Abstract
We have read the article entitled "Diabetic Driving Studies-Part 1: Brake Response Time in Diabetic Drivers With Lower Extremity Neuropathy" (JFAS 56:568-572, 2017) published in the May/June issue of your Journal with outmost interest because it has presented the data from a valuable and important study in an attempt to find an answer to a substantial question. The presented results bring an interesting finding that the study participants with a history of any ulceration, amputation, or Charcot neuroarthropathy (n = 136 trials [68.0%]) had a mean brake response time that was shorter (0.721 +- 0.139 seconds) and the range narrower (range 0.50 to 1.30 seconds) compared with participants without such a history (n = 64 trials [32.0%]) who had a brake response time of 0.833 +- 0.229 (range 0.51 to 1.68) seconds (p < .001).
From the clinical viewpoint, we would expect the opposite, because these complications usually signal a greater degree of lower extremity neuropathy. In a search for an explanation, in addition to the comparatively small number of participants, a question was raised of possible hypoglycemia which could have occurred during or shortly before some of "the brake tests," thus would have accidentally influenced the subjects' reaction time.
Furthermore, the study population consisted of type 2 diabetes mellitus patients-their treatment, however, was not described. The wide range of hemoglobin A1c values (5.5% to 10.1%) suggests that the study group might have also included patients treated with hypoglycemic drugs such as insulin or sulphonylurea derivatives.
We would, therefore, like to ask Meyr et al to specify whether the blood glucose levels were checked, a history of recent hypoglycemia had been determined before "the brake test," and whether all the patients involved had been treated with nonhypoglycemic agents. We also, with great respect, suggest considering the question of hypoglycemia into the protocol of this interesting and important study, if its continuation is planned.