Diabetes Forecast

Sniffing Out Hypoglycemia: How Dogs Can Detect Low Blood Glucose Levels

What to Know

If you have diabetes, then you know that hypoglycemia (low blood glucose levels) is an everyday concern. It can also be very dangerous. Untreated, it can cause seizures and lead to unconsciousness. Such episodes may occur with little warning in some people with type 1 diabetes. According to some reports, dogs have alerted owners to changes in their blood glucose levels. Researchers set out to study this phenomenon in hopes that it might lead to new tools for better early detection of hypoglycemia.

The Study

The researchers suspected that the dogs were responding to a particular chemical in their owner’s breath. Perhaps, they reasoned, that chemical reacts when blood glucose levels drop. To identify the chemical, they recruited eight women with type 1 diabetes who were between the ages of 41 and 51. They took samples of each woman’s breath when they had normal blood glucose levels and then again when they had low blood glucose levels. They then compared the samples to see if anything stood out.

The Results

One chemical caught the researchers’ attention: isoprene, one of the most common chemical components of human breath. When blood glucose levels dropped, isoprene levels rose significantly. None of the other chemicals in the women’s breath reacted to drops in blood glucose levels.


A simple breath test may offer an easy way to monitor changes in blood glucose levels for people with diabetes. Though the study was small and researchers were not able to determine how hypoglycemia affects isoprene, it likely explains how low blood glucose levels can be detected by dogs, who may be able to be trained to do just that.

Exhaled breath isoprene rises during hypoglycemia in type 1 diabetes, by Sankalpa Neupane and colleagues. Diabetes Care 2016;39:e97-e98. https://doi.org/10.2337/dc16-0461

The information on this screen does not take the place of care from your doctor or other health care provider. If you have general questions about diabetes or diabetes-related research, e-mail askada@diabetes.org or call 1-800-DIABETES (800-342-2382).



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