Diabetes mellitus and traffic incidents

At present, no clear evidence is available that, as a group, patients with diabetes mellitus are at increased risk of becoming involved in traffic accidents. However, accidents as a consequence of hypoglycaemia do occur, and the percentage of accidents in patients with insulin-dependent diabetes mellitus resulting from hypoglycaemia has been estimated at 5.2%. A recent study using computer-simulation techniques showed that during moderate hypoglycaemia (2.6 mmol/l) driving performance deteriorated significantly. Only one third of these subject were aware of it. Surprisingly, only half of them stated that they would not to drive under such circumstances. Unawareness of hypoglycaemia forms a major risk factor. With the present efforts to improve metabolic control with intensive insulin therapies the incidence of unawareness and therefore of severe hypoglycaemic reactions is increasing. With intensive education programs such as blood glucose awareness training (BGAT) introduced by Cox et al. patients learn to estimate blood glucose concentrations and specifically to detect hypoglycaemia at an early stage. The first studies show that after BGAT the incidence of hypoglycaemia decreases. Interestingly, after BGAT, patients were less frequently involved in traffic accidents (crash rates per 1 000 000 miles 6.8 vs. 29.8, p = 0.01). Therefore, although many questions remain to be answered, BGAT has proved beneficial in reducing hypoglycaemic episodes and in reducing traffic accidents.