OBJECTIVE - To examine the impact on glycemic control of substituting a range of premixed insulins for the standard treatment with patient-mixed insulin combinations. In addition, a pen-type syringe was substituted for the conventional insulin syringe, and the patients' preference was ascertained at the end of the study. RESEARCH DESIGN AND METHODS - Before the study, all patients had maintained a constant insulin dosage for 2 months. For the first month of the study, all patients were encouraged to make any adjustment in insulin dosage required to optimize control. Twenty-seven patients participated in the study. At the end of the first month, patients were randomized either to change to premixed insulins or to continue with self-mixed insulins for 2 months. At the end of the 2-month period, participants changed to the alternative regime for a further 2 months. Glycemic control was measured by assessment of glycosylated hemoglobin levels at the start of the study and after each 2-month period of the study. In addition, during the 1-month run-in period and during both 2-month study periods, a seven-point blood glucose profile was obtained extending from before breakfast to just before retiring for sleep. RESULTS - Glycosylated hemoglobin levels were unchanged throughout the duration of the study. Similarly, there were no systematic changes in individual seven-point blood glucose profiles. The frequency of hypoglycemic reactions was similar on patient-mixed and premixed insulin programs. However, 83% of patients expressed a preference for premixed insulins. A similar percentage regarded pen-type insulin syringes to be preferable to the conventional syringe. CONCLUSIONS - Glycemic control was similar on patient-mixed and premixed insulins, and patients had a marked preference for premixed insulins delivered in a pen-type syringe over conventional insulin therapy. Premixed insulin delivered by a pen-type syringe promises to ease the burden of daily injections for many diabetic patients.
