ABSTRACT
Objective To study the physiological indexes of children receiving cardiopulmonary exercise testing (CPET) in order to provide some data for establishing the normal CPET reference value in Chinese children.Methods One hundred and twenty-eight healthy children underwent the CPET with the standard scheme.All children were divided into 3 groups according to ages:3-6 years old, ＞6-10 years old and ＞ 10-14 years old.The physiological indexes of CPET were collected, including maximal oxygen uptake (VO2max/kg) , oxygen uptake at anaerobic threshold (VO2/kg@AT), maximal tolerance power (Pmax), maximal heart rate (HRmax), peak respiratory minute volume to CO2 (peak VE/VCO2), slope of respiratory minute volume to CO2 (VE/VCO2 slope), maximal tidal volume (VTmax) and the maximal minute ventilation (VEmax).The range in normal values for physiological CPET variables was recorded.Results The VO2max/kg was (31.71 ± 7.31) mL/(min · kg), (31.05 ± 5.96) mL/(min · kg), and (34.10 ±8.72) mL/(min · kg) in the 3-6 years old group, ＞6-10 years old group and ＞ 10-14 years old group of boys.The VO2/kg@AT was (28.32 ± 10.20) mL/ (min · kg), (23.13 ± 9.56) mL/(min · kg), and (22.18 ± 7.72) mL/(min · kg)in the 3-6 years old group, ＞6-10 years old group and ＞ 10-14 years old group of boys.The VO2 max/kg was (29.27 ± 4.19) mL/(min · kg), (30.67 ± 5.59) mL/ (min · kg) (29.18 ± 6.56) mL/ (min · kg) in the 3-6 years old group, ＞ 6-10 years old group and ＞ 10-14 years old group of girls.The VO2@AT was (26.64 ±9.49) mL/(min · kg) ,(20.53 ±7.66) mL/(min · kg) ,(17.83 ±6.49) mL/(min · kg)in the 3-6 years old group, ＞6-10 years old group and ＞ 10-14 years old group of girls.VO2max/kg and VO2/kg@AT did not change with age,there was no gender difference in VO2max/kg(P ＞0.05).VO2/kg@AT of boys was higher than girls in the 3-6 years old group(t =2.351 ,P =0.023).The Pmax,VEmax and VTmax increased with the growth of age(boy: F =49.436,24.290,28.958, all P ＜ 0.001;girl : F =58.287,42.990,28.802, all P ＜ 0.001), but not significant in different gender group(P ＞ 0.05).In boys peak VE/VCO2, VE/VCO2 slope and HRmax were significantly different (F =4.758,P =0.012;F =8.050, P =0.001;F =3.869, P =0.026), however these indexes were not significantly different in girls(all P ＞ 0.05).Conclusions This study provides a set of data for the most important CPET variables in Chinese children.VO2max/kg does not change with age,so it can be used as a valuable parameter in exercise ability evaluation.