title: Ladder-Climbing Training Prevents Bone Loss and Microarchitecture Deterioration in Diet-Induced Obese Rats.
abstract: Resistance exercise has been proved to be effective in improving bone quality in both animal and human studies. However, the issue about whether resistance exercise can inhibit obesity-induced bone loss has not been previously investigated. In the present study, we have evaluated the effects of ladder-climbing training, one of the resistance exercises, on bone mechanical properties and microarchitecture in high-fat (HF) diet-induced obese rats. Twenty-four rats were randomly assigned to the Control, HF + sedentary (HF-S) and HF + ladder-climbing training (HF-LCT) groups. Rats in the HF-LCT group performed ladder-climbing training for 8 weeks. The results showed that ladder-climbing training significantly reduced body and fat weight, and increased muscle mass along with a trend toward enhanced muscle strength in diet-induced obese rats. MicroCT analysis demonstrated that obesity-induced bone loss and architecture deterioration were significantly mitigated by ladder-climbing training, as evidenced by increased trabecular bone mineral density, bone volume over total volume, trabecular number and thickness, and decreased trabecular separation and structure model index. However, neither HF diet nor ladder-climbing training had an impact on femoral biomechanical properties. Moreover, ladder-climbing training significantly increased serum adiponectin, decreased serum leptin, TNF-α, IL-6 levels, and downregulated myostatin (MSTN) expression in diet-induced obese rats. Taken together, ladder-climbing training prevents bone loss and microarchitecture deterioration in diet-induced obese rats through multiple mechanisms including increasing mechanical loading on bone due to improved skeletal muscle mass and strength, regulating the levels of myokines and adipokines, and suppressing the release of pro-inflammatory cytokines. It indicates that resistance exercise may be a promising therapy for treating obesity-induced bone loss.
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Tang
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Xiaohang
authors.initials: X
authors.lastname: Gao
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Physical Education, Northwest University, Xi'an, 710069, China.
authors.forename: Chentao
authors.initials: C
authors.lastname: Liu
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Xudan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Yanqi
authors.initials: Y
authors.lastname: Han
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Xinjuan
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Aiping
authors.initials: A
authors.lastname: Chi
authors.affiliation: Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China. sunlijun@snnu.edu.cn.|Postdoctoral Research Station of Biology, Shaanxi Normal University, Xi'an, 710119, China. sunlijun@snnu.edu.cn.
authors.forename: Lijun
authors.initials: L
authors.lastname: Sun
mesh_terms: D000818:Animals; D001823:Body Composition; D015519:Bone Density / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging / Q000473:pathology / Q000517:prevention & control*; D059305:Diet, High-Fat; D008297:Male; D009765:Obesity / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D010805:Physical Conditioning, Animal / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016474:Weight-Bearing / Q000502:physiology; D055114:X-Ray Microtomography
keywords: Bone loss; Bone microarchitectures; Bone strength; Obesity; Resistance exercise