BACKGROUND Recent research has proposed an association between desaturation during a six minute walking test (6MWT) and osteoporosis in an elderly group of individuals with non-cystic fibrosis bronchiectasis. A causative pathway through activation of hypoxia-inducible factor 1-alpha (HIF-1α) has been proposed. COMMENTARY Queries regarding the statistical approaches used are identified and discussed within this correspondence. These predominate around the use of linear regression models to predict osteoporosis in a group that is already osteoporotic, presenting with extreme values for bone mineral density (BMD). Further queries are raised regarding the HIF-1α pathway, and physical activity (PA) is proposed as an upstream mechanism for both reduced exercise tolerance and low BMD. CONCLUSIONS It is suggested that osteoporosis cannot be predicted in a group that is already osteoporotic, and that PA is likely to be the causative mechanism between desaturation in the 6MWT and low BMD in non-cystic fibrosis bronchiectasis.

中文翻译：

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运动期间的去饱和度不足以预测非囊性纤维化支气管扩张症中的骨质疏松症。

背景技术最近的研究提出了在六分钟步行测试（6MWT）期间的去饱和与患有非囊性纤维化支气管扩张的老年组的骨质疏松之间的关联。已经提出了通过激活缺氧诱导因子1-α（HIF-1α）的病因途径。注释在此通信中识别并讨论了有关所用统计方法的查询。这些方法主要围绕使用线性回归模型来预测已经骨质疏松症的人群中的骨质疏松症，表现出极高的骨矿物质密度（BMD）值。关于HIF-1α途径的进一步质疑，体育活动（PA）被提议为降低运动耐力和降低BMD的上游机制。