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

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 (VO_2peak ) 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).

Thirty-six non-dialysing patients with CKD [17 male, age: 61 ± 12 years, eGFR: 25±7 ml/min/1.73 m² , body mass index (BMI): 31 ± 6 kg/m² ] carried out laboratory-based CPET on a cycle ergometer and ISWT on two separate occasions.

Linear regression revealed that DW/BMI was a significant predictor of VO_2Peak (r = 0.78) (VO_2Peak (ml/min/kg) = [0.5688 × (DW/BMI) (m)] + 11.50). No difference (p = 0.66) between CPET VO_2Peak (19.9 ± 5.5 ml/min/kg) and predicted VO_2Peak (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 × (DW × 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.

The present study demonstrates that VO_2Peak and W_Peak can be accurately estimated using the DW during an ISWT in CKD populations.