Short-Term Interruptions In CSII Therapy Result In Blood Glucose Elevations
Short-term interruptions of continuous subcutaneous insulin infusion (CSII) therapy in patients with type 1 diabetes can result in significant elevations in blood glucose levels.
In the 19-patient study, mean glucose values were significantly higher (p value < 0.001) at 0.5, 3.0, and 3.5 hours after CSII interruptions when compared to glucose levels in the 3 hours prior to the interruptions. The rate of rise in glucose concentration over 3 hours was approximately 1 mg/dL for each minute of insulin infusion interruption.
Study investigator Howard Zisser, MD, director of clinical research at the Sansum Diabetes Research Institute in Santa Barbara, CA, explained the clinical relevance of these findings: "Continuous subcutaneous insulin infusion therapy allows for the possibility of around-the-clock delivery of insulin for patients with type 1 diabetes. However, in practice, patients often have short-term interruptions in insulin delivery when they disconnect from their pumps for various reasons, such as showering, changing their clothes, swimming and intimate moments. This study provides concrete evidence that these interruptions raise blood glucose levels."
The prospective, open-label study was designed to measure the impact of these short-term infusion set disconnects on glucose levels. Eleven females and 8 males were enrolled in and completed the trial. They had a mean age of 44 years (range 20-68 years); had diabetes for a mean duration of 22.5 years (range 5-51 years); and had a mean A1C of 7.3% (range 5.0 - 9.3).
All subjects had used CSII therapy with rapid-acting insulin analogs for at least one year. Subjects wore the CGMS(R) System Gold (made by Medtronic Diabetes of Northridge, CA) device throughout the study, which recorded glucose values every 5 minutes. Calibrations for the CGMS were performed per the manufacturer's instructions using the Freestyle(R) blood glucose monitor integrated into the OmniPod Insulin Management System's Personal Diabetes Manager (PDM) (made by Insulet Corporation).
Study participants arrived at the clinic, fasting, at 7 a.m. with no previous correction boluses, treatment for hypoglycemia, or food intake since midnight. One hour after arriving at the clinic, subjects disconnected from their infusion sets for 30 minutes, then reconnected. Remaining in a fasting state, the subjects' glucose levels were collected for an additional 3 hours using CGMS. The mean glucose level was 128.8+/-22.3 mg/dL during the 3-hour period prior to disconnecting the infusion set. The mean glucose after the 30- minute disconnect was 138.3 +/-31.1 mg/dL. The mean glucose at 3 and 3.5 hours after disconnect were 160.0 +/-32.5 mg/dL and 156.5+/-32.2 mg/dL.
Sansum Diabetes Research Institute is a non-profit research center devoted to the prevention, treatment and cure of diabetes through research and education. In particular, it is known for its work on methods to detect and chart the progress of diabetes, its success in developing protocols to increase the incidence of healthy babies born to women with diabetes, its expertise in new diabetes technology, and its work on type 2 diabetes in young people.