Changes in bone mineral density in survivors of childhood acute lymphoblastic leukemia

Background. There is little information about factors modulating bone mineral density (BMD) in survivors of childhood acute lymphoblastic leukemia (ALL). Procedure. We analyzed data from 57 survivors (26 male, 52 Caucasian) who underwent two serial quantitative computed tomography (QCT) studies of BMD. Using multiple linear regression, we evaluated the association of BMD change with demographic variables, treatment history, hormone therapy, exercise, and tobacco and alcohol use. Results. The median age was 3.4 years (range, 0.9-17.4 years) at diagnosis of ALL; the median age at the first QCT (Study I) was 15.0 years (range, 10.6-31.0 years) and at the second QCT (Study II) was 18.2 years (range, 14.2-35.3 years). Mean height increased 4.7 cm and mean weight increased 8.8 kg between Studies I and II. While the mean BMD increased 9.33 mg/cc (P=0.003), the BMD Z-score increased only slightly (0.21 SD, P=0.035). Cortical bone density increased significantly (approximately 25.3 mg/cc; P=0.001), but the ratio of trabecular to cortical BMD decreased significantly (P=0.045). Factors independently associated with unfavorable BMD changes included older age at diagnosis (P=0.001), female sex (P=0.018), and nutritional supplementation (0.032). Alcohol (P=0.009) was an unfavorable factor in a univariable analysis. Conclusions. Bone mineral accretion during adolescence is attenuated in childhood ALL survivors by a comparative deficit in trabecular versus cortical bone deposition. BMD is influenced favorably by exercise in early adolescence and unfavorably by the use of nutritional supplements and alcohol. These results provide new information about behavioral factors that affect bone accrual in survivors of childhood ALL and warrant definitive evaluation in a larger cohort.