Clinical impact of sedentary behaviors in adult survivors of acute lymphoblastic leukemia: A report from the St. Jude Lifetime Cohort study

BACKGROUND Sedentary behaviors are associated with poor health outcomes in the general population, but their clinical impact on adult survivors of childhood acute lymphoblastic leukemia (ALL) has not been characterized to date. In the current study, we described the prevalence of sedentary behaviors in survivors of ALL and examined associations between time spent sedentary and body composition and onset of cardiovascular disease (CVD) risk factors. METHODS Participants' self-reported screen time (eg, television, computer) and activity as measured by accelerometer were used to determine activity time (sedentary, light activity, and moderate or vigorous physical activity). The percentage of time spent in each activity was compared between 331 survivors of ALL and 330 controls. Associations between time sedentary and body composition were evaluated in survivors using linear regression models. Cox proportional hazard models were used to examine the association between time sedentary at baseline and CVD risk factor onset during follow-up. RESULTS Survivors spent approximately 65% of their time sedentary, 32% in light activity, and 2% in moderate or vigorous physical activity compared with 67% (P = .04), 30% (P