Taking insulin shots is often a chore for diabetics who must regulate their blood sugar several times daily. Diabetics should be aware of the danger of relying on their ability to detect low blood sugar without measuring it, says lead author of the study, Dr. William L. Clarke of the University of Virginia Health Sciences Center at Charlottesville.
Almost 45 percent of the time, the diabetics in the study said they would drive when they believed their blood sugar to be below 70 milligrams per tenth of a liter of blood. The findings appeared in this week's Journal of the American Medical Association. Previous research among diabetics using driving simulators has shown that blood-sugar levels below 65 lead to loss of control swerving, spinning and wandering off the road, authors said.
The subjects all had type 1 diabetes, which affects about one million Americans. All type 1 diabetics must take insulin to compensate for their body's inability to make blood sugar.
The consequences of dangerously low-blood sugar on the road can be hazardous to everyone's health, as diabetes patient Laida Bushnell found out the hard way when she became disoriented and lost control of her car.
"Well, I hit the rail guard on the right side, and I spun from the right side through three lanes to the left and into the ditch," says Bushnell.
Clarke said diabetics might not realize their blood sugar has fallen because how and when people experience symptoms varies. Symptoms may include shakiness, trembling, sweating, pounding heart, irritability, inability to think well, visual disturbance and lack of coordination.
Previous studies have yielded conflicting data about whether type 1 diabetics have an increased risk of traffic accidents because of fluctuations in blood sugar, Clarke said. He and his colleagues did not analyze accident rates among their subjects.
Dr. Bruce R. Zimmerman, president of the American Diabetes Association, said the findings are "concerning." He agreed, however, that rather than being restricted, diabetics should be trained to be more aware of the potential danger in driving with low blood sugar.
In order to prevent an accident, diabetics should arrange their driving schedule so they aren't on the road when they should be eating a meal. Taking fast-acting sugar pills also helps boost blood sugar levels. By planning ahead, they can be prepared to take control and forgo posing risks to themselves and others.
Long-term diabetics tend to have less noticeable symptoms when blood sugar is low, noted Zimmerman, a Mayo Clinic endocrinologist who was not involved in the stud. Some diabetics have virtually no symptoms but can be trained to pick up subtle signals, he said.