Comparison of different VO2max equations in the ability to discriminate the metabolic risk in Portuguese adolescents.

Abstract: There is increasing evidence that cardiorespiratory fitness (CRF) is an important health marker already in youth. This study aimed to determine the ability of five VO_2max equations to discriminate between low/high Metabolic Risk in 450 Portuguese adolescents aged 10–18. We measured waist and hip circumferences, fasting glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and blood pressure. For each of these variables, a Z-score was computed. The HDL-cholesterol was multiplied by −1. A metabolic risk score was constructed by summing the Z scores of all individual risk factors. High risk was considered when the individual had ≥1 SD of this score. Cardiorespiratory fitness (CRF) was measured with the 20-m shuttle run test. We estimated VO_2max from the CRF tests using five equations. ROC analyses showed a significant discriminatory accuracy for the Matsuzaka and Barnett(a) equations in identifying the low/high metabolic risk in both genders (Matsuzaka girls: AUC=0.654, 95%CI: 0.591–0.713, p <0.001, VO_2max =39.5mLkg⁻¹ min⁻¹; boys: AUC=0.648, 95%CI: 0.576–0.716, p <0.001, VO_2max =41.8mLkg⁻¹ min⁻¹; Barnett(a) girls: AUC=0.620, 95%CI: 0.557–0.681, p <0.001, VO_2max =46.4mLkg⁻¹ min⁻¹; boys: AUC=0.628, 95%CI: 0.555–0.697, p =0.04, VO_2max =42.6mLkg⁻¹ min⁻¹), and the Ruiz equation in boys (AUC=0.638, 95%CI: 0.565–0.706, p <0.001, VO_2max =47.1mLkg⁻¹ min⁻¹). The VO_2max values found require further testing in other populations as well as in longitudinal studies; the identification of adolescents who have low CRF levels can help detect youth with an increased risk of metabolic disease. [ABSTRACT FROM AUTHOR]