Effect of Sensor-Augmented Insulin Pump Therapy and Automated Insulin Suspension vs Standard Insulin Pump Therapy on Hypoglycemia in Patients With Type 1 Diabetes

Abstract

IMPORTANCE Hypoglycemia is a critical obstacle to the care of patients with type 1 diabetes. Sensor-augmented insulin pump with automated low-glucose insulin suspension has the potential to reduce the incidence of major hypoglycemic events.OBJECTIVE To determine the incidence of severe and moderate hypoglycemia with sensor-augmented pump with low-glucose suspension compared with standard insulin pump therapy. DESIGN, SETTING, AND PARTICIPANTSA randomized clinical trial involving 95 patients with type 1 diabetes, recruited from December 2009 to January 2012 in Australia.INTERVENTIONS Patients were randomized to insulin pump only or automated insulin suspension for 6 months. MAIN OUTCOMES AND MEASURESThe primary outcome was the combined incidence of severe (hypoglycemic seizure or coma) and moderate hypoglycemia (an event requiring assistance for treatment). In a subgroup, counterregulatory hormone responses to hypoglycemia were assessed using the hypoglycemic clamp technique. RESULTSOf the 95 patients randomized, 49 were assigned to the standard-pump (pump-only) therapy and 46 to the low-glucose suspension group. The mean (SD) age was 18.6 (11.8) years; duration of diabetes, 11.0 (8.9) years; and duration of pump therapy, 4.1 (3.4) years. The baseline rate of severe and moderate hypoglycemic events in the pump-only group was 20.7 vs 129.6 events per 100 patient months in the low-glucose suspension group. After 6 months of treatment, the event rates decreased from 28 to 16 in the pump-only group vs 175 to 35 in the low-glucose suspension group. The adjusted incidence rate per 100 patient-months was 34.2 (95% CI, 22.0-53.3) for the pump-only group vs 9.5 (95% CI, 5.2-17.4) for the low-glucose suspension group. The incidence rate ratio was 3.6 (95% CI, 1.7-7.5; P <.001). There was no change in glycated hemoglobin in either group: mean, 7.4 (95% CI, 7.2-7.6) to 7.4 (95% CI, 7.2-7.7) in the pump-only group vs mean, 7.6 (95%, CI, 7.4-7.9) to 7.5 (95% CI, 7.3-7.7) in the low-glucose suspension group. Counterregulatory hormone responses to hypoglycemia were not changed. There were no episodes of diabetic ketoacidosis or hyperglycemia with ketosis.CONCLUSIONS AND RELEVANCE Sensor-augmented pump therapy with automated insulin suspension reduced the combined rate of severe and moderate hypoglycemia in patients with type 1 diabetes.

Clinical Use of Continuous Glucose Monitoring in Adults with Type 1 Diabetes

“…Also, results could not be deemed reliable due to the use of event rates. 33 The next generation of systems suspends insulin delivery in response to predicted hypoglycemia (Medtronic 640G; Medtronic, Inc.). This predictive LGS system was evaluated in 40 patients with T1DM.…”

Improving the clinical value and utility of CGM systems: issues and recommendations

“…Trends towards reductions in the occurrence of mild and severe hypoglycaemic events when using such combinations have been reported [35,36] but also challenged [37]. These represent an intermediate step towards automated insulin delivery (AID) systems [38].…”

Insulin delivery and nocturnal glucose control in children and adolescents with type 1 diabetes

“…The evidence from multicenter randomized controlled [20,23], (Table 1, and nonrandomized studies [45] including children and adolescents in real-life settings is that automated insulin suspension is safe and reduces the frequency and duration of overall and nocturnal hypoglycemic episodes compared to insulin pump therapy [23] or sensor augmented pump therapy [20,45]. The threshold-based suspend feature was shown to reduce the percentage of time spent with blood glucose levels in the hypoglycemic range overnight [20,23], and to reduce the overall risk of severe and moderate hypoglycemia in those with highest risk, including those with impaired hypoglycemia awareness and the highest frequency of severe hypoglycemia [23].…”

“…The threshold-based suspend feature was shown to reduce the percentage of time spent with blood glucose levels in the hypoglycemic range overnight [20,23], and to reduce the overall risk of severe and moderate hypoglycemia in those with highest risk, including those with impaired hypoglycemia awareness and the highest frequency of severe hypoglycemia [23]. …”

“…Periodic insulin suspension over up to 2 h did not result in elevated glucose concentration as indicated by similar average glucose levels and HbA1c levels over a period of 3-6 months compared to insulin pump therapy and sensor augmented pump therapy [20,23]. …”