How Dogs May Detect Low Blood Sugar

Dogs are famous for their remarkable sense of smell. They can detect subtle changes in human scent, including shifts linked to certain medical conditions. One of the most useful examples is the work of diabetic alert dogs, who can be trained to warn people with type 1 diabetes when their blood sugar is dropping dangerously low.

For people with type 1 diabetes, hypoglycemia can come on quickly. If blood sugar falls too far, it may cause weakness, confusion, fatigue, unconsciousness, or seizures. Organizations such as Medical Detection Dogs train assistance dogs to recognize these warning signs and alert their owners before the situation becomes an emergency.

For years, the big question was how could dogs detect a low-blood-sugar episode before the person noticed it. Research from the University of Cambridge offers a likely explanation. In a small, controlled study of women with type 1 diabetes, researchers measured chemicals in exhaled breath while blood sugar levels were gradually lowered. They found that levels of isoprene, a naturally occurring chemical in human breath, rose during hypoglycemia. In some cases, the increase was substantial.

Humans are not especially good at smelling isoprene, but dogs have a much more sensitive sense of smell. That makes it plausible that trained diabetic alert dogs are responding, at least in part, to changes in isoprene in a person’s breath.

This discovery may also point toward future improvements in diabetes care. Scientists hope that one day, breath-based testing could help monitor low blood sugar more comfortably and less invasively. Instead of relying only on blood samples or finger pricks, patients might eventually use a breath-based device to detect early signs of hypoglycemia.

Thanks to Dee and Tulah Monstah for the photo of Dixie, a medical alert assistance service dog.

Source:

Neupane S, Peverall R, Richmond G, et al. Exhaled Breath Isoprene Rises During Hypoglycemia in Type 1 Diabetes. Diabetes Care. 39 (7): e97-e98.