Changes in body mass index and prevalence of overweight in survivors of childhood acute lymphoblastic leukemia: role of cranial irradiation.
Academic Article
Overview
abstract
BACKGROUND: The risk factors responsible for an increased prevalence of obesity or overweight in survivors of acute lymphoblastic leukemia (ALL) remain controversial. We evaluated changes in body mass index (BMI) in a cohort of ALL survivors, all of whom have been followed until completion of linear growth. PROCEDURE: BMI (weight/height(2)) was used as an index of adiposity and was calculated at diagnosis, at the end of treatment, and at attainment of final height in a cohort of 126 (59 males) survivors of ALL. BMI was adjusted for age and sex by computing a BMI standard deviation score (SDS) or z score. The spectrum of therapies used included intrathecal chemotherapy given alone (n = 38) or combined with cranial irradiation (CRT; 18 Gy, n = 35; 24 Gy, n = 53) and exposure to prednisone at a low dose (<3.5 gm, n = 49), medium dose (3.5-9.4 gm, n = 46), or high dose (>9.4 gm, n = 30). RESULTS: Overall, mean +/- SEM BMI-SDS increased significantly between diagnosis (-0.18 +/- 0.08) and the end of therapy (0.41 +/- 0.09, P < 0.01), with no significant change thereafter. For patients without CRT, mean BMI-SDS remained unchanged, whereas, for those so treated, mean BMI-SDS increased significantly between diagnosis and the completion of therapy (P < 0.001). The change in mean BMI-SDS was greater in the 24 Gy group vs. the 18 Gy CRT sample (P < 0.005). In a multivariate logistic regression model, CRT was an independent predictor of being overweight (BMI >/=85 percentile) at attainment of final height [odds ratio = 1.6 (95% confidence interval 1.0-23. 1)]. The percentage of subjects who were overweight at attainment of final height was 10.5%, 40%, and 38% for subjects treated with no CRT, 18 Gy CRT, or 24 Gy CRT, respectively (P < 0.01). CONCLUSIONS: Children with ALL given CRT develop increases in their BMI-SDS early on and during treatment and remain at significant risk for becoming overweight as young adults, a development that may increase their already heightened risk for various adverse health outcomes.
