Insulin pump therapy with automated insulin suspension: Toward freedom from nocturnal hypoglycemia

摘要

Patients with diabetes and physicians are aware of the distress and on rare occasions mortality causedby severe hypoglycemia, in particular by nocturnal hypoglycemia. Up to 75% of severe hypoglycemia episodes in children occur at night,1 and concern about hypoglycemia is a major barrier to achieving target glyce-mic levels, often leading to maladaptive behaviors, such as underdosing insulin or taking extra carbohydrates, that increase blood glucose levels, again most pronounced at night. When continuous glucose monitoring first became available, there was hope that real-time information about glucose levels and trends with alarms to warn patients about impending hypoglycemia would significantly reduce hypoglycemic episodes. It was therefore disappointing that Related article page 1240 initial trials, including large trials such as Juvenile Diabetes Research Foundation Continuous Glucose Monitoring (JDRF-CGM) and Sensor-Augmented Pump Therapy for Alc Reduction 3 (STAR-3), failed to show a reduction in hypoglycemia. Despite use of continuous glucose monitoring, there was a high incidence of prolonged nocturnal hypoglycemia. The Sensing With Insulin Pump Therapy to Control HbAlc (SWITCH) study did demonstrate a 51% reduction in time with sensor glucose levels lower than 63 mg/dL when patients were using continuous glucose monitoring compared with those who did not, but there were no severe hypoglycemia events in the study in either group of this crossover study. Several factors may help explain the apparent lack of efficacy of continuous glucose monitoring for reducing hypoglycemia. First, the hypoglycemia rate among patients entered into the trials was very low, and some trials excluded patients with problematic hypoglycemia. Second, even though alarms alert the patient about impending hypoglycemia, this alert was not beneficial at night, because patients were observed to sleep through 74% of the alarms. Third, the delay between interstitial and capillary glucose, and overall [in]accuracy of the systems, particularly at night, was also likely a contributing factor.