Peak aerobic capacity from incremental shuttle walk test in chronic kidney disease

Background Assessment of cardiorespiratory fitness is an important outcome in chronic kidney disease (CKD). We aimed to develop a predictive equation to estimate peak oxygen uptake (VO2peak) and power output (W-Peak), as measured during a cardiopulmonary exercise test (CPET), from the distance walked (DW) during the incremental shuttle walk test (ISWT). Methods Thirty-six non-dialysing patients with CKD [17 male, age: 61 +/- 12 years, eGFR: 25 +/- 7 ml/min/1.73 m(2), body mass index (BMI): 31 +/- 6 kg/m(2)] carried out laboratory-based CPET on a cycle ergometer and ISWT on two separate occasions. Results Linear regression revealed that DW/BMI was a significant predictor of VO2Peak (r = 0.78) (VO2Peak (ml/min/kg) = [0.5688 x (DW/BMI) (m)] + 11.50). No difference (p = 0.66) between CPET VO2Peak (19.9 +/- 5.5 ml/min/kg) and predicted VO2Peak (19.9 +/- 4.3 ml/min/kg) was observed. DW multiplied by body mass (BM) was a significant predictor of W-Peak (r = 0.80) [W-Peak (W) = (0.0018 x (DW x BM)) + 50.47]. No difference (p = 0.97) between CPET W-Peak (116.2 +/- 38.9 W) and estimated W-Peak (113.9 +/- 30.1 W) was seen. Conclusion The present study demonstrates that VO2Peak and W-Peak can be accurately estimated using the DW during an ISWT in CKD populations.