No abstract

No abstract

Objectives: To learn how high concentration in hyperbaric oxygen therapy (HBO) acts on the expression of genes related to bone metabolism in osteoblast cell lines and human trabecular bone. Material and methods: The differential expression of several genes related to bone metabolism (SOST, RUNX2, MMP14, OPG, HIF-1α and SIRT1) in two human osteoblastic cell lines (Saos and Super-Saos) and in human trabecular bone fragments subjected to one, three or five HBO sessions (90 minutes, 100% oxygen; 2.3 atmospheres). In each experiment, a control that did not receive HBO was used. Results: We did not find significant differences after HBO in the expression of the genes studied, neither in the cells nor in trabecular bone. Only in the Super-Saos cell line the expression of OPG after 5 sessions of HBO decreased 6 times with respect to that of the control group (2-ΔCt Ct of 72; p=0.01). Conclusions: High concentration oxygen in the hyperbaric chamber (HC) does not seem to influence the expression of genes related to bone metabolism.

Introduction: Oxygen is emerging as an important factor in the local regulation of bone remodeling. Some preclinical data suggest that hyperoxia may have deleterious effects on bone cells. However, its clinical relevance is unclear. Hence, we studied the effect of hyperbaric oxygen therapy (HBOT) on serum biomarkers reflecting the status of the Wnt and receptor activator of NF-κB ligand (RANKL) pathways, two core pathways for bone homeostasis. Materials and methods: This was a prospective study of 20 patients undergoing HBOT (mean age 58 yrs., range 35–82 yrs.) because of complications of radiotherapy or chronic anal fissure. Patients were subjected to HBOT (100% oxygen; 2.4 atmospheres absolute for 90 min). The average number of HBOT sessions was 20 ± 5 (range 8–31). Serum hypoxia-inducible factor 1-α (HIF1-α), osteoprotegerin (OPG), RANKL, and the Wnt inhibitors sclerostin and dickkopf-1 (DKK1) were measured at baseline and after HBOT by using specific immunoassays. Results: HIF-1α in eight patients with measurable serum levels increased from 0.084 (0.098) ng/mL at baseline to 0.146 (0.130) ng/mL after HBOT (p = 0.028). However, HBOT did not induce any significant changes in the serum levels of OPG, RANKL, sclerostin or DKK1. This was independent of the patients’ diagnosis, either neoplasia or benign. Conclusion: Despite the potential concerns about hyperoxia, we found no evidence that HBOT has any detrimental effect on bone homeostasis.