Gender specific equation to estimate peak oxygen uptake in female patients with cardiovascular diseas

Purpose: Women continue to be labeled as a ‘special population’ in many guidelines related to cardiovascular disease (CVD), which remains the leading cause of death in women. The aim of this study was to develop a specific prediction equation for estimating peak oxygen uptake (VO2peak) based on a moderate 1-km treadmill walking test (1 k-TWT), in female patients with cardiovascular disease. Methods: 84 female patients, aged 68 ± 10, completed a ramp-like protocol cardiopulmonary exercise test (CPX) for directly measured VO2peak and a 1KTWT using a self-regulated intensity of 11 to 13 of 20 on the Borg Scale to estimate CRF (eCRF). The data from the two tests were used to develop an equation for estimating VO2peak (mL/ kg/min) using best subsets multiple regression analysis including age, body weight, height, body mass index, and mean and maximal walking speed during the 1 k-TWT. Data were analyzed by the D’Agostino-Pearson test for normal distribution. The equation obtained was then validated using Pearson product moment correlation, spread standard error (SEE) and paired Student t-test to compare measured and estimated VO2peak. To evaluate the agreement between the prediction equation and directly measured VO2peak, an intraclass correlation coefficient (ICC) estimate was calculated. The level of statistical significance was set at P\0.05. Results: Data analysis included the results of 75 subjects. Multiple regression analysis showed that age, body mass index, walking speed, were the most powerful predictors of VO2peak. The comparison between measured and estimated VO2peak values yielded a multiple correlation of R = 0.82 (P\ 0.001), and there were no significant differences between measured and estimated VO2peak. Conclusions: The equation developed from the 1 k-TWT accurately predict VO2peak in female patients with cardiovascular disease. The model may represent a feasible, low cost, and simple tool for indirect estimations of cardiorespiratory fitness in an outpatient setting when CPX is not available. The current results may therefore be useful in providing a sex-specific approach to managing CVD in women. References 1. Gulati M. Improving the Cardiovascular Health of Women in the Nation. Moving Beyond the Bikini Boundaries. Circulation 2017; 135:495–498. 2. Chiaranda G, Myers J, Mazzoni G, et al. Peak oxygen uptake prediction from a moderate, perceptually regulated, 1-km treadmill walk in male cardiac patients. J Cardiopulm Rehabil Prev 2012; 32: 262–269.