Physiologic response of the six-minute walk test in children with juvenile idiopathic arthritis

Objective. To determine the physiologic response of the 6-minute walk test (6-mwt) in children with juvenile idiopathic arthritis (JIA). Methods. Eighteen children with JIA (age 7-17 years; 6 boys, 12 girls) performed a 6-mwt and a maximal exercise test. Results. The physiologic response of the 6-mwt was on average between 80% and 85% of the peak values of heart rate and oxygen uptake (VO2peak) during the maximal exercise test, except for the minute ventilation, which had a mean percentage of 68.5%. Backward regression analysis showed that height and distance walked were the best predictors of V-O2peak during cycling (R-2 = 0.883, P < 0.001). During the 6-mwt, the difference between the first and second minute was significant in every variable, except for heart rate. The range of walking distance of children with JIA was comparable with that of healthy elderly people. Conclusion. The physiologic response of the 6-mwt is at a submaximal, intense level of exercise. The course of the responses during the 6-mwt was normal. The 6-mwt can be regarded as a good test for measuring functional exercise capacity.