Habitual Physical Activity and Exercise Patterns in Children and Adolescents with Sickle Cell Disease

Background Sickle cell disease (SCD) and its complications have a major impact on physical functioning in affected children and adolescents. However, little is known about habitual physical activity patterns and exercise routines in this population. The aims of this study were to evaluate the amount of time spent in moderate (MPA) or vigorous (VPA) physical activity, examine participation in school-based physical education or organized sports, and explore factors that influence physical activity or exercise habits in children and adolescents with SCD.

Methods A58-question, self-administered survey was given to a cross-sectional group of children with SCD (all genotypes) in grades 6 through 12 followed in the Comprehensive Sickle Cell Programs at Ann & Robert H. Lurie Children’s Hospital of Chicago and the University of Illinois at Chicago. Children on hydroxyurea therapy and chronic transfusions were included. The survey included 2 sections: 1) questions adapted from the National Health and Nutrition Examination Survey (NHANES) Physical Activity Questionnaire and 2) supplemental questions addressing participation in school-based physical education and organized sports; disease severity and impact on physical activity; and attitudes about physical activity and exercise. We performed standard descriptive analyses and bivariate analysis using Pearson’s chi-square or Student’s t-test for independent samples for comparison of categorical and continuous data, respectively. Responses from NHANES questions were compared to age, sex and race matched data collected from the 2009-2010 NHANES survey.

Results A total of 88 surveys have been collected to date. Among respondents with SCD, 59% were between 11 and 15 years old, 51% were male, 66% had hemoglobin SS disease, 44% were on hydroxyurea and 19% were on chronic transfusions. Data were compared to extracted data from 1362 NHANES participants weighted to adjust for differences in distributions in age, sex and race between groups. The proportion of children with SCD who reported at least 10 minutes of VPA in a typical week (66 vs. 65%, p = 0.91) and their frequency of VPA (2.8 vs. 2.5 days per week, p = 0.44) did not differ from that of children from the NHANES cohort. However, a higher proportion of children with SCD reported MPA (67 vs. 42%, p < 0.001) with a frequency (2.3 vs. 1.4 days per week, p < 0.001) that was significantly higher than that reported in NHANES. The duration of VPA or MPA on a typical day also differed significantly between groups. Compared to children from NHANES, fewer children with SCD reported spending more than 60 minutes in VPA or MPA on a typical day. Overall, only 13% of children with SCD met US physical activity guidelines recommending at least 60 minutes of physical activity every day. Of those children with SCD surveyed, 47% reported participating in school-based sports teams or physical activity clubs and 74% reported participating in physical education when offered at their school. Finally, we examined those variables that were associated with physical activity and participation in organized sports or physical education in children with SCD. Children 11 to 15 years old, when compared to children greater than 15 years old, were more likely to report 60 min of physical activity on more than 2 days per week (73 vs. 27%, p < 0.05). However, neither age nor sex affected participation in organized sports or physical education. We found that physical activity and participation in organized sports or physical education were not significantly affected by respondent beliefs regarding the impact of SCD on enjoyment of those activities. Sickle cell genotype, hydroxyurea use, chronic transfusions, and parental and personal attitudes toward physical activity also had no influence on participation in physical activity, organized sports or physical education in children with SCD.

Conclusions When compared to matched peers in the NHANES study, children with SCD participate in comparable levels of VPA and even exceed their peers in levels of MPA. Participation in school-based organized sports and physical education was also common in children with SCD despite the previously reported impact of SCD on physical functioning in this population. Further studies are needed to determine the safety and potential health benefits of regular exercise and athletic participation in this population.