Use of Short-Term Real-Time Continuous Glucose Monitoring in Type 1 Diabetes Patients on Continuous Intraperitoneal Insulin Infusion: A Feasibility Study

Background: In diabetes, strict glycemic control reduces risk of complications. One mode of therapy is continuous intraperitoneal insulin infusion (CIPII). With CIPII, like all intensified treatment strategies, frequent assessment of glucose levels is mandatory. Real-time (RT)-continuous glucose monitoring (CGM) gives RT information without the need for multiple invasive measurements. In theory, CIPII combined with RT-CGM could provide near normal glucose profiles. The objective of this study is to investigate effectiveness and safety of RT-CGM in patients treated with intraperitoneal insulin through an implanted pump. Methods: In an open-label, crossover, randomized study, effects of 6-day open RT-CGM use were studied in 12 type 1 diabetes patients on CIPII, with blinded RT-CGM used as a control. Primary outcome was time in euglycemia. Secondary outcomes included time in other glucose ranges, incidence of adverse events, and patient satisfaction. Agreement of self-measurement of blood glucose (SMBG) and RT-CGM measurements was assessed. Results: Median time spent in euglycemia was 68.2% (55.9-72.3%) with open RT-CGM and 64.9% (55.3-71.2%) with blinded RT-CGM (P = 0.25). Time spent in other glucose ranges did not differ (P>0.05). There were no serious adverse events. Patient satisfaction was good. Median relative absolute difference of SMBG and RT-CGM values was 13.9%. Bland-Altman analysis showed a mean difference of -0.31 mg/dL with lower and upper limits of agreement of -77.0 and +76.4 mg/dL, respectively. Conclusions: Short-term use of RT-CGM, although safe and with good patient satisfaction, does not result in more time spent in euglycemia, nor does it change time spent in other glucose ranges in our population of type 1 diabetes patients receiving CIPII.