Every Move Counts to Improve Bone Health at Clinical Sites in Young Pediatric Cancer Survivors: the Ibonefit Project.

PurposeWe aimed to examine the associations of 24-h movement behaviors (moderate to vigorous physical activity [MVPA], light physical activity [LPA], sedentary behavior [SB], and sleep) with age-, sex-, and race-specific areal bone mineral density (aBMD) z-score parameters at clinical sites in young pediatric cancer survivors.MethodsThis cross-sectional multicenter study was carried out within the iBoneFIT framework in which 116 young pediatric cancer survivors (12.1 +/- 3.3 yr old; 42% female) were recruited. We obtained anthropometric and body composition data (i.e., body mass, stature, body mass index, and region-specific lean mass), time spent in movement behaviors over at least seven consecutive 24-h periods (wGT3x-BT accelerometer, ActiGraph), and aBMD z-score parameters (age-, sex-, and race-specific total at the body, total hip, femoral neck and lumbar spine). Survivors were classified according to somatic maturity (pre or peri/postpubertal depending on the estimated years from peak height velocity). The adjusted models' coefficients were used to predict the effect of reallocating time proportionally across behaviors on the outcomes.ResultsIn prepubertal young pediatric cancer survivors, reallocating time to MVPA from LPA, SB, and sleep was significantly associated with higher aBMD at total body (B = 1.765, P = 0.005), total hip (B = 1.709, P = 0.003), and lumbar spine (B = 2.093, P = 0.001). In peri/postpubertal survivors, reallocating time to LPA from MVPA, SB, and sleep was significantly associated with higher aBMD at all sites (B = 2.090 to 2.609, P = 0.003 to 0.038). Reallocating time to SB from MVPA or LPA was significantly associated with lower aBMD at most sites in prepubertal and peri/postpubertal survivors, respectively. Finally, reallocating time to sleep from MVPA, LPA, and SB was significantly associated with lower aBMD at total body (B = -2.572, P = 0.036) and total hip (B = -3.371, P = 0.015).ConclusionsThese findings suggest that every move counts and underline the benefits of increasing MVPA or LPA, when low MVPA levels are present, for bone regeneration after pediatric cancer treatment completion.