No impact of disease and its treatment on bone mineral density in survivors of childhood acute lymphoblastic leukemia

Background: Acute lymphoblastic leukemia (ALL) and its treatment are often implicated in adversely affecting bone health. Conflicting reports in the literature and a paucity of studies from the developing world prompted us to study bone mineral density (BMD) in childhood ALL survivors. Methods: BMD lumbar spine (LS) and whole body (WB) were evaluated, using dual energy x-ray absorptiometry in 65 pediatric ALL survivors who had been off-therapy for at least 2 years. The control group constituted of 50 age-and sex-matched healthy siblings. Kernel density plots were used to compareBMDamong cases and controls. The disease-, treatment-, hormone-and lifestylerelated factors likely to modulate BMD were analyzed using the Mann-Whitney U test and Student's t-test. Results: At amedian of 4.3 years (range, 2-14.8 years) since cessation of therapy, height-adjusted (HA) mean BMD Z-scores of LS (-0.67 +/- 1.11, -0.607 +/- 1.05, P = 0.759) andWB (-0.842 +/- 0.92, -0.513 +/- 0.97, P = 0.627) were comparable among the cases and controls. Disease, treatment (chemotherapy, cranial radiotherapy) and endocrine factors did not predict low BMD. However, survivors with calcium intake < 800 mg/day (WB, P = 0.018) and hypovitaminosis D (= 25 nmol/L) had lower BMDvalues (HA-WB, P = 0.046) than the controls. A significant proportion of survivors were overweight or obese and had higherBMDZ-scores (HA-LS, P = 0.003; HA-WB, P = 0.028). Conclusion: BMD Z-scores were similar among ALL survivors and controls. It was reassuring that there was no detrimental impact of the disease or its treatment on BMD. Future studies are required to determine the best possible ways to target the modifiable risk factors (diet, vitamin D) to optimize bone health.