This study examined the bone mineral density (BMD) of 46 (median age 16.3, 8-29) survivors of autologous and allogeneic bone marrow transplantation (BMT). Areal (g/m2) BMD was acquired with dual energy x-ray absorptiometry and volumetric (g/cm3) BMD values were calculated. Abnormal BMD was identified in 24% (11/46) of survivors with areal measures and 22% (10/46) with volumetric measures. Comparison of areal and volumetric BMD revealed the measures were highly correlated (r = 0.73, p<0.001) but clinical diagnosis of osteopenia/osteoporosis were not consistent. Volumetric z-scores were higher for 7/8 of the survivors who were < 3rd percentile for height. Associations of BMD and body composition and disease and treatment factors were assessed with multiple linear regression. When controlling for other significant associations and cumulative steroid dose, the body composition measure of fat mass index (FMI) was associated with higher volumetric BMD z-scores (CI: 0.006, 0.193; p = 0.037). CNS irradiation (CI: -1.710,-0.200; p = 0.015), age at time of testing (CI: -0.116, -0.024; p = 0.004) and female sex (CI: -1.375, -0.155; p = 0.015) were associated with lower volumetric BMD z-scores. Childhood BMT survivors are at risk for diminished BMD. Areal and volumetric DEXA derived measures of BMD are highly correlated and volumetric measures may correct for underestimation of BMD in BMT survivors who are small for age. Survivors who received CNS irradiation, are older and female may be at greater risk for diminished BMD while fat mass is associated with higher BMD in childhood BMT survivors.

Background: : Inadequate physical activity (PA) in childhood cancer survivors may lead to compromised health outcomes. The purpose of this pilot study was to evaluate the feasibility and effect of a PA intervention in childhood cancer survivors ages 8–12 who report < 1 hour of moderate-to-vigorous physical (MVPA) per day.Methods: Twenty survivors were randomized to a 6-month group PA intervention or to a control group. A pre/post measure of MVPA was completed by all participants, and a pre/post measure of self-efficacy was completed by the intervention group. Analysis included measures of feasibility, change in percentage of awake time spent in MVPA, self-efficacy scores, and correlations in MVPA and self-efficacy.Results: All feasibility parameters were confirmed. Increases in percent of awake time spent in MVPA were seen in 67% of the intervention group and 14% of the control group. A medium effect size (r = 0.55) was calculated for the correlation between change in MVPA and change in total self-efficacy scores; the largest effect size (r = 0.62) was found for the subscale for adequacy.Conclusions: Increases in MVPA can be seen in childhood cancer survivors who participate in a group intervention that includes support of self-efficacy.