Paediatric cancer survivors: lean mass attenuates negative impact of watching television on bone.

Objective: To investigate the associations of television (TV) watching time with bone parameters and to examine whether high lean mass attenuates the negative impact of watching TV more than one hour per day on bone parameters.

Methods: This cross-sectional study comprised 116 young paediatric cancer survivors. Dual-energy X-ray Absorptiometry was used to obtain total body and regional areal bone mineral density (g/cm²), and lean mass (kg) outcomes. Hip Structural Analysis was performed at the narrowest point of the femoral neck. Trabecular Bone Score was obtained in the lumbar spine. TV watching time was obtained using the "Youth Activity Profile" questionnaire.

Results: Multiple linear regression models showed negative associations of watching TV more than one hour with bone parameters in peri/post pubertal survivors (β = -0.359 to -0.614, P < 0.001 to 0.047). Those survivors watching TV more than one hour per day and with high lean mass presented higher bone parameter Z-score than those with low lean mass.

Conclusion: These findings underline the necessity of identifying strategies that promote musculoskeletal development while reducing TV watching time in young paediatric cancer survivors to maximise bone regeneration.

Impact: The results indicate that watching television (TV) more than one hour (compared to not watching TV) is negatively associated with bone parameters in peri/post pubertal survivors. Survivors with high lean mass counteract these negative associations of watching TV with bone parameters. It is important to promote musculoskeletal development in this vulnerable population to maximise bone regeneration.