Cardiorespiratory fitness in persons with lower limb amputation

The aim of this study is to gain insight in the cardiorespiratory fitness of persons with lower limb amputation (LLA) during rehabilitation, and in potential factors influencing their cardiorespiratory fitness. We performed a retrospective cohort study using data from cardiopulmonary exercise tests. Included participants were adults with LLA. Main outcome was cardiorespiratory fitness expressed as V˙O₂peak (ml/min/kg) and was directly determined using breath-by-breath gas analysis. V˙O₂peak was compared to reference values for able-bodied controls. Multivariate regression analysis was performed to investigate potential factors related to V˙O₂peak in persons with LLA. Potential factors were age, BMI adjusted, gender, level of amputation, aetiology of amputation, unilateral/bilateral, type of ergometry and use of beta blockers. Data of 74 participants with LLA are presented; 84% male (n = 62), mean age 58.9 (SD 11.6), mean BMI 26.7 (SD 5.6), 44 participants have a LLA above the knee, 30 below the knee. Overall V˙O₂peak was lower in persons with LLA compared to reference values for able-bodied controls, with mean V˙O₂peak for the total LLA group of 14.6 ± 4.1 ml/kg/min. In the multivariate regression analysis, only age was a significant predictor for lower V˙O₂peak (regression coefficient: -0.15, 95% CI [0.23-0.069], r² = 0.166). These results indicate that the cardiorespiratory fitness in persons with LLA is low, while they actually need more energy to walk and perform other daily activities. Cardiorespiratory fitness is not closely associated with the analysed demographic or clinical factors and will have to be determined on an individual basis for use in daily practice.