Objective: To evaluate glycemic variation and hypoglycemia in patients with well-controlled type 1 diabetes receiving multiple daily insulin injections during glargine and Ultralente use as basal insulin in a clinical trial.
Methods: Twenty-two patients (12 men and 10 women; median age, 43 years), with a hemoglobin A1c level <7.8%, were randomized in a crossover design to receive either insulin glargine or Ultralente insulin as basal insulin for 4 months each, with insulin aspart as prandial insulin. Continuous glucose monitoring and the Fear of Hypoglycemia questionnaire were used at baseline and at the end of each treatment period.
Results: Whereas the mean amplitude of glycemic excursions showed a correlation with the area under the curve of blood glucose <3.89 mmol/L per day, the number of periods during the day with hypoglycemia was significantly correlated with the M value. Measures of glycemic variation did not differ significantly between glargine and Ultralente treatment. With use of glargine therapy, the SD of blood glucose levels showed a tendency to be lower and the SD of nocturnal blood glucose concentrations was significantly lower. Glucose concentrations were significantly lower during the 1 hour before and the 3 hours after lunch with use of Ultralente. The "Worry" scale on the Fear of Hypoglycemia questionnaire was less during Ultralente therapy and correlated with the number of times blood glucose concentrations were <3.89 mmol/L daily.
Conclusion: Measures of glycemic variability and hypoglycemia need to be studied more in clinical trials of glycemic control in patients with type 1 diabetes. Glycemic variability is less, particularly at night, with glargine as basal insulin.