Chronic intermittent hypobaric hypoxia ameliorates osteoporosis after spinal cord injury through balancing osteoblast and osteoclast activities in rats

This study investigates the effects of chronic intermittent hypobaric hypoxia (CIHH) on osteoporosis in rats after spinal cord injury (SCI). CIHH involves exposing the rats to moderate hypoxia, simulating high altitude conditions with interrupted normoxia. The study found that CIHH treatment can reverse the decrease in bone mineral density and improve bone structure in SCI rats. This suggests that CIHH might have a protective effect against osteoporosis caused by SCI. The researchers also looked at the underlying mechanisms and found that CIHH may work by balancing the activity of bone-forming cells (osteoblasts) and bone-resorbing cells (osteoclasts), potentially through the hypoxia-inducible factor-1 alpha (HIF-1a) signaling pathway.

• 1
  CIHH treatment effectively reversed the SCI-induced reduction of bone mineral density (BMD), bone volume to tissue volume, trabecular thickness and number.
• 2
  Histomorphometry showed that CIHH treatment increased bone formation of SCI rats, as evidenced by the increased osteoid formation and the decreased number and surface of TRAP-positive osteoclasts.
• 3
  CIHH treatment improved deviations in osteoblastogenesis and osteoclastogenesis-related biomarkers in SCI rats, suggesting a balance between bone formation and resorption.