The decision not to drive during hypoglycemia in patients with type 1 and type 2 diabetes according to hypoglycemia awareness.

OBJECTIVE

In recent years, there has been an ongoing discussion on the relationship between diabetes and driving. As driving performance will inevitably decline at lower levels of glycemia, patients' decisions concerning driving or taking corrective action when hypoglycemia occurs immediately before or during driving seems paramount.

RESEARCH DESIGN AND METHODS

Twenty-four type 1 diabetic patients with normal awareness of hypoglycemia (T1Norm group), 21 type 1 diabetic patients with impaired awareness of hypoglycemia (T1Imp group), and 20 type 2 diabetic patients with normal awareness of hypoglycemia (T2 group) were studied. They were asked whether they felt hypoglycemic and whether they would currently drive during experimental euglycemia (5.0 mmol/l) and hypoglycemia (2.7 mmol/l).

RESULTS

In the T1Norm group, 1 patient (4.2%) decided to drive during hypoglycemia. In the T1Imp group, 9 patients (42.9%) said they would drive in the hypoglycemic condition. In the T2 group, 5 patients (25%) would drive. This was more frequently the case for patients on oral hypoglycemic agents (chi2 = 4.44; P = 0.04). No effect of sex (chi2 = 0.78; P = 0.38) or age (chi2 = 0.22; P = 0.64) was noted.

CONCLUSIONS

Patients with type 1 diabetes and impaired awareness of hypoglycemia frequently decided to drive while hypoglycemic, whereas patients with type 1 diabetes and normal awareness of hypoglycemia appeared to make safe decisions concerning hypoglycemia and driving. Strikingly, patients with type 2 diabetes and normal hypoglycemia awareness frequently made potentially dangerous decisions as well, particularly when using oral hypoglycemic agents. Therefore, early, clear, and consistent education is imperative.