Evaluation of an Algorithm to Guide Patients With Type 1 Diabetes Treated With Continuous Subcutaneous Insulin Infusion on How to Respond to Real-Time Continuous Glucose Levels: A randomized controlled trial

Diabetes Care, Jun 2010

OBJECTIVE To evaluate an algorithm guiding responses of continuous subcutaneous insulin infusion (CSII)–treated type 1 diabetic patients using real-time continuous glucose monitoring (RT-CGM).

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

https://care.diabetesjournals.org/content/33/6/1242.full.pdf

Evaluation of an Algorithm to Guide Patients With Type 1 Diabetes Treated With Continuous Subcutaneous Insulin Infusion on How to Respond to Real-Time Continuous Glucose Levels: A randomized controlled trial

ALICIA J. JENKINS BALASUBRAMANIUM KRISHNAMURTHY JAMES D. BEST FERGUS J. CAMERON PETER G. COLMAN STEVEN FARISH MED PETER S. HAMBLIN FRACP MICHELE A. O'CONNELL MRCPI CHRISTINE RODDA PHD KEVIN ROWLEY PHD HELENA TEEDE PHD DAVID N. O'NEAL OBJECTIVE - To evaluate an algorithm guiding responses of continuous subcutaneous insulin infusion (CSII)-treated type 1 diabetic patients using real-time continuous glucose monitoring (RT-CGM). RESEARCH DESIGN AND METHODS - Sixty CSII-treated type 1 diabetic participants (aged 13-70 years, including adult and adolescent subgroups, with A1C 9.5%) were randomized in age-, sex-, and A1C-matched pairs. Phase 1 was an open 16-week multicenter randomized controlled trial. Group A was treated with CSII/RT-CGM with the algorithm, and group B was treated with CSII/RT-CGM without the algorithm. The primary outcome was the difference in time in target (4 -10 mmol/l) glucose range on 6-day masked CGM. Secondary outcomes were differences in A1C, low (3.9 mmol/l) glucose CGM time, and glycemic variability. Phase 2 was the week 16 -32 follow-up. Group A was returned to usual care, and group B was provided with the algorithm. Glycemia parameters were as above. Comparisons were made between baseline and 16 weeks and 32 weeks. RESULTS - In phase 1, after withdrawals 29 of 30 subjects were left in group A and 28 of 30 subjects were left in group B. The change in target glucose time did not differ between groups. A1C fell (mean 7.9% [95% CI 7.7- 8.2to 7.6% [7.2- 8.0]; P 0.03) in group A but not in group B (7.8% [7.5- 8.1] to 7.7 [7.3- 8.0]; NS) with no difference between groups. More subjects in group A achieved A1C 7% than those in group B (2 of 29 to 14 of 29 vs. 4 of 28 to 7 of 28; P 0.015). In phase 2, one participant was lost from each group. In group A, A1C returned to baseline with RT-CGM discontinuation but did not change in group B, who continued RT-CGM with addition of the algorithm. - CONCLUSIONS Early but not late algorithm provision to type 1 diabetic patients using CSII/RT-CGM did not increase the target glucose time but increased achievement of A1C 7%. Upon RT-CGM cessation, A1C returned to baseline. R toring (RT-CGM) can be integrated eal time-continuous glucose moniwith a continuous subcutaneous insulin infusion (CSII) device (1,2). Interstitial glucose readings, with direction and rate of change, are displayed and linked to low and high glucose alarms. Data can be uploaded and reviewed retrospectively. Apart from recent devices with automatic shutoff for low glucose, RT-CGM cannot initiate insulin delivery. Insulin changes must be initiated by the patient or caregiver. Continuous glucose monitoring (CGM) data interpretation can be difficult, and advice guiding insulin or lifestyle change may enhance benefits (3). In this study, we tested the glycemia effects of an algorithm guiding responses to RT-CGM in CSII-using type 1 diabetic subjects. We also evaluated whether glucose changes persisted after RT-CGM withdrawal and whether late algorithm introduction improved glycemia. RESEARCH DESIGN AND METHODS The study was an ethics committeeapproved randomized controlled trial at three adult and two pediatric Australian centers. Written informed consent was obtained, including guardian consent for pediatric participants. Participants were recruited in pairs matched for age (within 5 years), sex, and A1C (within 1%). Inclusion criteria were age 13 years, type 1 diabetes duration 1 year, 3 months CSII with bolus calculator use, A1C 9.5%, self-monitoring of blood glucose 4 times daily, Internet access, and willingness to use RT-CGM for 6 of each 7 days for the study duration. Exclusion criteria were physical or intellectual limitations, renal impairment (estimated glomerular filtration rate 60 ml/ min), using or likely to require steroid therapy, gastroparesis, untreated celiac or thyroid disease, hemoglobinopathies, regular blood transfusions, current or planned pregnancy, and breast-feeding. No data were available regarding glycemia after RT-CGM initiation at time of study design. The only CGM data available were retrospective continuous glucose monitoring system (Medtronic, Northridge, CA) traces recorded within 3 months after CSII commencement (without RT-CGM) in 40 patients at one adult center, which demonstrated a 33% increase in 4 10 mmol/l time to 58% (17%) and mean SD A1C reduction from 7.9 1.4 to 7.1 1.0%. A betweengroup difference in the target glycemia time increment of 25% was chosen for the study because the impact of RT-CGM and the algorithm was expected to be less than that of CSII initiation. Thirty participants in each (algorithm and nonalgorithm) group had 99% power to detect a 25% difference between groups at the 0.05 significance level. Corresponding power for 18 adults and 12 adolescents per group was 95 and 90%, respectively. Protocol A history was obtained, physical examination was performed, and blood an (...truncated)


This is a preview of a remote PDF: https://care.diabetesjournals.org/content/33/6/1242.full.pdf

Alicia J. Jenkins, Balasubramanium Krishnamurthy, James D. Best, Fergus J. Cameron, Peter G. Colman, Steven Farish, Peter S. Hamblin, Michele A. O'Connell, Christine Rodda, Kevin Rowley, Helena Teede, David N. O'Neal. Evaluation of an Algorithm to Guide Patients With Type 1 Diabetes Treated With Continuous Subcutaneous Insulin Infusion on How to Respond to Real-Time Continuous Glucose Levels: A randomized controlled trial, Diabetes Care, 2010, pp. 1242-1248, 33/6, DOI: 10.2337/dc09-1481