Oxygen is key to life but could it also be a key factor in insulin resistance and type 2 diabetes?
We take a look at the evidence behind this idea and also which methods could use oxygen towards our advantage in tackling insulin resistance.
Low oxygen levels at Mount Everest
Some research studies appear to show quite conclusively that restricting oxygen intake does indeed result in increased insulin resistance.
A study carried out by researchers from the University of Southampton and University College London, published in 2014, investigated the effects of low oxygen levels on insulin resistance by taking adults up Mount Everest.
The researchers found that as the participants reached higher altitudes, and were thus exposed to low levels of oxygen to breathe, they developed insulin resistance.
Oxygen chamber improves insulin sensitivity
By contrast, the opposite effect has also been observed. Researchers from the University of Adelaide tested the effects by exposing people with type 2 diabetes to a total of six periods of 90 minutes of hyperbaric oxygen therapy over a five-week period.
Hyperbaric oxygen therapy involves spending time in a pressurised diving chamber containing 100% oxygen. The technique resulted in a dramatic 40% improvement in insulin sensitivity, an effect that would usually require a 13% loss of body weight.
It seems apparent from this that the more oxygen we get, the better insulin sensitivity we have. Could oxygen also explain why people get insulin resistance in normal life at normal non-mountainous altitudes?
Sleep apnea
It is notable that sleep apnea, a problem that results in disrupted breathing during sleep, is very closely related with type 2 diabetes. Sleep apnea shares obesity as a common major risk factor with type 2 diabetes but oxygen also seems to play a key role.
A study published on 21 April 2015 in the American Journal of Respiratory and Critical Care Medicine has shown that giving sleep apnea patients breathing treatment overnight improved insulin sensitivity and blood glucose levels.
It seems apparent from this that the more oxygen we get, the better insulin sensitivity we have
The breathing treatment, known as continuous positive airway pressure (CPAP), involved wearing a face mask that delivers pressurised air eight hours per night for a period of two weeks.
Why should oxygen lead to insulin resistance?
In 2014, researchers from the University of California, San Diego found that diminished oxygen available to fat cells in mice led to a greater level of inflammation, which had a knock-on effect on the liver and resulted in the development of insulin resistance.
If we were to assume that oxygen intake is indeed a key factor in insulin resistance, the next question is how we could could we increase the oxygen flowing into and through our body?
One answer is to raise our breathing rate through physical activity. Exercise that brings your heart rate up and leaves you at least slightly out of breath is recommended as one of the key lifestyle changes for type 2 diabetes, as well as being recommended the population in general.
High intensity training
The oxygen factor may offer some explanation as to why High Intensity Interval Training has been so successful at improving glucose tolerance.
If we were to assume that oxygen intake is indeed a key factor in insulin resistance, the next question is how we could could we increase the oxygen flowing into and through our body?
In a six-month study by researchers from Queen’s University in Ontario, Canada, which involved involving obese middle-aged adults, higher intensity exercise was shown to result in a 9% improvement in glucose tolerance compared to participants performing lower intensity activity.
Whilst oxygen may be just one out of a number of factors linked with insulin resistance, it is a factor we have some power to influence and it will be interesting to follow future research into the effects of oxygen intake on type 2 diabetes.
