The metabolic demands of driving for drivers with type 1 diabetes mellitus.
BACKGROUND
The active cognitive-motor demands of driving may have a significant metabolic demand that could contribute to the development of hypoglycemia. Conversely, symptoms caused by the stress of driving may be confused with hypoglycemia and lead to false alarms. This study examined the metabolic demand and the physiological stress of driving on type 1 diabetes mellitus (T1DM) drivers.


METHODS
Forty-three T1DM drivers were placed on a constant insulin infusion/variable dextrose infusion to maintain euglycemia for 30 min while either watching a driving video or actually driving a simulator, in a counterbalanced crossover design. Dextrose infusion, heart rate, epinephrine, and subjective symptom ratings were measured every 5 min. Additionally, subjects were monitored for self-treatment (drinking soda).


RESULTS
While blood glucose (BG) levels were equivalent across both conditions, actual driving was associated with a higher dextrose infusion rate (p = 0.02), more autonomic symptoms (p < 0.05), increased heart rate (p < 0.001), a trend (p = 0.09) for greater epinephrine release, and more frequent hypoglycemic self-treatment (p < 0.001).


CONCLUSIONS
Driving is a task with a significant metabolic demand, which may lower BG, and also that driving stress may be associated with symptoms similar to those of hypoglycemia. Physicians should discuss with their T1DM patients hypoglycemia and driving, and encourage measuring blood glucose before driving and during long drives.
Cox
Daniel J
DJ
University of Virginia Health System, Charlottesville, VA 22908, USA. djc4f@virginia.edu
Gonder-Frederick
Linda A
LA
Kovatchev
Boris P
BP
Clarke
William L
WL
D000328:Adult; D001334:Automobile Driving / Q000592:standards*; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D004837:Epinephrine / Q000097:blood; D005260:Female; D005947:Glucose / Q000008:administration & dosage; D006339:Heart Rate; D006801:Humans; D007262:Infusions, Intravenous; D007332:Insulin Infusion Systems; D008297:Male; D012449:Safety; D013997:Time Factors
D001786:Blood Glucose; D005947:Glucose; D004837:Epinephrine