VENTILATORY AND METABOLIC RESPONSES DURING FIELD TESTS AND CPX IN OBESE ADULTS

Abstract

The 6 minute walk test (6MWT) and the incremental shuttle walking test (ISWT) have been used as an alternative to the Cardiopulmonary Exercise Test (CPX) for functional evaluation as well after rehabilitation programs. The objective was to analysis the cardiorespiratory and metabolic demands among the ISWT, 6MWT and CPX in the obese and the contribution of adiposity markers on this response. An observational and cross-sectional study was conducted with fifteen obese (10 women; 39.4+10.1years), performing CPX, 6MWT and ISWT. The subjects were as initial part of a rehabilitation program and bariatric surgery at the University Hospital. Metabolic and ventilatory variables were recorded by a telemetry system during all tests. Peak oxygen uptake-VO2peak was similar between CPX (18.6±4.0ml/kg/min) and ISWT (15.4±2.9ml/kg/min) and different from 6MWT (13.2±2.5ml/kg/min). There was agreement (3.2ml/kg/min; 95%; IC-3.0-9.4) between VO2peak of CPX and ISWT. CPX duration (R2=0.61;p=0.001) was best-fit by waist circumference (WC) and the body adiposity index(BAI) that reduced 4.7% and 3.2% CPX duration respectively. Forced vital capacity-FVC and WC predicts increasing of carbon dioxide production (VCO2) on CPX (R2=0.95;p=0.001) and ISWT (R2=0.67;p=0.001). In conclusion the obese individuals perform the ISWT and CPX test with similar physiological responses. It is suggested that, ISWT could be an alternative to CPX and that metabolic monitoring of ISWT by telemetry can be useful for the clinical assessment of the functional capacity of the obese.