The six-minute walking test (6MWT) may be a practical test for the evaluation functional exercise capacity in children with end-stage renal disease (ESRD). The aim of this study was to investigate the 6MWT performance in children with ESRD compared to reference values obtained in healthy children and, secondly, to study the relationship between 6MWT performance with anthropometric variables, clinical parameters, aerobic capacity and muscle strength. Twenty patients (13 boys and seven girls; mean age 14.1 ± 3.4 years) on dialysis participated in this study. Anthropometrics were taken in a standardized manner. The 6MWT was performed in a 20-m-long track in a straight hallway. Aerobic fitness was measured using a cycle ergometer test to determine peak oxygen uptake (V̇O2peak), peak rate (Wpeak) and ventilatory threshold (VT). Muscle strength was measured using hand-held myometry. Children with ESRD showed a reduced 6MWT performance (83% of predicted, p < 0.0001), irrespective of the reference values used. The strongest predictors of 6MWT performance were haematocrit and height. Regression models explained 59% (haematocrit and height) to 60% (haematocrit) of the variance in 6MWT performance. 6MWT performance was not associated with V̇O2peak, strength, or other anthropometric variables, but it was significantly associated with haematocrit and height. Children with ESRD scored lower on the 6MWT than healthy children. Based on these results, the 6MWT may be a useful instrument for monitoring clinical status in children with ESRD, however it cannot substitute for other fitness tests, such as a progressive exercise test to measure V̇O2peak or muscle strength tests.

Additional Metadata
Keywords Exercise capacity, Kidney disease, Muscle strength, Physical activity, adolescent, adult, aerobic capacity, article, body height, body mass, body weight, child, childhood disease, clinical article, construct validity, controlled study, diastolic blood pressure, discriminant validity, ergometer, exercise test, female, fitness, health status, hematocrit, hemodialysis, hemoglobin, human, kidney failure, lung capacity, male, muscle strength, oxygen consumption, patient assessment, peritoneal dialysis, priority journal, reference value, school child, systolic blood pressure, walking
Persistent URL dx.doi.org/10.1007/s00467-009-1259-x, hdl.handle.net/1765/17878
Citation
Takken, T., Engelbert, R.H.H., van Bergen, M., Groothoff, J., Nauta, J., van Hoeck, J., … Helders, P.. (2009). Six-minute walking test in children with ESRD: Discrimination validity and construct validity. Pediatric Nephrology, 24(11), 2217–2223. doi:10.1007/s00467-009-1259-x