Influence of hyperbaric oxygen therapy on bone metabolism in patients with neoplasm

BACKGROUND: Hyperbaric oxygen therapy (HBOT) is useful in the treatment of complications due to radiotherapy in patients with neoplasm. Its effects on bone metabolism are unclear. In our study, we analyzed the effects of HBOT on bone remodeling in oncological patients with radiotherapy. MATERIALS AND METHODS: Prospective clinical study in 23 patients with neoplasms undergoing treatment with HBOT due to complications of radiotherapy (hemorrhagic cystitis, proctitis or radionecrosis) and 25 patients with chronic anal fissure. The average number of HBOT sessions was 20 ± 5 (100% oxygen, 2.3 atmospheres and 90 min per day). Serum levels of aminoterminal propeptide of type I collagen (P1NP), C terminal telopeptide of type I collagen (CTX), alkaline phosphatase (AP), 25hydroxyvitamin D (25-OHD), parathyroid hormone (PTH), were measured at 3 time points: T0 (before beginning HBOT), T1 (at the end of HBOT) and T2 (6 months after HBOT). RESULTS: At baseline, the patients with neoplasm have higher bone turnover than those with anal fissure. These differences were 41% in CTX (0.238 ± 0.202 ng/mL in neoplasm and 0.141 ± 0.116 ng/mL in fissure; p = 0.04), 30% for PTH (46 ± 36 pg/mL in neoplasm and 32 ± 17 pg/mL in fissure; p = 0.04) and 15% for alkaline phosphatase (80 ± 24 U/L in neoplasm and 68 ± 16 U/L in fissure; p = 0.04). In the group with neoplasm, the values of P1NP decreased 6% after HBOT (T0: 49 ± 31 ng/mL, T2: 46 ± 12 ng/mL; p = 0.03). Also, there were non-significant decreases in PTH (−34%) and CTX (−30%). CONCLUSIONS: Patients with neoplasm and complications with radiotherapy have an increase in bone remodeling that may be diminished after HBOT.