Physiology of oxygen uptake kinetics: Insights from incremental cardiopulmonary exercise testing in the Study of Health in Pomerania

Abstract

BackgroundCardiopulmonary exercise testing allows for assessment of cardiac and respiratory limitation, but is often affected by patient effort. Indices of oxygen kinetics, including the oxygen uptake efficiency slope (OUES), oxygen uptake–work-rate slope (VO2–WR slope) and the heart rate–oxygen uptake slope (HR–VO2 slope) are relatively effort independent but may be affected by patient characteristics.The objective of this study is to identify the impact of factors, such as age, gender, body size, respiratory function, smoking and beta-blockade on these parameters, as well as generate predictive equations.Methods1708 volunteers from the population-based Study of Health in Pomerania underwent an incremental bicycle exercise protocol. Markers of oxygen kinetics were calculated. Participants with structural heart disease, echocardiographic or lung function pathology were excluded, leaving 577 males and 625 females. Age, height, weight, smoking, forced expiratory volume in 1 s (FEV1) and beta-blockers were analysed for their influencing power by gender. Quantile regression analysis determined the reference equations for each parameter.ResultsAge, gender, height, weight and FEV1 (but not percent predicted FEV1) are strongly related to OUES. Participants using beta-blockers and male smokers had significantly lower OUES values. VO2–WR slope was minimally affected by age, gender, weight and FEV1. Gender, height, weight and beta-blocker use, but not FEV1 and smoking status, were related to the HR–VO2 slope whilst age was only related in females.ConclusionsMarkers of oxygen kinetics are differentially affected by patient characteristics. This study provides normal reference values for these variables thereby facilitating interpretation of oxygen uptake kinetics in health and disease.

The association of N-terminal pro-brain-type natriuretic peptide with hemodynamics and functional capacity in therapy-naive precapillary pulmonary hypertension: results from a cohort study

“…In our trial, NT-proBNP levels were better correlated with CPET parameters in females compared to males. In general, exercise capacity is gender dependent [ 11 ], probably reflecting differences in muscle mass [ 12 ] or myocardial geometries and functions [ 13 ]. Recently, a study by Swift and colleagues [ 14 ] demonstrated that male PAH patients have proportionally worse right heart function despite a similar afterload compared to females.…”

Oxygen Uptake Efficiency Slope and Breathing Reserve, Not Anaerobic Threshold, Discriminate Between Patients With Cardiovascular Disease Over Chronic Obstructive Pulmonary Disease

“…Maximal voluntary ventilation (MVV) was calculated as: 40 · forced expiratory volume in 1 s (FEV 1 ). Predicted values for peak VO 2 and OUES were generated from the SHIP study 13 , 14 . All other calculations were performed using standard methods.…”

“…The percent predicted oxygen uptake efficiency slope (OUES) was calculated using data from Barron et al. (14) . COPD = chronic obstructive pulmonary disease; VO 2 = oxygen uptake.…”

Reference values for cardiopulmonary exercise testing in healthy subjects – an updated systematic review

“…No results in adults were found. Five studies reported oxygen uptake efficiency slope (OUES) values, two in adults [42,43], two in a pediatric population [29,34], and one study reporting up to young adulthood (21 years of age) [44].…”