Childhood leukaemia: a model of pre-obesity

Abstract

The prevalence of obesity in children, as in adults, is increasing dramatically. The extent to which this is due to reduced energy expenditure, increased energy intake, or both, is unclear at present. This in part reflects the limitations of existing models of the pre-obese state. In childhood acute lymphoblastic leukaemia (ALL), patients typically gain weight excessively during and after 2 years of therapy, and are at high risk of becoming obese. Previous studies have failed to identify the cause of obesity in these patients. We have tested the hypothesis that excess weight gain in ALL is due to reduced total energy expenditure (TEE), measured using the doubly-labelled water method, and have identified risk factors for excess weight gain in ALL. Pre-obese children with ALL in the dynamic phase of weight gain are less physically active than their peers, with a reduced TEE of approximately 1.2 (95 % CI 0.2, 2.2) MJ/d. While other factors might contribute to excess weight gain, lifestyle (i.e. reduced habitual physical activity) plays a central role in ALL. Several considerations suggest that ALL might be a useful model of the pre-obese state: lifestyle is critical to development of obesity in ALL; ALL is relatively common; approximately 70 % of patients survive; patients are readily accessible during the 2 years of therapy and beyond.

Physical activity of pediatric patients with acute leukemia undergoing induction or consolidation chemotherapy

“…Leukemic children have been shown to be particularly at risk of low bone mass density and osteoporosis [39] as well as obesity [5,6,40,41]. Physical activity is important for pediatric patients because it influences growth by promoting tolerable musculoskeletal stress and bone loading for bone strength, and it may improve body composition [31].…”

Potential benefits of physical activity for children with acute lymphoblastic leukaemia

“…Research studies suggest that 40-56% of children with ALL gain excessive weight during and following chemotherapy [33][34][35][36][37][38][39]. As a result, physicians often suggest that parents encourage their children to participate in more physical activity and eat more healthy diets in an effort to combat this negative side effect [37].…”

“…The majority of the literature suggests that changes in body composition occur due to a combination of increased total energy intake, caused by a glucocorticoidstimulated increase in appetite and decreased total energy expenditure, caused by increased fatigue [34,35]. With diminished habitual PA, a decrease in total energy expenditure and increases in energy intake, a positive energy balance may occur, resulting in weight gain [33,34]. The psychosocial consequences of leukaemia and its treatment (e.g.…”

Epidemiologic and Physiologic Approaches to Understanding the Etiology of Pediatric Obesity: Finding the Needle in the Haystack

“…in ALL, the natural history is well understood (30), to identify children in the preobese state. The clinical studies have been successful in testing hypotheses that have been generated by the natural history studies (24 -26).…”