Effects of Hyperbaric Oxygen Therapy on Diabetes
1. Mechanism of Action of Hyperbaric Oxygen Therapy
The core principle of HBOT is to increase the concentration of dissolved oxygen in plasma. Under 2-3 atmospheres of pressure, the amount of oxygen physically dissolved in the blood can be increased by more than 20 times, directly improving the state of tissue hypoxia. This feature is particularly important for diabetic patients, because microvascular lesions and oxidative stress caused by hyperglycemia can aggravate tissue hypoxia, leading to complications such as neuropathy and wound ulcers. Animal experiments have shown that HBOT can promote angiogenesis and cell repair by activating the hypoxia-inducible factor-1α (HIF-1α) pathway.
2. Application of HBOT in diabetic complicationsDiabetic foot ulcers
About 15% of diabetic patients will develop foot ulcers in their lifetime, and HBOT has been shown to significantly accelerate wound healing. A randomized controlled trial of 120 patients (Gill & Bell, 2021) showed that the complete healing rate of ulcers in the HBOT group was 40% higher than that in the control group, and the average healing time was shortened by 3 weeks. Its mechanism may involve inhibiting the release of inflammatory factors (such as TNF-α, IL-6) and enhancing the bactericidal ability of neutrophils.
Peripheral neuropathy
The improvement effect of HBOT on diabetic peripheral neuropathy has been gradually confirmed. Kessler et al. (2020) found through neuroelectrophysiological testing that the sensory nerve conduction velocity of patients in the HBOT treatment group increased by 25% and the pain score decreased by 30%. This may be related to HBOT regulating oxidative stress levels and reducing endoneurial microvascular damage.
Diabetic retinopathy
The current evidence is still controversial. Some studies have pointed out that HBOT may delay retinal ischemic damage by inhibiting the overexpression of vascular endothelial growth factor (VEGF); however, there are also reports that high concentrations of oxygen may aggravate oxidative stress, and the risks need to be carefully assessed.
3. Potential benefits and research limitations
Existing evidence shows that HBOT may assist in diabetes management through the following pathways:
Improve insulin sensitivity: Animal experiments have shown that HBOT can upregulate the expression of skeletal muscle GLUT4 transporter and promote glucose uptake.
Reduce inflammatory response: HBOT can reduce C-reactive protein (CRP) and lipopolysaccharide binding protein (LBP) levels and relieve chronic inflammatory states.
However, most studies have limitations such as small sample size and insufficient treatment courses. The 2022 Cochrane systematic review pointed out that the quality of existing randomized controlled trials is mixed, and the effect of HBOT on improving glycated hemoglobin (HbA1c) has not been consistently verified. In addition, HBOT needs to be completed in a hyperbaric oxygen chamber, the treatment cost is high, and there are risks such as ear barotrauma and oxygen poisoning, which limits its clinical popularity.
4. Controversy and future directions
Some scholars question the long-term safety and economy of HBOT. For example, long-term exposure to high concentrations of oxygen may induce pulmonary fibrosis or cataracts. A recent meta-analysis (2023) suggests that HBOT is only effective for specific subgroups of patients (such as those with severe hypoxic ulcers), but has no significant benefit for mild patients. In the future, large-sample, multicenter studies are needed to clarify the applicable population and optimal intervention plan for HBOT.
5. Conclusion
As an adjuvant treatment for diabetic complications, hyperbaric oxygen chamber therapy has shown the potential to improve tissue oxygen supply and promote wound healing, but its efficacy is significantly affected by individual differences in patients and treatment parameters. Current evidence does not support HBOT to replace conventional hypoglycemic treatment. Clinical application needs to strictly grasp the indications and be carried out under the guidance of a multidisciplinary team. With the deepening of molecular biology research, HBOT may provide a new combined treatment strategy for diabetes management.
