Demographic correlates of body size changes in children undergoing treatment for acute lymphoblastic leukemia

While it is known that leukemia therapy is associated with obesity in survivorship, limited information is available on its time-related pattern of development and its variation across patient subgroups. The goal of the present study was to examine demographic correlates of body mass index (BMI) changes over time from diagnosis through chemotherapy for children with B-precursor acute lymphoblastic leukemia (ALL).

The study cohort consisted of 307 pediatric patients diagnosed with ALL who were treated at four South Texas pediatric oncology centers between 1990 and 2002. To minimize treatment-related variability, we excluded patients who received cranial irradiation as part of their treatment. Variation in age- and gender-standardized BMI z-scores according to age at diagnosis, gender, and ethnicity were assessed.

The overall study cohort exhibited an increase in age- and gender-adjusted BMI z-scores for the first 24 months of chemotherapy followed by a slight decrease in BMI at 30 months (end of therapy). A repeated measures analysis indicated a statistically significant difference in the time-related pattern of BMI changes for age at diagnosis (P = 0.001) but no significant effect for gender (P = 0.32) or Hispanic versus non-Hispanic ethnicity (P = 0.89).

In our cohort of ALL patients, BMI was elevated at diagnosis (mean standardized BMI z-score = 0.22, standard deviation = 1.4) then increased and remained elevated for the entire duration of chemotherapy. Children who were 2-9 years of age at diagnosis began therapy with a substantially lower BMI and remained lower over the course of chemotherapy than patients aged 10-18 years at diagnosis. It will be important for future investigations to explore the biological and behavioral factors that may underlie such differential patterns of BMI change over time.