Xiangxu Chen

Osteoporosis (OP) is a systemic bone disease characterized by the decreased bone mass and destruction of bone microstructure, which tends to result in the enhanced bone fragility and related fractures, as well as high disability rate and mortality. Exercise is one of the most common, reliable and cost-effective interventions for the prevention and treatment of OP currently, and numerous studies have revealed the close association between gut microbiota (GM) and bone metabolism recently. Moreover, exercise can alter the structure, composition and abundance of GM, and further influence the body health via GM and its metabolites, and the changes of GM also depend on the choice of exercise modes. Herein, combined with relevant studies and based on the inseparable relationship between exercise intervention-GM-OP, this review is aimed to discuss the moderating effects and potential mechanisms of exercise intervention on GM and bone metabolism, as well as the interaction between them.

Osteoporosis is a systemic metabolic skeletal disease characterized by low bone mass and strength associated with fragility fractures. Oxidative stress, which results from elevated intracellular reactive oxygen species (ROS) and arises in the aging organism, is considered one of the critical factors contributing to osteoporosis. Mitochondrial (mt)ROS, as the superoxide anion (O2−) generated during mitochondrial respiration, are eliminated in the young organism by antioxidant defense mechanisms, including superoxide dismutase 2 (SOD2), the expression and activity of which are decreased in aging mesenchymal progenitor cells, accompanied by increased mtROS production. Using a mouse model of osteoblast lineage cells with Sod2 deficiency, we observed significant bone loss in trabecular and cortical bones accompanied by decreased osteoblast activity, increased adipocyte accumulation in the bone marrow and augmented osteoclast activity, suggestive of altered mesenchymal progenitor cell differentiation and osteoclastogenesis. Furthermore, osteoblast senescence was increased. To date, there are only a few studies suggesting a causal association between mtROS and cellular senescence in tissue in vivo. Targeting SOD2 to improve redox homeostasis could represent a potential therapeutic strategy for maintaining bone health during aging.

Objective: The purpose of this study was to investigate the kind of low-energy fracture which is a precursor of hip fracture in the elderly, and to suggest the importance of osteoporosis treatment and gait training for fall prevention after this low-energy fracture to prevent the occurrence of secondary hip fracture. Methods: From January 2017 to December 2020, a total of 564 patients who underwent surgical treatment for hip fractures were admitted to the Zhongda Hospital affiliated to Southeast University. Baseline information including gender, age, diagnosis and type of low-energy fracture before hip fracture were collected. FRAX score, the number of patients received functional training and the number of patients received anti-osteoporosis treatment were analyzed. Results: There were180 male patients and 384 female patients in the total 564 patients. The number of male patients with low-energy fractures before hip fracture was 28, including hip fracture (8 cases), vertebral fracture (8 cases) and humeral fracture (7 cases), and radial fracture (5 cases). The number of female hip fracture patients with a low-energy fracture before fracture was 62, containing vertebral fracture (31 cases), hip fracture (15 cases), radial fracture (9 cases) and humeral fracture (7 cases). It was found that vertebral fractures were the most frequent low-energy fractures that preceded hip fractures in elderly women compared to other low-energy fractures. It was showed that the 10-year probability of hip fracture and other site fractures was significantly higher in the group with lumbar fractures and other site fractures than those in the group without fractures assessed by using the FRAX measurement system. There were no statistical significance among the three groups of patients who underwent functional training and anti-osteoporosis treatment. We could not find statistical significance among the three groups of patients who underwent functional training and anti-osteoporosis treatment. Conclusion: Vertebral fracture is a precursor of hip fracture in elderly women. In face of the vertebral fractures, surgeons, especially orthopedic surgeons, should pay extra attention to the treatment of osteoporosis and anti-fall functional training.