Effect of Automated Bolus Calculation on Glucose Variability and Quality of Life in Patients With Type 1 Diabetes on CSII Treatment

Abstract

PURPOSE: Automated bolus calculation may benefit patients with poorly controlled type 1 diabetes who are relatively new to continuous subcutaneous insulin infusion (CSII). This study investigated the effect of automated bolus calculation on glucose variability, glucose control, and diabetes-related quality of life in patients with reasonably well-controlled type 1 diabetes, accustomed to treatment with CSII for several years. METHODS: This open-label, single-center study included 32 patients (mean age, 45.9 [15.1] years; 34% male; disease duration, 27.3 [12.9] years; glycosylated hemoglobin [HbA1c] level, 64.6 [12.5] mmol/mol [8.1% (1.1%)]; CSII treatment, 9.0 [7.8] years) who were randomly assigned to receive 4 months' treatment with a bolus calculator (n = 14) or continuation of standard care without a bolus calculator (n = 18). All participants received dietary counseling on carbohydrate counting. Primary outcome was glucose variability, as assessed by the SD of 7-point glucose profiles. Secondary outcomes included HbA1c, rate of (severe) hypoglycemia, and diabetes-related quality of life. FINDINGS: After 4 months of follow-up, glucose variability had improved in the bolus calculator group compared with the control group (change, -0.8 [0.9] vs 0.1 [0.9] mmol/L; P = 0.030). Mean glucose levels did not change in either group (0.4 [1.1] vs 0.3 [0.9] mmol/L; P = 0.95). There were also no differences in change in hypoglycemia rate (-0.6 [1.6] vs -0.4 [1.6] event per patient per week; P = 0.67), HbA1c value (-0.5 [6.6] vs -4.9 [10.6] mmol/mol; P = 0.21), or diabetes-related quality of life between the bolus calculator group and the control group. IMPLICATIONS: Use of a bolus calculator modestly improved glucose variability in this relatively small group of patients with longstanding type 1 diabetes on CSII but did not affect other parameters of glycemic control or diabetes-related quality of life.