A Reference Equation for Peak Oxygen Uptake for Pediatric Patients Who Undergo Treadmill Cardiopulmonary Exercise Testing

Pediatric patients are often referred to cardiopulmonary exercise testing (CPET) laboratories for assessment of exercise-related symptoms. For clinicians to understand results in the context of performance relative to peers, adequate fitness-based prediction equations must be available. However, reference equations for prediction of peak oxygen uptake (VO_2peak) in pediatrics are largely developed from field-based testing, and equations derived from CPET are primarily developed using adult data. Our objective was to develop a pediatric reference equation for VO_2peak. Clinical CPET data from a validation cohort of 1,383 pediatric patients aged 6 to 18 years who achieved a peak respiratory exchange ratio ≥1.00 were analyzed to identify clinical and exercise testing factors that contributed to the prediction of VO_2peak from tests performed using the Bruce protocol. The resultant prediction equation was applied to a cross-validation cohort of 1,367 pediatric patients. Exercise duration, gender, weight, and age contributed to the prediction of VO_2peak, generating the following prediction equation: (R² = 0.645, p <0.001, standard error of the estimate = 6.19 ml/kg/min): VO_2peak (ml/kg/min) =16.411+ 3.423 (exercise duration [minutes]) - 5.145 (gender [0 = male, 1 = female]) - 0.121 (weight [kg]) + 0.179 (age [years]). This equation was stable across the age range included in the present study, with differences ≤0.5 ml/kg/min between mean measured and predicted VO_2peak in all age groups. In conclusion, this study represents what we believe is the largest pediatric CPET-derived VO_2peak prediction effort to date, and this VO_2peak prediction equation provides clinicians who perform and interpret exercise tests in pediatric patients with a resource with which to better quantify fitness when CPET is not available.