Oxygen uptake efficiency slope as a useful measure of cardiorespiratory fitness in morbidly obese women

Abstract

Cardiopulmonary assessment through oxygen uptake efficiency slope (OUES) data has shown encouraging results, revealing that we can obtain important clinical information about functional status. Until now, the use of OUES has not been established as a measure of cardiorespiratory capacity in an obese adult population, only in cardiac and pulmonary diseases or pediatric patients. The aim of this study was to characterize submaximal and maximal levels of OUES in a sample of morbidly obese women and analyze its relationship with traditional measures of cardiorespiratory fitness, anthropometry and pulmonary function. Thirty-three morbidly obese women (age 39.1 ± 9.2 years) performed Cardiopulmonary Exercise Testing (CPX) on a treadmill using the ramp protocol. In addition, anthropometric measurements and pulmonary function were also evaluated. Maximal and submaximal OUES were measured, being calculated from data obtained in the first 50% (OUES50%) and 75% (OUES75%) of total CPX duration. In one-way ANOVA analysis, OUES did not significantly differ between the three different exercise intensities, as observed through a Bland-Altman concordance of 58.9 mL/min/log(L/min) between OUES75% and OUES100%, and 0.49 mL/kg/min/log(l/min) between OUES/kg75% and OUES/kg100%. A strong positive correlation between the maximal (r = 0.79) and submaximal (r = 0.81) OUES/kg with oxygen consumption at peak exercise (VO2peak) and ventilatory anaerobic threshold (VO2VAT) was observed, and a moderate negative correlation with hip circumference (r = -0.46) and body adiposity index (r = -0.50) was also verified. There was no significant difference between maximal and submaximal OUES, showing strong correlations with each other and oxygen consumption (peak and VAT). These results indicate that OUES can be a useful parameter which could be used as a cardiopulmonary fitness index in subjects with severe limitations to perform CPX, as for morbidly obese women.

Women with metabolic syndrome show similar health benefits from high-intensity interval training than men

“…OUES was higher in men suggesting a better O 2 delivery and extraction of oxygen during exercise. Baseline OUES correlated positively with VO 2MAX [18, 48] in women and men. Our data showed that baseline OUES correlated significantly with VO 2MAX being the correlation coefficient higher in women.…”

Oxygen Supply System Management in an Overweight Adult after 12 Months in Antarctica—Study Case

“…Oxygen uptake efficiency slope (OUES), as a submaximal measure of cardiorespiratory functional reserve, is derived from the relation between oxygen uptake (V o 2 , mL/min) and minute ventilation (V e , liters/min) during incremental exercise and is determined by V o 2 = a log V e + b, where a = OUES, which shows the effectiveness of V o 2 [ 30 ]. Determination of the efficiency of oxygen uptake in overweight persons is already a golden standard of modern physiology [ 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. It is an indicator determining an organism’s oxygen consumption under dynamic conditions of physical activity.…”

Cardiopulmonary Exercise Testing for Preoperative Evaluation: What Does the Future Hold?

“…In common with the measurement of AT, one benefit of the OUES is that it can be obtained from a submaximal test, and so it is not as dependent on patient volition as a V O 2 measurement. It may also be useful in patients who are unable to perform a maximal exercise test as may be the case in morbid obesity [41] and those with poor mobility or joint problems. It is therefore possible to obtain useful data for the vast majority of patients.…”