Effects Of An Exercise Program On Bone Health In Pediatric Cancer Survivors: Randomized Controlled Trial

Pediatric cancer survivors are at increased risk of later bone health complications as treatment includes exposure to DNA damaging agents during critical periods of active skeletal growth. Exercise may counteract bone loss and reduce risk of osteoporosis later in life. PURPOSE: To investigate the effect of a 9-month online exercise program on age-, sex- and race-specific areal bone mineral density (aBMD) Z-score in young pediatric cancer survivors. METHODS: A total of 116 survivors aged 6 to 18 years (12.1 ± 3.3 years old; 42% female) were randomized into an exercise intervention (n = 58) or control group (n = 58), and were included in the intention-to-treat analyses. All participants received diet counselling on calcium and vitamin D. The exercise group remotely performed a periodized intervention with a total of 2000 squats and 5296 jumps (progressive intensity). The doses were composed of 136 sessions (10-20 min/session) over 36 weeks (three to four days/week). The total body (less head), total hip, femoral neck and lumbar spine (mean of L1-L4) aBMD (g/cm2) were evaluated by Dual-energy X-ray absorptiometry. Age-, sex- and race-specific aBMD Z-score at each site were calculated using international reference data from the Bone Mineral Density in Childhood Study and intervention effects were assessed using linear mixed-effects models. RESULTS: The exercise intervention group improved aBMD Z-score at total hip (estimated mean difference of exercise group compared to the control group: 0.3 [95% CI, 0.018 to 0.661]). The rest of the bone Z-score parameters were not improved by the exercise intervention compared to the control group; total body (0.1 [95% CI, -0.166 to 0.414]), femoral neck (-0.1 [95% CI, -0.392 to 0.125]) and lumbar spine (-0.1 [95% CI, -0.205 to 0.095]). CONCLUSIONS: In this randomized controlled trial, a 9-month online exercise program mainly improved total hip aBMD Z-score during growth among young pediatric cancer survivors.Spanish Ministry of Science and Innovation (PID2020-117302RA-I00), La Caixa Foundation (LCF/BQ/PR19/11700007), Excellence actions: Unit of Excellence on Exercise, Nutrition, and Health and by Centro de Investigación Biomédica en Red (CB22/3/00058)