Childhood cancer survivors (CCS) are at risk of reduced bone health and premature osteoporosis. As physical activity with high impact loading (IL‐PA) is known to promote bone health, we compared bone densitometry and microstructure between groups of CCS who performed different amounts of physical activities in their daily life. We used baseline data of a single‐center PA trial including 161 CCS from the Swiss Childhood Cancer Registry, aged <16 at diagnosis, ≥16 at study and ≥5 years since diagnosis. Lower body bone health was assessed with peripheral quantitative computed tomography (pQCT) and dual‐energy X‐ray absorptiometry (DXA). Daily IL‐PA (duration in activities >2 g acceleration and numbers of vertical impacts/hr >2 g) was captured using hip‐worn accelerometers (1–3 weeks). For both IL‐PA approaches, we formed low, middle and high activity groups based on tertiles. Bone health of the high and middle active groups was compared to the low active group. 63% of CCS had indication of at least one bone mineral density z ‐score ≤ −1 measured by pQCT or DXA. The high IL‐PA group performing 2.8 min/day or 19.1 impact peaks/hr > 2 g (median) showed about 3–13% better microstructural and densitometric bone health as compared to the low IL‐PA group with 0.38 min/day or 0.85 peaks/hr > 2 g. Just a few minutes and repetitions of high IL‐PA as easily modifiable lifestyle factor may be sufficient to improve bone health in adult CCS. Future longitudinal research is needed to better understand pattern and dosage of minimal impact loading needed to strengthen bone in growing and adult CCS.

中文翻译：

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儿童癌症幸存者的下肢高强度体育锻炼和下肢骨骼健康：SURfit的横断面研究。

儿童癌症幸存者（CCS）有降低骨骼健康和过早骨质疏松症的风险。由于已知具有高冲击负荷的体育活动（IL‐PA）可以促进骨骼健康，因此我们比较了在日常生活中进行不同数量体育活动的CCS组之间的骨密度和显微结构。我们使用了一项单中心PA试验的基线数据，包括来自瑞士儿童癌症登记处的161个CCS，诊断时年龄小于16岁，研究中≥16岁，诊断后≥5年。下肢骨骼健康状况通过外周定量计算机断层扫描（pQCT）和双能X线骨密度仪（DXA）进行评估。使用髋部加速计（1-3周）捕获每日IL-PA（活动持续时间> 2 g加速度，垂直冲击次数/小时> 2 g）。对于这两种IL‐PA方法，我们形成了较低的 基于三分位数的中，高活动群体。比较高和中度活动组的骨骼健康状况。63％的CCS具有至少一种骨矿物质密度的迹象通过pQCT或DXA测量的z分数≤-1。高IL-PA组的2.8分钟/天或19.1冲击峰/小时> 2 g（中值）显示出比低IL-PA组的0.38分钟/天或更低的微结构和光密度法骨骼健康大约3–13％ 0.85峰/小时> 2克 短短几分钟并重复服用高IL-PA作为易于改变的生活方式因素可能足以改善成人CCS的骨骼健康。需要进一步的纵向研究，以更好地了解在成长中的和成年的CCS中加强骨骼所需的最小冲击载荷的方式和剂量。