Discussion
generalised, skeletal muscle, inflammation, beta cell loss, diabetes endotypes, hyperglycaemia, normoglycaemia, mitochondrial damage
INFLAMMATION, DISEASE, IMPAIRED GLUCOSE TOLERANCE, INSULIN RESISTANCE, HYPERGLYCAEMIA, TYPE 2 DIABETES, PATHOGENESIS, INSULIN SENSITIVITY
This study demonstrates that a single HBO treatment with 100% OThe observation of a clinically meaningful reduction in fasting hyperglycaemia in humans with type 2 diabetes extends previous data [The novelty resides in the investigation of the initial tissue-specific cellular mechanisms underlying the beneficial metabolic effects of HBO treatment. In general, improvements in tissue-specific insulin sensitivity in type 2 diabetes may result from reductions in lipotoxic insulin signalling, low-grade inflammation, and oxidative and/or ER stress [We also found that short-term HBO leads to higher production of ROS as well as antioxidative defence markers in both skeletal muscle and WAT of humans with type 2 diabetes. While chronic ROS overproduction can cause mitochondrial damage and reduced function in type 2 diabetes [This study also provides evidence for a substantial decrease in biomarkers of ER stress after a single session of HBO in humans with type 2 diabetes. ER stress has been shown to be involved in the pathogenesis of type 2 diabetes by leading to pancreatic beta cell loss and insulin resistance [Interestingly, the present study failed to detect any changes in circulating biomarkers of subclinical inflammation in humans with type 2 diabetes after HBO. While this is in line with a previous study [The limitations of this study include the use of a single dose of HBO, which does not allow extrapolation to long-term metabolic effects. Second, the applied study design neither clarifies how long the glucose-lowering effect persists after one session of HBO nor allows for detailed insights into changes in lipid metabolism upon HBO. Third, the study comprised male volunteers with type 2 diabetes, so findings cannot be generalised to women or to people with normoglycaemia or impaired glucose tolerance. In addition, the results may not be generalisable to all individuals with type 2 diabetes because of the short known disease duration as well as the rather narrow range of age and of insulin resistance, given the different diabetes endotypes [In conclusion, one single treatment of HBO with 100% O