Scientists Discover How Dogs Detect Low Blood Sugar In Humans

Your best friend may one day be your life-saver if you have diabetes.

Many people with diabetes rely on assistance dogs to assist them in emergency situations. Dogs have an uncanny ability to detect hypoglycemic attacks before they happen, and scientists at Cambridge University have just made a major breakthrough in understanding how they do it.

Dogs are capable of detecting low blood sugar levels from a compound in our breath, which means that specialized sensors could be produced to detect this compound in the near future.

Photo: pixabay/Alexas_Fotos
Photo: pixabay/Alexas_Fotos

Claire Pesterfield, a pediatric diabetes specialist nurse at Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust with type 1 diabetes, relies on her assistance dog Magic. Magic was trained by Medical Detection Dogs, and can alert her when her blood sugar level gets low.

“Low blood sugar is an everyday threat to me and if it falls too low — which it can do quickly — it can be very dangerous,” Pesterfield said. “Magic is incredible — he’s not just a wonderful companion, but he’s my ‘nose’ to warn me if I’m at risk of a hypo. If he smells a hypo coming, he’ll jump up and put his paws on my shoulders to let me know.”

Pesterfield said small hypos (hypoglycemic attacks) were common for her throughout the week, with large ones more likely to occur at night. But, since finding Magic, she’s been able to rest much easier.

“Since I’ve had Magic, I haven’t had a severe hypo in the two years that I’ve been together with him,” she said.

The research at Cambridge was aimed at isolating certain naturally-occurring chemicals in human breath that change in correlation with blood sugar levels. Scientists examined the breath of eight women, all in their 40s and all with type 1 diabetes, while their blood sugar levels were altered. At the point of hypoglycemia, the scientists noted a marked increase in the chemical isoprene.

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“Isoprene is one of the commonest natural chemicals that we find in human breath, but we know surprisingly little about where it comes from,” said Dr. Mark Evans, Honorary Consultant Physician at Addenbrooke’s Hospital, University of Cambridge. “We suspect it’s a by-product of the production of cholesterol, but it isn’t clear why levels of the chemical rise when patients get very low blood sugar.”

Photo: AdobeStock/hitdelight
Photo: AdobeStock/hitdelight

“Humans aren’t sensitive to the presence of isoprene, but dogs with their incredible sense of smell find it easy to identify, and can be trained to alert their owners about dangerously low blood sugar levels,” Evans said. “It provides a ‘scent’ that could help us develop new tests for detecting hypoglycemia and reducing the risk of potentially life-threatening complications for patients living with diabetes.”

Now that scientists understand the link between isoprene in our breath and dogs’ keen olfactory receptors, they can work on developing sensors to warn of impending hypoglycemic attacks. Follow this link to read more about dogs helping people with diabetes.

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