Relative osteopenia after treatment for acute lymphoblastic leukemia

Osteoporosis in adult life is associated with a significant morbidity and m ay be predisposed to by osteopenia and failure to reach peak bone mass in c hildhood, Children treated for acute lymphoblastic leukemia (ALL) may be at risk of osteopenia as a result of previous therapy or as a consequence of the disease process itself. Dual energy x-ray absorptiometry measurements o f bone mineral content (BMC) for the whole body and at the lumbar spine and hip were taken in 35 (14 male) long-term survivors of ALL and compared wit h results in 20 (10 male) survivors of other malignancies and 31 (17 male) healthy sibling controls. The measured BMC was expressed as a percentage of a predicted value derived from the control group and based on the variable s that had influence upon it. BMC (%) was reduced at the spine in the ALL g roup compared with controls [92.4 (8.0)% versus 100.4 (9.7)%, respectively; p < 0.005] and at the hip compared with both other malignancies and contro ls [89.0 (11.5)% versus 96.1 (11.7)% and 100.4 (9.2)%, respectively; p < 0. 0005]. Increasing length of time off therapy was associated with a signific ant increase in %BMC at both the spine and the hip. For the spine, this ass ociation was significantly different between the ALL group and other malign ancies, suggesting that any gain in %BMC after therapy was slower in childr en treated for ALL. Both exercise capacity and levels of physical activity were correlated with %BMC at the hip (r = 0.44, p < 0.001 and r = 0.29, P < 0.01, respectively). Previous exposure to methotrexate, ifosfamide, and bl eomycin was associated with a reduction in %BMC at the spine. Exposure to 6 -mercaptopurine and cisplatin was associated with a reduction at the hip. I n conclusion, children treated for ALL are osteopenic, The mechanism is pro bably multifactorial but is partially related to previous chemotherapy, lim ited exercise capacity, rind relative physical inactivity.