Physical activity level and performance in the six-minute walk test of children and adolescents with sickle cell anemia

BACKGROUND: To establish determinants of maximum walking distance in the 6-minute walk test of children and adolescents with sickle cell anemia, and to compare the performance in this test with physical activity level between patients and healthy controls. METHODS: A cross-sectional study was performed in which the participants answered the Physical Activity Questionnaire for Older Children and Adolescents, and completed the 6-minute walk test. MAIN RESULTS: Fifty-seven patients and 58 controls were studied. By univariate analysis of the patients, age (p < 0.0001) and indirect bilirubin (p = 0.008) were associated with maximum walking distance in the 6-minute walk test. In multivariate analysis, age was positively associated (p < 0.0001; beta: 0.75), while body mass index was inversely associated with distance walked (p = 0.047; beta: −0.32). This yields the following equation: maximum distance walked = 487.7 (age × 18.3) − (12 × body mass index) meters. Patients reported a lower physical activity level however there was no significant difference in the distance walked in six minutes between patients (500.6 ± 88.7 m) and controls (536.3 ± 94 m). CONCLUSION: The determinants for the 6-minute walk test in children and adolescents with sickle cell anemia were age and body mass index. There was no significant difference in the 6-minute walk test but patients with sickle cell anemia had a lower physical activity level compared to healthy controls.