Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria.
Gerontology. 2012;58(2):139-49. doi: 10.1159/000329113. Epub 2011 Jun 25.
The pathophysiology of age-related bone loss and whether age-related bone loss can be prevented by exercise are still a matter of debate.
It was the aim of this study to investigate the long-term effects of exercise and mild food restriction on bone mineral density (BMD) and bone geometry in the appendicular skeleton of aging male rats.
Male Sprague-Dawley rats were studied from 5 to 23 months of age. The rats were divided into 4 groups: baseline, free access to food and running wheels (RW), fed to pair weight with the RW group (PW) and sedentary control animals with free access to food (SED). All rats were housed individually. Volumetric BMD and geometry of femurs and tibiae were assessed by peripheral quantitative computed tomography (pQCT). In addition, the tibial shafts were analyzed by cortical bone histomorphometry.
At the end of the experiment, RW and PW rats had similar body weight. The body weight of SED rats was 31% greater than that of RW rats. pQCT analysis of femurs and tibiae as well as histomorphometric analysis of the tibial shafts showed that dietary restriction resulted in an enlargement of the marrow cavity and cortical thinning at the femoral and tibial shafts relative to the RW and SED groups. Voluntary running exercise provided no additional protection against age-related bone loss when compared with the 31% heavier SED control rats. Neither exercise nor increased body weight in SED animals could completely prevent age-related bone loss between 19 and 23 months of age.
We conclude that dietary restriction had clear negative effects on BMD and bone geometry and that running wheel exercise provided partial protection but could not prevent age-related bone loss.
与年龄相关的骨丢失的病理生理学以及运动是否可以预防与年龄相关的骨丢失仍然存在争议。
本研究旨在探讨运动和轻度饮食限制对衰老雄性大鼠四肢骨骼骨矿物质密度（BMD）和骨几何形状的长期影响。
从 5 至 23 月龄雄性 Sprague-Dawley 大鼠进行研究。将大鼠分为 4 组：基线组、自由获取食物和跑步轮（RW）组、与 RW 组等重喂养（PW）组和自由获取食物的安静对照动物（SED）组。所有大鼠均单独饲养。通过外周定量计算机断层扫描（pQCT）评估股骨和胫骨的体积 BMD 和几何形状。此外，通过皮质骨组织形态计量学分析胫骨骨干。
实验结束时，RW 和 PW 组大鼠的体重相似。SED 组大鼠的体重比 RW 组大鼠高 31%。pQCT 分析股骨和胫骨以及胫骨骨干的组织形态计量学分析表明，与 RW 和 SED 组相比，饮食限制导致骨髓腔扩大和股骨和胫骨骨干皮质变薄。与体重增加 31%的 SED 对照大鼠相比，自愿跑步运动对与年龄相关的骨丢失没有提供额外的保护。运动或 SED 动物的体重增加都不能完全预防 19 至 23 月龄之间的与年龄相关的骨丢失。
我们得出结论，饮食限制对 BMD 和骨几何形状有明显的负面影响，而跑步轮运动提供了部分保护，但不能预防与年龄相关的骨丢失。
