Pulsed Electromagnetic Field Prevents Lumbar Bone Loss in Orchiectomy Mice Without Altering Systemic Iron Metabolism

Jiancheng Yang^1,2*Yan Feng¹Mingming Pan¹Yuhong Zeng^1*

• ¹Xi'an Honghui Hospital, Xi'an, China
• ²Xi'an Jiaotong University, Xi'an, China

Background: The therapeutic efficacy of pulsed electromagnetic fields (PEMF) for postmenopausal osteoporosis has been established; however, its effect on male osteoporosis remains uncertain. Osteoporosis development is associated with dysregulation of systemic iron metabolism. This study aimed to investigate the therapeutic effect of PEMF on orchiectomy (ORX)-induced osteoporosis in mice and determine whether its mechanism involves regulating systemic iron metabolism. Methods: Twenty-four 10-week-old male C57BL/6J mice were divided into Sham, ORX, and ORX+PEMF groups (n=8 each). The ORX+PEMF group received PEMF treatment (15 Hz, peak 3.82 mT, 40 min/day for 2 months) starting 2 weeks post-surgery. Bone loss was assessed using micro-CT, biomechanical testing, dynamic histomorphometry, and TRAP staining. Systemic iron metabolism was evaluated via Prussian blue staining, atomic absorption spectrometry, and serum ELISA (hepcidin, ferritin). Results: PEMF treatment partially prevented ORX-induced bone loss in the lumbar spine, evidenced by significant improvements in bone microstructure and mechanical properties, along with partially restored bone formation and suppressed bone resorption compared to untreated ORX mice. However, PEMF showed no significant protective effect on femoral bone microstructure or cortical parameters. Crucially, PEMF did not alter systemic iron metabolism markers: no changes were observed in tissue iron deposition, iron content, serum ferritin, serum hepcidin, or liver hepcidin expression. 2 Conclusions: PEMF exerts a site-specific protective effect against ORX-induced osteoporosis in the lumbar spine of male mice, partially restoring bone formation and reducing resorption. This therapeutic efficacy occurs independently of alterations in systemic iron metabolism. The findings support PEMF as a potential physical therapy for male osteoporosis but highlight the need for site-optimized strategies.