Risk factors for excess weight gain in children treated for acute lymphoblastic leukaemia

OBJECTIVE: To test whether excess weight gain in patients treated for childhood acute lymphoblastic leukaemia (ALL) was predictable using patient characteristics at diagnosis. DESIGN AND SUBJECTS: Longitudinal study of changes in body mass index (BMI) in all 98 patients treated in Scotland on treatment protocol MRC UKALL-XI who had reached at least 3 y post-diagnosis in first remission. MEASUREMENTS: The influence of the following variables on changes in BMI, expressed as a standard deviation score (SDS), was tested using variable selection techniques and classification and regression trees: BMI SDS at diagnosis; age at diagnosis; gender; socioeconomic status; treatment. RESULTS: Prevalence of obesity (BMI SDS>2.0) was<2% at diagnosis, but increased to 16% at 3y. Gain in BMI SDS was significantly inversely influenced by BMI SDS at diagnosis (P<0.01) and age at diagnosis (P<0.01). CONCLUSION: Obesity is common in ALL by the end of therapy, and is more likely in children who are younger and thinner at diagnosis. Excess weight gain was not readily predictable from routinely collected information available at diagnosis and so all children treated for ALL should be considered 'at risk' of excess weight gain and the target of obesity prevention.