Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Health and Rehabilitation Science, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
Honghui Hospital, College of Medicine, Xi'an Jiaotong University, Xi'an, China.
Phys Ther. 2022 Oct 6;102(10). doi: 10.1093/ptj/pzac097.
Physical factors have been used to address disuse osteoporosis, but their effects and mechanism remain unclear. The purpose of this study was to determine the effects of pulsed electromagnetic field (PEMF) and whole-body vibration (WBV) on disuse osteoporosis to increase knowledge about treating osteoporosis.
A disuse osteoporosis rat model was developed by hind-limb unloading (HU) for 6 weeks. Forty 4-month-old female Sprague-Dawley rats were divided into 5 groups and given the following interventions: HU, HU treated with PEMF (HUP), HU treated with WBV (HUW), HU treated with both PEMF and WBV (HUPW), and no intervention (controls). After 8 weeks of intervention, measurements were taken.
HU induced a decrease in bone mineral density (BMD), whereas HUP, HUW, and HUPW increased it. Moreover, the bone resorption markers tartrate-resistant acid phosphatase (TRAP) and C-terminal peptide of type 1 collagen in the HU group significantly increased, whereas the osteogenesis markers osteocalcin and N-terminal propeptide of type 1 procollagen significantly decreased. The markers osteocalcin and N-terminal propeptide of type 1 procollagen significantly increased, but TRAP and C-terminal peptide of type 1 collagen significantly decreased in the HUPW, HUP, and HUW groups compared with the HU group. In particular, HUPW effectively increased osteocalcin and decreased TRAP compared with HUP and WBV. Microcomputed tomography analysis of the femur indicated that HUPW improved trabecular number, bone volume over total volume, bone surface over bone volume, trabecular separation, and the structure model index compared with HUP and that it improved bone surface over bone volume, trabecular separation, and structure model index compared with HUW. The HUPW group showed a significant increase in maximum load compared with the HUW group and a significant increase in elastic modulus compared with the HUP group.
PEMF, WBV, and their combination all attenuated bone resorption and enhanced osteogenesis. WBV and the combination of treatments have great potential to improve osteogenesis compared with PEMF. In addition, HUPW significantly attenuated bone resorption compared with HUW and HUP.
The results of this study indicated that HUPW could effectively improve disuse osteoporosis compared with HUP, given that trabecular number and bone volume over total volume are associated with disuse osteoporosis. Moreover, BMD recovered well with HUP, HUW, and HUPW but the bone structure-especially mechanical performance-did not, indicating that osteoporosis should be evaluated with BMD and mechanical performance, not with BMD in isolation.
已经使用物理因素来解决废用性骨质疏松症，但它们的作用和机制仍不清楚。本研究的目的是确定脉冲电磁场（PEMF）和全身振动（WBV）对废用性骨质疏松症的影响，以增加对骨质疏松症治疗的认识。
通过后肢去负荷（HU）6 周建立废用性骨质疏松症大鼠模型。将 40 只 4 月龄雌性 Sprague-Dawley 大鼠分为 5 组，并进行以下干预：HU、HU 联合 PEMF（HUP）、HU 联合 WBV（HUW）、HU 联合 PEMF 和 WBV（HUPW）以及无干预（对照组）。干预 8 周后进行测量。
HU 导致骨密度（BMD）降低，而 HUP、HUW 和 HUPW 则增加了 BMD。此外，HU 组的骨吸收标志物抗酒石酸酸性磷酸酶（TRAP）和 1 型胶原 C 端肽显著增加，而成骨标志物骨钙素和 1 型原胶原 N 端前肽显著减少。与 HU 组相比，HUPW、HUP 和 HUW 组的骨钙素和 1 型原胶原 N 端前肽显著增加，而 TRAP 和 1 型胶原 C 端肽显著减少。与 HUP 和 WBV 相比，HUPW 可有效增加骨钙素并降低 TRAP。股骨的微计算机断层扫描分析表明，与 HUP 和 HUW 相比，HUPW 可改善骨小梁数量、骨体积/总体积、骨表面/骨体积、骨小梁分离度和结构模型指数，与 HUW 相比，HUPW 可改善骨表面/骨体积、骨小梁分离度和结构模型指数。与 HUW 组相比，HUPW 组的最大载荷显著增加，与 HUP 组相比，弹性模量显著增加。
PEMF、WBV 及其联合应用均可减轻骨吸收，增强成骨作用。与 PEMF 相比，WBV 及其联合治疗具有更大的改善成骨作用的潜力。此外，与 HUW 和 HUP 相比，HUPW 可显著减轻骨吸收。
本研究结果表明，与 HUP 相比，HUPW 可有效改善废用性骨质疏松症，因为骨小梁数量和骨体积/总体积与废用性骨质疏松症有关。此外，HUP、HUW 和 HUPW 可使 BMD 得到很好的恢复，但骨结构-特别是机械性能-没有得到恢复，这表明骨质疏松症的评估不仅要依赖于 BMD，还要结合机械性能，而不能仅仅依赖于 BMD。
