
BMI ≥ 30 kg/m²		298 (28.2%)
Smoking status	2
Never smokers		404 (38.3%)
Former smokers		485 (46.0%)
Current smokers		165 (15.7%)
Physically active^a		870 (82.4%)
Myocardial infarction	2	25 (2.4%)
Atrial fibrillation	8	54 (5.1%)
Heart failure	125	30 (3.2%)
Fractional shortening below normal^b	324	2 (0.3%)
Heart operation	1	22 (2.1%)
Pacemaker	3	5 (0.5%)
Previous pulmonary disease	2	52 (4.9%)
Chronic bronchitis^c	1	53 (5.0%)
Asthma	4	55 (5.2%)
Maximum exercise duration, s			536 (420–670)
Maximum power, W			148 (132–196)
peak VO₂, mL/min	2		1,812 (1,482–2,292)
VO₂@AT, mL/min			1,009 (867–1,204)
VO₂@AT/peak VO_{2 reference}, % ^d			54.6 (47.1–63.7)
VO₂@AT/peak VO_{2 reference} < 45% ^d		163 (15.4%)
RER@AT			0.82 (0.77–0.86)
FEV₁/FVC, %	3		75.7 (71.4–79.7)
FEV₁/FVC < 70%		199 (18.9%)

Anamnestic data based on survey by professional interviewer. Continuous data are expressed as the median (25^th; 75^th quartile). Nominal data are given as percentages
^a Volunteers were asked about their physical activity and categorized as “Physically active” in case of 1–2 h of activity per week in summer and winter
^b The echocardiographic parameter “fractional shortening” was calculated as (left ventricular diastolic – systolic diameter [in cm]) × 100. Pathologic values were < 19% in males and < 21% in females
^c Subgroups may overlap
^d Predicted values were calculated according to Gläser S et al. [28] These were: peak VO₂ in males = 254.76–22.69 × age [years] + 17.25 × height [cm] + 4.41 × weight [kg]; and peak VO₂ in females = −54.74 – 9.81 × age [years] + 9.92 × height [cm] + 8.06 × weight [kg]
BMI Body mass index, peak VO₂ Peak oxygen uptake, VO₂@AT Oxygen uptake at the aerobic-anaerobic threshold, RER Respiratory exchange ratio, FEV₁/FVC Forced expiratory volume in 1 s/forced vital capacity

ISSN: 2049-6958