Improvement in bone mineral density and body composition in survivors of childhood acute lymphoblastic leukemia:: A 1-year prospective study

Objectives. Abnormalities in bone mineral density (BMD), body composition, and bone metabolism have been reported in children who were treated for acute lymphoblastic leukemia (ALL) during and after completion of therapy. However, these studies are cross-sectional, and no longitudinal data are available in a large group of patients after completion of therapy. In the present study, 1-year longitudinal changes in BMD, body composition, and bone metabolism were evaluated in children with ALL during the first 3 years after completion of therapy without cranial irradiation. Methods. BMD of total body (TB; g/cm(2)), areal and apparent volumetric lumbar spine (L2 - L4), lean body mass, and percentage of body fat were measured by dual- energy x- ray absorptiometry in 37 children (median age: 7.9 years; range: 4.7 - 20.6 years) who were treated for ALL at a median age of 3.3 years (range: 1.1 - 16.6 years), after a median time of 2.2 years after the completion of treatment, and after a 1- year follow- up period. Two control subjects (n = 74) who were matched for gender, age, and pubertal stage were also longitudinally investigated for body composition for 1 year. Usual serum biochemical markers of calcium metabolism and bone turnover were measured in patients during the study period. Results. A slight decrease in TB BMD was found after a median time of 2.2 years after the completion of therapy for ALL in childhood. Patients showed a significantly lower median TB BMD when evaluated < 1.5 years as compared with those at >= 1.5 years since completion of therapy. At the time of first evaluation, the percentage of body fat mass was significantly higher and patients were physically less active than their matched control subjects. Although, as expected, during the 1 year of follow- up both groups showed an annual increment in their BMD measurements, a significantly higher increase in TB BMD was observed in patients in comparison with control subjects. During this same period, the increase in the percentage of body fat mass was slightly lower in ALL patients as compared with control subjects. At the end of the follow- up year, BMD, body-composition parameters, and physical activity of ALL patients were similar to those observed in matched control subjects. Serum biochemical markers of bone turnover were normal at both evaluations. Conclusions. A significant increase in TB BMD and a tendency to a lesser increase in percentage of body fat mass were observed during the study period in ALL patients as compared with chronological age-, gender-, and pubertal stage - matched control subjects. These findings suggest a positive effect of long- term completion therapy and increase in physical activity on BMD, body composition, and bone metabolism in patients who have been treated for ALL.