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

Purpose: We 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 a real bone mineral density (aBMD) z-score parameters at clinical sites in young pediatric cancer survivors. Methods: This 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. Results: In 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 atmost 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). Conclusions: These 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. [ABSTRACT FROM AUTHOR]