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

Abstract

Purpose We aimed to examine the associations of 24-hour 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. Methods This cross-sectional multicenter study was carried out within the iBoneFIT framework in which 116 young pediatric cancer survivors (12.1 ± 3.3 years 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-hour 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/post-pubertal 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 pre-pubertal 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 = .005), total hip (B = 1.709, P = .003) and lumbar spine (B = 2.093, P = .001). In peri/post-pubertal 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 = .003 to .038). Reallocating time to SB from MVPA or LPA was significantly associated with lower aBMD at most sites in pre-pubertal and peri/post-pubertal 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 = .036) and total hip (B = -3.371, P = .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 following pediatric cancer treatment completion.