Prediction Equations for Maximum Aerobic Capacity Using Cardiopulmonary Exercise Testing Among Thais

Abstract

Maximum aerobic capacity  is the most important parameter of cardiopulmonary fitness and an independent parameter for cardiovascular and respiratory disease prognosis. Prediction equations for  varies with age, gender, body size, level of ordinary activity, type of exercise and races. Those equations have never been studied in Thais. This study aimed to provide prediction equations for  in Thai males and females and to evaluate associations between age, weight and height, and . The maximum aerobic capacity was analysed in 44 healthy Thai subjects (20 males and 24 females; aged 20 – 50 years) who underwent cardiopulmonary exercise testing (CPET) using a treadmill and an incremental protocol until symptom limitation. All subjects had normal ranges of clinical characteristics and pulmonary function except those of weight and height in males were higher than in females (p<0.001) while age in males was lower than in females (p<0.05). Predictive equations for  were obtained from multiple linear regression analysis and significant correlations demonstrated a negative correlation between  and age (p<0.05), and positive correlations between  and weight and height (p<0.001). The  prediction equation:  = 3222.9 + (792.4 * sex) + (-11.3 * age) + (21.0 * weight) + (-15.7 * height) (R 2 = 0.72, SEE=308.5 ml/min) (1 = male, 0 = female; age in years (yr); weight in kilograms (kg); height in centimeters (cm)). In addition,  in males was significantly higher than in females by 59% (p<0.001). The present study provides the prediction equation for  applicable to the Thai population. Nonetheless, it is compulsory to have more sets of normal values to be accumulated so that reference values can be established in the future. We also demonstrate that males have  higher than those of females.