Does the 6‐min walk test correlate with the exercise stress test in children?

Abstract

Is there a correlation between the 6-min walk and aerobic fitness in children? We studied healthy and cystic fibrosis (CF) subjects age 8-20 years using the 6-min walk test, treadmill graded exercise stress test, and spirometry. Six-minute walk distance (6MWD) and the product of 6MWD and body weight (6MWORK) were related to aerobic capacity. Data were analyzed using Student's t-test and Pearson correlation. 13 healthy subjects [9 females, mean age 15.8 +/- 3.6 years, % predicted forced expiratory volume in one second (FEV(1)) 105 +/- 12%, 6MWD 557 +/- 73 m, peak oxygen uptake (V' O2 max) 41.4 +/- 7.2 ml/kg/min, and heart rate (HR) at V' O2 max 180 +/- 10] and 11 CF subjects (3 females, mean age 14.3 +/- 3.8 years, FEV(1) 67 +/- 25.9%, 6MWD 468 +/- 68 m, V' O2 max 27.0 +/- 8.1 ml/kg, and HR at V' O2 max 163 +/- 22] were studied. 6MWD correlates with V' O2 max in normal subjects (r = 0.59, P < 0.05) but not in CF subjects (r = 0.09, NS). 6MWORK correlates with V' O2 max in CF subjects (r = 0.65, P < 0.05) but not in normal subjects (r = 0.278, NS). We conclude that the 6MWD corresponds with aerobic fitness in normal pediatric subjects and 6MWORK corresponds with aerobic fitness in CF subjects. We speculate that 6MWORK is superior to 6MWD for assessment of aerobic fitness in children with CF.

Desempenho funcional de pacientes com fibrose cística e indivíduos saudáveis no teste de caminhada de seis minutos

“…This value falls within previously reported rates, (7,8,15,18) which range from 25% to 66%. (26) Functional performance on the six-minute walk test in patients with cystic fibrosis…”

“…However, the authors did not analyze the distances covered. Lesser et al (15) administered the 6MWT to healthy individuals and cystic fibrosis patients (mean age: 14.3 ± 3.8 years). The 6MWD was shorter among the cystic fibrosis patients than among the controls (468 ± 68 m vs. 557 ± 73 m, respectively; p < 0.05).…”

Six-minute walking test predicts maximal fat oxidation in obese children

“…The six-minute walking test (6MWT) has emerged as a common approach, and recent normative data have extended its application. 13 --15 The 6MWT has shown good validity and reliability, and is considered as the more relevant test that reflects physical activities of daily living, as well as cardiopulmonary fitness in healthy children 16,17 and in children with various diseases. 14,15,18 --20 Therefore, in addition to the assessment of cardiopulmonary and functional status, it has been reported that 6MWT could be a reliable parameter to predict peak oxygen uptake (VO 2 peak) in patients with varied diseases; 21,22 however, additional data linking the 6MWT performance to selected physiological measures of gas exchange were needed to optimize the use of this test.…”

Pulmonary hypertension in children

“…Normal values for 6MWD for children have recently been published. [66][67][68][69] However baseline 6MWD is not a predictor of survival, neither when expressed as an absolute distance in meters nor when adjusted to reference values expressed as z score or as percentage of predicted value. 12,70 Cardiopulmonary exercise testing in children over 7 years of age is useful to determine peak oxygen consumption, ventilator efficiency slope (VE/VCO2), and anaerobic threshold.…”