Diabetes Forecast

Blood Glucose Behind the Wheel

By David Marrero, PhD ,

How does taking insulin affect your driving? This is an important question for me as a person with type 1 diabetes, because the stakes are high. Not only does driving with hypoglycemia (low blood glucose) put ourselves and others at risk for injury or death, but it also could affect the rights of other people with diabetes, who already face restrictions on their driving privileges in certain situations.

In this context, the latest research is both interesting and sobering. Some 80 percent of people with type 1 diabetes have no significant history of driving problems associated with hypoglycemia. The remaining 20 percent, however, account for a number of accidents that can be attributed to driving while hypoglycemic. Moreover, the data suggest that a large proportion of the latter group either do not perceive the onset of low blood glucose (because of hypoglycemia unawareness) or, more troubling, do not believe that hypoglycemia can impair their driving. Many of them report driving even when they know they are low, believing that somehow they will be OK.

How can this be? Clearly, those of us who have experienced hypoglycemia know that you can get pretty stupid and klutzy—not ideal conditions for driving—when you are low. And yet in all of my years as a patient with type 1 diabetes, no health care provider has ever discussed with me how my using insulin might present a risk on the roads. Indeed, none has ever recommended that I test to make sure that I am not hypoglycemic before driving or likely to be so while behind the wheel.

The research is clear: You can have a serious or even fatal accident driving while hypoglycemic. We as a community of people with diabetes need to take corrective action to ensure that we do not present a risk to ourselves or others. How? The answer is pretty simple: Always test before you drive. Make sure that your glucose level doesn't suggest that you're likely to get low while you're in the driver's seat. This will require a bit of thought about insulin action times and the impact of foods and physical activity on your blood glucose levels. In addition, people with hypoglycemia unawareness should consider using a continuous glucose monitor.

Anyone who is low behind the wheel must take immediate corrective action. Sure, one might well feel reluctant about pulling off the road, taking glucose, and waiting before driving. That said, I wish all Forecast readers could hear the gut-wrenching stories I have heard about people who felt that they couldn't be bothered and suffered the awful consequences of their poor judgment.

We need to remember that driving is not a right; it is a privilege. As people with a serious chronic disease, we need to take personal responsibility to ensure that our condition does not jeopardize others. Failure to do so increases the risk that the government will make decisions for us about our driving privileges—decisions that, with a little education and the use of common sense, are totally avoidable.



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