The Minnesota Diabetes Complications Clinical Trial cognitive functions under long-term maximized and standard metabolic controls.

We have studied memory (Wechsler Memory Scale) and mood states in 20 insulin dependent diabetics under maximized metabolic control (treated with multiple insulin injections daily or insulin pumps) and 12 patients under standard control (treated with one or more injections of insulin daily). Both groups of patients have been enrolled in the Minnesota Diabetes Complications Clinical Trial for two years or longer. The patients in the maximized control group (mean +/- SD) blood glucose 130 +/- 9 mg/dl) had hypoglycemic episodes much more frequently than the patients in the standard control group (mean +/- SD blood glucose 242 +/- 22 mg/dl). Both groups of patients had normal cognitive functions, including a few patients with numerous hypoglycemic episodes. Only one patient who developed a hypoglycemic coma for several weeks has had lasting abnormal cognitive functions including a few patients with numerous hypoglycemic episodes. We conclude that long-term maximized diabetic control (at least 2 years), although not devoid of danger, does not seem to affect cognitive functions in the patients tested according to the parameters used.