Several diabetes-related conditions can impair the driving ability of diabetic patients. These include visual loss due to
retinopathy, sensory-motor impairment due to neuropathy, cardiovascular disease, and amputation. Caused sometimes by rapid
onset, hypoglycaemic events belong to the most dangerous situations in traffic not only for the diabetic patient, but for
other traffic participants as well. The main reason for hypoglycaemias is insulin therapy, but some oral antidiabetic drugs
(sulfonylureas, glinides) in widespread use also have hypoglycaemia-inducing properties. To date, insulin therapy and its
consequences on traffic safety have been at the focus of research.
Unfortunately, the available studies provide no consistent picture of the traffic safety of insulin-treated patients. Frequent
methodological problems include retrospective analysis, not distinguishing between insulin-dependent and insulin-independent
patients, no distinction between the different modes of insulin therapy, no clear emphasis and description of comorbidities
and other medications of the patients. Furthermore, many of these studies rely on official data that only quantify accidents
or traffic violations or are predicated on self reports. Although there is no doubt that hypoglycaemias during driving occur,
the studies show a tendency - but no clear evidence — that patients with diabetes are significantly more involved in road
traffic accidents than the population in general. The ambiguous picture presented by the different studies has led to variable
strategies by the licensing authorities concerning diabetic patients throughout the world. Since the outcome of a traffic
hypoglycaemia also depends on the patient’s ability to detect and to counteract this situation, the increase in patient education
of recent decades may have played a positive role. Apart from the participation of subjects with hypoglycaemia unawareness
in hypoglycaemia awareness trainings, further recommendations include measuring blood glucose levels before and also during
longer drives, especially for those individuals who have lost the symptoms of low blood glucose and have a history of driving
mishaps.