Our Research Fellow Dr Catriona Farrell discusses a new approach that could help people with type 1 who have lost their ability to detect hypos.
Hypos happen when blood glucose levels drop too low. You feel confused, shaky, your vision becomes blurry and they’re a massive annoyance.
If you’re able to detect the symptoms, you can grab your hypo treatment and get yourself back in a safe blood glucose range fairly quickly. Problem solved until the next hypo rears its ugly head.
But many people with type 1 diabetes can develop hypo unawareness. This means they lose the ability to sense when they’re going low. Not only can this be really scary, but it can have serious consequences. People could lose consciousness and, in extreme cases, go into a coma.
We don’t yet fully understand why people lose their ability to sense when their blood glucose is too low. But we know that if someone has repeated hypos, they’re more likely to stop noticing when new hypos happen. If you can avoid hypos, your awareness may return – but avoiding hypos is not always an easy task.
So we need to find better ways to help people with type 1 diabetes bring back their hypo awareness. And our researchers are trying to figure it out.
High intensity exercise
In 2017, we awarded our Sir George Alberti Research Fellowship to Dr Catriona Farrell at the University of Dundee.
She’s hoping to work out if high intensity exercise can be used to bring back hypo awareness. She’s studying people with type 1 diabetes who have lost their ability to sense lows. One group will be given a high intensity exercise regime, and another group will do moderate intensity exercise. Dr Farrell will look at how the two different approaches may affect their hypo awareness.
We asked Dr Farrell to fill us in on her pioneering research and her hopes for its future impact.
The science behind it
“The study is based on the idea that repeated hypos build up memory in the brain. The cells in the brain learn to adapt to lows because each hypo causes stress to the brain, which is damaging in the long term. This type of learned memory and behaviour is in keeping with an idea called habituation.
“So we started thinking about introducing a new stress, or a dishabituating stimulus, that could override this and restore hypo awareness.
“We think high intensity exercise could be a good type of stress to do this. There’s been a lot of research done around exercise and diabetes, but we don’t think it’s ever been looked at for bringing back hypo awareness before.”
Dr Farrell's project began will a small study to test our the idea. She asked 12 participants to either undertake a 20 minute single burst of high intensity exercise or rest. The following day, they were given infusions of insulin and glucose to gradually reduce their blood sugar levels to 2.5 mmol/l, before returning to a normal range.
Dr Farrell measured the participants’ hormonal responses throughout the hypo experiment and asked participants to rate their awareness of low blood sugar symptoms and complete cognitive tests.
Two weeks later the participants carried out the intervention (high intensity exercise or rest) they had not yet completed. This was followed by another hypo experiment the next day.
Dr Farrell found, in comparison to rest, a single episode of high intensity exercise led to a 29% increase in adrenaline response, improved awareness of hypo symptoms and improved cognitive functioning when tested during hypoglycaemia.
To find out whether high intensity exercise could be an effective future treatment, we need to know if its benefits could be maintained over time. Dr Farrell's now exploring this in a longer-term clinical trial and we'll keep you updated on her findings.
Improving the lives of people with diabetes
“I believe this research could have a really big impact. There are a lot of people with type 1 diabetes who are struggling to improve their blood glucose control because of their fear of hypos, and not being able to sense them.
“What’s more, if we find out high intensity exercise works this could be a really useful and accessible treatment option. It doesn’t involve taking medication, it doesn’t cost anything and it’s got added health benefits. We should be encouraging everyone, whether they have diabetes or not, to exercise.
“I think if it’s successful, and I really hope it will be, then we can roll out this approach on a larger scale and it could be beneficial for thousands of people with type 1 diabetes.”
If you're not keen on exercise
“It’s not necessarily the treatment of choice for everyone, but exercise could be good for a specific group of people with type 1 diabetes. And if we work out that dishabituation is the key to hypo awareness, then we can look at other approaches that could also override it, like exposure to cold.”
Interested in more hypo research?
Our researchers are also working on other ways to fight hypos. Dr Craig Beall is studying a drug that works on a molecule that's involved in sensing energy levels, called AMPK. He's working out how it might be used to boost the body’s defences against hypos. This research could lead to the development of new drugs that can prevent hypos and improve peoples’ ability to recognise the signs of low blood sugars.